Fix default case

* `DataColumnStorageSummary`: Implement `HasAtLeastOneIndex`.

* `DataColumnStorage.Get`: Exit early if the root is found but no corresponding columns.

* `custodyColumnsFromPeers`: Simplify.

* Remove duplicate `uint64MapToSortedSlice` function.

* `DataColumnStorageSummary`: Add `Stored`.

* Refactor reconstruction related code.

CHANGELOG.md

@@ -4,6 +4,54 @@ All notable changes to this project will be documented in this file.
 
 The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.
 
+## [v6.0.1](https://github.com/prysmaticlabs/prysm/compare/v6.0.0...v6.0.1) - 2025-05-02
+
+This release fixes two bugs related to the `payload_attributes` [event stream](https://ethereum.github.io/beacon-APIs/#/Events/eventstream). If you are using or planning to use this endpoint, upgrading to version 6.0.1 is mandatory.  
+Also, a reminder: like other Beacon API endpoints, when a node is syncing, it may return historical data as `finalized` or `head`. Until the node is fully synced to the head of the chain, you should avoid using this data, depending on your application's needs.
+
+We currently recommend against using the `--enable-beacon-rest-api` flag on Mainnet. As you may have noticed, we put a deprecation notice on our gRPC code, in particular on gRPC-related flags. The reason for this is that we want to eventually remove gRPC and have REST HTTP as the standard way of communication between the validator client and the beacon node. That being said, the REST option is still unstable and thus marked as experimental in the flag's description (the flag is `--enable-beacon-rest-api`). Therefore we encourage everyone to keep using gRPC, which is currently the default. It is fine to test the REST option on testnets, but doing it on Mainnet can lead to missing attestations and even missing blocks.
+
+**Updating to v6.0.0 or later is required for Pectra Mainnet!**
+
+This patch release has a few important fixes from v6.0.0. Updating to this release is encouraged.
+
+### Added
+
+- `UpgradeToFulu` spectests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15190)
+- PeerDAS related KZG wrappers. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15186)
+- Add light client p2p broadcaster functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15175)
+- Added immediate broadcasting of proposer slashings when equivocating blocks are detected during block processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14693)
+- Added 2 new errors: `HeadStateErr` and `ErrCouldNotVerifyBlockHeader`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14693)
+- Implement pending consolidations Beacon API endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15219)
+- PeerDAS: Add needed proto files and corresponding generated code. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15187)
+- Add light client p2p validator and subscriber functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15214)
+
+### Changed
+
+- Refactored internal function `reValidateSubscriptions` to `pruneSubscriptions` in `beacon-chain/sync/subscriber.go` for improved clarity, addressing a TODO comment. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15160)
+- Updated geth to v1.15.9. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15216)
+- Removed the slot from `UpdateDuties`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15223)
+- Update hoodie bootnodes. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15240)
+
+### Fixed
+
+- avoid nondeterministic default fork value when generate genesis. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15151)
+- `UpgradeToFulu`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15190)
+- fixed underflow with balances in leaking edge case with expected withdrawals. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15191)
+- Fixes our generated ssz files to have the correct package name. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15199)
+- Fixes our blob sidecar by root request lists for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15209)
+- Ensure that the `payload_attributes` event has a consistent view of the head state by passing the head block in the event and using stategen to retrieve the corresponding state. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15213)
+- Pass parent context to update duties when dependent roots change. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15221)
+- Process slots across epoch for payload attribute event. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15228)
+- extend the payload attribute computation deadline to the beginning of the proposal slot. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15230)
+
+### Security
+
+- Fix CVE-2025-22869. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-22870. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-22872. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-30204. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+
 ## [v6.0.0](https://github.com/prysmaticlabs/prysm/compare/v5.3.2...v6.0.0) - 2025-04-21
 
 This release introduces Mainnet support for the upcoming Electra + Prague (Pectra) fork. The fork is scheduled for mainnet epoch 364032 (May 7, 2025, 10:05:11 UTC). You MUST update Prysm Beacon Node, Prysm Validator Client, and your execution layer client to the Pectra ready release prior to the fork to stay on the correct chain.

WORKSPACE

@@ -1,7 +1,7 @@
 workspace(name = "prysm")
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 http_archive(
     name = "rules_pkg",
@@ -16,8 +16,6 @@ load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies")
 
 rules_pkg_dependencies()
 
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
 http_archive(
     name = "toolchains_protoc",
     sha256 = "abb1540f8a9e045422730670ebb2f25b41fa56ca5a7cf795175a110a0a68f4ad",

api/client/builder/client.go

@@ -241,7 +241,7 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 		return nil, errors.Wrap(err, "error getting header from builder server")
 	}
 
-	bid, err := c.parseHeaderResponse(data, header)
+	bid, err := c.parseHeaderResponse(data, header, slot)
 	if err != nil {
 		return nil, errors.Wrapf(
 			err,
@@ -254,7 +254,7 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 	return bid, nil
 }
 
-func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid, error) {
+func (c *Client) parseHeaderResponse(data []byte, header http.Header, slot primitives.Slot) (SignedBid, error) {
 	var versionHeader string
 	if c.sszEnabled || header.Get(api.VersionHeader) != "" {
 		versionHeader = header.Get(api.VersionHeader)
@@ -276,7 +276,7 @@ func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid
 	}
 
 	if ver >= version.Electra {
-		return c.parseHeaderElectra(data)
+		return c.parseHeaderElectra(data, slot)
 	}
 	if ver >= version.Deneb {
 		return c.parseHeaderDeneb(data)
@@ -291,7 +291,7 @@ func (c *Client) parseHeaderResponse(data []byte, header http.Header) (SignedBid
 	return nil, fmt.Errorf("unsupported header version %s", versionHeader)
 }
 
-func (c *Client) parseHeaderElectra(data []byte) (SignedBid, error) {
+func (c *Client) parseHeaderElectra(data []byte, slot primitives.Slot) (SignedBid, error) {
 	if c.sszEnabled {
 		sb := &ethpb.SignedBuilderBidElectra{}
 		if err := sb.UnmarshalSSZ(data); err != nil {
@@ -303,7 +303,7 @@ func (c *Client) parseHeaderElectra(data []byte) (SignedBid, error) {
 	if err := json.Unmarshal(data, hr); err != nil {
 		return nil, errors.Wrap(err, "could not unmarshal ExecHeaderResponseElectra JSON")
 	}
-	p, err := hr.ToProto()
+	p, err := hr.ToProto(slot)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not convert ExecHeaderResponseElectra to proto")
 	}

api/client/builder/client_test.go

@@ -532,7 +532,7 @@ func TestClient_GetHeader(t *testing.T) {
 				require.Equal(t, expectedPath, r.URL.Path)
 				epr := &ExecHeaderResponseElectra{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponseElectra), epr))
-				pro, err := epr.ToProto()
+				pro, err := epr.ToProto(100)
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)

api/client/builder/types.go

@@ -1284,8 +1284,8 @@ type ExecHeaderResponseElectra struct {
 }
 
 // ToProto creates a SignedBuilderBidElectra Proto from ExecHeaderResponseElectra.
-func (ehr *ExecHeaderResponseElectra) ToProto() (*eth.SignedBuilderBidElectra, error) {
-	bb, err := ehr.Data.Message.ToProto()
+func (ehr *ExecHeaderResponseElectra) ToProto(slot types.Slot) (*eth.SignedBuilderBidElectra, error) {
+	bb, err := ehr.Data.Message.ToProto(slot)
 	if err != nil {
 		return nil, err
 	}
@@ -1296,13 +1296,14 @@ func (ehr *ExecHeaderResponseElectra) ToProto() (*eth.SignedBuilderBidElectra, e
 }
 
 // ToProto creates a BuilderBidElectra Proto from BuilderBidElectra.
-func (bb *BuilderBidElectra) ToProto() (*eth.BuilderBidElectra, error) {
+func (bb *BuilderBidElectra) ToProto(slot types.Slot) (*eth.BuilderBidElectra, error) {
 	header, err := bb.Header.ToProto()
 	if err != nil {
 		return nil, err
 	}
-	if len(bb.BlobKzgCommitments) > params.BeaconConfig().MaxBlobsPerBlockByVersion(version.Electra) {
-		return nil, fmt.Errorf("blob commitment count %d exceeds the maximum %d", len(bb.BlobKzgCommitments), params.BeaconConfig().MaxBlobsPerBlockByVersion(version.Electra))
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	if len(bb.BlobKzgCommitments) > maxBlobsPerBlock {
+		return nil, fmt.Errorf("blob commitment count %d exceeds the maximum %d", len(bb.BlobKzgCommitments), maxBlobsPerBlock)
 	}
 	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
 	for i, commit := range bb.BlobKzgCommitments {

beacon-chain/blockchain/BUILD.bazel

@@ -25,6 +25,7 @@ go_library(
         "receive_attestation.go",
         "receive_blob.go",
         "receive_block.go",
+        "receive_data_column.go",
         "service.go",
         "setup_forchoice.go",
         "tracked_proposer.go",
@@ -50,6 +51,7 @@ go_library(
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
@@ -146,6 +148,7 @@ go_test(
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/das:go_default_library",

beacon-chain/blockchain/error.go

@@ -40,10 +40,12 @@ var (
 	errNotGenesisRoot = errors.New("root is not the genesis block root")
 	// errBlacklistedBlock is returned when a block is blacklisted as invalid.
 	errBlacklistedRoot = verification.AsVerificationFailure(errors.New("block root is blacklisted"))
+	// errMaxBlobsExceeded is returned when the number of blobs in a block exceeds the maximum allowed.
+	errMaxBlobsExceeded = verification.AsVerificationFailure(errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK"))
+	// errMaxDataColumnsExceeded is returned when the number of data columns exceeds the maximum allowed.
+	errMaxDataColumnsExceeded = verification.AsVerificationFailure(errors.New("Expected data columns for node exceeds NUMBER_OF_COLUMNS"))
 )
 
-var errMaxBlobsExceeded = verification.AsVerificationFailure(errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK"))
-
 // An invalid block is the block that fails state transition based on the core protocol rules.
 // The beacon node shall not be accepting nor building blocks that branch off from an invalid block.
 // Some examples of invalid blocks are:

beacon-chain/blockchain/execution_engine.go

@@ -439,6 +439,9 @@ func (s *Service) removeInvalidBlockAndState(ctx context.Context, blkRoots [][32
 			// Blobs may not exist for some blocks, leading to deletion failures. Log such errors at debug level.
 			log.WithError(err).Debug("Could not remove blob from blob storage")
 		}
+		if err := s.dataColumnStorage.Remove(root); err != nil {
+			log.WithError(err).Debug("Could not remove data columns from data column storage")
+		}
 	}
 	return nil
 }

beacon-chain/blockchain/options.go

@@ -1,10 +1,13 @@
 package blockchain
 
 import (
+	"time"
+
 	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
@@ -127,9 +130,9 @@ func WithBLSToExecPool(p blstoexec.PoolManager) Option {
 }
 
 // WithP2PBroadcaster to broadcast messages after appropriate processing.
-func WithP2PBroadcaster(p p2p.Broadcaster) Option {
+func WithP2PBroadcaster(p p2p.Acceser) Option {
 	return func(s *Service) error {
-		s.cfg.P2p = p
+		s.cfg.P2P = p
 		return nil
 	}
 }
@@ -208,6 +211,14 @@ func WithBlobStorage(b *filesystem.BlobStorage) Option {
 	}
 }
 
+// WithDataColumnStorage sets the data column storage backend for the blockchain service.
+func WithDataColumnStorage(b *filesystem.DataColumnStorage) Option {
+	return func(s *Service) error {
+		s.dataColumnStorage = b
+		return nil
+	}
+}
+
 func WithSyncChecker(checker Checker) Option {
 	return func(s *Service) error {
 		s.cfg.SyncChecker = checker
@@ -215,6 +226,13 @@ func WithSyncChecker(checker Checker) Option {
 	}
 }
 
+func WithCustodyInfo(custodyInfo *peerdas.CustodyInfo) Option {
+	return func(s *Service) error {
+		s.cfg.CustodyInfo = custodyInfo
+		return nil
+	}
+}
+
 func WithSlasherEnabled(enabled bool) Option {
 	return func(s *Service) error {
 		s.slasherEnabled = enabled
@@ -222,6 +240,13 @@ func WithSlasherEnabled(enabled bool) Option {
 	}
 }
 
+func WithGenesisTime(genesisTime time.Time) Option {
+	return func(s *Service) error {
+		s.genesisTime = genesisTime
+		return nil
+	}
+}
+
 func WithLightClientStore(lcs *lightclient.Store) Option {
 	return func(s *Service) error {
 		s.lcStore = lcs

beacon-chain/blockchain/process_block.go

@@ -3,10 +3,12 @@ package blockchain
 import (
 	"context"
 	"fmt"
+	"slices"
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
@@ -239,8 +241,9 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 				return err
 			}
 		}
+
 		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
-			return errors.Wrapf(err, "could not validate blob data availability at slot %d", b.Block().Slot())
+			return errors.Wrapf(err, "could not validate sidecar availability at slot %d", b.Block().Slot())
 		}
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b,
 			JustifiedCheckpoint: jCheckpoints[i],
@@ -601,20 +604,208 @@ func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte
 	return missing, nil
 }
 
-// isDataAvailable blocks until all BlobSidecars committed to in the block are available,
-// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
-// The function will first check the database to see if all sidecars have been persisted. If any
-// sidecars are missing, it will then read from the blobNotifier channel for the given root until the channel is
-// closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
-func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed interfaces.ReadOnlySignedBeaconBlock) error {
-	if signed.Version() < version.Deneb {
-		return nil
+func missingDataColumns(bs *filesystem.DataColumnStorage, root [32]byte, expected map[uint64]bool) (map[uint64]bool, error) {
+	if len(expected) == 0 {
+		return nil, nil
 	}
 
-	block := signed.Block()
+	if len(expected) > int(params.BeaconConfig().NumberOfColumns) {
+		return nil, errMaxDataColumnsExceeded
+	}
+
+	// Get a summary of the data columns stored in the database.
+	summary := bs.Summary(root)
+
+	// Check all expected data columns against the summary.
+	missing := make(map[uint64]bool)
+	for column := range expected {
+		if !summary.HasIndex(column) {
+			missing[column] = true
+		}
+	}
+
+	return missing, nil
+}
+
+// isDataAvailable blocks until all sidecars committed to in the block are available,
+// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
+// The function will first check the database to see if all sidecars have been persisted. If any
+// sidecars are missing, it will then read from the sidecar notifier channel for the given root until the channel is
+// closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
+func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signedBlock interfaces.ReadOnlySignedBeaconBlock) error {
+	block := signedBlock.Block()
 	if block == nil {
 		return errors.New("invalid nil beacon block")
 	}
+
+	blockVersion := block.Version()
+	if blockVersion >= version.Fulu {
+		return s.areDataColumnsAvailable(ctx, root, block)
+	}
+
+	if blockVersion >= version.Deneb {
+		return s.areBlobsAvailable(ctx, root, block)
+	}
+
+	return nil
+}
+
+// areDataColumnsAvailable blocks until all data columns committed to in the block are available,
+// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
+func (s *Service) areDataColumnsAvailable(ctx context.Context, root [fieldparams.RootLength]byte, block interfaces.ReadOnlyBeaconBlock) error {
+	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
+	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
+
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return nil
+	}
+
+	body := block.Body()
+	if body == nil {
+		return errors.New("invalid nil beacon block body")
+	}
+
+	kzgCommitments, err := body.BlobKzgCommitments()
+	if err != nil {
+		return errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// If block has not commitments there is nothing to wait for.
+	if len(kzgCommitments) == 0 {
+		return nil
+	}
+
+	// All columns to sample need to be available for the block to be considered available.
+	// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/das-core.md#custody-sampling
+	nodeID := s.cfg.P2P.NodeID()
+
+	// Prevent custody group count to change during the rest of the function.
+	s.cfg.CustodyInfo.Mut.RLock()
+	defer s.cfg.CustodyInfo.Mut.RUnlock()
+
+	// Get the custody group sampling size for the node.
+	custodyGroupSamplingSize := s.cfg.CustodyInfo.CustodyGroupSamplingSize(peerdas.Actual)
+	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupSamplingSize)
+	if err != nil {
+		return errors.Wrap(err, "peer info")
+	}
+
+	// Subscribe to newly data columns stored in the database.
+	identsChan := make(chan filesystem.DataColumnsIdent)
+	subscription := s.dataColumnStorage.DataColumnFeed.Subscribe(identsChan)
+	defer subscription.Unsubscribe()
+
+	// Get the count of data columns we already have in the store.
+	summary := s.dataColumnStorage.Summary(root)
+	storedDataColumnsCount := summary.Count()
+
+	minimumColumnCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+
+	// As soon as we have enough data column sidecars, we can reconstruct the missing ones.
+	// We don't need to wait for the rest of the data columns to declare the block as available.
+	if storedDataColumnsCount >= minimumColumnCountToReconstruct {
+		return nil
+	}
+
+	// Get a map of data column indices that are not currently available.
+	missingMap, err := missingDataColumns(s.dataColumnStorage, root, peerInfo.CustodyColumns)
+	if err != nil {
+		return errors.Wrap(err, "missing data columns")
+	}
+
+	// If there are no missing indices, all data column sidecars are available.
+	// This is the happy path.
+	if len(missingMap) == 0 {
+		return nil
+	}
+
+	// Log for DA checks that cross over into the next slot; helpful for debugging.
+	nextSlot := slots.BeginsAt(block.Slot()+1, s.genesisTime)
+
+	// Avoid logging if DA check is called after next slot start.
+	if nextSlot.After(time.Now()) {
+		timer := time.AfterFunc(time.Until(nextSlot), func() {
+			missingMapCount := uint64(len(missingMap))
+
+			if missingMapCount == 0 {
+				return
+			}
+
+			var (
+				expected interface{} = "all"
+				missing  interface{} = "all"
+			)
+
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
+			colMapCount := uint64(len(peerInfo.CustodyColumns))
+
+			if colMapCount < numberOfColumns {
+				expected = uint64MapToSortedSlice(peerInfo.CustodyColumns)
+			}
+
+			if missingMapCount < numberOfColumns {
+				missing = uint64MapToSortedSlice(missingMap)
+			}
+
+			log.WithFields(logrus.Fields{
+				"slot":            block.Slot(),
+				"root":            fmt.Sprintf("%#x", root),
+				"columnsExpected": expected,
+				"columnsWaiting":  missing,
+			}).Warning("Data columns still missing at slot end")
+		})
+		defer timer.Stop()
+	}
+
+	for {
+		select {
+		case idents := <-identsChan:
+			if idents.Root != root {
+				// This is not the root we are looking for.
+				continue
+			}
+
+			for _, index := range idents.Indices {
+				// This is a data column we are expecting.
+				if _, ok := missingMap[index]; ok {
+					storedDataColumnsCount++
+				}
+
+				// As soon as we have more than half of the data columns, we can reconstruct the missing ones.
+				// We don't need to wait for the rest of the data columns to declare the block as available.
+				if storedDataColumnsCount >= minimumColumnCountToReconstruct {
+					return nil
+				}
+
+				// Remove the index from the missing map.
+				delete(missingMap, index)
+
+				// Return if there is no more missing data columns.
+				if len(missingMap) == 0 {
+					return nil
+				}
+			}
+
+		case <-ctx.Done():
+			var missingIndices interface{} = "all"
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
+			missingIndicesCount := uint64(len(missingMap))
+
+			if missingIndicesCount < numberOfColumns {
+				missingIndices = uint64MapToSortedSlice(missingMap)
+			}
+
+			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing %v", block.Slot(), root, missingIndices)
+		}
+	}
+}
+
+// areBlobsAvailable blocks until all BlobSidecars committed to in the block are available,
+// or an error or context cancellation occurs. A nil result means that the data availability check is successful.
+func (s *Service) areBlobsAvailable(ctx context.Context, root [fieldparams.RootLength]byte, block interfaces.ReadOnlyBeaconBlock) error {
+	blockSlot := block.Slot()
+
 	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
 	if !params.WithinDAPeriod(slots.ToEpoch(block.Slot()), slots.ToEpoch(s.CurrentSlot())) {
 		return nil
@@ -636,7 +827,7 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 	// get a map of BlobSidecar indices that are not currently available.
 	missing, err := missingIndices(s.blobStorage, root, kzgCommitments, block.Slot())
 	if err != nil {
-		return err
+		return errors.Wrap(err, "missing indices")
 	}
 	// If there are no missing indices, all BlobSidecars are available.
 	if len(missing) == 0 {
@@ -648,15 +839,20 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 	nc := s.blobNotifiers.forRoot(root, block.Slot())
 
 	// Log for DA checks that cross over into the next slot; helpful for debugging.
-	nextSlot := slots.BeginsAt(signed.Block().Slot()+1, s.genesisTime)
+	nextSlot := slots.BeginsAt(block.Slot()+1, s.genesisTime)
 	// Avoid logging if DA check is called after next slot start.
 	if nextSlot.After(time.Now()) {
 		nst := time.AfterFunc(time.Until(nextSlot), func() {
 			if len(missing) == 0 {
 				return
 			}
-			log.WithFields(daCheckLogFields(root, signed.Block().Slot(), expected, len(missing))).
-				Error("Still waiting for DA check at slot end.")
+
+			log.WithFields(logrus.Fields{
+				"slot":          blockSlot,
+				"root":          fmt.Sprintf("%#x", root),
+				"blobsExpected": expected,
+				"blobsWaiting":  len(missing),
+			}).Error("Still waiting for blobs DA check at slot end.")
 		})
 		defer nst.Stop()
 	}
@@ -678,13 +874,14 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 	}
 }
 
-func daCheckLogFields(root [32]byte, slot primitives.Slot, expected, missing int) logrus.Fields {
-	return logrus.Fields{
-		"slot":          slot,
-		"root":          fmt.Sprintf("%#x", root),
-		"blobsExpected": expected,
-		"blobsWaiting":  missing,
+// uint64MapToSortedSlice produces a sorted uint64 slice from a map.
+func uint64MapToSortedSlice(input map[uint64]bool) []uint64 {
+	output := make([]uint64, 0, len(input))
+	for idx := range input {
+		output = append(output, idx)
 	}
+	slices.Sort[[]uint64](output)
+	return output
 }
 
 // lateBlockTasks  is called 4 seconds into the slot and performs tasks
@@ -770,7 +967,7 @@ func (s *Service) waitForSync() error {
 	}
 }
 
-func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, blockRoot [32]byte, parentRoot [32]byte) error {
+func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, blockRoot, parentRoot [32]byte) error {
 	if IsInvalidBlock(err) && InvalidBlockLVH(err) != [32]byte{} {
 		return s.pruneInvalidBlock(ctx, blockRoot, parentRoot, InvalidBlockLVH(err))
 	}

beacon-chain/blockchain/process_block_helpers.go

@@ -310,7 +310,7 @@ func (s *Service) processLightClientFinalityUpdate(
 		Data: newUpdate,
 	})
 
-	if err = s.cfg.P2p.BroadcastLightClientFinalityUpdate(ctx, newUpdate); err != nil {
+	if err = s.cfg.P2P.BroadcastLightClientFinalityUpdate(ctx, newUpdate); err != nil {
 		return errors.Wrap(err, "could not broadcast light client finality update")
 	}
 
@@ -363,7 +363,7 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		Data: newUpdate,
 	})
 
-	if err = s.cfg.P2p.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
+	if err = s.cfg.P2P.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
 		return errors.Wrap(err, "could not broadcast light client optimistic update")
 	}
 

beacon-chain/blockchain/process_block_test.go

@@ -2,6 +2,7 @@ package blockchain
 
 import (
 	"context"
+	"crypto/rand"
 	"fmt"
 	"math/big"
 	"strconv"
@@ -13,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
@@ -26,6 +28,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations/kv"
 	mockp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -3246,6 +3249,154 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 	reset()
 }
 
+type testIsAvailableParams struct {
+	options                 []Option
+	blobKzgCommitmentsCount uint64
+	columnsToSave           []uint64
+}
+
+func testIsAvailableSetup(t *testing.T, params testIsAvailableParams) (context.Context, context.CancelFunc, *Service, [fieldparams.RootLength]byte, interfaces.SignedBeaconBlock) {
+	ctx, cancel := context.WithCancel(context.Background())
+	dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+	options := append(params.options, WithDataColumnStorage(dataColumnStorage))
+	service, _ := minimalTestService(t, options...)
+
+	genesisState, secretKeys := util.DeterministicGenesisStateElectra(t, 32 /*validator count*/)
+
+	err := service.saveGenesisData(ctx, genesisState)
+	require.NoError(t, err)
+
+	conf := util.DefaultBlockGenConfig()
+	conf.NumBlobKzgCommitments = params.blobKzgCommitmentsCount
+
+	signedBeaconBlock, err := util.GenerateFullBlockFulu(genesisState, secretKeys, conf, 10 /*block slot*/)
+	require.NoError(t, err)
+
+	root, err := signedBeaconBlock.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	dataColumnsParams := make([]verification.DataColumnParams, 0, len(params.columnsToSave))
+	for _, i := range params.columnsToSave {
+		dataColumnParam := verification.DataColumnParams{ColumnIndex: i}
+		dataColumnsParams = append(dataColumnsParams, dataColumnParam)
+	}
+
+	dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: dataColumnsParams}
+	_, verifiedRODataColumns := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+	err = dataColumnStorage.Save(verifiedRODataColumns)
+	require.NoError(t, err)
+
+	signed, err := consensusblocks.NewSignedBeaconBlock(signedBeaconBlock)
+	require.NoError(t, err)
+
+	return ctx, cancel, service, root, signed
+}
+
+func TestIsDataAvailable(t *testing.T) {
+	t.Run("Fulu - out of retention window", func(t *testing.T) {
+		params := testIsAvailableParams{options: []Option{WithGenesisTime(time.Unix(0, 0))}}
+		ctx, _, service, root, signed := testIsAvailableSetup(t, params)
+
+		err := service.isDataAvailable(ctx, root, signed)
+		require.NoError(t, err)
+	})
+
+	t.Run("Fulu - no commitment in blocks", func(t *testing.T) {
+		ctx, _, service, root, signed := testIsAvailableSetup(t, testIsAvailableParams{})
+
+		err := service.isDataAvailable(ctx, root, signed)
+		require.NoError(t, err)
+	})
+
+	t.Run("Fulu - more than half of the columns in custody", func(t *testing.T) {
+		halfNumberOfColumns := params.BeaconConfig().NumberOfColumns / 2
+		indices := make([]uint64, 0, halfNumberOfColumns)
+		for i := range halfNumberOfColumns {
+			indices = append(indices, i)
+		}
+
+		params := testIsAvailableParams{
+			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
+			columnsToSave:           indices,
+			blobKzgCommitmentsCount: 3,
+		}
+
+		ctx, _, service, root, signed := testIsAvailableSetup(t, params)
+
+		err := service.isDataAvailable(ctx, root, signed)
+		require.NoError(t, err)
+	})
+
+	t.Run("Fulu - no missing data columns", func(t *testing.T) {
+		params := testIsAvailableParams{
+			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
+			columnsToSave:           []uint64{1, 17, 19, 42, 75, 87, 102, 117, 119}, // 119 is not needed
+			blobKzgCommitmentsCount: 3,
+		}
+
+		ctx, _, service, root, signed := testIsAvailableSetup(t, params)
+
+		err := service.isDataAvailable(ctx, root, signed)
+		require.NoError(t, err)
+	})
+
+	t.Run("Fulu - some initially missing data columns (no reconstruction)", func(t *testing.T) {
+		var custodyInfo peerdas.CustodyInfo
+		custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(128)
+		custodyInfo.ToAdvertiseGroupCount.Set(128)
+
+		testParams := testIsAvailableParams{
+			options:                 []Option{WithCustodyInfo(&custodyInfo)},
+			blobKzgCommitmentsCount: 3,
+		}
+
+		ctx, _, service, root, signed := testIsAvailableSetup(t, testParams)
+
+		// If needed, generate a random root that is different from the block root.
+		var randomRoot [fieldparams.RootLength]byte
+		for randomRoot == root {
+			randomRootSlice := make([]byte, fieldparams.RootLength)
+			_, err := rand.Read(randomRootSlice)
+			require.NoError(t, err)
+			copy(randomRoot[:], randomRootSlice)
+		}
+
+		// TODO: Achieve the same result without using time.AfterFunc.
+		time.AfterFunc(10*time.Millisecond, func() {
+			halfNumberOfColumns := params.BeaconConfig().NumberOfColumns / 2
+			indices := make([]uint64, 0, halfNumberOfColumns)
+			for i := range halfNumberOfColumns {
+				indices = append(indices, i)
+			}
+
+			withSomeRequiredColumns := filesystem.DataColumnsIdent{Root: root, Indices: indices}
+			service.dataColumnStorage.DataColumnFeed.Send(withSomeRequiredColumns)
+		})
+
+		err := service.isDataAvailable(ctx, root, signed)
+		require.NoError(t, err)
+	})
+
+	t.Run("Fulu - some columns are definitively missing", func(t *testing.T) {
+		params := testIsAvailableParams{
+			options:                 []Option{WithCustodyInfo(&peerdas.CustodyInfo{})},
+			blobKzgCommitmentsCount: 3,
+		}
+
+		ctx, cancel, service, root, signed := testIsAvailableSetup(t, params)
+
+		// TODO: Achieve the same result without using time.AfterFunc.
+		time.AfterFunc(10*time.Millisecond, func() {
+			cancel()
+		})
+
+		err := service.isDataAvailable(ctx, root, signed)
+		require.NotNil(t, err)
+	})
+}
+
 func setupLightClientTestRequirements(ctx context.Context, t *testing.T, s *Service, v int, options ...util.LightClientOption) (*util.TestLightClient, *postBlockProcessConfig) {
 	var l *util.TestLightClient
 	switch v {
@@ -3310,7 +3461,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 	params.OverrideBeaconConfig(beaconCfg)
 
 	s, tr := minimalTestService(t)
-	s.cfg.P2p = &mockp2p.FakeP2P{}
+	s.cfg.P2P = &mockp2p.FakeP2P{}
 	ctx := tr.ctx
 
 	testCases := []struct {
@@ -3446,7 +3597,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 	params.OverrideBeaconConfig(beaconCfg)
 
 	s, tr := minimalTestService(t)
-	s.cfg.P2p = &mockp2p.FakeP2P{}
+	s.cfg.P2P = &mockp2p.FakeP2P{}
 	ctx := tr.ctx
 
 	testCases := []struct {

beacon-chain/blockchain/receive_block.go

@@ -52,6 +52,13 @@ type BlobReceiver interface {
 	ReceiveBlob(context.Context, blocks.VerifiedROBlob) error
 }
 
+// DataColumnReceiver interface defines the methods of chain service for receiving new
+// data columns
+type DataColumnReceiver interface {
+	ReceiveDataColumn(blocks.VerifiedRODataColumn) error
+	ReceiveDataColumns([]blocks.VerifiedRODataColumn) error
+}
+
 // SlashingReceiver interface defines the methods of chain service for receiving validated slashing over the wire.
 type SlashingReceiver interface {
 	ReceiveAttesterSlashing(ctx context.Context, slashing ethpb.AttSlashing)
@@ -74,6 +81,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring already synced block")
 		return nil
 	}
+
 	receivedTime := time.Now()
 	s.blockBeingSynced.set(blockRoot)
 	defer s.blockBeingSynced.unset(blockRoot)
@@ -82,6 +90,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err != nil {
 		return err
 	}
+
 	preState, err := s.getBlockPreState(ctx, blockCopy.Block())
 	if err != nil {
 		return errors.Wrap(err, "could not get block's prestate")
@@ -97,10 +106,12 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err != nil {
 		return err
 	}
+
 	daWaitedTime, err := s.handleDA(ctx, blockCopy, blockRoot, avs)
 	if err != nil {
 		return err
 	}
+
 	// Defragment the state before continuing block processing.
 	s.defragmentState(postState)
 
@@ -229,24 +240,32 @@ func (s *Service) handleDA(
 	block interfaces.SignedBeaconBlock,
 	blockRoot [32]byte,
 	avs das.AvailabilityStore,
-) (time.Duration, error) {
-	daStartTime := time.Now()
-	if avs != nil {
-		rob, err := blocks.NewROBlockWithRoot(block, blockRoot)
-		if err != nil {
-			return 0, err
+) (elapsed time.Duration, err error) {
+	defer func(start time.Time) {
+		elapsed := time.Since(start)
+
+		if err == nil {
+			dataAvailWaitedTime.Observe(float64(elapsed.Milliseconds()))
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), rob); err != nil {
-			return 0, errors.Wrap(err, "could not validate blob data availability (AvailabilityStore.IsDataAvailable)")
-		}
-	} else {
-		if err := s.isDataAvailable(ctx, blockRoot, block); err != nil {
-			return 0, errors.Wrap(err, "could not validate blob data availability")
+	}(time.Now())
+
+	if avs == nil {
+		if err = s.isDataAvailable(ctx, blockRoot, block); err != nil {
+			return
 		}
+
+		return
 	}
-	daWaitedTime := time.Since(daStartTime)
-	dataAvailWaitedTime.Observe(float64(daWaitedTime.Milliseconds()))
-	return daWaitedTime, nil
+
+	var rob blocks.ROBlock
+	rob, err = blocks.NewROBlockWithRoot(block, blockRoot)
+	if err != nil {
+		return
+	}
+
+	err = avs.IsDataAvailable(ctx, s.CurrentSlot(), rob)
+
+	return
 }
 
 func (s *Service) reportPostBlockProcessing(

beacon-chain/blockchain/receive_data_column.go

@@ -0,0 +1,25 @@
+package blockchain
+
+import (
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/pkg/errors"
+)
+
+// ReceiveDataColumns receives a batch of data columns.
+func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataColumn) error {
+	if err := s.dataColumnStorage.Save(dataColumnSidecars); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	return nil
+}
+
+// ReceiveDataColumn receives a single data column.
+// (It is only a wrapper around ReceiveDataColumns.)
+func (s *Service) ReceiveDataColumn(dataColumnSidecar blocks.VerifiedRODataColumn) error {
+	if err := s.dataColumnStorage.Save([]blocks.VerifiedRODataColumn{dataColumnSidecar}); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	return nil
+}

beacon-chain/blockchain/service.go

@@ -16,6 +16,7 @@ import (
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
@@ -30,6 +31,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -64,6 +66,7 @@ type Service struct {
 	blobNotifiers        *blobNotifierMap
 	blockBeingSynced     *currentlySyncingBlock
 	blobStorage          *filesystem.BlobStorage
+	dataColumnStorage    *filesystem.DataColumnStorage
 	slasherEnabled       bool
 	lcStore              *lightClient.Store
 }
@@ -81,7 +84,7 @@ type config struct {
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
 	BLSToExecPool           blstoexec.PoolManager
-	P2p                     p2p.Broadcaster
+	P2P                     p2p.Acceser
 	MaxRoutines             int
 	StateNotifier           statefeed.Notifier
 	ForkChoiceStore         f.ForkChoicer
@@ -93,6 +96,7 @@ type config struct {
 	FinalizedStateAtStartUp state.BeaconState
 	ExecutionEngineCaller   execution.EngineCaller
 	SyncChecker             Checker
+	CustodyInfo             *peerdas.CustodyInfo
 }
 
 // Checker is an interface used to determine if a node is in initial sync
@@ -106,22 +110,26 @@ var ErrMissingClockSetter = errors.New("blockchain Service initialized without a
 type blobNotifierMap struct {
 	sync.RWMutex
 	notifiers map[[32]byte]chan uint64
-	seenIndex map[[32]byte][]bool
+	// TODO: Separate blobs from data columns
+	// seenIndex map[[32]byte][]bool
+	seenIndex map[[32]byte][fieldparams.NumberOfColumns]bool
 }
 
 // notifyIndex notifies a blob by its index for a given root.
 // It uses internal maps to keep track of seen indices and notifier channels.
 func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitives.Slot) {
-	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
-	if idx >= uint64(maxBlobsPerBlock) {
-		return
-	}
+	// TODO: Separate blobs from data columns
+	// maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	// if idx >= uint64(maxBlobsPerBlock) {
+	// 	return
+	// }
 
 	bn.Lock()
 	seen := bn.seenIndex[root]
-	if seen == nil {
-		seen = make([]bool, maxBlobsPerBlock)
-	}
+	// TODO: Separate blobs from data columns
+	// if seen == nil {
+	// seen = make([]bool, maxBlobsPerBlock)
+	// }
 	if seen[idx] {
 		bn.Unlock()
 		return
@@ -132,7 +140,9 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitive
 	// Retrieve or create the notifier channel for the given root.
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, maxBlobsPerBlock)
+		// TODO: Separate blobs from data columns
+		// c = make(chan uint64, maxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 
@@ -142,12 +152,15 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitive
 }
 
 func (bn *blobNotifierMap) forRoot(root [32]byte, slot primitives.Slot) chan uint64 {
-	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	// TODO: Separate blobs from data columns
+	// maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	bn.Lock()
 	defer bn.Unlock()
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, maxBlobsPerBlock)
+		// TODO: Separate blobs from data columns
+		// c = make(chan uint64, maxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 	return c
@@ -173,7 +186,9 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 	ctx, cancel := context.WithCancel(ctx)
 	bn := &blobNotifierMap{
 		notifiers: make(map[[32]byte]chan uint64),
-		seenIndex: make(map[[32]byte][]bool),
+		// TODO: Separate blobs from data columns
+		// seenIndex: make(map[[32]byte][]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 	}
 	srv := &Service{
 		ctx:                  ctx,

beacon-chain/blockchain/service_test.go

@@ -97,7 +97,7 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		WithAttestationPool(attestations.NewPool()),
 		WithSlashingPool(slashings.NewPool()),
 		WithExitPool(voluntaryexits.NewPool()),
-		WithP2PBroadcaster(&mockBroadcaster{}),
+		WithP2PBroadcaster(&mockAccesser{}),
 		WithStateNotifier(&mockBeaconNode{}),
 		WithForkChoiceStore(fc),
 		WithAttestationService(attService),
@@ -587,7 +587,9 @@ func (s *MockClockSetter) SetClock(g *startup.Clock) error {
 func TestNotifyIndex(t *testing.T) {
 	// Initialize a blobNotifierMap
 	bn := &blobNotifierMap{
-		seenIndex: make(map[[32]byte][]bool),
+		// TODO: Separate blobs from data columns
+		// seenIndex: make(map[[32]byte][]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 		notifiers: make(map[[32]byte]chan uint64),
 	}
 

beacon-chain/blockchain/setup_test.go

@@ -20,8 +20,10 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -47,6 +49,11 @@ type mockBroadcaster struct {
 	broadcastCalled bool
 }
 
+type mockAccesser struct {
+	mockBroadcaster
+	p2pTesting.MockPeerManager
+}
+
 func (mb *mockBroadcaster) Broadcast(_ context.Context, _ proto.Message) error {
 	mb.broadcastCalled = true
 	return nil
@@ -77,6 +84,11 @@ func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
+func (mb *mockBroadcaster) BroadcastDataColumn(_ context.Context, _ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }
 
@@ -132,8 +144,10 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithDepositCache(dc),
 		WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
 		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
+		WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)),
 		WithSyncChecker(mock.MockChecker{}),
 		WithExecutionEngineCaller(&mockExecution.EngineClient{}),
+		WithP2PBroadcaster(&mockAccesser{}),
 		WithLightClientStore(&lightclient.Store{}),
 	}
 	// append the variadic opts so they override the defaults by being processed afterwards

beacon-chain/blockchain/testing/mock.go

@@ -75,6 +75,7 @@ type ChainService struct {
 	BlockSlot                   primitives.Slot
 	SyncingRoot                 [32]byte
 	Blobs                       []blocks.VerifiedROBlob
+	DataColumns                 []blocks.VerifiedRODataColumn
 	TargetRoot                  [32]byte
 	MockHeadSlot                *primitives.Slot
 }
@@ -715,6 +716,17 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 	return nil
 }
 
+// ReceiveDataColumn implements the same method in chain service
+func (c *ChainService) ReceiveDataColumn(dc blocks.VerifiedRODataColumn) error {
+	c.DataColumns = append(c.DataColumns, dc)
+	return nil
+}
+
+// ReceiveDataColumns implements the same method in chain service
+func (*ChainService) ReceiveDataColumns(_ []blocks.VerifiedRODataColumn) error {
+	return nil
+}
+
 // TargetRootForEpoch mocks the same method in the chain service
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil

beacon-chain/cache/committee.go

@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
 	mathutil "github.com/OffchainLabs/prysm/v6/math"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	lru "github.com/hashicorp/golang-lru"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -104,11 +105,16 @@ func (c *CommitteeCache) CompressCommitteeCache() {
 // Committee fetches the shuffled indices by slot and committee index. Every list of indices
 // represent one committee. Returns true if the list exists with slot and committee index. Otherwise returns false, nil.
 func (c *CommitteeCache) Committee(ctx context.Context, slot primitives.Slot, seed [32]byte, index primitives.CommitteeIndex) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "committeeCache.Committee")
+	defer span.End()
+	span.SetAttributes(trace.Int64Attribute("slot", int64(slot)), trace.Int64Attribute("index", int64(index))) // lint:ignore uintcast -- OK for tracing.
+
 	if err := c.checkInProgress(ctx, seed); err != nil {
 		return nil, err
 	}
 
 	obj, exists := c.CommitteeCache.Get(key(seed))
+	span.SetAttributes(trace.BoolAttribute("cache_hit", exists))
 	if exists {
 		CommitteeCacheHit.Inc()
 	} else {
@@ -157,11 +163,14 @@ func (c *CommitteeCache) AddCommitteeShuffledList(ctx context.Context, committee
 
 // ActiveIndices returns the active indices of a given seed stored in cache.
 func (c *CommitteeCache) ActiveIndices(ctx context.Context, seed [32]byte) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "committeeCache.ActiveIndices")
+	defer span.End()
+
 	if err := c.checkInProgress(ctx, seed); err != nil {
 		return nil, err
 	}
 	obj, exists := c.CommitteeCache.Get(key(seed))
-
+	span.SetAttributes(trace.BoolAttribute("cache_hit", exists))
 	if exists {
 		CommitteeCacheHit.Inc()
 	} else {

beacon-chain/core/blocks/payload.go

@@ -229,13 +229,16 @@ func verifyBlobCommitmentCount(slot primitives.Slot, body interfaces.ReadOnlyBea
 	if body.Version() < version.Deneb {
 		return nil
 	}
+
 	kzgs, err := body.BlobKzgCommitments()
 	if err != nil {
 		return err
 	}
-	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
-	if len(kzgs) > maxBlobsPerBlock {
-		return fmt.Errorf("too many kzg commitments in block: %d", len(kzgs))
+
+	commitmentCount, maxBlobsPerBlock := len(kzgs), params.BeaconConfig().MaxBlobsPerBlock(slot)
+	if commitmentCount > maxBlobsPerBlock {
+		return fmt.Errorf("too many kzg commitments in block: actual count %d - max allowed %d", commitmentCount, maxBlobsPerBlock)
 	}
+
 	return nil
 }

beacon-chain/core/blocks/payload_test.go

@@ -926,8 +926,10 @@ func TestVerifyBlobCommitmentCount(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
 
-	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())+1)}}
+	maxCommitmentsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())
+
+	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, maxCommitmentsPerBlock+1)}}
 	rb, err = consensusblocks.NewBeaconBlock(b)
 	require.NoError(t, err)
-	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: %d", params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())+1), blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
+	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: actual count %d - max allowed %d", maxCommitmentsPerBlock+1, maxCommitmentsPerBlock), blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
 }

beacon-chain/core/blocks/signature.go

@@ -96,6 +96,24 @@ func VerifyBlockHeaderSignature(beaconState state.BeaconState, header *ethpb.Sig
 	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
 }
 
+func VerifyBlockHeaderSignatureUsingCurrentFork(beaconState state.BeaconState, header *ethpb.SignedBeaconBlockHeader) error {
+	currentEpoch := slots.ToEpoch(header.Header.Slot)
+	fork, err := forks.Fork(currentEpoch)
+	if err != nil {
+		return err
+	}
+	domain, err := signing.Domain(fork, currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorsRoot())
+	if err != nil {
+		return err
+	}
+	proposer, err := beaconState.ValidatorAtIndex(header.Header.ProposerIndex)
+	if err != nil {
+		return err
+	}
+	proposerPubKey := proposer.PublicKey
+	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
+}
+
 // VerifyBlockSignatureUsingCurrentFork verifies the proposer signature of a beacon block. This differs
 // from the above method by not using fork data from the state and instead retrieving it
 // via the respective epoch.

beacon-chain/core/feed/operation/events.go

@@ -37,8 +37,11 @@ const (
 	// SingleAttReceived is sent after a single attestation object is received from gossip or rpc
 	SingleAttReceived = 9
 
+	// DataColumnSidecarReceived is sent after a data column sidecar is received from gossip or rpc.
+	DataColumnSidecarReceived = 10
+
 	// BlockGossipReceived is sent after a block has been received from gossip or API that passes validation rules.
-	BlockGossipReceived = 10
+	BlockGossipReceived = 11
 )
 
 // UnAggregatedAttReceivedData is the data sent with UnaggregatedAttReceived events.
@@ -90,6 +93,11 @@ type SingleAttReceivedData struct {
 	Attestation ethpb.Att
 }
 
+// DataColumnSidecarReceivedData is the data sent with DataColumnSidecarReceived events.
+type DataColumnSidecarReceivedData struct {
+	DataColumn *blocks.VerifiedRODataColumn
+}
+
 // BlockGossipReceivedData is the data sent with BlockGossipReceived events.
 type BlockGossipReceivedData struct {
 	// SignedBlock is the block that was received.

beacon-chain/core/helpers/beacon_committee.go

@@ -119,6 +119,9 @@ func attestationCommittees(
 
 // BeaconCommittees returns the list of all beacon committees for a given state at a given slot.
 func BeaconCommittees(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot) ([][]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.BeaconCommittees")
+	defer span.End()
+
 	epoch := slots.ToEpoch(slot)
 	activeCount, err := ActiveValidatorCount(ctx, state, epoch)
 	if err != nil {
@@ -245,6 +248,9 @@ func BeaconCommittee(
 	slot primitives.Slot,
 	committeeIndex primitives.CommitteeIndex,
 ) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.BeaconCommittee")
+	defer span.End()
+
 	committee, err := committeeCache.Committee(ctx, slot, seed, committeeIndex)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not interface with committee cache")
@@ -439,6 +445,9 @@ func CommitteeIndices(committeeBits bitfield.Bitfield) []primitives.CommitteeInd
 // UpdateCommitteeCache gets called at the beginning of every epoch to cache the committee shuffled indices
 // list with committee index and epoch number. It caches the shuffled indices for the input epoch.
 func UpdateCommitteeCache(ctx context.Context, state state.ReadOnlyBeaconState, e primitives.Epoch) error {
+	ctx, span := trace.StartSpan(ctx, "committeeCache.UpdateCommitteeCache")
+	defer span.End()
+
 	seed, err := Seed(state, e, params.BeaconConfig().DomainBeaconAttester)
 	if err != nil {
 		return err

beacon-chain/core/helpers/sync_committee_test.go

@@ -78,6 +78,7 @@ func TestIsCurrentEpochSyncCommittee_UsingCommittee(t *testing.T) {
 
 func TestIsCurrentEpochSyncCommittee_DoesNotExist(t *testing.T) {
 	helpers.ClearCache()
+	params.SetupTestConfigCleanup(t)
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)
 	syncCommittee := &ethpb.SyncCommittee{
@@ -264,6 +265,7 @@ func TestCurrentEpochSyncSubcommitteeIndices_UsingCommittee(t *testing.T) {
 }
 
 func TestCurrentEpochSyncSubcommitteeIndices_DoesNotExist(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
 	helpers.ClearCache()
 
 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)

beacon-chain/core/helpers/validators.go

@@ -102,6 +102,9 @@ func checkValidatorSlashable(activationEpoch, withdrawableEpoch primitives.Epoch
 //	  """
 //	  return [ValidatorIndex(i) for i, v in enumerate(state.validators) if is_active_validator(v, epoch)]
 func ActiveValidatorIndices(ctx context.Context, s state.ReadOnlyBeaconState, epoch primitives.Epoch) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.ActiveValidatorIndices")
+	defer span.End()
+
 	seed, err := Seed(s, epoch, params.BeaconConfig().DomainBeaconAttester)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get seed")

beacon-chain/core/peerdas/BUILD.bazel

@@ -7,9 +7,10 @@ go_library(
         "info.go",
         "metrics.go",
         "p2p_interface.go",
+        "peer_sampling.go",
         "reconstruction.go",
-        "util.go",
         "validator.go",
+        "verification.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas",
     visibility = ["//visibility:public"],
@@ -44,9 +45,11 @@ go_test(
         "das_core_test.go",
         "info_test.go",
         "p2p_interface_test.go",
+        "peer_sampling_test.go",
         "reconstruction_test.go",
         "utils_test.go",
         "validator_test.go",
+        "verification_test.go",
     ],
     deps = [
         ":go_default_library",
@@ -67,5 +70,6 @@ go_test(
         "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
+        "@org_golang_x_sync//errgroup:go_default_library",
     ],
 )

beacon-chain/core/peerdas/das_core.go

@@ -20,10 +20,12 @@ import (
 
 var (
 	// Custom errors
-	ErrCustodyGroupTooLarge           = errors.New("custody group too large")
-	ErrCustodyGroupCountTooLarge      = errors.New("custody group count too large")
-	ErrMismatchSize                   = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
-	errWrongComputedCustodyGroupCount = errors.New("wrong computed custody group count, should never happen")
+	ErrCustodyGroupTooLarge               = errors.New("custody group too large")
+	ErrCustodyGroupCountTooLarge          = errors.New("custody group count too large")
+	ErrSizeMismatch                       = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
+	ErrNotEnoughDataColumnSidecars        = errors.New("not enough columns")
+	ErrDataColumnSidecarsNotSortedByIndex = errors.New("data column sidecars are not sorted by index")
+	errWrongComputedCustodyGroupCount     = errors.New("wrong computed custody group count, should never happen")
 
 	// maxUint256 is the maximum value of an uint256.
 	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
@@ -139,7 +141,7 @@ func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsA
 	}
 
 	if len(blobKzgCommitments) != len(cellsAndProofs) {
-		return nil, ErrMismatchSize
+		return nil, ErrSizeMismatch
 	}
 
 	signedBlockHeader, err := signedBlock.Header()
@@ -152,19 +154,72 @@ func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsA
 		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
 	}
 
-	dataColumnSidecars, err := DataColumnsSidecarsFromItems(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	dataColumnSidecars, err := dataColumnsSidecars(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
 	if err != nil {
-		return nil, errors.Wrap(err, "data column sidecars from items")
+		return nil, errors.Wrap(err, "data column sidecars")
 	}
 
 	return dataColumnSidecars, nil
 }
 
-// DataColumnsSidecarsFromItems computes the data column sidecars from the signed block header, the blob KZG commiments,
+// ComputeCustodyGroupForColumn computes the custody group for a given column.
+// It is the reciprocal function of ComputeColumnsForCustodyGroup.
+func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
+	beaconConfig := params.BeaconConfig()
+	numberOfColumns := beaconConfig.NumberOfColumns
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
+
+	if columnIndex >= numberOfColumns {
+		return 0, ErrIndexTooLarge
+	}
+
+	return columnIndex % numberOfCustodyGroups, nil
+}
+
+// CustodyGroupSamplingSize returns the number of custody groups the node should sample from.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#custody-sampling
+func (custodyInfo *CustodyInfo) CustodyGroupSamplingSize(ct CustodyType) uint64 {
+	custodyGroupCount := custodyInfo.TargetGroupCount.Get()
+
+	if ct == Actual {
+		custodyGroupCount = custodyInfo.ActualGroupCount()
+	}
+
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+	return max(samplesPerSlot, custodyGroupCount)
+}
+
+// CustodyColumns computes the custody columns from the custody groups.
+func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+
+	custodyGroupCount := len(custodyGroups)
+
+	// Compute the columns for each custody group.
+	columns := make(map[uint64]bool, custodyGroupCount)
+	for _, group := range custodyGroups {
+		if group >= numberOfCustodyGroups {
+			return nil, ErrCustodyGroupTooLarge
+		}
+
+		groupColumns, err := ComputeColumnsForCustodyGroup(group)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute columns for custody group")
+		}
+
+		for _, column := range groupColumns {
+			columns[column] = true
+		}
+	}
+
+	return columns, nil
+}
+
+// dataColumnsSidecars computes the data column sidecars from the signed block header, the blob KZG commiments,
 // the KZG commitment includion proofs and cells and cell proofs.
 // The returned value contains pointers to function parameters.
 // (If the caller alterates input parameters afterwards, the returned value will be modified as well.)
-func DataColumnsSidecarsFromItems(
+func dataColumnsSidecars(
 	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
 	blobKzgCommitments [][]byte,
 	kzgCommitmentsInclusionProof [][]byte,
@@ -172,7 +227,7 @@ func DataColumnsSidecarsFromItems(
 ) ([]*ethpb.DataColumnSidecar, error) {
 	start := time.Now()
 	if len(blobKzgCommitments) != len(cellsAndProofs) {
-		return nil, ErrMismatchSize
+		return nil, ErrSizeMismatch
 	}
 
 	numberOfColumns := params.BeaconConfig().NumberOfColumns
@@ -219,184 +274,3 @@ func DataColumnsSidecarsFromItems(
 	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
 	return sidecars, nil
 }
-
-// ComputeCustodyGroupForColumn computes the custody group for a given column.
-// It is the reciprocal function of ComputeColumnsForCustodyGroup.
-func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
-	beaconConfig := params.BeaconConfig()
-	numberOfColumns := beaconConfig.NumberOfColumns
-	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
-
-	if columnIndex >= numberOfColumns {
-		return 0, ErrIndexTooLarge
-	}
-
-	return columnIndex % numberOfCustodyGroups, nil
-}
-
-// Blobs extract blobs from `dataColumnsSidecar`.
-// This can be seen as the reciprocal function of DataColumnSidecars.
-// `dataColumnsSidecar` needs to contain the datacolumns corresponding to the non-extended matrix,
-// else an error will be returned.
-// (`dataColumnsSidecar` can contain extra columns, but they will be ignored.)
-func Blobs(indices map[uint64]bool, dataColumnsSidecar []*ethpb.DataColumnSidecar) ([]*blocks.VerifiedROBlob, error) {
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	// Compute the number of needed columns, including the number of columns is odd case.
-	neededColumnCount := (numberOfColumns + 1) / 2
-
-	// Check if all needed columns are present.
-	sliceIndexFromColumnIndex := make(map[uint64]int, len(dataColumnsSidecar))
-	for i := range dataColumnsSidecar {
-		dataColumnSideCar := dataColumnsSidecar[i]
-		index := dataColumnSideCar.Index
-
-		if index < neededColumnCount {
-			sliceIndexFromColumnIndex[index] = i
-		}
-	}
-
-	actualColumnCount := uint64(len(sliceIndexFromColumnIndex))
-
-	// Get missing columns.
-	if actualColumnCount < neededColumnCount {
-		var missingColumnsSlice []uint64
-
-		for i := range neededColumnCount {
-			if _, ok := sliceIndexFromColumnIndex[i]; !ok {
-				missingColumnsSlice = append(missingColumnsSlice, i)
-			}
-		}
-
-		slices.Sort[[]uint64](missingColumnsSlice)
-		return nil, errors.Errorf("some columns are missing: %v", missingColumnsSlice)
-	}
-
-	// It is safe to retrieve the first column since we already checked that `dataColumnsSidecar` is not empty.
-	firstDataColumnSidecar := dataColumnsSidecar[0]
-
-	blobCount := uint64(len(firstDataColumnSidecar.Column))
-
-	// Check all colums have te same length.
-	for i := range dataColumnsSidecar {
-		if uint64(len(dataColumnsSidecar[i].Column)) != blobCount {
-			return nil, errors.Errorf("mismatch in the length of the data columns, expected %d, got %d", blobCount, len(dataColumnsSidecar[i].Column))
-		}
-	}
-
-	// Reconstruct verified RO blobs from columns.
-	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
-
-	// Populate and filter indices.
-	indicesSlice := populateAndFilterIndices(indices, blobCount)
-
-	for _, blobIndex := range indicesSlice {
-		var blob kzg.Blob
-
-		// Compute the content of the blob.
-		for columnIndex := range neededColumnCount {
-			sliceIndex, ok := sliceIndexFromColumnIndex[columnIndex]
-			if !ok {
-				return nil, errors.Errorf("missing column %d, this should never happen", columnIndex)
-			}
-
-			dataColumnSideCar := dataColumnsSidecar[sliceIndex]
-			cell := dataColumnSideCar.Column[blobIndex]
-
-			for i := range cell {
-				blob[columnIndex*kzg.BytesPerCell+uint64(i)] = cell[i]
-			}
-		}
-
-		// Retrieve the blob KZG commitment.
-		blobKZGCommitment := kzg.Commitment(firstDataColumnSidecar.KzgCommitments[blobIndex])
-
-		// Compute the blob KZG proof.
-		blobKzgProof, err := kzg.ComputeBlobKZGProof(&blob, blobKZGCommitment)
-		if err != nil {
-			return nil, errors.Wrap(err, "compute blob KZG proof")
-		}
-
-		blobSidecar := &ethpb.BlobSidecar{
-			Index:                    blobIndex,
-			Blob:                     blob[:],
-			KzgCommitment:            blobKZGCommitment[:],
-			KzgProof:                 blobKzgProof[:],
-			SignedBlockHeader:        firstDataColumnSidecar.SignedBlockHeader,
-			CommitmentInclusionProof: firstDataColumnSidecar.KzgCommitmentsInclusionProof,
-		}
-
-		roBlob, err := blocks.NewROBlob(blobSidecar)
-		if err != nil {
-			return nil, errors.Wrap(err, "new RO blob")
-		}
-
-		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
-		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
-	}
-
-	return verifiedROBlobs, nil
-}
-
-// CustodyGroupSamplingSize returns the number of custody groups the node should sample from.
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#custody-sampling
-func (custodyInfo *CustodyInfo) CustodyGroupSamplingSize(ct CustodyType) uint64 {
-	custodyGroupCount := custodyInfo.TargetGroupCount.Get()
-
-	if ct == Actual {
-		custodyGroupCount = custodyInfo.ActualGroupCount()
-	}
-
-	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
-	return max(samplesPerSlot, custodyGroupCount)
-}
-
-// CustodyColumns computes the custody columns from the custody groups.
-func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
-	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
-
-	custodyGroupCount := len(custodyGroups)
-
-	// Compute the columns for each custody group.
-	columns := make(map[uint64]bool, custodyGroupCount)
-	for _, group := range custodyGroups {
-		if group >= numberOfCustodyGroups {
-			return nil, ErrCustodyGroupTooLarge
-		}
-
-		groupColumns, err := ComputeColumnsForCustodyGroup(group)
-		if err != nil {
-			return nil, errors.Wrap(err, "compute columns for custody group")
-		}
-
-		for _, column := range groupColumns {
-			columns[column] = true
-		}
-	}
-
-	return columns, nil
-}
-
-// populateAndFilterIndices returns a sorted slices of indices, setting all indices if none are provided,
-// and filtering out indices higher than the blob count.
-func populateAndFilterIndices(indices map[uint64]bool, blobCount uint64) []uint64 {
-	// If no indices are provided, provide all blobs.
-	if len(indices) == 0 {
-		for i := range blobCount {
-			indices[i] = true
-		}
-	}
-
-	// Filter blobs index higher than the blob count.
-	indicesSlice := make([]uint64, 0, len(indices))
-	for i := range indices {
-		if i < blobCount {
-			indicesSlice = append(indicesSlice, i)
-		}
-	}
-
-	// Sort the indices.
-	slices.Sort[[]uint64](indicesSlice)
-
-	return indicesSlice
-}

beacon-chain/core/peerdas/das_core_test.go

@@ -11,18 +11,21 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/ethereum/go-ethereum/p2p/enode"
-	"github.com/pkg/errors"
 )
 
 func TestCustodyGroups(t *testing.T) {
+	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
+	// --------------------------------------------
 	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
 	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroup+1)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupCountTooLarge)
 }
 
 func TestComputeColumnsForCustodyGroup(t *testing.T) {
+	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
+	// --------------------------------------------
 	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
 	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroup)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
@@ -62,14 +65,10 @@ func TestDataColumnSidecars(t *testing.T) {
 		cellsAndProofs := make([]kzg.CellsAndProofs, 1)
 
 		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
-		require.ErrorIs(t, err, peerdas.ErrMismatchSize)
+		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
 	})
 }
 
-// --------------------------------------------------------------------------------------------------------------------------------------
-// DataColumnsSidecarsFromItems is tested as part of the DataColumnSidecars tests, in the TestDataColumnsSidecarsBlobsRoundtrip function.
-// --------------------------------------------------------------------------------------------------------------------------------------
-
 func TestComputeCustodyGroupForColumn(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig()
@@ -105,136 +104,6 @@ func TestComputeCustodyGroupForColumn(t *testing.T) {
 	})
 }
 
-func TestBlobs(t *testing.T) {
-	blobsIndice := map[uint64]bool{}
-
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	almostAllColumns := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns/2)
-	for i := uint64(2); i < numberOfColumns/2+2; i++ {
-		almostAllColumns = append(almostAllColumns, &ethpb.DataColumnSidecar{
-			Index: i,
-		})
-	}
-
-	testCases := []struct {
-		name     string
-		input    []*ethpb.DataColumnSidecar
-		expected []*blocks.VerifiedROBlob
-		err      error
-	}{
-		{
-			name:     "empty input",
-			input:    []*ethpb.DataColumnSidecar{},
-			expected: nil,
-			err:      errors.New("some columns are missing: [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63]"),
-		},
-		{
-			name:     "missing columns",
-			input:    almostAllColumns,
-			expected: nil,
-			err:      errors.New("some columns are missing: [0 1]"),
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			actual, err := peerdas.Blobs(blobsIndice, tc.input)
-			if tc.err != nil {
-				require.Equal(t, tc.err.Error(), err.Error())
-			} else {
-				require.NoError(t, err)
-			}
-			require.DeepSSZEqual(t, tc.expected, actual)
-		})
-	}
-}
-
-func TestDataColumnsSidecarsBlobsRoundtrip(t *testing.T) {
-	const blobCount = 5
-	blobsIndex := map[uint64]bool{}
-
-	// Start the trusted setup.
-	err := kzg.Start()
-	require.NoError(t, err)
-
-	// Create a protobuf signed beacon block.
-	signedBeaconBlockPb := util.NewBeaconBlockDeneb()
-
-	// Generate random blobs and their corresponding commitments and proofs.
-	blobs := make([]kzg.Blob, 0, blobCount)
-	blobKzgCommitments := make([]*kzg.Commitment, 0, blobCount)
-	blobKzgProofs := make([]*kzg.Proof, 0, blobCount)
-
-	for blobIndex := range blobCount {
-		// Create a random blob.
-		blob := getRandBlob(int64(blobIndex))
-		blobs = append(blobs, blob)
-
-		// Generate a blobKZGCommitment for the blob.
-		blobKZGCommitment, proof, err := generateCommitmentAndProof(&blob)
-		require.NoError(t, err)
-
-		blobKzgCommitments = append(blobKzgCommitments, blobKZGCommitment)
-		blobKzgProofs = append(blobKzgProofs, proof)
-	}
-
-	// Set the commitments into the block.
-	blobZkgCommitmentsBytes := make([][]byte, 0, blobCount)
-	for _, blobKZGCommitment := range blobKzgCommitments {
-		blobZkgCommitmentsBytes = append(blobZkgCommitmentsBytes, blobKZGCommitment[:])
-	}
-
-	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = blobZkgCommitmentsBytes
-
-	// Generate verified RO blobs.
-	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
-
-	// Create a signed beacon block from the protobuf.
-	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
-	require.NoError(t, err)
-
-	commitmentInclusionProof, err := blocks.MerkleProofKZGCommitments(signedBeaconBlock.Block().Body())
-	require.NoError(t, err)
-
-	for blobIndex := range blobCount {
-		blob := blobs[blobIndex]
-		blobKZGCommitment := blobKzgCommitments[blobIndex]
-		blobKzgProof := blobKzgProofs[blobIndex]
-
-		// Get the signed beacon block header.
-		signedBeaconBlockHeader, err := signedBeaconBlock.Header()
-		require.NoError(t, err)
-
-		blobSidecar := &ethpb.BlobSidecar{
-			Index:                    uint64(blobIndex),
-			Blob:                     blob[:],
-			KzgCommitment:            blobKZGCommitment[:],
-			KzgProof:                 blobKzgProof[:],
-			SignedBlockHeader:        signedBeaconBlockHeader,
-			CommitmentInclusionProof: commitmentInclusionProof,
-		}
-
-		roBlob, err := blocks.NewROBlob(blobSidecar)
-		require.NoError(t, err)
-
-		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
-		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
-	}
-
-	// Compute data columns sidecars from the signed beacon block and from the blobs.
-	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
-	dataColumnsSidecar, err := peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
-	require.NoError(t, err)
-
-	// Compute the blobs from the data columns sidecar.
-	roundtripBlobs, err := peerdas.Blobs(blobsIndex, dataColumnsSidecar)
-	require.NoError(t, err)
-
-	// Check that the blobs are the same.
-	require.DeepSSZEqual(t, verifiedROBlobs, roundtripBlobs)
-}
-
 func TestCustodyGroupSamplingSize(t *testing.T) {
 	testCases := []struct {
 		name                         string

beacon-chain/core/peerdas/info.go

@@ -117,7 +117,7 @@ func (custodyInfo *CustodyInfo) ActualGroupCount() uint64 {
 // CustodyGroupCount returns the number of groups we should participate in for custody.
 func (tcgc *targetCustodyGroupCount) Get() uint64 {
 	// If subscribed to all subnets, return the number of custody groups.
-	if flags.Get().SubscribeToAllSubnets {
+	if flags.Get().SubscribeAllDataSubnetsubnets {
 		return params.BeaconConfig().NumberOfCustodyGroups
 	}
 
@@ -144,7 +144,7 @@ func (tcgc *targetCustodyGroupCount) SetValidatorsCustodyRequirement(value uint6
 // Get returns the to advertise custody group count.
 func (tacgc *toAdverstiseCustodyGroupCount) Get() uint64 {
 	// If subscribed to all subnets, return the number of custody groups.
-	if flags.Get().SubscribeToAllSubnets {
+	if flags.Get().SubscribeAllDataSubnetsubnets {
 		return params.BeaconConfig().NumberOfCustodyGroups
 	}
 

beacon-chain/core/peerdas/info_test.go

@@ -30,25 +30,25 @@ func TestInfo(t *testing.T) {
 func TestTargetCustodyGroupCount(t *testing.T) {
 	testCases := []struct {
 		name                         string
-		subscribeToAllSubnets        bool
+		subscribeToAllColumns        bool
 		validatorsCustodyRequirement uint64
 		expected                     uint64
 	}{
 		{
 			name:                         "subscribed to all subnets",
-			subscribeToAllSubnets:        true,
+			subscribeToAllColumns:        true,
 			validatorsCustodyRequirement: 100,
 			expected:                     128,
 		},
 		{
 			name:                         "no validators attached",
-			subscribeToAllSubnets:        false,
+			subscribeToAllColumns:        false,
 			validatorsCustodyRequirement: 0,
 			expected:                     4,
 		},
 		{
 			name:                         "some validators attached",
-			subscribeToAllSubnets:        false,
+			subscribeToAllColumns:        false,
 			validatorsCustodyRequirement: 100,
 			expected:                     100,
 		},
@@ -57,10 +57,10 @@ func TestTargetCustodyGroupCount(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			// Subscribe to all subnets if needed.
-			if tc.subscribeToAllSubnets {
+			if tc.subscribeToAllColumns {
 				resetFlags := flags.Get()
 				gFlags := new(flags.GlobalFlags)
-				gFlags.SubscribeToAllSubnets = true
+				gFlags.SubscribeAllDataSubnetsubnets = true
 				flags.Init(gFlags)
 				defer flags.Init(resetFlags)
 			}
@@ -82,25 +82,25 @@ func TestTargetCustodyGroupCount(t *testing.T) {
 func TestToAdvertiseCustodyGroupCount(t *testing.T) {
 	testCases := []struct {
 		name                         string
-		subscribeToAllSubnets        bool
+		subscribeToAllColumns        bool
 		toAdvertiseCustodyGroupCount uint64
 		expected                     uint64
 	}{
 		{
 			name:                         "subscribed to all subnets",
-			subscribeToAllSubnets:        true,
+			subscribeToAllColumns:        true,
 			toAdvertiseCustodyGroupCount: 100,
 			expected:                     128,
 		},
 		{
 			name:                         "higher than custody requirement",
-			subscribeToAllSubnets:        false,
+			subscribeToAllColumns:        false,
 			toAdvertiseCustodyGroupCount: 100,
 			expected:                     100,
 		},
 		{
 			name:                         "lower than custody requirement",
-			subscribeToAllSubnets:        false,
+			subscribeToAllColumns:        false,
 			toAdvertiseCustodyGroupCount: 1,
 			expected:                     4,
 		},
@@ -109,10 +109,10 @@ func TestToAdvertiseCustodyGroupCount(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			// Subscribe to all subnets if needed.
-			if tc.subscribeToAllSubnets {
+			if tc.subscribeToAllColumns {
 				resetFlags := flags.Get()
 				gFlags := new(flags.GlobalFlags)
-				gFlags.SubscribeToAllSubnets = true
+				gFlags.SubscribeAllDataSubnetsubnets = true
 				flags.Init(gFlags)
 				defer flags.Init(resetFlags)
 			}

beacon-chain/core/peerdas/peer_sampling.go

@@ -0,0 +1,56 @@
+package peerdas
+
+import (
+	"math/big"
+
+	"github.com/OffchainLabs/prysm/v6/config/params"
+)
+
+// ExtendedSampleCount computes, for a given number of samples per slot and allowed failures the
+// number of samples we should actually query from peers.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/peer-sampling.md#get_extended_sample_count
+func ExtendedSampleCount(samplesPerSlot, allowedFailures uint64) uint64 {
+	// Retrieve the columns count
+	columnsCount := params.BeaconConfig().NumberOfColumns
+
+	// If half of the columns are missing, we are able to reconstruct the data.
+	// If half of the columns + 1 are missing, we are not able to reconstruct the data.
+	// This is the smallest worst case.
+	worstCaseMissing := columnsCount/2 + 1
+
+	// Compute the false positive threshold.
+	falsePositiveThreshold := HypergeomCDF(0, columnsCount, worstCaseMissing, samplesPerSlot)
+
+	var sampleCount uint64
+
+	// Finally, compute the extended sample count.
+	for sampleCount = samplesPerSlot; sampleCount < columnsCount+1; sampleCount++ {
+		if HypergeomCDF(allowedFailures, columnsCount, worstCaseMissing, sampleCount) <= falsePositiveThreshold {
+			break
+		}
+	}
+
+	return sampleCount
+}
+
+// HypergeomCDF computes the hypergeometric cumulative distribution function.
+// https://en.wikipedia.org/wiki/Hypergeometric_distribution
+func HypergeomCDF(k, M, n, N uint64) float64 {
+	denominatorInt := new(big.Int).Binomial(int64(M), int64(N)) // lint:ignore uintcast
+	denominator := new(big.Float).SetInt(denominatorInt)
+
+	rBig := big.NewFloat(0)
+
+	for i := uint64(0); i < k+1; i++ {
+		a := new(big.Int).Binomial(int64(n), int64(i)) // lint:ignore uintcast
+		b := new(big.Int).Binomial(int64(M-n), int64(N-i))
+		numeratorInt := new(big.Int).Mul(a, b)
+		numerator := new(big.Float).SetInt(numeratorInt)
+		item := new(big.Float).Quo(numerator, denominator)
+		rBig.Add(rBig, item)
+	}
+
+	r, _ := rBig.Float64()
+
+	return r
+}

beacon-chain/core/peerdas/peer_sampling_test.go

@@ -0,0 +1,60 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestExtendedSampleCount(t *testing.T) {
+	const samplesPerSlot = 16
+
+	testCases := []struct {
+		name                string
+		allowedMissings     uint64
+		extendedSampleCount uint64
+	}{
+		{name: "allowedMissings=0", allowedMissings: 0, extendedSampleCount: 16},
+		{name: "allowedMissings=1", allowedMissings: 1, extendedSampleCount: 20},
+		{name: "allowedMissings=2", allowedMissings: 2, extendedSampleCount: 24},
+		{name: "allowedMissings=3", allowedMissings: 3, extendedSampleCount: 27},
+		{name: "allowedMissings=4", allowedMissings: 4, extendedSampleCount: 29},
+		{name: "allowedMissings=5", allowedMissings: 5, extendedSampleCount: 32},
+		{name: "allowedMissings=6", allowedMissings: 6, extendedSampleCount: 35},
+		{name: "allowedMissings=7", allowedMissings: 7, extendedSampleCount: 37},
+		{name: "allowedMissings=8", allowedMissings: 8, extendedSampleCount: 40},
+		{name: "allowedMissings=9", allowedMissings: 9, extendedSampleCount: 42},
+		{name: "allowedMissings=10", allowedMissings: 10, extendedSampleCount: 44},
+		{name: "allowedMissings=11", allowedMissings: 11, extendedSampleCount: 47},
+		{name: "allowedMissings=12", allowedMissings: 12, extendedSampleCount: 49},
+		{name: "allowedMissings=13", allowedMissings: 13, extendedSampleCount: 51},
+		{name: "allowedMissings=14", allowedMissings: 14, extendedSampleCount: 53},
+		{name: "allowedMissings=15", allowedMissings: 15, extendedSampleCount: 55},
+		{name: "allowedMissings=16", allowedMissings: 16, extendedSampleCount: 57},
+		{name: "allowedMissings=17", allowedMissings: 17, extendedSampleCount: 59},
+		{name: "allowedMissings=18", allowedMissings: 18, extendedSampleCount: 61},
+		{name: "allowedMissings=19", allowedMissings: 19, extendedSampleCount: 63},
+		{name: "allowedMissings=20", allowedMissings: 20, extendedSampleCount: 65},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			result := peerdas.ExtendedSampleCount(samplesPerSlot, tc.allowedMissings)
+			require.Equal(t, tc.extendedSampleCount, result)
+		})
+	}
+}
+
+func TestHypergeomCDF(t *testing.T) {
+	// Test case from https://en.wikipedia.org/wiki/Hypergeometric_distribution
+	// Population size: 1000, number of successes in population: 500, sample size: 10, number of successes in sample: 5
+	// Expected result: 0.072
+	const (
+		expected = 0.0796665913283742
+		margin   = 0.000001
+	)
+
+	actual := peerdas.HypergeomCDF(5, 128, 65, 16)
+	require.Equal(t, true, expected-margin <= actual && actual <= expected+margin)
+}

beacon-chain/core/peerdas/reconstruction.go

@@ -2,75 +2,321 @@ package peerdas
 
 import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
 )
 
-// CanSelfReconstruct returns true if the node can self-reconstruct all the data columns from its custody group count.
-func CanSelfReconstruct(custodyGroupCount uint64) bool {
-	total := params.BeaconConfig().NumberOfCustodyGroups
-	// If total is odd, then we need total / 2 + 1 columns to reconstruct.
-	// If total is even, then we need total / 2 columns to reconstruct.
-	return custodyGroupCount >= (total+1)/2
+var (
+	ErrColumnLengthsDiffer      = errors.New("columns do not have the same length")
+	ErrBlobIndexTooHigh         = errors.New("blob index is too high")
+	ErrBlockRootMismatch        = errors.New("block root mismatch")
+	ErrBlobsCellsProofsMismatch = errors.New("blobs and cells proofs mismatch")
+)
+
+// MinimumColumnsCountToReconstruct return the minimum number of columns needed to proceed to a reconstruction.
+func MinimumColumnsCountToReconstruct() uint64 {
+	// If the number of columns is odd, then we need total / 2 + 1 columns to reconstruct.
+	// If the number of columns is even, then we need total / 2 columns to reconstruct.
+	return (params.BeaconConfig().NumberOfColumns + 1) / 2
 }
 
-// RecoverCellsAndProofs recovers the cells and proofs from the data column sidecars.
-func RecoverCellsAndProofs(dataColumnSideCars []*ethpb.DataColumnSidecar) ([]kzg.CellsAndProofs, error) {
-	var wg errgroup.Group
-
-	dataColumnSideCarsCount := len(dataColumnSideCars)
-
-	if dataColumnSideCarsCount == 0 {
-		return nil, errors.New("no data column sidecars")
+// ReconstructDataColumnSidecars reconstructs all the data column sidecars from the given input data column sidecars.
+// All input sidecars must be committed to the same block.
+// `inVerifiedRoSidecars` should contain enough (unique) sidecars to reconstruct the missing columns.
+func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataColumn) ([]blocks.VerifiedRODataColumn, error) {
+	// Check if there is at least one input sidecar.
+	if len(inVerifiedRoSidecars) == 0 {
+		return nil, ErrNotEnoughDataColumnSidecars
 	}
 
-	// Check if all columns have the same length.
-	blobCount := len(dataColumnSideCars[0].Column)
-	for _, sidecar := range dataColumnSideCars {
-		length := len(sidecar.Column)
+	// Safely retrieve the first sidecar as a reference.
+	referenceSidecar := inVerifiedRoSidecars[0]
 
-		if length != blobCount {
-			return nil, errors.New("columns do not have the same length")
+	// Check if all columns have the same length and are commmitted to the same block.
+	blobCount := len(referenceSidecar.Column)
+	blockRoot := referenceSidecar.BlockRoot()
+	for _, sidecar := range inVerifiedRoSidecars[1:] {
+		if len(sidecar.Column) != blobCount {
+			return nil, ErrColumnLengthsDiffer
+		}
+
+		if sidecar.BlockRoot() != blockRoot {
+			return nil, ErrBlockRootMismatch
 		}
 	}
 
+	// Deduplicate sidecars.
+	sidecarByIndex := make(map[uint64]blocks.VerifiedRODataColumn, len(inVerifiedRoSidecars))
+	for _, inVerifiedRoSidecar := range inVerifiedRoSidecars {
+		sidecarByIndex[inVerifiedRoSidecar.Index] = inVerifiedRoSidecar
+	}
+
+	// Check if there is enough sidecars to reconstruct the missing columns.
+	sidecarCount := len(sidecarByIndex)
+	if uint64(sidecarCount) < MinimumColumnsCountToReconstruct() {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Sidecars are verified and are committed to the same block.
+	// All signed block headers, KZG commitments, and inclusion proofs are the same.
+	signedBlockHeader := referenceSidecar.SignedBlockHeader
+	kzgCommitments := referenceSidecar.KzgCommitments
+	kzgCommitmentsInclusionProof := referenceSidecar.KzgCommitmentsInclusionProof
+
 	// Recover cells and compute proofs in parallel.
-	recoveredCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
-
-	for blobIndex := 0; blobIndex < blobCount; blobIndex++ {
-		bIndex := blobIndex
+	var wg errgroup.Group
+	cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+	for blobIndex := range uint64(blobCount) {
 		wg.Go(func() error {
-			cellsIndices := make([]uint64, 0, dataColumnSideCarsCount)
-			cells := make([]kzg.Cell, 0, dataColumnSideCarsCount)
-
-			for _, sidecar := range dataColumnSideCars {
-				// Build the cell indices.
-				cellsIndices = append(cellsIndices, sidecar.Index)
-
-				// Get the cell.
-				column := sidecar.Column
-				cell := column[bIndex]
+			cellsIndices := make([]uint64, 0, sidecarCount)
+			cells := make([]kzg.Cell, 0, sidecarCount)
 
+			for columnIndex, sidecar := range sidecarByIndex {
+				cell := sidecar.Column[blobIndex]
 				cells = append(cells, kzg.Cell(cell))
+				cellsIndices = append(cellsIndices, columnIndex)
 			}
 
 			// Recover the cells and proofs for the corresponding blob
-			cellsAndProofs, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
+			cellsAndProofsForBlob, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
 
 			if err != nil {
-				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", bIndex)
+				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", blobIndex)
 			}
 
-			recoveredCellsAndProofs[bIndex] = cellsAndProofs
+			// It is safe for multiple goroutines to concurrently write to the same slice,
+			// as long as they are writing to different indices, which is the case here.
+			cellsAndProofs[blobIndex] = cellsAndProofsForBlob
 			return nil
 		})
 	}
 
 	if err := wg.Wait(); err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "wait for RecoverCellsAndKZGProofs")
 	}
 
-	return recoveredCellsAndProofs, nil
+	outSidecars, err := dataColumnsSidecars(signedBlockHeader, kzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidecars from items")
+	}
+
+	// Input sidecars are verified, and we reconstructed ourselves the missing sidecars.
+	// As a consequence, reconstructed sidecars are also verified.
+	outVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(outSidecars))
+	for _, sidecar := range outSidecars {
+		roSidecar, err := blocks.NewRODataColumnWithRoot(sidecar, blockRoot)
+		if err != nil {
+			return nil, errors.Wrap(err, "new RO data column with root")
+		}
+
+		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+		outVerifiedRoSidecars = append(outVerifiedRoSidecars, verifiedRoSidecar)
+	}
+
+	return outVerifiedRoSidecars, nil
+}
+
+// ConstructDataColumnSidecars constructs data column sidecars from a block, (un-extended) blobs and
+// cell proofs corresponding the extended blobs. The main purpose of this function is to
+// construct data columns sidecars from data obtained from the execution client via:
+// - `engine_getBlobsV2` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getblobsv2, or
+// - `engine_getPayloadV5` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getpayloadv5
+// Note: In this function, to stick with the `BlobsBundleV2` format returned by the execution client in `engine_getPayloadV5`,
+// cell proofs are "flattened".
+func ConstructDataColumnSidecars(block interfaces.ReadOnlySignedBeaconBlock, blobs [][]byte, cellProofs [][]byte) ([]*ethpb.DataColumnSidecar, error) {
+	// Check if the cells count is equal to the cell proofs count.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	blobCount := uint64(len(blobs))
+	cellProofsCount := uint64(len(cellProofs))
+
+	cellsCount := blobCount * numberOfColumns
+	if cellsCount != cellProofsCount {
+		return nil, ErrBlobsCellsProofsMismatch
+	}
+
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
+	for i, blob := range blobs {
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute cells")
+		}
+
+		var proofs []kzg.Proof
+		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
+				return nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			proofs = append(proofs, kzgProof)
+		}
+
+		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
+		cellsAndProofs = append(cellsAndProofs, cellsProofs)
+	}
+
+	dataColumnSidecars, err := DataColumnSidecars(block, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidcars")
+	}
+
+	return dataColumnSidecars, nil
+}
+
+// ReconstructBlobs constructs verified read only blobs sidecars from verified read only blob sidecars.
+// The following constraints must be satisfied:
+//   - All `dataColumnSidecars` has to be committed to the same block, and
+//   - `dataColumnSidecars` must be sorted by index and should not contain duplicates.
+//   - `dataColumnSidecars` must contain either all sidecars corresponding to (non-extended) blobs,
+//     or either enough sidecars to reconstruct the blobs.
+func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
+	// Return early if no blobs are requested.
+	if len(indices) == 0 {
+		return nil, nil
+	}
+
+	if len(verifiedDataColumnSidecars) == 0 {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Check if the sidecars are sorted by index and do not contain duplicates.
+	previousColumnIndex := verifiedDataColumnSidecars[0].Index
+	for _, dataColumnSidecar := range verifiedDataColumnSidecars[1:] {
+		columnIndex := dataColumnSidecar.Index
+		if columnIndex <= previousColumnIndex {
+			return nil, ErrDataColumnSidecarsNotSortedByIndex
+		}
+
+		previousColumnIndex = columnIndex
+	}
+
+	// Check if we have enough columns.
+	cellsPerBlob := fieldparams.CellsPerBlob
+	if len(verifiedDataColumnSidecars) < cellsPerBlob {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Check if the blob index is too high.
+	commitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	for _, blobIndex := range indices {
+		if blobIndex >= len(commitments) {
+			return nil, ErrBlobIndexTooHigh
+		}
+	}
+
+	// Check if the data column sidecars are aligned with the block.
+	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(verifiedDataColumnSidecars))
+	for _, verifiedDataColumnSidecar := range verifiedDataColumnSidecars {
+		dataColumnSicecar := verifiedDataColumnSidecar.RODataColumn
+		dataColumnSidecars = append(dataColumnSidecars, dataColumnSicecar)
+	}
+
+	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
+		return nil, errors.Wrap(err, "data columns align with block")
+	}
+
+	// If all column sidecars corresponding to (non-extended) blobs are present, no need to reconstruct.
+	if verifiedDataColumnSidecars[cellsPerBlob-1].Index == uint64(cellsPerBlob-1) {
+		// Convert verified data column sidecars to verified blob sidecars.
+		blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, verifiedDataColumnSidecars, indices)
+		if err != nil {
+			return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
+		}
+
+		return blobSidecars, nil
+	}
+
+	// We need to reconstruct the blobs.
+	reconstructedDataColumnSidecars, err := ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
+	if err != nil {
+		return nil, errors.Wrap(err, "reconstruct data column sidecars")
+	}
+
+	// Convert verified data column sidecars to verified blob sidecars.
+	blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, reconstructedDataColumnSidecars, indices)
+	if err != nil {
+		return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
+	}
+
+	return blobSidecars, nil
+}
+
+// blobSidecarsFromDataColumnSidecars converts verified data column sidecars to verified blob sidecars.
+func blobSidecarsFromDataColumnSidecars(roBlock blocks.ROBlock, dataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
+	referenceSidecar := dataColumnSidecars[0]
+
+	kzgCommitments := referenceSidecar.KzgCommitments
+	signedBlockHeader := referenceSidecar.SignedBlockHeader
+
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, len(indices))
+	for _, blobIndex := range indices {
+		var blob kzg.Blob
+
+		// Compute the content of the blob.
+		for columnIndex := range fieldparams.CellsPerBlob {
+			dataColumnSidecar := dataColumnSidecars[columnIndex]
+			cell := dataColumnSidecar.Column[blobIndex]
+			if copy(blob[kzg.BytesPerCell*columnIndex:], cell) != kzg.BytesPerCell {
+				return nil, errors.New("wrong cell size - should never happen")
+			}
+		}
+
+		// Extract the KZG commitment.
+		var kzgCommitment kzg.Commitment
+		if copy(kzgCommitment[:], kzgCommitments[blobIndex]) != len(kzgCommitment) {
+			return nil, errors.New("wrong KZG commitment size - should never happen")
+		}
+
+		// Compute the blob KZG proof.
+		blobKzgProof, err := kzg.ComputeBlobKZGProof(&blob, kzgCommitment)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute blob KZG proof")
+		}
+
+		// Build the inclusion proof for the blob.
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob[:]) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		commitmentInclusionProof, err := blocks.MerkleProofKZGCommitment(roBlock.Block().Body(), blobIndex)
+		if err != nil {
+			return nil, errors.Wrap(err, "merkle proof KZG commitment")
+		}
+
+		// Build the blob sidecar.
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    uint64(blobIndex),
+			Blob:                     blob[:],
+			KzgCommitment:            kzgCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        signedBlockHeader,
+			CommitmentInclusionProof: commitmentInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		if err != nil {
+			return nil, errors.Wrap(err, "new RO blob")
+		}
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	return verifiedROBlobs, nil
 }

beacon-chain/core/peerdas/reconstruction_test.go

@@ -1,43 +1,41 @@
 package peerdas_test
 
 import (
+	"encoding/binary"
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/pkg/errors"
+	"golang.org/x/sync/errgroup"
 )
 
-func TestCanSelfReconstruct(t *testing.T) {
+func TestMinimumColumnsCountToReconstruct(t *testing.T) {
 	testCases := []struct {
-		name                       string
-		totalNumberOfCustodyGroups uint64
-		custodyNumberOfGroups      uint64
-		expected                   bool
+		name            string
+		numberOfColumns uint64
+		expected        uint64
 	}{
 		{
-			name:                       "totalNumberOfCustodyGroups=64, custodyNumberOfGroups=31",
-			totalNumberOfCustodyGroups: 64,
-			custodyNumberOfGroups:      31,
-			expected:                   false,
+			name:            "numberOfColumns=128",
+			numberOfColumns: 128,
+			expected:        64,
 		},
 		{
-			name:                       "totalNumberOfCustodyGroups=64, custodyNumberOfGroups=32",
-			totalNumberOfCustodyGroups: 64,
-			custodyNumberOfGroups:      32,
-			expected:                   true,
+			name:            "numberOfColumns=129",
+			numberOfColumns: 129,
+			expected:        65,
 		},
 		{
-			name:                       "totalNumberOfCustodyGroups=65, custodyNumberOfGroups=32",
-			totalNumberOfCustodyGroups: 65,
-			custodyNumberOfGroups:      32,
-			expected:                   false,
-		},
-		{
-			name:                       "totalNumberOfCustodyGroups=63, custodyNumberOfGroups=33",
-			totalNumberOfCustodyGroups: 65,
-			custodyNumberOfGroups:      33,
-			expected:                   true,
+			name:            "numberOfColumns=130",
+			numberOfColumns: 130,
+			expected:        65,
 		},
 	}
 
@@ -46,12 +44,278 @@ func TestCanSelfReconstruct(t *testing.T) {
 			// Set the total number of columns.
 			params.SetupTestConfigCleanup(t)
 			cfg := params.BeaconConfig().Copy()
-			cfg.NumberOfCustodyGroups = tc.totalNumberOfCustodyGroups
+			cfg.NumberOfColumns = tc.numberOfColumns
 			params.OverrideBeaconConfig(cfg)
 
-			// Check if reconstuction is possible.
-			actual := peerdas.CanSelfReconstruct(tc.custodyNumberOfGroups)
+			// Compute the minimum number of columns needed to reconstruct.
+			actual := peerdas.MinimumColumnsCountToReconstruct()
 			require.Equal(t, tc.expected, actual)
 		})
 	}
 }
+
+func TestReconstructDataColumnSidecars(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("empty input", func(t *testing.T) {
+		_, err := peerdas.ReconstructDataColumnSidecars(nil)
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("columns lengths differ", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// Arbitrarily alter the column with index 3
+		verifiedRoSidecars[3].Column = verifiedRoSidecars[3].Column[1:]
+
+		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars)
+		require.ErrorIs(t, err, peerdas.ErrColumnLengthsDiffer)
+	})
+
+	t.Run("roots differ", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{1}))
+		_, _, verifiedRoSidecarsAlter := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{2}))
+
+		// Arbitrarily alter the column with index 3
+		verifiedRoSidecars[3] = verifiedRoSidecarsAlter[3]
+		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockRootMismatch)
+	})
+
+	const blobCount = 6
+	signedBeaconBlockPb := util.NewBeaconBlockFulu()
+	block := signedBeaconBlockPb.Block
+
+	commitments := make([][]byte, 0, blobCount)
+	for i := range uint64(blobCount) {
+		var commitment [fieldparams.KzgCommitmentSize]byte
+		binary.BigEndian.PutUint64(commitment[:], i)
+		commitments = append(commitments, commitment[:])
+	}
+
+	block.Body.BlobKzgCommitments = commitments
+
+	t.Run("not enough columns to enable reconstruction", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		minimum := peerdas.MinimumColumnsCountToReconstruct()
+		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars[:minimum-1])
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		// Build a full set of verified data column sidecars.
+		_, _, inputVerifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// Arbitrarily keep only the even sicars.
+		filteredVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(inputVerifiedRoSidecars)/2)
+		for i := 0; i < len(inputVerifiedRoSidecars); i += 2 {
+			filteredVerifiedRoSidecars = append(filteredVerifiedRoSidecars, inputVerifiedRoSidecars[i])
+		}
+
+		// Reconstruct the data column sidecars.
+		reconstructedVerifiedRoSidecars, err := peerdas.ReconstructDataColumnSidecars(filteredVerifiedRoSidecars)
+		require.NoError(t, err)
+
+		// Verify that the reconstructed sidecars are equal to the original ones.
+		require.DeepSSZEqual(t, inputVerifiedRoSidecars, reconstructedVerifiedRoSidecars)
+	})
+}
+
+func TestConstructDataColumnSidecars(t *testing.T) {
+	const (
+		blobCount    = 3
+		cellsPerBlob = fieldparams.CellsPerBlob
+	)
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	roBlock, _, baseVerifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
+
+	// Extract blobs and proofs from the sidecars.
+	blobs := make([][]byte, 0, blobCount)
+	cellProofs := make([][]byte, 0, cellsPerBlob)
+	for blobIndex := range blobCount {
+		blob := make([]byte, 0, cellsPerBlob)
+		for columnIndex := range cellsPerBlob {
+			cell := baseVerifiedRoSidecars[columnIndex].Column[blobIndex]
+			blob = append(blob, cell...)
+		}
+
+		blobs = append(blobs, blob)
+
+		for columnIndex := range numberOfColumns {
+			cellProof := baseVerifiedRoSidecars[columnIndex].KzgProofs[blobIndex]
+			cellProofs = append(cellProofs, cellProof)
+		}
+	}
+
+	actual, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
+	require.NoError(t, err)
+
+	// Extract the base verified ro sidecars into sidecars.
+	expected := make([]*ethpb.DataColumnSidecar, 0, len(baseVerifiedRoSidecars))
+	for _, verifiedRoSidecar := range baseVerifiedRoSidecars {
+		expected = append(expected, verifiedRoSidecar.DataColumnSidecar)
+	}
+
+	require.DeepSSZEqual(t, expected, actual)
+}
+
+func TestReconstructBlobs(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	var emptyBlock blocks.ROBlock
+
+	t.Run("no index", func(t *testing.T) {
+		actual, err := peerdas.ReconstructBlobs(emptyBlock, nil, nil)
+		require.NoError(t, err)
+		require.IsNil(t, actual)
+	})
+
+	t.Run("empty input", func(t *testing.T) {
+		_, err := peerdas.ReconstructBlobs(emptyBlock, nil, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("not sorted", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// Arbitrarily change the order of the sidecars.
+		verifiedRoSidecars[3], verifiedRoSidecars[2] = verifiedRoSidecars[2], verifiedRoSidecars[3]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
+	t.Run("not enough columns", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		inputSidecars := verifiedRoSidecars[:fieldparams.CellsPerBlob-1]
+		_, err := peerdas.ReconstructBlobs(emptyBlock, inputSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("index too high", func(t *testing.T) {
+		const blobCount = 3
+
+		roBlock, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
+
+		_, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, []int{1, blobCount})
+		require.ErrorIs(t, err, peerdas.ErrBlobIndexTooHigh)
+	})
+
+	t.Run("not committed to the same block", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{1}))
+		roBlock, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{2}))
+
+		_, err = peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, []int{0})
+		require.ErrorContains(t, peerdas.ErrRootMismatch.Error(), err)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		const blobCount = 3
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+		roBlock, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)
+
+		// Compute cells and proofs from blob sidecars.
+		var wg errgroup.Group
+		blobs := make([][]byte, blobCount)
+		cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		for i := range blobCount {
+			blob := roBlobSidecars[i].Blob
+			blobs[i] = blob
+
+			wg.Go(func() error {
+				var kzgBlob kzg.Blob
+				count := copy(kzgBlob[:], blob)
+				require.Equal(t, len(kzgBlob), count)
+
+				cp, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				if err != nil {
+					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
+				}
+
+				// It is safe for multiple goroutines to concurrently write to the same slice,
+				// as long as they are writing to different indices, which is the case here.
+				cellsAndProofs[i] = cp
+
+				return nil
+			})
+		}
+
+		err := wg.Wait()
+		require.NoError(t, err)
+
+		// Flatten proofs.
+		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
+		for _, cp := range cellsAndProofs {
+			for _, proof := range cp.Proofs {
+				cellProofs = append(cellProofs, proof[:])
+			}
+		}
+
+		// Construct data column sidecars.
+		// It is OK to use the public function `ConstructDataColumnSidecars`, as long as
+		// `TestConstructDataColumnSidecars` tests pass.
+		dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
+		require.NoError(t, err)
+
+		// Convert to verified data column sidecars.
+		verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
+		for _, dataColumnSidecar := range dataColumnSidecars {
+			roSidecar, err := blocks.NewRODataColumn(dataColumnSidecar)
+			require.NoError(t, err)
+
+			verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+			verifiedRoSidecars = append(verifiedRoSidecars, verifiedRoSidecar)
+		}
+
+		indices := []int{2, 0}
+
+		t.Run("no reconstruction needed", func(t *testing.T) {
+			// Reconstruct blobs.
+			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, indices)
+			require.NoError(t, err)
+
+			// Compare blobs.
+			for i, blobIndex := range indices {
+				expected := roBlobSidecars[blobIndex]
+				actual := reconstructedVerifiedRoBlobSidecars[i].ROBlob
+
+				require.DeepSSZEqual(t, expected, actual)
+			}
+		})
+
+		t.Run("reconstruction needed", func(t *testing.T) {
+			// Arbitrarily keep only the even sidecars.
+			filteredSidecars := make([]blocks.VerifiedRODataColumn, 0, len(verifiedRoSidecars)/2)
+			for i := 0; i < len(verifiedRoSidecars); i += 2 {
+				filteredSidecars = append(filteredSidecars, verifiedRoSidecars[i])
+			}
+
+			// Reconstruct blobs.
+			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(roBlock, filteredSidecars, indices)
+			require.NoError(t, err)
+
+			// Compare blobs.
+			for i, blobIndex := range indices {
+				expected := roBlobSidecars[blobIndex]
+				actual := reconstructedVerifiedRoBlobSidecars[i].ROBlob
+
+				require.DeepSSZEqual(t, expected, actual)
+			}
+		})
+
+	})
+
+}

beacon-chain/core/peerdas/util.go

@@ -1,54 +0,0 @@
-package peerdas
-
-import (
-	"fmt"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
-	"github.com/pkg/errors"
-)
-
-// ConstructDataColumnSidecars constructs data column sidecars from a block, blobs and their cell proofs.
-// This is a convenience method as blob and cell proofs are common inputs.
-func ConstructDataColumnSidecars(block interfaces.SignedBeaconBlock, blobs [][]byte, cellProofs [][]byte) ([]*ethpb.DataColumnSidecar, error) {
-	// Check if the block is at least a Fulu block.
-	if block.Version() < version.Fulu {
-		return nil, nil
-	}
-
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-	if uint64(len(blobs))*numberOfColumns != uint64(len(cellProofs)) {
-		return nil, fmt.Errorf("number of blobs and cell proofs do not match: %d * %d != %d", len(blobs), numberOfColumns, len(cellProofs))
-	}
-
-	cellsAndProofs := make([]kzg.CellsAndProofs, 0, len(blobs))
-
-	for i, blob := range blobs {
-		var b kzg.Blob
-		copy(b[:], blob)
-		cells, err := kzg.ComputeCells(&b)
-		if err != nil {
-			return nil, err
-		}
-
-		var proofs []kzg.Proof
-		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
-			proofs = append(proofs, kzg.Proof(cellProofs[idx]))
-		}
-
-		cellsAndProofs = append(cellsAndProofs, kzg.CellsAndProofs{
-			Cells:  cells,
-			Proofs: proofs,
-		})
-	}
-
-	dataColumnSidecars, err := DataColumnSidecars(block, cellsAndProofs)
-	if err != nil {
-		return nil, errors.Wrap(err, "data column sidcars")
-	}
-
-	return dataColumnSidecars, nil
-}

beacon-chain/core/peerdas/verification.go

@@ -0,0 +1,64 @@
+package peerdas
+
+import (
+	"bytes"
+
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/pkg/errors"
+)
+
+var (
+	ErrBlockColumnSizeMismatch = errors.New("size mismatch between data column and block")
+	ErrTooManyCommitments      = errors.New("too many commitments")
+	ErrRootMismatch            = errors.New("root mismatch between data column and block")
+	ErrCommitmentMismatch      = errors.New("commitment mismatch between data column and block")
+)
+
+func DataColumnsAlignWithBlock(block blocks.ROBlock, dataColumns []blocks.RODataColumn) error {
+	// No data columns before Fulu.
+	if block.Version() < version.Fulu {
+		return nil
+	}
+
+	// Compute the maximum number of blobs per block.
+	blockSlot := block.Block().Slot()
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(blockSlot)
+
+	// Check if the block has not too many commitments.
+	blockCommitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return errors.Wrap(err, "blob KZG commitments")
+	}
+
+	blockCommitmentCount := len(blockCommitments)
+	if blockCommitmentCount > maxBlobsPerBlock {
+		return ErrTooManyCommitments
+	}
+
+	blockRoot := block.Root()
+
+	for _, dataColumn := range dataColumns {
+		// Check if the root of the data column sidecar matches the block root.
+		if dataColumn.BlockRoot() != blockRoot {
+			return ErrRootMismatch
+		}
+
+		// Check if the content length of the data column sidecar matches the block.
+		if len(dataColumn.Column) != blockCommitmentCount ||
+			len(dataColumn.KzgCommitments) != blockCommitmentCount ||
+			len(dataColumn.KzgProofs) != blockCommitmentCount {
+			return ErrBlockColumnSizeMismatch
+		}
+
+		// Check if the commitments of the data column sidecar match the block.
+		for i := range blockCommitments {
+			if !bytes.Equal(blockCommitments[i], dataColumn.KzgCommitments[i]) {
+				return ErrCommitmentMismatch
+			}
+		}
+	}
+
+	return nil
+}

beacon-chain/core/peerdas/verification_test.go

@@ -0,0 +1,78 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+)
+
+func TestDataColumnsAlignWithBlock(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.FuluForkEpoch = 0
+	config.DeprecatedMaxBlobsPerBlockFulu = 2
+	params.OverrideBeaconConfig(config)
+
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("pre fulu", func(t *testing.T) {
+		block, _ := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 0, 0)
+		err := peerdas.DataColumnsAlignWithBlock(block, nil)
+		require.NoError(t, err)
+	})
+
+	t.Run("too many commitmnets", func(t *testing.T) {
+		block, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 3)
+		err := peerdas.DataColumnsAlignWithBlock(block, nil)
+		require.ErrorIs(t, err, peerdas.ErrTooManyCommitments)
+	})
+
+	t.Run("root mismatch", func(t *testing.T) {
+		_, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		block, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 0)
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrRootMismatch)
+	})
+
+	t.Run("column size mismatch", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		sidecars[0].Column = [][]byte{}
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockColumnSizeMismatch)
+	})
+
+	t.Run("KZG commitments size mismatch", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		sidecars[0].KzgCommitments = [][]byte{}
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockColumnSizeMismatch)
+	})
+
+	t.Run("KZG proofs mismatch", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		sidecars[0].KzgProofs = [][]byte{}
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockColumnSizeMismatch)
+	})
+
+	t.Run("commitment mismatch", func(t *testing.T) {
+		block, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		_, alteredSidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		alteredSidecars[1].KzgCommitments[0][0]++ // Overflow is OK
+		err := peerdas.DataColumnsAlignWithBlock(block, alteredSidecars)
+		require.ErrorIs(t, err, peerdas.ErrCommitmentMismatch)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.NoError(t, err)
+	})
+}

beacon-chain/core/time/slot_epoch.go

@@ -53,6 +53,11 @@ func HigherEqualThanAltairVersionAndEpoch(s state.BeaconState, e primitives.Epoc
 	return s.Version() >= version.Altair && e >= params.BeaconConfig().AltairForkEpoch
 }
 
+// PeerDASIsActive checks whether peerDAS is active at the provided slot.
+func PeerDASIsActive(slot primitives.Slot) bool {
+	return params.FuluEnabled() && slots.ToEpoch(slot) >= params.BeaconConfig().FuluForkEpoch
+}
+
 // CanUpgradeToAltair returns true if the input `slot` can upgrade to Altair.
 // Spec code:
 // If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == ALTAIR_FORK_EPOCH

beacon-chain/das/BUILD.bazel

@@ -4,21 +4,26 @@ go_library(
     name = "go_default_library",
     srcs = [
         "availability.go",
+        "availability_columns.go",
         "cache.go",
+        "data_column_cache.go",
         "iface.go",
         "mock.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/das",
     visibility = ["//visibility:public"],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//runtime/logging:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -27,13 +32,18 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "availability_columns_test.go",
         "availability_test.go",
         "cache_test.go",
+        "data_column_cache_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/primitives:go_default_library",
@@ -41,6 +51,7 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/das/availability.go

@@ -53,10 +53,16 @@ func NewLazilyPersistentStore(store *filesystem.BlobStorage, verifier BlobBatchV
 // Persist adds blobs to the working blob cache. Blobs stored in this cache will be persisted
 // for at least as long as the node is running. Once IsDataAvailable succeeds, all blobs referenced
 // by the given block are guaranteed to be persisted for the remainder of the retention period.
-func (s *LazilyPersistentStore) Persist(current primitives.Slot, sc ...blocks.ROBlob) error {
-	if len(sc) == 0 {
+func (s *LazilyPersistentStore) Persist(current primitives.Slot, scg ...blocks.ROSidecar) error {
+	if len(scg) == 0 {
 		return nil
 	}
+
+	sc, err := blocks.BlobSidecarsFromSidecars(scg)
+	if err != nil {
+		return errors.Wrap(err, "blob sidecars from sidecars")
+	}
+
 	if len(sc) > 1 {
 		first := sc[0].BlockRoot()
 		for i := 1; i < len(sc); i++ {

beacon-chain/das/availability_columns.go

@@ -0,0 +1,200 @@
+package das
+
+import (
+	"context"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	errors "github.com/pkg/errors"
+)
+
+// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
+// This implementation will hold any data columns passed to Persist until the IsDataAvailable is called for their
+// block, at which time they will undergo full verification and be saved to the disk.
+type LazilyPersistentStoreColumn struct {
+	store                  *filesystem.DataColumnStorage
+	nodeID                 enode.ID
+	cache                  *dataColumnCache
+	custodyInfo            *peerdas.CustodyInfo
+	newDataColumnsVerifier verification.NewDataColumnsVerifier
+}
+
+var _ AvailabilityStore = &LazilyPersistentStoreColumn{}
+
+// DataColumnsVerifier enables LazilyPersistentStoreColumn to manage the verification process
+// going from RODataColumn->VerifiedRODataColumn, while avoiding the decision of which individual verifications
+// to run and in what order. Since LazilyPersistentStoreColumn always tries to verify and save data columns only when
+// they are all available, the interface takes a slice of data column sidecars.
+type DataColumnsVerifier interface {
+	VerifiedRODataColumns(ctx context.Context, blk blocks.ROBlock, scs []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error)
+}
+
+func NewLazilyPersistentStoreColumn(store *filesystem.DataColumnStorage, nodeID enode.ID, newDataColumnsVerifier verification.NewDataColumnsVerifier, custodyInfo *peerdas.CustodyInfo) *LazilyPersistentStoreColumn {
+	return &LazilyPersistentStoreColumn{
+		store:                  store,
+		nodeID:                 nodeID,
+		cache:                  newDataColumnCache(),
+		custodyInfo:            custodyInfo,
+		newDataColumnsVerifier: newDataColumnsVerifier,
+	}
+}
+
+// PersistColumns adds columns to the working column cache. Columns stored in this cache will be persisted
+// for at least as long as the node is running. Once IsDataAvailable succeeds, all columns referenced
+// by the given block are guaranteed to be persisted for the remainder of the retention period.
+func (s *LazilyPersistentStoreColumn) Persist(current primitives.Slot, sidecars ...blocks.ROSidecar) error {
+	if len(sidecars) == 0 {
+		return nil
+	}
+
+	dataColumnSidecars, err := blocks.DataColumnSidecarsFromSidecars(sidecars)
+	if err != nil {
+		return errors.Wrap(err, "blob sidecars from sidecars")
+	}
+
+	// It is safe to retrieve the first sidecar.
+	firstSidecar := dataColumnSidecars[0]
+
+	if len(sidecars) > 1 {
+		firstRoot := firstSidecar.BlockRoot()
+		for _, sidecar := range dataColumnSidecars[1:] {
+			if sidecar.BlockRoot() != firstRoot {
+				return errMixedRoots
+			}
+		}
+	}
+
+	firstSidecarEpoch, currentEpoch := slots.ToEpoch(firstSidecar.Slot()), slots.ToEpoch(current)
+	if !params.WithinDAPeriod(firstSidecarEpoch, currentEpoch) {
+		return nil
+	}
+
+	key := dataColumnCacheKey{slot: firstSidecar.Slot(), root: firstSidecar.BlockRoot()}
+	entry := s.cache.ensure(key)
+
+	for i := range sidecars {
+		if err := entry.stash(&dataColumnSidecars[i]); err != nil {
+			return errors.Wrap(err, "stash DataColumnSidecar")
+		}
+	}
+
+	return nil
+}
+
+// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
+// DataColumnsSidecars already in the db are assumed to have been previously verified against the block.
+func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, currentSlot primitives.Slot, block blocks.ROBlock) error {
+	blockCommitments, err := s.fullCommitmentsToCheck(s.nodeID, block, currentSlot)
+	if err != nil {
+		return errors.Wrapf(err, "full commitments to check with block root `%#x` and current slot `%d`", block.Root(), currentSlot)
+	}
+
+	// Return early for blocks that do not have any commitments.
+	if blockCommitments.count() == 0 {
+		return nil
+	}
+
+	// Get the root of the block.
+	blockRoot := block.Root()
+
+	// Build the cache key for the block.
+	key := dataColumnCacheKey{slot: block.Block().Slot(), root: blockRoot}
+
+	// Retrieve the cache entry for the block, or create an empty one if it doesn't exist.
+	entry := s.cache.ensure(key)
+
+	// Delete the cache entry for the block at the end.
+	defer s.cache.delete(key)
+
+	// Set the disk summary for the block in the cache entry.
+	entry.setDiskSummary(s.store.Summary(blockRoot))
+
+	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
+	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
+	// ignore their response and decrease their peer score.
+	roDataColumns, err := entry.filter(blockRoot, blockCommitments)
+	if err != nil {
+		return errors.Wrap(err, "filter")
+	}
+
+	// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
+	verifier := s.newDataColumnsVerifier(roDataColumns, verification.ByRangeRequestDataColumnSidecarRequirements)
+
+	if err := verifier.Valid(); err != nil {
+		return errors.Wrap(err, "valid")
+	}
+
+	if err := verifier.SidecarInclusionProven(); err != nil {
+		return errors.Wrap(err, "sidecar inclusion proven")
+	}
+
+	if err := verifier.SidecarKzgProofVerified(); err != nil {
+		return errors.Wrap(err, "sidecar KZG proof verified")
+	}
+
+	verifiedRoDataColumns, err := verifier.VerifiedRODataColumns()
+	if err != nil {
+		return errors.Wrap(err, "verified RO data columns - should never happen")
+	}
+
+	if err := s.store.Save(verifiedRoDataColumns); err != nil {
+		return errors.Wrap(err, "save data column sidecars")
+	}
+
+	return nil
+}
+
+// fullCommitmentsToCheck returns the commitments to check for a given block.
+func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, block blocks.ROBlock, currentSlot primitives.Slot) (*safeCommitmentsArray, error) {
+	// Return early for blocks that are pre-Fulu.
+	if block.Version() < version.Fulu {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Compute the block epoch.
+	blockSlot := block.Block().Slot()
+	blockEpoch := slots.ToEpoch(blockSlot)
+
+	// Compute the current spoch.
+	currentEpoch := slots.ToEpoch(currentSlot)
+
+	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Retrieve the KZG commitments for the block.
+	kzgCommitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// Return early if there are no commitments in the block.
+	if len(kzgCommitments) == 0 {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Retrieve the groups count.
+	custodyGroupCount := s.custodyInfo.ActualGroupCount()
+
+	// Retrieve peer info.
+	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "peer info")
+	}
+
+	// Create a safe commitments array for the custody columns.
+	commitmentsArray := &safeCommitmentsArray{}
+	for column := range peerInfo.CustodyColumns {
+		commitmentsArray[column] = kzgCommitments
+	}
+
+	return commitmentsArray, nil
+}

beacon-chain/das/availability_columns_test.go

@@ -0,0 +1,301 @@
+package das
+
+import (
+	"context"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+func roSidecarsFromDataColumnParamsByBlockRoot(t *testing.T, dataColumnParamsByBlockRoot verification.DataColumnsParamsByRoot) ([]blocks.ROSidecar, []blocks.RODataColumn) {
+	roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+	roSidecars := make([]blocks.ROSidecar, 0, len(roDataColumns))
+	for _, roDataColumn := range roDataColumns {
+		roSidecars = append(roSidecars, blocks.NewSidecarFromDataColumnSidecar(roDataColumn))
+	}
+
+	return roSidecars, roDataColumns
+}
+
+func newSignedRoBlock(t *testing.T, signedBeaconBlock interface{}) blocks.ROBlock {
+	sb, err := blocks.NewSignedBeaconBlock(signedBeaconBlock)
+	require.NoError(t, err)
+
+	rb, err := blocks.NewROBlock(sb)
+	require.NoError(t, err)
+
+	return rb
+}
+
+var commitments = [][]byte{
+	bytesutil.PadTo([]byte("a"), 48),
+	bytesutil.PadTo([]byte("b"), 48),
+	bytesutil.PadTo([]byte("c"), 48),
+	bytesutil.PadTo([]byte("d"), 48),
+}
+
+func TestPersist(t *testing.T) {
+	t.Run("no sidecars", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+		err := lazilyPersistentStoreColumns.Persist(0)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
+	})
+
+	t.Run("mixed roots", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		dataColumnParamsByBlockRoot := map[[fieldparams.RootLength]byte][]verification.DataColumnParams{
+			{1}: {{ColumnIndex: 1}},
+			{2}: {{ColumnIndex: 2}},
+		}
+
+		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
+		require.ErrorIs(t, err, errMixedRoots)
+		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
+	})
+
+	t.Run("outside DA period", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		dataColumnParamsByBlockRoot := map[[fieldparams.RootLength]byte][]verification.DataColumnParams{
+			{1}: {{ColumnIndex: 1}},
+		}
+
+		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.Persist(1_000_000, roSidecars...)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		dataColumnParamsByBlockRoot := map[[fieldparams.RootLength]byte][]verification.DataColumnParams{
+			{}: {{ColumnIndex: 1}, {ColumnIndex: 5}},
+		}
+
+		roSidecars, roDataColumns := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
+		require.NoError(t, err)
+		require.Equal(t, 1, len(lazilyPersistentStoreColumns.cache.entries))
+
+		key := dataColumnCacheKey{slot: 0, root: [32]byte{}}
+		entry := lazilyPersistentStoreColumns.cache.entries[key]
+
+		// A call to Persist does NOT save the sidecars to disk.
+		require.Equal(t, uint64(0), entry.diskSummary.Count())
+
+		require.DeepSSZEqual(t, roDataColumns[0], *entry.scs[1])
+		require.DeepSSZEqual(t, roDataColumns[1], *entry.scs[5])
+
+		for i, roDataColumn := range entry.scs {
+			if map[int]bool{1: true, 5: true}[i] {
+				continue
+			}
+
+			require.IsNil(t, roDataColumn)
+		}
+	})
+}
+
+func TestIsDataAvailable(t *testing.T) {
+	newDataColumnsVerifier := func(dataColumnSidecars []blocks.RODataColumn, _ []verification.Requirement) verification.DataColumnsVerifier {
+		return &mockDataColumnsVerifier{t: t, dataColumnSidecars: dataColumnSidecars}
+	}
+
+	ctx := context.Background()
+
+	t.Run("without commitments", func(t *testing.T) {
+		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
+		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
+
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
+
+		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
+		require.NoError(t, err)
+	})
+
+	t.Run("with commitments", func(t *testing.T) {
+		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
+		signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
+		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
+		root := signedRoBlock.Root()
+
+		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
+		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, &peerdas.CustodyInfo{})
+
+		indices := [...]uint64{1, 17, 87, 102}
+		dataColumnsParams := make([]verification.DataColumnParams, 0, len(indices))
+		for _, index := range indices {
+			dataColumnParams := verification.DataColumnParams{
+				ColumnIndex:    index,
+				KzgCommitments: commitments,
+			}
+
+			dataColumnsParams = append(dataColumnsParams, dataColumnParams)
+		}
+
+		dataColumnsParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: dataColumnsParams}
+		_, verifiedRoDataColumns := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnsParamsByBlockRoot)
+
+		key := dataColumnCacheKey{root: root}
+		entry := lazilyPersistentStoreColumns.cache.ensure(key)
+		defer lazilyPersistentStoreColumns.cache.delete(key)
+
+		for _, verifiedRoDataColumn := range verifiedRoDataColumns {
+			err := entry.stash(&verifiedRoDataColumn.RODataColumn)
+			require.NoError(t, err)
+		}
+
+		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
+		require.NoError(t, err)
+
+		actual, err := dataColumnStorage.Get(root, indices[:])
+		require.NoError(t, err)
+
+		summary := dataColumnStorage.Summary(root)
+		require.Equal(t, uint64(len(indices)), summary.Count())
+		require.DeepSSZEqual(t, verifiedRoDataColumns, actual)
+	})
+}
+
+func TestFullCommitmentsToCheck(t *testing.T) {
+	windowSlots, err := slots.EpochEnd(params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest)
+	require.NoError(t, err)
+
+	testCases := []struct {
+		name        string
+		commitments [][]byte
+		block       func(*testing.T) blocks.ROBlock
+		slot        primitives.Slot
+	}{
+		{
+			name: "Pre-Fulu block",
+			block: func(t *testing.T) blocks.ROBlock {
+				return newSignedRoBlock(t, util.NewBeaconBlockElectra())
+			},
+		},
+		{
+			name: "Commitments outside data availability window",
+			block: func(t *testing.T) blocks.ROBlock {
+				beaconBlockElectra := util.NewBeaconBlockElectra()
+
+				// Block is from slot 0, "current slot" is window size +1 (so outside the window)
+				beaconBlockElectra.Block.Body.BlobKzgCommitments = commitments
+
+				return newSignedRoBlock(t, beaconBlockElectra)
+			},
+			slot: windowSlots + 1,
+		},
+		{
+			name: "Commitments within data availability window",
+			block: func(t *testing.T) blocks.ROBlock {
+				signedBeaconBlockFulu := util.NewBeaconBlockFulu()
+				signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
+				signedBeaconBlockFulu.Block.Slot = 100
+
+				return newSignedRoBlock(t, signedBeaconBlockFulu)
+			},
+			commitments: commitments,
+			slot:        100,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			resetFlags := flags.Get()
+			gFlags := new(flags.GlobalFlags)
+			gFlags.SubscribeAllDataSubnetsubnets = true
+			flags.Init(gFlags)
+			defer flags.Init(resetFlags)
+
+			b := tc.block(t)
+			s := NewLazilyPersistentStoreColumn(nil, enode.ID{}, nil, &peerdas.CustodyInfo{})
+
+			commitmentsArray, err := s.fullCommitmentsToCheck(enode.ID{}, b, tc.slot)
+			require.NoError(t, err)
+
+			for _, commitments := range commitmentsArray {
+				require.DeepEqual(t, tc.commitments, commitments)
+			}
+		})
+	}
+}
+
+type mockDataColumnsVerifier struct {
+	t                                                                        *testing.T
+	dataColumnSidecars                                                       []blocks.RODataColumn
+	validCalled, SidecarInclusionProvenCalled, SidecarKzgProofVerifiedCalled bool
+}
+
+var _ verification.DataColumnsVerifier = &mockDataColumnsVerifier{}
+
+func (m *mockDataColumnsVerifier) VerifiedRODataColumns() ([]blocks.VerifiedRODataColumn, error) {
+	require.Equal(m.t, true, m.validCalled && m.SidecarInclusionProvenCalled && m.SidecarKzgProofVerifiedCalled)
+
+	verifiedDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(m.dataColumnSidecars))
+	for _, dataColumnSidecar := range m.dataColumnSidecars {
+		verifiedDataColumnSidecar := blocks.NewVerifiedRODataColumn(dataColumnSidecar)
+		verifiedDataColumnSidecars = append(verifiedDataColumnSidecars, verifiedDataColumnSidecar)
+	}
+
+	return verifiedDataColumnSidecars, nil
+}
+
+func (m *mockDataColumnsVerifier) SatisfyRequirement(verification.Requirement) {}
+
+func (m *mockDataColumnsVerifier) Valid() error {
+	m.validCalled = true
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) CorrectSubnet(expectedTopics []string) error      { return nil }
+func (m *mockDataColumnsVerifier) NotFromFutureSlot() error                         { return nil }
+func (m *mockDataColumnsVerifier) SlotAboveFinalized() error                        { return nil }
+func (m *mockDataColumnsVerifier) ValidProposerSignature(ctx context.Context) error { return nil }
+
+func (m *mockDataColumnsVerifier) SidecarParentSeen(parentSeen func([fieldparams.RootLength]byte) bool) error {
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarParentValid(badParent func([fieldparams.RootLength]byte) bool) error {
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarParentSlotLower() error       { return nil }
+func (m *mockDataColumnsVerifier) SidecarDescendsFromFinalized() error { return nil }
+
+func (m *mockDataColumnsVerifier) SidecarInclusionProven() error {
+	m.SidecarInclusionProvenCalled = true
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarKzgProofVerified() error {
+	m.SidecarKzgProofVerifiedCalled = true
+	return nil
+}
+
+func (m *mockDataColumnsVerifier) SidecarProposerExpected(ctx context.Context) error { return nil }

beacon-chain/das/availability_test.go

@@ -116,9 +116,11 @@ func TestLazilyPersistent_Missing(t *testing.T) {
 	ctx := context.Background()
 	store := filesystem.NewEphemeralBlobStorage(t)
 
-	blk, scs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
+	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
 
-	mbv := &mockBlobBatchVerifier{t: t, scs: scs}
+	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
+	mbv := &mockBlobBatchVerifier{t: t, scs: blobSidecars}
 	as := NewLazilyPersistentStore(store, mbv)
 
 	// Only one commitment persisted, should return error with other indices
@@ -141,12 +143,14 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 	ctx := context.Background()
 	store := filesystem.NewEphemeralBlobStorage(t)
 
-	blk, scs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
+	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
 
 	mbv := &mockBlobBatchVerifier{t: t, err: errors.New("kzg check should not run")}
-	scs[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
+	blobSidecars[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
 	as := NewLazilyPersistentStore(store, mbv)
 
+	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
 	// Only one commitment persisted, should return error with other indices
 	require.NoError(t, as.Persist(1, scs[0]))
 	err := as.IsDataAvailable(ctx, 1, blk)
@@ -155,7 +159,10 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 }
 
 func TestLazyPersistOnceCommitted(t *testing.T) {
-	_, scs := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 6)
+	_, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 6)
+
+	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
+
 	as := NewLazilyPersistentStore(filesystem.NewEphemeralBlobStorage(t), &mockBlobBatchVerifier{})
 	// stashes as expected
 	require.NoError(t, as.Persist(1, scs...))
@@ -163,10 +170,13 @@ func TestLazyPersistOnceCommitted(t *testing.T) {
 	require.ErrorIs(t, as.Persist(1, scs...), ErrDuplicateSidecar)
 
 	// ignores index out of bound
-	scs[0].Index = 6
-	require.ErrorIs(t, as.Persist(1, scs[0]), errIndexOutOfBounds)
+	blobSidecars[0].Index = 6
+	require.ErrorIs(t, as.Persist(1, blocks.NewSidecarFromBlobSidecar(blobSidecars[0])), errIndexOutOfBounds)
+
+	_, moreBlobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 4)
+
+	more := blocks.NewSidecarsFromBlobSidecars(moreBlobSidecars)
 
-	_, more := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 4)
 	// ignores sidecars before the retention period
 	slotOOB, err := slots.EpochStart(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest)
 	require.NoError(t, err)

beacon-chain/das/cache.go

@@ -10,12 +10,7 @@ import (
 	"github.com/pkg/errors"
 )
 
-var (
-	ErrDuplicateSidecar   = errors.New("duplicate sidecar stashed in AvailabilityStore")
-	errIndexOutOfBounds   = errors.New("sidecar.index > MAX_BLOBS_PER_BLOCK")
-	errCommitmentMismatch = errors.New("KzgCommitment of sidecar in cache did not match block commitment")
-	errMissingSidecar     = errors.New("no sidecar in cache for block commitment")
-)
+var errIndexOutOfBounds = errors.New("sidecar.index > MAX_BLOBS_PER_BLOCK")
 
 // cacheKey includes the slot so that we can easily iterate through the cache and compare
 // slots for eviction purposes. Whether the input is the block or the sidecar, we always have

beacon-chain/das/data_column_cache.go

@@ -0,0 +1,135 @@
+package das
+
+import (
+	"reflect"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+var (
+	ErrDuplicateSidecar   = errors.New("duplicate sidecar stashed in AvailabilityStore")
+	errColumnIndexTooHigh = errors.New("column index too high")
+	errCommitmentMismatch = errors.New("KzgCommitment of sidecar in cache did not match block commitment")
+	errMissingSidecar     = errors.New("no sidecar in cache for block commitment")
+)
+
+// dataColumnCacheKey includes the slot so that we can easily iterate through the cache and compare
+// slots for eviction purposes. Whether the input is the block or the sidecar, we always have
+// the root+slot when interacting with the cache, so it isn't an inconvenience to use both.
+type dataColumnCacheKey struct {
+	slot primitives.Slot
+	root [32]byte
+}
+
+type dataColumnCache struct {
+	entries map[dataColumnCacheKey]*dataColumnCacheEntry
+}
+
+func newDataColumnCache() *dataColumnCache {
+	return &dataColumnCache{entries: make(map[dataColumnCacheKey]*dataColumnCacheEntry)}
+}
+
+// ensure returns the entry for the given key, creating it if it isn't already present.
+func (c *dataColumnCache) ensure(key dataColumnCacheKey) *dataColumnCacheEntry {
+	entry, ok := c.entries[key]
+	if !ok {
+		entry = &dataColumnCacheEntry{}
+		c.entries[key] = entry
+	}
+
+	return entry
+}
+
+// delete removes the cache entry from the cache.
+func (c *dataColumnCache) delete(key dataColumnCacheKey) {
+	delete(c.entries, key)
+}
+
+// dataColumnCacheEntry holds a fixed-length cache of BlobSidecars.
+type dataColumnCacheEntry struct {
+	scs         [fieldparams.NumberOfColumns]*blocks.RODataColumn
+	diskSummary filesystem.DataColumnStorageSummary
+}
+
+func (e *dataColumnCacheEntry) setDiskSummary(sum filesystem.DataColumnStorageSummary) {
+	e.diskSummary = sum
+}
+
+// stash adds an item to the in-memory cache of DataColumnSidecars.
+// Only the first DataColumnSidecar of a given Index will be kept in the cache.
+// stash will return an error if the given data colunn is already in the cache, or if the Index is out of bounds.
+func (e *dataColumnCacheEntry) stash(sc *blocks.RODataColumn) error {
+	if sc.Index >= fieldparams.NumberOfColumns {
+		return errors.Wrapf(errColumnIndexTooHigh, "index=%d", sc.Index)
+	}
+
+	if e.scs[sc.Index] != nil {
+		return errors.Wrapf(ErrDuplicateSidecar, "root=%#x, index=%d, commitment=%#x", sc.BlockRoot(), sc.Index, sc.KzgCommitments)
+	}
+
+	e.scs[sc.Index] = sc
+
+	return nil
+}
+
+func (e *dataColumnCacheEntry) filter(root [32]byte, commitmentsArray *safeCommitmentsArray) ([]blocks.RODataColumn, error) {
+	nonEmptyIndices := commitmentsArray.nonEmptyIndices()
+	if e.diskSummary.AllAvailable(nonEmptyIndices) {
+		return nil, nil
+	}
+
+	commitmentsCount := commitmentsArray.count()
+	sidecars := make([]blocks.RODataColumn, 0, commitmentsCount)
+
+	for i := range nonEmptyIndices {
+		if e.diskSummary.HasIndex(i) {
+			continue
+		}
+
+		if e.scs[i] == nil {
+			return nil, errors.Wrapf(errMissingSidecar, "root=%#x, index=%#x", root, i)
+		}
+
+		if !reflect.DeepEqual(commitmentsArray[i], e.scs[i].KzgCommitments) {
+			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, e.scs[i].KzgCommitments, commitmentsArray[i])
+		}
+
+		sidecars = append(sidecars, *e.scs[i])
+	}
+
+	return sidecars, nil
+}
+
+// safeCommitmentsArray is a fixed size array of commitments.
+// This is helpful for avoiding gratuitous bounds checks.
+type safeCommitmentsArray [fieldparams.NumberOfColumns][][]byte
+
+// count returns the number of commitments in the array.
+func (s *safeCommitmentsArray) count() int {
+	count := 0
+
+	for i := range s {
+		if s[i] != nil {
+			count++
+		}
+	}
+
+	return count
+}
+
+// nonEmptyIndices returns a map of indices that are non-nil in the array.
+func (s *safeCommitmentsArray) nonEmptyIndices() map[uint64]bool {
+	columns := make(map[uint64]bool)
+
+	for i := range s {
+		if s[i] != nil {
+			columns[uint64(i)] = true
+		}
+	}
+
+	return columns
+}

beacon-chain/das/data_column_cache_test.go

@@ -0,0 +1,124 @@
+package das
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestEnsureDeleteSetDiskSummary(t *testing.T) {
+	c := newDataColumnCache()
+	key := dataColumnCacheKey{}
+	entry := c.ensure(key)
+	require.DeepEqual(t, dataColumnCacheEntry{}, *entry)
+
+	diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{true})
+	entry.setDiskSummary(diskSummary)
+	entry = c.ensure(key)
+	require.DeepEqual(t, dataColumnCacheEntry{diskSummary: diskSummary}, *entry)
+
+	c.delete(key)
+	entry = c.ensure(key)
+	require.DeepEqual(t, dataColumnCacheEntry{}, *entry)
+}
+
+func TestStash(t *testing.T) {
+	t.Run("Index too high", func(t *testing.T) {
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{{1}: {{ColumnIndex: 10_000}}}
+		roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var entry dataColumnCacheEntry
+		err := entry.stash(&roDataColumns[0])
+		require.NotNil(t, err)
+	})
+
+	t.Run("Nominal and already existing", func(t *testing.T) {
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{{1}: {{ColumnIndex: 1}}}
+		roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var entry dataColumnCacheEntry
+		err := entry.stash(&roDataColumns[0])
+		require.NoError(t, err)
+
+		require.DeepEqual(t, roDataColumns[0], entry.scs[1])
+
+		err = entry.stash(&roDataColumns[0])
+		require.NotNil(t, err)
+	})
+}
+
+func TestFilterDataColumns(t *testing.T) {
+	t.Run("All available", func(t *testing.T) {
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}, nil, [][]byte{[]byte{3}}}
+
+		diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{false, true, false, true})
+
+		dataColumnCacheEntry := dataColumnCacheEntry{diskSummary: diskSummary}
+
+		actual, err := dataColumnCacheEntry.filter([fieldparams.RootLength]byte{}, &commitmentsArray)
+		require.NoError(t, err)
+		require.IsNil(t, actual)
+	})
+
+	t.Run("Some scs missing", func(t *testing.T) {
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}}
+
+		diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{})
+
+		dataColumnCacheEntry := dataColumnCacheEntry{diskSummary: diskSummary}
+
+		_, err := dataColumnCacheEntry.filter([fieldparams.RootLength]byte{}, &commitmentsArray)
+		require.NotNil(t, err)
+	})
+
+	t.Run("Commitments not equal", func(t *testing.T) {
+		root := [fieldparams.RootLength]byte{}
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}}
+
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: {{ColumnIndex: 1}}}
+		roDataColumns, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var scs [fieldparams.NumberOfColumns]*blocks.RODataColumn
+		scs[1] = &roDataColumns[0]
+
+		dataColumnCacheEntry := dataColumnCacheEntry{scs: scs}
+
+		_, err := dataColumnCacheEntry.filter(root, &commitmentsArray)
+		require.NotNil(t, err)
+	})
+
+	t.Run("Nominal", func(t *testing.T) {
+		root := [fieldparams.RootLength]byte{}
+		commitmentsArray := safeCommitmentsArray{nil, [][]byte{[]byte{1}}, nil, [][]byte{[]byte{3}}}
+
+		diskSummary := filesystem.NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{false, true})
+
+		dataColumnParamsByBlockRoot := verification.DataColumnsParamsByRoot{root: {{ColumnIndex: 3, KzgCommitments: [][]byte{[]byte{3}}}}}
+		expected, _ := verification.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnParamsByBlockRoot)
+
+		var scs [fieldparams.NumberOfColumns]*blocks.RODataColumn
+		scs[3] = &expected[0]
+
+		dataColumnCacheEntry := dataColumnCacheEntry{scs: scs, diskSummary: diskSummary}
+
+		actual, err := dataColumnCacheEntry.filter(root, &commitmentsArray)
+		require.NoError(t, err)
+
+		require.DeepEqual(t, expected, actual)
+	})
+}
+
+func TestCount(t *testing.T) {
+	s := safeCommitmentsArray{nil, [][]byte{[]byte{1}}, nil, [][]byte{[]byte{3}}}
+	require.Equal(t, 2, s.count())
+}
+
+func TestNonEmptyIndices(t *testing.T) {
+	s := safeCommitmentsArray{nil, [][]byte{[]byte{10}}, nil, [][]byte{[]byte{20}}}
+	actual := s.nonEmptyIndices()
+	require.DeepEqual(t, map[uint64]bool{1: true, 3: true}, actual)
+}

beacon-chain/das/iface.go

@@ -15,5 +15,5 @@ import (
 // durably persisted before returning a non-error value.
 type AvailabilityStore interface {
 	IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
-	Persist(current primitives.Slot, sc ...blocks.ROBlob) error
+	Persist(current primitives.Slot, sc ...blocks.ROSidecar) error
 }

beacon-chain/das/mock.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	errors "github.com/pkg/errors"
 )
 
 // MockAvailabilityStore is an implementation of AvailabilityStore that can be used by other packages in tests.
@@ -24,9 +25,13 @@ func (m *MockAvailabilityStore) IsDataAvailable(ctx context.Context, current pri
 }
 
 // Persist satisfies the corresponding method of the AvailabilityStore interface in a way that is useful for tests.
-func (m *MockAvailabilityStore) Persist(current primitives.Slot, sc ...blocks.ROBlob) error {
+func (m *MockAvailabilityStore) Persist(current primitives.Slot, sc ...blocks.ROSidecar) error {
+	blobSidecars, err := blocks.BlobSidecarsFromSidecars(sc)
+	if err != nil {
+		return errors.Wrap(err, "blob sidecars from sidecars")
+	}
 	if m.PersistBlobsCallback != nil {
-		return m.PersistBlobsCallback(current, sc...)
+		return m.PersistBlobsCallback(current, blobSidecars...)
 	}
 	return nil
 }

beacon-chain/db/filesystem/BUILD.bazel

@@ -5,6 +5,9 @@ go_library(
     srcs = [
         "blob.go",
         "cache.go",
+        "data_column.go",
+        "data_column_cache.go",
+        "doc.go",
         "iteration.go",
         "layout.go",
         "layout_by_epoch.go",
@@ -17,6 +20,8 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem",
     visibility = ["//visibility:public"],
     deps = [
+        "//async:go_default_library",
+        "//async/event:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -25,6 +30,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//io/file:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/logging:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
@@ -41,6 +47,8 @@ go_test(
     srcs = [
         "blob_test.go",
         "cache_test.go",
+        "data_column_cache_test.go",
+        "data_column_test.go",
         "iteration_test.go",
         "layout_test.go",
         "migration_test.go",
@@ -50,6 +58,7 @@ go_test(
     deps = [
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",

beacon-chain/db/filesystem/data_column_cache.go

@@ -0,0 +1,242 @@
+package filesystem
+
+import (
+	"sync"
+
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+var errDataColumnIndexOutOfBounds = errors.New("data column index too high")
+
+// DataColumnStorageSummary represents cached information about the DataColumnSidecars on disk for each root the cache knows about.
+type DataColumnStorageSummary struct {
+	epoch primitives.Epoch
+	mask  [fieldparams.NumberOfColumns]bool
+}
+
+// NewDataColumnStorageSummary creates a new DataColumnStorageSummary for a given epoch and mask.
+func NewDataColumnStorageSummary(epoch primitives.Epoch, mask [fieldparams.NumberOfColumns]bool) DataColumnStorageSummary {
+	return DataColumnStorageSummary{
+		epoch: epoch,
+		mask:  mask,
+	}
+}
+
+// HasIndex returns true if the DataColumnSidecar at the given index is available in the filesystem.
+func (s DataColumnStorageSummary) HasIndex(index uint64) bool {
+	if index >= uint64(fieldparams.NumberOfColumns) {
+		return false
+	}
+	return s.mask[index]
+}
+
+// HasAtLeastOneIndex returns true if at least one of the DataColumnSidecars at the given indices is available in the filesystem.
+func (s DataColumnStorageSummary) HasAtLeastOneIndex(indices []uint64) bool {
+	for _, index := range indices {
+		if s.mask[index] {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Count returns the number of available data columns.
+func (s DataColumnStorageSummary) Count() uint64 {
+	count := uint64(0)
+
+	for _, available := range s.mask {
+		if available {
+			count++
+		}
+	}
+
+	return count
+}
+
+// AllAvailable returns true if we have all data columns for corresponding indices.
+func (s DataColumnStorageSummary) AllAvailable(indices map[uint64]bool) bool {
+	if len(indices) > len(s.mask) {
+		return false
+	}
+
+	for index := range indices {
+		if !s.mask[index] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Stored returns a map of all stored data columns.
+func (s DataColumnStorageSummary) Stored() map[uint64]bool {
+	stored := make(map[uint64]bool, fieldparams.NumberOfColumns)
+	for index, exists := range s.mask {
+		if exists {
+			stored[uint64(index)] = true
+		}
+	}
+
+	return stored
+}
+
+// DataColumnStorageSummarizer can be used to receive a summary of metadata about data columns on disk for a given root.
+// The DataColumnStorageSummary can be used to check which indices (if any) are available for a given block by root.
+type DataColumnStorageSummarizer interface {
+	Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary
+}
+
+type dataColumnStorageSummaryCache struct {
+	mu                 sync.RWMutex
+	dataColumnCount    float64
+	lowestCachedEpoch  primitives.Epoch
+	highestCachedEpoch primitives.Epoch
+	cache              map[[fieldparams.RootLength]byte]DataColumnStorageSummary
+}
+
+var _ DataColumnStorageSummarizer = &dataColumnStorageSummaryCache{}
+
+func newDataColumnStorageSummaryCache() *dataColumnStorageSummaryCache {
+	return &dataColumnStorageSummaryCache{
+		cache:             make(map[[fieldparams.RootLength]byte]DataColumnStorageSummary),
+		lowestCachedEpoch: params.BeaconConfig().FarFutureEpoch,
+	}
+}
+
+// Summary returns the DataColumnStorageSummary for `root`.
+// The DataColumnStorageSummary can be used to check for the presence of DataColumnSidecars based on Index.
+func (sc *dataColumnStorageSummaryCache) Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+
+	return sc.cache[root]
+}
+
+func (sc *dataColumnStorageSummaryCache) HighestEpoch() primitives.Epoch {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+	return sc.highestCachedEpoch
+}
+
+// set updates the cache.
+func (sc *dataColumnStorageSummaryCache) set(dataColumnsIdent DataColumnsIdent) error {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	summary := sc.cache[dataColumnsIdent.Root]
+	summary.epoch = dataColumnsIdent.Epoch
+
+	count := uint64(0)
+	for _, index := range dataColumnsIdent.Indices {
+		if index >= numberOfColumns {
+			return errDataColumnIndexOutOfBounds
+		}
+
+		if summary.mask[index] {
+			continue
+		}
+
+		count++
+
+		summary.mask[index] = true
+		sc.cache[dataColumnsIdent.Root] = summary
+		sc.lowestCachedEpoch = min(sc.lowestCachedEpoch, dataColumnsIdent.Epoch)
+		sc.highestCachedEpoch = max(sc.highestCachedEpoch, dataColumnsIdent.Epoch)
+	}
+
+	countFloat := float64(count)
+	sc.dataColumnCount += countFloat
+	dataColumnDiskCount.Set(sc.dataColumnCount)
+	dataColumnWrittenCounter.Add(countFloat)
+
+	return nil
+}
+
+// get returns the DataColumnStorageSummary for the given block root.
+// If the root is not in the cache, the second return value will be false.
+func (sc *dataColumnStorageSummaryCache) get(blockRoot [fieldparams.RootLength]byte) (DataColumnStorageSummary, bool) {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+
+	v, ok := sc.cache[blockRoot]
+	return v, ok
+}
+
+// evict removes the DataColumnStorageSummary for the given block root from the cache.
+func (s *dataColumnStorageSummaryCache) evict(blockRoot [fieldparams.RootLength]byte) int {
+	deleted := 0
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	summary, ok := s.cache[blockRoot]
+	if !ok {
+		return 0
+	}
+
+	for i := range summary.mask {
+		if summary.mask[i] {
+			deleted += 1
+		}
+	}
+
+	delete(s.cache, blockRoot)
+	if deleted > 0 {
+		s.dataColumnCount -= float64(deleted)
+		dataColumnDiskCount.Set(s.dataColumnCount)
+	}
+
+	// The lowest and highest cached epoch may no longer be valid here,
+	// but is not worth the effort to recalculate.
+
+	return deleted
+}
+
+// pruneUpTo removes all entries from the cache up to the given target epoch included.
+func (sc *dataColumnStorageSummaryCache) pruneUpTo(targetEpoch primitives.Epoch) uint64 {
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	prunedCount := uint64(0)
+	newLowestCachedEpoch := params.BeaconConfig().FarFutureEpoch
+	newHighestCachedEpoch := primitives.Epoch(0)
+
+	for blockRoot, summary := range sc.cache {
+		epoch := summary.epoch
+
+		if epoch > targetEpoch {
+			newLowestCachedEpoch = min(newLowestCachedEpoch, epoch)
+			newHighestCachedEpoch = max(newHighestCachedEpoch, epoch)
+		}
+
+		if epoch <= targetEpoch {
+			for i := range summary.mask {
+				if summary.mask[i] {
+					prunedCount += 1
+				}
+			}
+
+			delete(sc.cache, blockRoot)
+		}
+	}
+
+	if prunedCount > 0 {
+		sc.lowestCachedEpoch = newLowestCachedEpoch
+		sc.highestCachedEpoch = newHighestCachedEpoch
+		sc.dataColumnCount -= float64(prunedCount)
+		dataColumnDiskCount.Set(sc.dataColumnCount)
+	}
+
+	return prunedCount
+}
+
+// clear removes all entries from the cache.
+func (sc *dataColumnStorageSummaryCache) clear() uint64 {
+	return sc.pruneUpTo(params.BeaconConfig().FarFutureEpoch)
+}

beacon-chain/db/filesystem/data_column_cache_test.go

@@ -0,0 +1,257 @@
+package filesystem
+
+import (
+	"testing"
+
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestHasIndex(t *testing.T) {
+	summary := NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{false, true})
+
+	hasIndex := summary.HasIndex(1_000_000)
+	require.Equal(t, false, hasIndex)
+
+	hasIndex = summary.HasIndex(0)
+	require.Equal(t, false, hasIndex)
+
+	hasIndex = summary.HasIndex(1)
+	require.Equal(t, true, hasIndex)
+}
+
+func TestHasAtLeastOneIndex(t *testing.T) {
+	summary := NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{false, true})
+
+	hasAtLeastOneIndex := summary.HasAtLeastOneIndex([]uint64{3, 1, 2})
+	require.Equal(t, true, hasAtLeastOneIndex)
+
+	hasAtLeastOneIndex = summary.HasAtLeastOneIndex([]uint64{3, 4, 2})
+	require.Equal(t, false, hasAtLeastOneIndex)
+}
+
+func TestCount(t *testing.T) {
+	summary := NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{false, true, false, true})
+
+	count := summary.Count()
+	require.Equal(t, uint64(2), count)
+}
+
+func TestAllAvailableDataColumns(t *testing.T) {
+	const count = uint64(1_000)
+
+	summary := NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{false, true, false, true})
+
+	indices := make(map[uint64]bool, count)
+	for i := range count {
+		indices[i] = true
+	}
+
+	allAvailable := summary.AllAvailable(indices)
+	require.Equal(t, false, allAvailable)
+
+	indices = map[uint64]bool{1: true, 2: true}
+	allAvailable = summary.AllAvailable(indices)
+	require.Equal(t, false, allAvailable)
+
+	indices = map[uint64]bool{1: true, 3: true}
+	allAvailable = summary.AllAvailable(indices)
+	require.Equal(t, true, allAvailable)
+}
+
+func TestStored(t *testing.T) {
+	summary := NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{false, true, true, false})
+
+	expected := map[uint64]bool{1: true, 2: true}
+	actual := summary.Stored()
+
+	require.Equal(t, len(expected), len(actual))
+	for k, v := range expected {
+		require.Equal(t, v, actual[k])
+	}
+}
+
+func TestSummary(t *testing.T) {
+	root := [fieldparams.RootLength]byte{}
+
+	summaryCache := newDataColumnStorageSummaryCache()
+	expected := NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{})
+	actual := summaryCache.Summary(root)
+	require.DeepEqual(t, expected, actual)
+
+	summaryCache = newDataColumnStorageSummaryCache()
+	expected = NewDataColumnStorageSummary(0, [fieldparams.NumberOfColumns]bool{true, false, true, false})
+	summaryCache.cache[root] = expected
+	actual = summaryCache.Summary(root)
+	require.DeepEqual(t, expected, actual)
+}
+
+func TestHighestEpoch(t *testing.T) {
+	root1 := [fieldparams.RootLength]byte{1}
+	root2 := [fieldparams.RootLength]byte{2}
+	root3 := [fieldparams.RootLength]byte{3}
+
+	summaryCache := newDataColumnStorageSummaryCache()
+	actual := summaryCache.HighestEpoch()
+	require.Equal(t, primitives.Epoch(0), actual)
+
+	err := summaryCache.set(DataColumnsIdent{Root: root1, Epoch: 42, Indices: []uint64{1, 3}})
+	require.NoError(t, err)
+	require.Equal(t, primitives.Epoch(42), summaryCache.HighestEpoch())
+
+	err = summaryCache.set(DataColumnsIdent{Root: root2, Epoch: 43, Indices: []uint64{1, 3}})
+	require.NoError(t, err)
+	require.Equal(t, primitives.Epoch(43), summaryCache.HighestEpoch())
+
+	err = summaryCache.set(DataColumnsIdent{Root: root3, Epoch: 40, Indices: []uint64{1, 3}})
+	require.NoError(t, err)
+	require.Equal(t, primitives.Epoch(43), summaryCache.HighestEpoch())
+}
+
+func TestSet(t *testing.T) {
+	t.Run("Index out of bounds", func(t *testing.T) {
+		summaryCache := newDataColumnStorageSummaryCache()
+		err := summaryCache.set(DataColumnsIdent{Indices: []uint64{1_000_000}})
+		require.ErrorIs(t, err, errDataColumnIndexOutOfBounds)
+		require.Equal(t, params.BeaconConfig().FarFutureEpoch, summaryCache.lowestCachedEpoch)
+		require.Equal(t, 0, len(summaryCache.cache))
+	})
+
+	t.Run("Nominal", func(t *testing.T) {
+		root1 := [fieldparams.RootLength]byte{1}
+		root2 := [fieldparams.RootLength]byte{2}
+
+		summaryCache := newDataColumnStorageSummaryCache()
+
+		err := summaryCache.set(DataColumnsIdent{Root: root1, Epoch: 42, Indices: []uint64{1, 3}})
+		require.NoError(t, err)
+		require.Equal(t, primitives.Epoch(42), summaryCache.lowestCachedEpoch)
+		require.Equal(t, 1, len(summaryCache.cache))
+		expected := DataColumnStorageSummary{epoch: 42, mask: [fieldparams.NumberOfColumns]bool{false, true, false, true}}
+		actual := summaryCache.cache[root1]
+		require.DeepEqual(t, expected, actual)
+
+		err = summaryCache.set(DataColumnsIdent{Root: root1, Epoch: 42, Indices: []uint64{0, 1}})
+		require.NoError(t, err)
+		require.Equal(t, primitives.Epoch(42), summaryCache.lowestCachedEpoch)
+		require.Equal(t, 1, len(summaryCache.cache))
+		expected = DataColumnStorageSummary{epoch: 42, mask: [fieldparams.NumberOfColumns]bool{true, true, false, true}}
+		actual = summaryCache.cache[root1]
+		require.DeepEqual(t, expected, actual)
+
+		err = summaryCache.set(DataColumnsIdent{Root: root2, Epoch: 43, Indices: []uint64{1}})
+		require.NoError(t, err)
+		require.Equal(t, primitives.Epoch(42), summaryCache.lowestCachedEpoch) // Epoch 42 is still the lowest
+		require.Equal(t, 2, len(summaryCache.cache))
+		expected = DataColumnStorageSummary{epoch: 43, mask: [fieldparams.NumberOfColumns]bool{false, true}}
+		actual = summaryCache.cache[root2]
+		require.DeepEqual(t, expected, actual)
+	})
+}
+
+func TestGet(t *testing.T) {
+	t.Run("Not in cache", func(t *testing.T) {
+		summaryCache := newDataColumnStorageSummaryCache()
+		root := [fieldparams.RootLength]byte{}
+		_, ok := summaryCache.get(root)
+		require.Equal(t, false, ok)
+	})
+
+	t.Run("In cache", func(t *testing.T) {
+		root := [fieldparams.RootLength]byte{}
+		summaryCache := newDataColumnStorageSummaryCache()
+		summaryCache.cache[root] = NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{true, false, true, false})
+		actual, ok := summaryCache.get(root)
+		require.Equal(t, true, ok)
+		expected := NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{true, false, true, false})
+		require.DeepEqual(t, expected, actual)
+	})
+}
+
+func TestEvict(t *testing.T) {
+	t.Run("No eviction", func(t *testing.T) {
+		root := [fieldparams.RootLength]byte{}
+		summaryCache := newDataColumnStorageSummaryCache()
+
+		evicted := summaryCache.evict(root)
+		require.Equal(t, 0, evicted)
+	})
+
+	t.Run("Eviction", func(t *testing.T) {
+		root1 := [fieldparams.RootLength]byte{1}
+		root2 := [fieldparams.RootLength]byte{2}
+		summaryCache := newDataColumnStorageSummaryCache()
+		summaryCache.cache[root1] = NewDataColumnStorageSummary(42, [fieldparams.NumberOfColumns]bool{true, false, true, false})
+		summaryCache.cache[root2] = NewDataColumnStorageSummary(43, [fieldparams.NumberOfColumns]bool{false, true, false, true})
+
+		evicted := summaryCache.evict(root1)
+		require.Equal(t, 2, evicted)
+		require.Equal(t, 1, len(summaryCache.cache))
+
+		_, ok := summaryCache.cache[root1]
+		require.Equal(t, false, ok)
+
+		_, ok = summaryCache.cache[root2]
+		require.Equal(t, true, ok)
+	})
+}
+
+func TestPruneUpTo(t *testing.T) {
+	t.Run("No pruning", func(t *testing.T) {
+		summaryCache := newDataColumnStorageSummaryCache()
+		err := summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{1}, Epoch: 42, Indices: []uint64{1}})
+		require.NoError(t, err)
+
+		err = summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{2}, Epoch: 43, Indices: []uint64{2, 4}})
+		require.NoError(t, err)
+
+		count := summaryCache.pruneUpTo(41)
+		require.Equal(t, uint64(0), count)
+		require.Equal(t, 2, len(summaryCache.cache))
+		require.Equal(t, primitives.Epoch(42), summaryCache.lowestCachedEpoch)
+	})
+
+	t.Run("Pruning", func(t *testing.T) {
+		summaryCache := newDataColumnStorageSummaryCache()
+		err := summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{1}, Epoch: 42, Indices: []uint64{1}})
+		require.NoError(t, err)
+
+		err = summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{2}, Epoch: 44, Indices: []uint64{2, 4}})
+		require.NoError(t, err)
+
+		err = summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{3}, Epoch: 45, Indices: []uint64{2, 4}})
+		require.NoError(t, err)
+
+		count := summaryCache.pruneUpTo(42)
+		require.Equal(t, uint64(1), count)
+		require.Equal(t, 2, len(summaryCache.cache))
+		require.Equal(t, primitives.Epoch(44), summaryCache.lowestCachedEpoch)
+
+		count = summaryCache.pruneUpTo(45)
+		require.Equal(t, uint64(4), count)
+		require.Equal(t, 0, len(summaryCache.cache))
+		require.Equal(t, params.BeaconConfig().FarFutureEpoch, summaryCache.lowestCachedEpoch)
+		require.Equal(t, primitives.Epoch(0), summaryCache.highestCachedEpoch)
+
+	})
+
+	t.Run("Clear", func(t *testing.T) {
+		summaryCache := newDataColumnStorageSummaryCache()
+		err := summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{1}, Epoch: 42, Indices: []uint64{1}})
+		require.NoError(t, err)
+
+		err = summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{2}, Epoch: 44, Indices: []uint64{2, 4}})
+		require.NoError(t, err)
+
+		err = summaryCache.set(DataColumnsIdent{Root: [fieldparams.RootLength]byte{3}, Epoch: 45, Indices: []uint64{2, 4}})
+		require.NoError(t, err)
+
+		count := summaryCache.clear()
+		require.Equal(t, uint64(5), count)
+		require.Equal(t, 0, len(summaryCache.cache))
+		require.Equal(t, params.BeaconConfig().FarFutureEpoch, summaryCache.lowestCachedEpoch)
+		require.Equal(t, primitives.Epoch(0), summaryCache.highestCachedEpoch)
+	})
+}

beacon-chain/db/filesystem/data_column_test.go

@@ -0,0 +1,762 @@
+package filesystem
+
+import (
+	"context"
+	"encoding/binary"
+	"os"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/spf13/afero"
+)
+
+func TestNewDataColumnStorage(t *testing.T) {
+	ctx := context.Background()
+
+	t.Run("No base path", func(t *testing.T) {
+		_, err := NewDataColumnStorage(ctx)
+		require.ErrorIs(t, err, errNoBasePath)
+	})
+
+	t.Run("Nominal", func(t *testing.T) {
+		dir := t.TempDir()
+
+		storage, err := NewDataColumnStorage(ctx, WithDataColumnBasePath(dir))
+		require.NoError(t, err)
+		require.Equal(t, dir, storage.base)
+	})
+}
+
+func TestWarmCache(t *testing.T) {
+	storage, err := NewDataColumnStorage(
+		context.Background(),
+		WithDataColumnBasePath(t.TempDir()),
+		WithDataColumnRetentionEpochs(10_000),
+	)
+	require.NoError(t, err)
+
+	_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+		t,
+		verification.DataColumnsParamsByRoot{
+			{0}: {
+				{Slot: 33, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 1
+				{Slot: 33, ColumnIndex: 4, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 1
+			},
+			{1}: {
+				{Slot: 128_002, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 4000
+				{Slot: 128_002, ColumnIndex: 4, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 4000
+			},
+			{2}: {
+				{Slot: 128_003, ColumnIndex: 1, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 4000
+				{Slot: 128_003, ColumnIndex: 3, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 4000
+			},
+			{3}: {
+				{Slot: 128_034, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 4001
+				{Slot: 128_034, ColumnIndex: 4, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 4001
+			},
+			{4}: {
+				{Slot: 131_138, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4098
+			},
+			{5}: {
+				{Slot: 131_138, ColumnIndex: 1, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4098
+			},
+			{6}: {
+				{Slot: 131_168, ColumnIndex: 0, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4099
+			},
+		},
+	)
+
+	err = storage.Save(verifiedRoDataColumnSidecars)
+	require.NoError(t, err)
+
+	storage.retentionEpochs = 4_096
+
+	storage.WarmCache()
+	require.Equal(t, primitives.Epoch(4_000), storage.cache.lowestCachedEpoch)
+	require.Equal(t, 6, len(storage.cache.cache))
+
+	summary, ok := storage.cache.get([fieldparams.RootLength]byte{1})
+	require.Equal(t, true, ok)
+	require.DeepEqual(t, DataColumnStorageSummary{epoch: 4_000, mask: [fieldparams.NumberOfColumns]bool{false, false, true, false, true}}, summary)
+
+	summary, ok = storage.cache.get([fieldparams.RootLength]byte{2})
+	require.Equal(t, true, ok)
+	require.DeepEqual(t, DataColumnStorageSummary{epoch: 4_000, mask: [fieldparams.NumberOfColumns]bool{false, true, false, true}}, summary)
+
+	summary, ok = storage.cache.get([fieldparams.RootLength]byte{3})
+	require.Equal(t, true, ok)
+	require.DeepEqual(t, DataColumnStorageSummary{epoch: 4_001, mask: [fieldparams.NumberOfColumns]bool{false, false, true, false, true}}, summary)
+
+	summary, ok = storage.cache.get([fieldparams.RootLength]byte{4})
+	require.Equal(t, true, ok)
+	require.DeepEqual(t, DataColumnStorageSummary{epoch: 4_098, mask: [fieldparams.NumberOfColumns]bool{false, false, true}}, summary)
+
+	summary, ok = storage.cache.get([fieldparams.RootLength]byte{5})
+	require.Equal(t, true, ok)
+	require.DeepEqual(t, DataColumnStorageSummary{epoch: 4_098, mask: [fieldparams.NumberOfColumns]bool{false, true}}, summary)
+
+	summary, ok = storage.cache.get([fieldparams.RootLength]byte{6})
+	require.Equal(t, true, ok)
+	require.DeepEqual(t, DataColumnStorageSummary{epoch: 4_099, mask: [fieldparams.NumberOfColumns]bool{true}}, summary)
+}
+
+func TestSaveDataColumnsSidecars(t *testing.T) {
+	t.Run("wrong numbers of columns", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		cfg.NumberOfColumns = 0
+		params.OverrideBeaconConfig(cfg)
+		params.SetupTestConfigCleanup(t)
+
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{}: {{ColumnIndex: 12}, {ColumnIndex: 1_000_000}, {ColumnIndex: 48}},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.ErrorIs(t, err, errWrongNumberOfColumns)
+	})
+
+	t.Run("one of the column index is too large", func(t *testing.T) {
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{{}: {{ColumnIndex: 12}, {ColumnIndex: 1_000_000}, {ColumnIndex: 48}}},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.ErrorIs(t, err, errDataColumnIndexTooLarge)
+	})
+
+	t.Run("different slots", func(t *testing.T) {
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{}: {
+					{Slot: 1, ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+					{Slot: 2, ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+				},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.ErrorIs(t, err, errDataColumnSidecarsFromDifferentSlots)
+	})
+
+	t.Run("new file - no data columns to save", func(t *testing.T) {
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{{}: {}},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+	})
+
+	t.Run("new file - different data column size", func(t *testing.T) {
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{}: {
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+					{ColumnIndex: 11, DataColumn: []byte{1, 2, 3, 4}},
+				},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.ErrorIs(t, err, errWrongSszEncodedDataColumnSidecarSize)
+	})
+
+	t.Run("existing file - wrong incoming SSZ encoded size", func(t *testing.T) {
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{{1}: {{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}}}},
+		)
+
+		// Save data columns into a file.
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		// Build a data column sidecar for the same block but with a different
+		// column index and an different SSZ encoded size.
+		_, verifiedRoDataColumnSidecars = verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{{1}: {{ColumnIndex: 13, DataColumn: []byte{1, 2, 3, 4}}}},
+		)
+
+		// Try to rewrite the file.
+		err = dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.ErrorIs(t, err, errWrongSszEncodedDataColumnSidecarSize)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		_, inputVerifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{1}: {
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+					{ColumnIndex: 11, DataColumn: []byte{3, 4, 5}},
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}}, // OK if duplicate
+					{ColumnIndex: 13, DataColumn: []byte{6, 7, 8}},
+				},
+				{2}: {
+					{ColumnIndex: 12, DataColumn: []byte{3, 4, 5}},
+					{ColumnIndex: 13, DataColumn: []byte{6, 7, 8}},
+				},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(inputVerifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		_, inputVerifiedRoDataColumnSidecars = verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{1}: {
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}}, // OK if duplicate
+					{ColumnIndex: 15, DataColumn: []byte{2, 3, 4}},
+					{ColumnIndex: 1, DataColumn: []byte{2, 3, 4}},
+				},
+				{3}: {
+					{ColumnIndex: 6, DataColumn: []byte{3, 4, 5}},
+					{ColumnIndex: 2, DataColumn: []byte{6, 7, 8}},
+				},
+			},
+		)
+
+		err = dataColumnStorage.Save(inputVerifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		type fixture struct {
+			fileName         string
+			blockRoot        [fieldparams.RootLength]byte
+			expectedIndices  [mandatoryNumberOfColumns]byte
+			dataColumnParams []verification.DataColumnParams
+		}
+
+		fixtures := []fixture{
+			{
+				fileName:  "0/0/0x0100000000000000000000000000000000000000000000000000000000000000.sszs",
+				blockRoot: [fieldparams.RootLength]byte{1},
+				expectedIndices: [mandatoryNumberOfColumns]byte{
+					0, nonZeroOffset + 4, 0, 0, 0, 0, 0, 0,
+					0, 0, 0, nonZeroOffset + 1, nonZeroOffset, nonZeroOffset + 2, 0, nonZeroOffset + 3,
+					// The rest is filled with zeroes.
+				},
+				dataColumnParams: []verification.DataColumnParams{
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+					{ColumnIndex: 11, DataColumn: []byte{3, 4, 5}},
+					{ColumnIndex: 13, DataColumn: []byte{6, 7, 8}},
+					{ColumnIndex: 15, DataColumn: []byte{2, 3, 4}},
+					{ColumnIndex: 1, DataColumn: []byte{2, 3, 4}},
+				},
+			},
+			{
+				fileName:  "0/0/0x0200000000000000000000000000000000000000000000000000000000000000.sszs",
+				blockRoot: [fieldparams.RootLength]byte{2},
+				expectedIndices: [mandatoryNumberOfColumns]byte{
+					0, 0, 0, 0, 0, 0, 0, 0,
+					0, 0, 0, 0, nonZeroOffset, nonZeroOffset + 1, 0, 0,
+					// The rest is filled with zeroes.
+				},
+				dataColumnParams: []verification.DataColumnParams{
+					{ColumnIndex: 12, DataColumn: []byte{3, 4, 5}},
+					{ColumnIndex: 13, DataColumn: []byte{6, 7, 8}},
+				},
+			},
+			{
+				fileName:  "0/0/0x0300000000000000000000000000000000000000000000000000000000000000.sszs",
+				blockRoot: [fieldparams.RootLength]byte{3},
+				expectedIndices: [mandatoryNumberOfColumns]byte{
+					0, 0, nonZeroOffset + 1, 0, 0, 0, nonZeroOffset, 0,
+					// The rest is filled with zeroes.
+				},
+				dataColumnParams: []verification.DataColumnParams{
+					{ColumnIndex: 6, DataColumn: []byte{3, 4, 5}},
+					{ColumnIndex: 2, DataColumn: []byte{6, 7, 8}},
+				},
+			},
+		}
+
+		for _, fixture := range fixtures {
+			// Build expected data column sidecars.
+			_, expectedDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+				t,
+				verification.DataColumnsParamsByRoot{fixture.blockRoot: fixture.dataColumnParams},
+			)
+
+			// Build expected bytes.
+			firstSszEncodedDataColumnSidecar, err := expectedDataColumnSidecars[0].MarshalSSZ()
+			require.NoError(t, err)
+
+			dataColumnSidecarsCount := len(expectedDataColumnSidecars)
+			sszEncodedDataColumnSidecarSize := len(firstSszEncodedDataColumnSidecar)
+
+			sszEncodedDataColumnSidecars := make([]byte, 0, dataColumnSidecarsCount*sszEncodedDataColumnSidecarSize)
+			sszEncodedDataColumnSidecars = append(sszEncodedDataColumnSidecars, firstSszEncodedDataColumnSidecar...)
+			for _, dataColumnSidecar := range expectedDataColumnSidecars[1:] {
+				sszEncodedDataColumnSidecar, err := dataColumnSidecar.MarshalSSZ()
+				require.NoError(t, err)
+				sszEncodedDataColumnSidecars = append(sszEncodedDataColumnSidecars, sszEncodedDataColumnSidecar...)
+			}
+
+			var encodedSszEncodedDataColumnSidecarSize [encodedSszEncodedDataColumnSidecarSizeSize]byte
+			binary.BigEndian.PutUint32(encodedSszEncodedDataColumnSidecarSize[:], uint32(sszEncodedDataColumnSidecarSize))
+
+			expectedBytes := make([]byte, 0, headerSize+dataColumnSidecarsCount*sszEncodedDataColumnSidecarSize)
+			expectedBytes = append(expectedBytes, []byte{0x01}...)
+			expectedBytes = append(expectedBytes, encodedSszEncodedDataColumnSidecarSize[:]...)
+			expectedBytes = append(expectedBytes, fixture.expectedIndices[:]...)
+			expectedBytes = append(expectedBytes, sszEncodedDataColumnSidecars...)
+
+			// Check the actual content of the file.
+			actualBytes, err := afero.ReadFile(dataColumnStorage.fs, fixture.fileName)
+			require.NoError(t, err)
+			require.DeepSSZEqual(t, expectedBytes, actualBytes)
+
+			// Check the summary.
+			indices := map[uint64]bool{}
+			for _, dataColumnParam := range fixture.dataColumnParams {
+				indices[dataColumnParam.ColumnIndex] = true
+			}
+
+			summary := dataColumnStorage.Summary(fixture.blockRoot)
+			for index := range uint64(mandatoryNumberOfColumns) {
+				require.Equal(t, indices[index], summary.HasIndex(index))
+			}
+
+			err = dataColumnStorage.Remove(fixture.blockRoot)
+			require.NoError(t, err)
+
+			summary = dataColumnStorage.Summary(fixture.blockRoot)
+			for index := range uint64(mandatoryNumberOfColumns) {
+				require.Equal(t, false, summary.HasIndex(index))
+			}
+
+			_, err = afero.ReadFile(dataColumnStorage.fs, fixture.fileName)
+			require.ErrorIs(t, err, os.ErrNotExist)
+		}
+	})
+}
+
+func TestGetDataColumnSidecars(t *testing.T) {
+	t.Run("root not found", func(t *testing.T) {
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+
+		verifiedRODataColumnSidecars, err := dataColumnStorage.Get([fieldparams.RootLength]byte{1}, []uint64{12, 13, 14})
+		require.NoError(t, err)
+		require.Equal(t, 0, len(verifiedRODataColumnSidecars))
+	})
+
+	t.Run("indices not found", func(t *testing.T) {
+		_, savedVerifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{1}: {
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+					{ColumnIndex: 14, DataColumn: []byte{2, 3, 4}},
+				},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(savedVerifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		verifiedRODataColumnSidecars, err := dataColumnStorage.Get([fieldparams.RootLength]byte{1}, []uint64{3, 1, 2})
+		require.NoError(t, err)
+		require.Equal(t, 0, len(verifiedRODataColumnSidecars))
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		_, expectedVerifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{1}: {
+					{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}},
+					{ColumnIndex: 14, DataColumn: []byte{2, 3, 4}},
+				},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(expectedVerifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		verifiedRODataColumnSidecars, err := dataColumnStorage.Get([fieldparams.RootLength]byte{1}, nil)
+		require.NoError(t, err)
+		require.DeepSSZEqual(t, expectedVerifiedRoDataColumnSidecars, verifiedRODataColumnSidecars)
+
+		verifiedRODataColumnSidecars, err = dataColumnStorage.Get([fieldparams.RootLength]byte{1}, []uint64{12, 13, 14})
+		require.NoError(t, err)
+		require.DeepSSZEqual(t, expectedVerifiedRoDataColumnSidecars, verifiedRODataColumnSidecars)
+	})
+}
+
+func TestRemove(t *testing.T) {
+	t.Run("not found", func(t *testing.T) {
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Remove([fieldparams.RootLength]byte{1})
+		require.NoError(t, err)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		_, inputVerifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{1}: {
+					{Slot: 32, ColumnIndex: 10, DataColumn: []byte{1, 2, 3}},
+					{Slot: 32, ColumnIndex: 11, DataColumn: []byte{2, 3, 4}},
+				},
+				{2}: {
+					{Slot: 33, ColumnIndex: 10, DataColumn: []byte{1, 2, 3}},
+					{Slot: 33, ColumnIndex: 11, DataColumn: []byte{2, 3, 4}},
+				},
+			},
+		)
+
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(inputVerifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		err = dataColumnStorage.Remove([fieldparams.RootLength]byte{1})
+		require.NoError(t, err)
+
+		summary := dataColumnStorage.Summary([fieldparams.RootLength]byte{1})
+		require.Equal(t, primitives.Epoch(0), summary.epoch)
+		require.Equal(t, uint64(0), summary.Count())
+
+		summary = dataColumnStorage.Summary([fieldparams.RootLength]byte{2})
+		require.Equal(t, primitives.Epoch(1), summary.epoch)
+		require.Equal(t, uint64(2), summary.Count())
+
+		actual, err := dataColumnStorage.Get([fieldparams.RootLength]byte{1}, nil)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(actual))
+
+		actual, err = dataColumnStorage.Get([fieldparams.RootLength]byte{2}, nil)
+		require.NoError(t, err)
+		require.Equal(t, 2, len(actual))
+	})
+}
+
+func TestClear(t *testing.T) {
+	_, inputVerifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+		t,
+		verification.DataColumnsParamsByRoot{
+			{1}: {{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}}},
+			{2}: {{ColumnIndex: 13, DataColumn: []byte{6, 7, 8}}},
+		},
+	)
+
+	_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+	err := dataColumnStorage.Save(inputVerifiedRoDataColumnSidecars)
+	require.NoError(t, err)
+
+	filePaths := []string{
+		"0/0/0x0100000000000000000000000000000000000000000000000000000000000000.sszs",
+		"0/0/0x0200000000000000000000000000000000000000000000000000000000000000.sszs",
+	}
+
+	for _, filePath := range filePaths {
+		_, err = afero.ReadFile(dataColumnStorage.fs, filePath)
+		require.NoError(t, err)
+	}
+
+	err = dataColumnStorage.Clear()
+	require.NoError(t, err)
+
+	summary := dataColumnStorage.Summary([fieldparams.RootLength]byte{1})
+	for index := range uint64(mandatoryNumberOfColumns) {
+		require.Equal(t, false, summary.HasIndex(index))
+	}
+
+	for _, filePath := range filePaths {
+		_, err = afero.ReadFile(dataColumnStorage.fs, filePath)
+		require.ErrorIs(t, err, os.ErrNotExist)
+	}
+}
+
+func TestMetadata(t *testing.T) {
+	t.Run("wrong version", func(t *testing.T) {
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{1}: {{ColumnIndex: 12, DataColumn: []byte{1, 2, 3}}},
+			},
+		)
+
+		// Save data columns into a file.
+		_, dataColumnStorage := NewEphemeralDataColumnStorageAndFs(t)
+		err := dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		// Alter the version.
+		const filePath = "0/0/0x0100000000000000000000000000000000000000000000000000000000000000.sszs"
+		file, err := dataColumnStorage.fs.OpenFile(filePath, os.O_WRONLY, os.FileMode(0600))
+		require.NoError(t, err)
+
+		count, err := file.Write([]byte{42})
+		require.NoError(t, err)
+		require.Equal(t, 1, count)
+
+		// Try to read the metadata.
+		_, err = dataColumnStorage.metadata(file)
+		require.ErrorIs(t, err, errWrongVersion)
+
+		err = file.Close()
+		require.NoError(t, err)
+	})
+}
+
+func TestNewStorageIndices(t *testing.T) {
+	t.Run("wrong number of columns", func(t *testing.T) {
+		_, err := newStorageIndices(nil)
+		require.ErrorIs(t, err, errWrongNumberOfColumns)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		var indices [mandatoryNumberOfColumns]byte
+		indices[0] = 1
+
+		storageIndices, err := newStorageIndices(indices[:])
+		require.NoError(t, err)
+		require.Equal(t, indices, storageIndices.indices)
+	})
+}
+
+func TestStorageIndicesGet(t *testing.T) {
+	t.Run("index too large", func(t *testing.T) {
+		var indices storageIndices
+		_, _, err := indices.get(1_000_000)
+		require.ErrorIs(t, errDataColumnIndexTooLarge, err)
+	})
+
+	t.Run("index not set", func(t *testing.T) {
+		const expected = false
+		var indices storageIndices
+		actual, _, err := indices.get(0)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+	})
+
+	t.Run("index set", func(t *testing.T) {
+		const (
+			expectedOk       = true
+			expectedPosition = int64(3)
+		)
+
+		indices := storageIndices{indices: [mandatoryNumberOfColumns]byte{0, 131}}
+		actualOk, actualPosition, err := indices.get(1)
+		require.NoError(t, err)
+		require.Equal(t, expectedOk, actualOk)
+		require.Equal(t, expectedPosition, actualPosition)
+	})
+}
+
+func TestStorageIndicesLen(t *testing.T) {
+	const expected = int64(2)
+	indices := storageIndices{count: 2}
+	actual := indices.len()
+	require.Equal(t, expected, actual)
+}
+
+func TestStorageIndicesAll(t *testing.T) {
+	expectedIndices := []uint64{1, 3}
+	indices := storageIndices{indices: [mandatoryNumberOfColumns]byte{0, 131, 0, 128}}
+	actualIndices := indices.all()
+	require.DeepEqual(t, expectedIndices, actualIndices)
+}
+
+func TestStorageIndicesSet(t *testing.T) {
+	t.Run("data column index too large", func(t *testing.T) {
+		var indices storageIndices
+		err := indices.set(1_000_000, 0)
+		require.ErrorIs(t, errDataColumnIndexTooLarge, err)
+	})
+
+	t.Run("position too large", func(t *testing.T) {
+		var indices storageIndices
+		err := indices.set(0, 255)
+		require.ErrorIs(t, errDataColumnIndexTooLarge, err)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		expected := [mandatoryNumberOfColumns]byte{0, 0, 128, 0, 131}
+		var storageIndices storageIndices
+		require.Equal(t, int64(0), storageIndices.len())
+
+		err := storageIndices.set(2, 1)
+		require.NoError(t, err)
+		require.Equal(t, int64(1), storageIndices.len())
+
+		err = storageIndices.set(4, 3)
+		require.NoError(t, err)
+		require.Equal(t, int64(2), storageIndices.len())
+
+		err = storageIndices.set(2, 0)
+		require.NoError(t, err)
+		require.Equal(t, int64(2), storageIndices.len())
+
+		actual := storageIndices.indices
+		require.Equal(t, expected, actual)
+	})
+}
+
+func TestPrune(t *testing.T) {
+	t.Run(("nothing to prune"), func(t *testing.T) {
+		dir := t.TempDir()
+		dataColumnStorage, err := NewDataColumnStorage(context.Background(), WithDataColumnBasePath(dir))
+		require.NoError(t, err)
+
+		dataColumnStorage.prune()
+	})
+	t.Run("nominal", func(t *testing.T) {
+		var compareSlices = func(left, right []string) bool {
+			if len(left) != len(right) {
+				return false
+			}
+
+			leftMap := make(map[string]bool, len(left))
+			for _, leftItem := range left {
+				leftMap[leftItem] = true
+			}
+
+			for _, rightItem := range right {
+				if _, ok := leftMap[rightItem]; !ok {
+					return false
+				}
+			}
+
+			return true
+		}
+		_, verifiedRoDataColumnSidecars := verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{0}: {
+					{Slot: 33, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 1
+					{Slot: 33, ColumnIndex: 4, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 1
+				},
+				{1}: {
+					{Slot: 128_002, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 4000
+					{Slot: 128_002, ColumnIndex: 4, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 4000
+				},
+				{2}: {
+					{Slot: 128_003, ColumnIndex: 1, DataColumn: []byte{1, 2, 3}}, // Period 0 - Epoch 4000
+					{Slot: 128_003, ColumnIndex: 3, DataColumn: []byte{2, 3, 4}}, // Period 0 - Epoch 4000
+				},
+				{3}: {
+					{Slot: 131_138, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4098
+					{Slot: 131_138, ColumnIndex: 3, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4098
+				},
+				{4}: {
+					{Slot: 131_169, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4099
+					{Slot: 131_169, ColumnIndex: 3, DataColumn: []byte{1, 2, 3}}, // Period 1 - Epoch 4099
+				},
+				{5}: {
+					{Slot: 262_144, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}, // Period 2 - Epoch 8192
+					{Slot: 262_144, ColumnIndex: 3, DataColumn: []byte{1, 2, 3}}, // Period 2 - Epoch 8292
+				},
+			},
+		)
+
+		dir := t.TempDir()
+		dataColumnStorage, err := NewDataColumnStorage(context.Background(), WithDataColumnBasePath(dir), WithDataColumnRetentionEpochs(10_000))
+		require.NoError(t, err)
+
+		err = dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		dirs, err := listDir(dataColumnStorage.fs, ".")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0", "1", "2"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "0")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"1", "4000"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "1")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"4099", "4098"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "2")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"8192"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "0/1")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0000000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "0/4000")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{
+			"0x0200000000000000000000000000000000000000000000000000000000000000.sszs",
+			"0x0100000000000000000000000000000000000000000000000000000000000000.sszs",
+		}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "1/4098")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0300000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "1/4099")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0400000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "2/8192")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0500000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+
+		_, verifiedRoDataColumnSidecars = verification.CreateTestVerifiedRoDataColumnSidecars(
+			t,
+			verification.DataColumnsParamsByRoot{
+				{6}: {{Slot: 451_141, ColumnIndex: 2, DataColumn: []byte{1, 2, 3}}}, // Period 3 - Epoch 14_098
+			},
+		)
+
+		err = dataColumnStorage.Save(verifiedRoDataColumnSidecars)
+		require.NoError(t, err)
+
+		// dataColumnStorage.prune(14_098)
+		dataColumnStorage.prune()
+
+		dirs, err = listDir(dataColumnStorage.fs, ".")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"1", "2", "3"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "1")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"4099"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "2")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"8192"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "3")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"14098"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "1/4099")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0400000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "2/8192")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0500000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+
+		dirs, err = listDir(dataColumnStorage.fs, "3/14098")
+		require.NoError(t, err)
+		require.Equal(t, true, compareSlices([]string{"0x0600000000000000000000000000000000000000000000000000000000000000.sszs"}, dirs))
+	})
+}

beacon-chain/db/filesystem/doc.go

@@ -0,0 +1,104 @@
+package filesystem
+
+// nolint:dupword
+/*
+Data column sidecars storage documentation
+==========================================
+
+File organisation
+-----------------
+- The first byte represents the version of the file structure (up to 0xff = 255).
+  We set it to 0x01.
+  Note: This is not strictly needed, but it will help a lot if, in the future,
+        we want to modify the file structure.
+- The next 4 bytes represents the size of a SSZ encoded data column sidecar.
+  (See the `Computation of the maximum size of a DataColumnSidecar` section to a description
+  of how this value is computed).
+- The next 128 bytes represent the index in the file of a given column.
+  The first bit of each byte in the index is set to 0 if there is no data column,
+  and set to 1 if there is a data column.
+  The remaining 7 bits (from 0 to 127) represent the index of the data column.
+  This sentinel bit is needed to distinguish between the column with index 0 and no column.
+  Example: If the column with index 5 is in the 3th position in the file, then indices[5] = 0x80 + 0x03 = 0x83.
+- The rest of the file is a repeat of the SSZ encoded data columns sidecars.
+
+
+|------------------------------------------|------------------------------------------------------------------------------------|
+|                Byte offset               |                                     Description                                    |
+|------------------------------------------|------------------------------------------------------------------------------------|
+|                                        0 | version (1 byte) | sszEncodedDataColumnSidecarSize (4 bytes) | indices (128 bytes) |
+|133 +   0*sszEncodedDataColumnSidecarSize | sszEncodedDataColumnSidecar (sszEncodedDataColumnSidecarSize bytes)                |
+|133 +   1*sszEncodedDataColumnSidecarSize | sszEncodedDataColumnSidecar (sszEncodedDataColumnSidecarSize bytes)                |
+|133 +   2*sszEncodedDataColumnSidecarSize | sszEncodedDataColumnSidecar (sszEncodedDataColumnSidecarSize bytes)                |
+|                  ...                     |                                 ...                                                |
+|133 + 127*sszEncodedDataColumnSidecarSize | sszEncodedDataColumnSidecar (sszEncodedDataColumnSidecarSize bytes)                |
+|------------------------------------------|------------------------------------------------------------------------------------|
+
+Each file is named after the block root where the data columns were data columns are committed to.
+Example: `0x259c6d2f6a0bb75e2405cea7cb248e5663dc26b9404fd3bcd777afc20de91c1e.sszs`
+
+Database organisation
+---------------------
+SSZ encoded data column sidecars are stored following the `by-epoch` layout.
+- The first layer is a directory corresponding to the `period`, which corresponds to the epoch divided by the 4096.
+- The second layer is a directory corresponding to the epoch.
+- Then all files are stored in the epoch directory.
+
+Example:
+data-columns
+├── 0
+│   ├── 3638
+│   │   ├── 0x259c6d2f6a0bb75e2405cea7cb248e5663dc26b9404fd3bcd777afc20de91c1e.sszs
+│   │   ├── 0x2a855b1f6e9a2f04f8383e336325bf7d5ba02d1eab3ef90ef183736f8c768533.sszs
+│   │   ├── ...
+│   │   ├── 0xeb78e2b2350a71c640f1e96fea9e42f38e65705ab7e6e100c8bc9c589f2c5f2b.sszs
+│   │   └── 0xeb7ee68da988fd20d773d45aad01dd62527734367a146e2b048715bd68a4e370.sszs
+│   └── 3639
+│       ├── 0x0fd231fe95e57936fa44f6c712c490b9e337a481b661dfd46768901e90444330.sszs
+│       ├── 0x1bf5edff6b6ba2b65b1db325ff3312bbb57da461ef2ae651bd741af851aada3a.sszs
+│       ├── ...
+│       ├── 0xa156a527e631f858fee79fab7ef1fde3f6117a2e1201d47c09fbab0c6780c937.sszs
+│       └── 0xcd80bc535ddc467dea1d19e0c39c1160875ccd1989061bcd8ce206e3c1261c87.sszs
+└── 1
+    ├── 4096
+    │   ├── 0x0d244009093e2bedb72eb265280290199e8c7bf1d90d7583c41af40d9f662269.sszs
+    │   ├── 0x11f420928d8de41c50e735caab0369996824a5299c5f054e097965855925697d.sszs
+    │   ├── ...
+    │   ├── 0xbe91fc782877ed400d95c02c61aebfdd592635d11f8e64c94b46abd84f45c967.sszs
+    │   └── 0xf246189f078f02d30173ff74605cf31c9e65b5e463275ebdbeb40476638135ff.sszs
+    └── 4097
+        ├── 0x454d000674793c479e90504c0fe9827b50bb176ae022dab4e37d6a21471ab570.sszs
+        ├── 0xac5eb7437d7190c48cfa863e3c45f96a7f8af371d47ac12ccda07129a06af763.sszs
+        ├── ...
+        ├── 0xb7df30561d9d92ab5fafdd96bca8b44526497c8debf0fc425c7a0770b2abeb83.sszs
+        └── 0xc1dd0b1ae847b6ec62303a36d08c6a4a2e9e3ec4be3ff70551972a0ee3de9c14.sszs
+
+Computation of the maximum size of a DataColumnSidecar
+------------------------------------------------------
+https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/das-core.md#datacolumnsidecar
+
+
+class DataColumnSidecar(Container):
+    index: ColumnIndex  # Index of column in extended matrix
+    column: List[Cell, MAX_BLOB_COMMITMENTS_PER_BLOCK]
+    kzg_commitments: List[KZGCommitment, MAX_BLOB_COMMITMENTS_PER_BLOCK]
+    kzg_proofs: List[KZGProof, MAX_BLOB_COMMITMENTS_PER_BLOCK]
+    signed_block_header: SignedBeaconBlockHeader
+    kzg_commitments_inclusion_proof: Vector[Bytes32, KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH]
+
+
+- index: 2 bytes (ColumnIndex)
+- `column`: 4,096 (MAX_BLOB_COMMITMENTS_PER_BLOCK) * 64 (FIELD_ELEMENTS_PER_CELL) * 32 bytes (BYTES_PER_FIELD_ELEMENT) = 8,388,608 bytes
+- kzg_commitments: 4,096 (MAX_BLOB_COMMITMENTS_PER_BLOCK) * 48 bytes (KZGCommitment) = 196,608 bytes
+- kzg_proofs: 4,096 (MAX_BLOB_COMMITMENTS_PER_BLOCK) * 48 bytes (KZGProof) = 196,608 bytes
+- signed_block_header: 2 bytes (Slot) + 2 bytes (ValidatorIndex) + 3 * 2 bytes (Root) + 96 bytes (BLSSignature) = 106 bytes
+- kzg_commitments_inclusion_proof: 4 (KZG_COMMITMENTS_INCLUSION_PROOF_DEPTH) * 32 bytes = 128 bytes
+
+TOTAL: 8,782,060 bytes = 70,256,480 bits
+log(70,256,480) / log(2) ~= 26.07
+
+==> 32 bits (4 bytes) are enough to store the maximum size of a data column sidecar.
+
+The maximum size of an SSZ encoded data column can be 2**32 bits = 536,879,912 bytes,
+which left a room of 536,879,912 bytes - 8,782,060 bytes ~= 503 mega bytes to store the extra data needed by SSZ encoding (which is more than enough.)
+*/

beacon-chain/db/filesystem/iteration_test.go

@@ -1,7 +1,6 @@
 package filesystem
 
 import (
-	"bytes"
 	"fmt"
 	"io"
 	"math"
@@ -220,28 +219,6 @@ func TestListDir(t *testing.T) {
 	}
 }
 
-func TestSlotFromBlob(t *testing.T) {
-	cases := []struct {
-		slot primitives.Slot
-	}{
-		{slot: 0},
-		{slot: 2},
-		{slot: 1123581321},
-		{slot: math.MaxUint64},
-	}
-	for _, c := range cases {
-		t.Run(fmt.Sprintf("slot %d", c.slot), func(t *testing.T) {
-			_, sidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, c.slot, 1)
-			sc := sidecars[0]
-			enc, err := sc.MarshalSSZ()
-			require.NoError(t, err)
-			slot, err := slotFromBlob(bytes.NewReader(enc))
-			require.NoError(t, err)
-			require.Equal(t, c.slot, slot)
-		})
-	}
-}
-
 func TestIterationComplete(t *testing.T) {
 	targets := []migrationTestTarget{
 		{

beacon-chain/db/filesystem/layout_flat.go

@@ -1,12 +1,11 @@
 package filesystem
 
 import (
-	"encoding/binary"
-	"io"
 	"os"
 	"path"
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
 	"github.com/spf13/afero"
@@ -115,29 +114,25 @@ func (l *flatLayout) pruneBefore(before primitives.Epoch) (*pruneSummary, error)
 
 // Read slot from marshaled BlobSidecar data in the given file. See slotFromBlob for details.
 func slotFromFile(name string, fs afero.Fs) (primitives.Slot, error) {
-	f, err := fs.Open(name)
+	// Read whole file, try to unmarshal it as data columns sidecar, if it fails, try to unmarshal it as blob sidecar.
+	content, err := afero.ReadFile(fs, name)
 	if err != nil {
 		return 0, err
 	}
-	defer func() {
-		if err := f.Close(); err != nil {
-			log.WithError(err).Errorf("Could not close blob file")
-		}
-	}()
-	return slotFromBlob(f)
-}
 
-// slotFromBlob reads the ssz data of a file at the specified offset (8 + 131072 + 48 + 48 = 131176 bytes),
-// which is calculated based on the size of the BlobSidecar struct and is based on the size of the fields
-// preceding the slot information within SignedBeaconBlockHeader.
-func slotFromBlob(at io.ReaderAt) (primitives.Slot, error) {
-	b := make([]byte, 8)
-	_, err := at.ReadAt(b, 131176)
-	if err != nil {
-		return 0, err
+	dataColumnSidecar := &ethpb.DataColumnSidecar{}
+	err = dataColumnSidecar.UnmarshalSSZ(content)
+	if err == nil {
+		return dataColumnSidecar.SignedBlockHeader.Header.Slot, nil
 	}
-	rawSlot := binary.LittleEndian.Uint64(b)
-	return primitives.Slot(rawSlot), nil
+
+	blobSidecar := &ethpb.BlobSidecar{}
+	err = blobSidecar.UnmarshalSSZ(content)
+	if err == nil {
+		return blobSidecar.SignedBlockHeader.Header.Slot, nil
+	}
+
+	return 0, errors.New("failed to unmarshal as blob sidecar or data column sidecar")
 }
 
 type flatSlotReader struct {

beacon-chain/db/filesystem/metrics.go

@@ -6,6 +6,7 @@ import (
 )
 
 var (
+	// Blobs
 	blobBuckets     = []float64{3, 5, 7, 9, 11, 13}
 	blobSaveLatency = promauto.NewHistogram(prometheus.HistogramOpts{
 		Name:    "blob_storage_save_latency",
@@ -33,4 +34,29 @@ var (
 		Name: "blob_disk_bytes",
 		Help: "Approximate number of bytes occupied by blobs in storage",
 	})
+
+	// Data columns
+	dataColumnBuckets     = []float64{3, 5, 7, 9, 11, 13}
+	dataColumnSaveLatency = promauto.NewHistogram(prometheus.HistogramOpts{
+		Name:    "data_column_storage_save_latency",
+		Help:    "Latency of DataColumnSidecar storage save operations in milliseconds",
+		Buckets: dataColumnBuckets,
+	})
+	dataColumnFetchLatency = promauto.NewHistogram(prometheus.HistogramOpts{
+		Name:    "data_column_storage_get_latency",
+		Help:    "Latency of DataColumnSidecar storage get operations in milliseconds",
+		Buckets: dataColumnBuckets,
+	})
+	dataColumnPrunedCounter = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "data_column_pruned",
+		Help: "Number of DataColumnSidecar pruned.",
+	})
+	dataColumnWrittenCounter = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "data_column_written",
+		Help: "Number of DataColumnSidecar written",
+	})
+	dataColumnDiskCount = promauto.NewGauge(prometheus.GaugeOpts{
+		Name: "data_column_disk_count",
+		Help: "Approximate number of data columns in storage",
+	})
 )

beacon-chain/db/filesystem/mock.go

@@ -1,14 +1,19 @@
 package filesystem
 
 import (
+	"context"
 	"testing"
 
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/spf13/afero"
 )
 
+// Blobs
+// -----
+
 // NewEphemeralBlobStorage should only be used for tests.
 // The instance of BlobStorage returned is backed by an in-memory virtual filesystem,
 // improving test performance and simplifying cleanup.
@@ -75,3 +80,52 @@ func NewMockBlobStorageSummarizer(t *testing.T, set map[[32]byte][]int) BlobStor
 	}
 	return c
 }
+
+// Data columns
+// ------------
+
+// NewEphemeralDataColumnStorage should only be used for tests.
+// The instance of DataColumnStorage returned is backed by an in-memory virtual filesystem,
+// improving test performance and simplifying cleanup.
+func NewEphemeralDataColumnStorage(t testing.TB, opts ...DataColumnStorageOption) *DataColumnStorage {
+	return NewWarmedEphemeralDataColumnStorageUsingFs(t, afero.NewMemMapFs(), opts...)
+}
+
+// NewEphemeralDataColumnStorageAndFs can be used by tests that want access to the virtual filesystem
+// in order to interact with it outside the parameters of the DataColumnStorage API.
+func NewEphemeralDataColumnStorageAndFs(t testing.TB, opts ...DataColumnStorageOption) (afero.Fs, *DataColumnStorage) {
+	fs := afero.NewMemMapFs()
+	dcs := NewWarmedEphemeralDataColumnStorageUsingFs(t, fs, opts...)
+	return fs, dcs
+}
+
+func NewWarmedEphemeralDataColumnStorageUsingFs(t testing.TB, fs afero.Fs, opts ...DataColumnStorageOption) *DataColumnStorage {
+	bs := NewEphemeralDataColumnStorageUsingFs(t, fs, opts...)
+	bs.WarmCache()
+	return bs
+}
+
+func NewEphemeralDataColumnStorageUsingFs(t testing.TB, fs afero.Fs, opts ...DataColumnStorageOption) *DataColumnStorage {
+	opts = append(opts,
+		WithDataColumnRetentionEpochs(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest),
+		WithDataColumnFs(fs),
+	)
+
+	bs, err := NewDataColumnStorage(context.Background(), opts...)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return bs
+}
+
+func NewMockDataColumnStorageSummarizer(t *testing.T, set map[[fieldparams.RootLength]byte][]uint64) DataColumnStorageSummarizer {
+	c := newDataColumnStorageSummaryCache()
+	for root, indices := range set {
+		if err := c.set(DataColumnsIdent{Root: root, Epoch: 0, Indices: indices}); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	return c
+}

beacon-chain/execution/BUILD.bazel

@@ -31,6 +31,7 @@ go_library(
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/execution/types:go_default_library",
@@ -97,6 +98,7 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//async/event:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",

beacon-chain/execution/engine_client.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -44,11 +45,16 @@ var (
 		GetPayloadMethodV3,
 		GetPayloadBodiesByHashV1,
 		GetPayloadBodiesByRangeV1,
+		GetBlobsV1,
 	}
 	electraEngineEndpoints = []string{
 		NewPayloadMethodV4,
 		GetPayloadMethodV4,
 	}
+	fuluEngineEndpoints = []string{
+		GetPayloadMethodV5,
+		GetBlobsV2,
+	}
 )
 
 const (
@@ -73,6 +79,8 @@ const (
 	GetPayloadMethodV3 = "engine_getPayloadV3"
 	// GetPayloadMethodV4 is the get payload method added for electra
 	GetPayloadMethodV4 = "engine_getPayloadV4"
+	// GetPayloadMethodV5 is the get payload method added for fulu
+	GetPayloadMethodV5 = "engine_getPayloadV5"
 	// BlockByHashMethod request string for JSON-RPC.
 	BlockByHashMethod = "eth_getBlockByHash"
 	// BlockByNumberMethod request string for JSON-RPC.
@@ -85,11 +93,21 @@ const (
 	ExchangeCapabilities = "engine_exchangeCapabilities"
 	// GetBlobsV1 request string for JSON-RPC.
 	GetBlobsV1 = "engine_getBlobsV1"
+	// GetBlobsV2 request string for JSON-RPC.
+	GetBlobsV2 = "engine_getBlobsV2"
 	// Defines the seconds before timing out engine endpoints with non-block execution semantics.
-	defaultEngineTimeout = time.Second
+	// TODO: Remove temporarily needed hack since geth takes an input blobs txs with blobs proofs, and
+	// does the heavy lifting of building cells proofs, while normally this is done by the tx sender.
+	// This is a cool hack because it lets the CL to act as if the tx sender actually computed the cells proofs.
+	// The only counter part is the `engine_getPayloadv<x>` takes a lot of time.
+	// defaultEngineTimeout = time.Second
+	defaultEngineTimeout = 2 * time.Second
 )
 
-var errInvalidPayloadBodyResponse = errors.New("engine api payload body response is invalid")
+var (
+	errInvalidPayloadBodyResponse  = errors.New("engine api payload body response is invalid")
+	errMissingBlobsAndProofsFromEL = errors.New("engine api payload body response is missing blobs and proofs")
+)
 
 // ForkchoiceUpdatedResponse is the response kind received by the
 // engine_forkchoiceUpdatedV1 endpoint.
@@ -108,6 +126,7 @@ type Reconstructor interface {
 		ctx context.Context, blindedBlocks []interfaces.ReadOnlySignedBeaconBlock,
 	) ([]interfaces.SignedBeaconBlock, error)
 	ReconstructBlobSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, hi func(uint64) bool) ([]blocks.VerifiedROBlob, error)
+	ReconstructDataColumnSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) ([]blocks.VerifiedRODataColumn, error)
 }
 
 // EngineCaller defines a client that can interact with an Ethereum
@@ -257,6 +276,9 @@ func (s *Service) ForkchoiceUpdated(
 
 func getPayloadMethodAndMessage(slot primitives.Slot) (string, proto.Message) {
 	pe := slots.ToEpoch(slot)
+	if pe >= params.BeaconConfig().FuluForkEpoch {
+		return GetPayloadMethodV5, &pb.ExecutionBundleFulu{}
+	}
 	if pe >= params.BeaconConfig().ElectraForkEpoch {
 		return GetPayloadMethodV4, &pb.ExecutionBundleElectra{}
 	}
@@ -289,7 +311,7 @@ func (s *Service) GetPayload(ctx context.Context, payloadId [8]byte, slot primit
 	}
 	res, err := blocks.NewGetPayloadResponse(result)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "new get payload response")
 	}
 	return res, nil
 }
@@ -302,6 +324,9 @@ func (s *Service) ExchangeCapabilities(ctx context.Context) ([]string, error) {
 	if params.ElectraEnabled() {
 		supportedEngineEndpoints = append(supportedEngineEndpoints, electraEngineEndpoints...)
 	}
+	if params.FuluEnabled() {
+		supportedEngineEndpoints = append(supportedEngineEndpoints, fuluEngineEndpoints...)
+	}
 	var result []string
 	err := s.rpcClient.CallContext(ctx, &result, ExchangeCapabilities, supportedEngineEndpoints)
 	if err != nil {
@@ -495,9 +520,10 @@ func (s *Service) HeaderByNumber(ctx context.Context, number *big.Int) (*types.H
 func (s *Service) GetBlobs(ctx context.Context, versionedHashes []common.Hash) ([]*pb.BlobAndProof, error) {
 	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.GetBlobs")
 	defer span.End()
+
 	// If the execution engine does not support `GetBlobsV1`, return early to prevent encountering an error later.
 	if !s.capabilityCache.has(GetBlobsV1) {
-		return nil, nil
+		return nil, errors.New(fmt.Sprintf("%s is not supported", GetBlobsV1))
 	}
 
 	result := make([]*pb.BlobAndProof, len(versionedHashes))
@@ -505,6 +531,19 @@ func (s *Service) GetBlobs(ctx context.Context, versionedHashes []common.Hash) (
 	return result, handleRPCError(err)
 }
 
+func (s *Service) GetBlobsV2(ctx context.Context, versionedHashes []common.Hash) ([]*pb.BlobAndProofV2, error) {
+	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.GetBlobsV2")
+	defer span.End()
+
+	if !s.capabilityCache.has(GetBlobsV2) {
+		return nil, errors.New(fmt.Sprintf("%s is not supported", GetBlobsV2))
+	}
+
+	result := make([]*pb.BlobAndProofV2, len(versionedHashes))
+	err := s.rpcClient.CallContext(ctx, &result, GetBlobsV2, versionedHashes)
+	return result, handleRPCError(err)
+}
+
 // ReconstructFullBlock takes in a blinded beacon block and reconstructs
 // a beacon block with a full execution payload via the engine API.
 func (s *Service) ReconstructFullBlock(
@@ -615,6 +654,73 @@ func (s *Service) ReconstructBlobSidecars(ctx context.Context, block interfaces.
 	return verifiedBlobs, nil
 }
 
+// ReconstructDataColumnSidecars reconstructs the verified data column sidecars for a given beacon block.
+// It retrieves the KZG commitments from the block body, fetches the associated blobs and cell proofs from the EL,
+// and constructs the corresponding verified read-only data column sidecars.
+func (s *Service) ReconstructDataColumnSidecars(ctx context.Context, signedROBlock interfaces.ReadOnlySignedBeaconBlock, blockRoot [fieldparams.RootLength]byte) ([]blocks.VerifiedRODataColumn, error) {
+	block := signedROBlock.Block()
+
+	log := log.WithFields(logrus.Fields{
+		"root": fmt.Sprintf("%#x", blockRoot),
+		"slot": block.Slot(),
+	})
+
+	kzgCommitments, err := block.Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, blockRoot, "blob KZG commitments")
+	}
+
+	// Collect KZG hashes for all blobs
+	var kzgHashes []common.Hash
+	for _, commitment := range kzgCommitments {
+		kzgHashes = append(kzgHashes, primitives.ConvertKzgCommitmentToVersionedHash(commitment))
+	}
+
+	// Fetch all blobsAndCellsProofs from EL
+	blobAndProofV2s, err := s.GetBlobsV2(ctx, kzgHashes)
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, blockRoot, "get blobs V2")
+	}
+
+	// Return early if nothing is returned from the EL.
+	if len(blobAndProofV2s) == 0 {
+		log.Debug("No blobs returned from EL")
+		return nil, nil
+	}
+
+	// Extract the blobs and proofs from the blobAndProofV2s.
+	blobs := make([][]byte, 0, len(blobAndProofV2s))
+	cellProofs := make([][]byte, 0, len(blobAndProofV2s))
+	for _, blobsAndProofs := range blobAndProofV2s {
+		if blobsAndProofs == nil {
+			return nil, wrapWithBlockRoot(errMissingBlobsAndProofsFromEL, blockRoot, "")
+		}
+		blobs = append(blobs, blobsAndProofs.Blob)
+		cellProofs = append(cellProofs, blobsAndProofs.KzgProofs...)
+	}
+
+	dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(signedROBlock, blobs, cellProofs)
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, blockRoot, "construct data column sidecars")
+	}
+
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
+	for _, dataColumnSidecar := range dataColumnSidecars {
+		roDataColumn, err := blocks.NewRODataColumnWithRoot(dataColumnSidecar, blockRoot)
+		if err != nil {
+			return nil, wrapWithBlockRoot(err, blockRoot, "new read-only data column with root")
+		}
+
+		// We trust the execution layer we are connected to, so we can upgrade the read only data column sidecar into a verified one.
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
+	}
+
+	log.Debug("Data columns successfully reconstructed from EL")
+
+	return verifiedRODataColumns, nil
+}
+
 func fullPayloadFromPayloadBody(
 	header interfaces.ExecutionData, body *pb.ExecutionPayloadBody, bVersion int,
 ) (interfaces.ExecutionData, error) {
@@ -902,3 +1008,8 @@ func toBlockNumArg(number *big.Int) string {
 	}
 	return hexutil.EncodeBig(number)
 }
+
+// wrapWithBlockRoot returns a new error with the given block root.
+func wrapWithBlockRoot(err error, blockRoot [32]byte, message string) error {
+	return errors.Wrap(err, fmt.Sprintf("%s for block %#x", message, blockRoot))
+}

beacon-chain/execution/engine_client_test.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	mocks "github.com/OffchainLabs/prysm/v6/beacon-chain/execution/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
@@ -167,6 +168,7 @@ func TestClient_HTTP(t *testing.T) {
 	cfg.CapellaForkEpoch = 1
 	cfg.DenebForkEpoch = 2
 	cfg.ElectraForkEpoch = 3
+	cfg.FuluForkEpoch = 4
 	params.OverrideBeaconConfig(cfg)
 
 	t.Run(GetPayloadMethod, func(t *testing.T) {
@@ -317,11 +319,11 @@ func TestClient_HTTP(t *testing.T) {
 		require.DeepEqual(t, uint64(2), g)
 
 		commitments := [][]byte{bytesutil.PadTo([]byte("commitment1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("commitment2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, commitments, resp.BlobsBundle.KzgCommitments)
+		require.DeepEqual(t, commitments, resp.BlobsBundler.GetKzgCommitments())
 		proofs := [][]byte{bytesutil.PadTo([]byte("proof1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("proof2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, proofs, resp.BlobsBundle.Proofs)
+		require.DeepEqual(t, proofs, resp.BlobsBundler.GetProofs())
 		blobs := [][]byte{bytesutil.PadTo([]byte("a"), fieldparams.BlobLength), bytesutil.PadTo([]byte("b"), fieldparams.BlobLength)}
-		require.DeepEqual(t, blobs, resp.BlobsBundle.Blobs)
+		require.DeepEqual(t, blobs, resp.BlobsBundler.GetBlobs())
 	})
 	t.Run(GetPayloadMethodV4, func(t *testing.T) {
 		payloadId := [8]byte{1}
@@ -372,11 +374,11 @@ func TestClient_HTTP(t *testing.T) {
 		require.DeepEqual(t, uint64(2), g)
 
 		commitments := [][]byte{bytesutil.PadTo([]byte("commitment1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("commitment2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, commitments, resp.BlobsBundle.KzgCommitments)
+		require.DeepEqual(t, commitments, resp.BlobsBundler.GetKzgCommitments())
 		proofs := [][]byte{bytesutil.PadTo([]byte("proof1"), fieldparams.BLSPubkeyLength), bytesutil.PadTo([]byte("proof2"), fieldparams.BLSPubkeyLength)}
-		require.DeepEqual(t, proofs, resp.BlobsBundle.Proofs)
+		require.DeepEqual(t, proofs, resp.BlobsBundler.GetProofs())
 		blobs := [][]byte{bytesutil.PadTo([]byte("a"), fieldparams.BlobLength), bytesutil.PadTo([]byte("b"), fieldparams.BlobLength)}
-		require.DeepEqual(t, blobs, resp.BlobsBundle.Blobs)
+		require.DeepEqual(t, blobs, resp.BlobsBundler.GetBlobs())
 		requests := &pb.ExecutionRequests{
 			Deposits: []*pb.DepositRequest{
 				{
@@ -405,7 +407,52 @@ func TestClient_HTTP(t *testing.T) {
 
 		require.DeepEqual(t, requests, resp.ExecutionRequests)
 	})
+	t.Run(GetPayloadMethodV5, func(t *testing.T) {
+		payloadId := [8]byte{1}
+		want, ok := fix["ExecutionBundleFulu"].(*pb.GetPayloadV5ResponseJson)
+		require.Equal(t, true, ok)
+		srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("Content-Type", "application/json")
+			defer func() {
+				require.NoError(t, r.Body.Close())
+			}()
+			enc, err := io.ReadAll(r.Body)
+			require.NoError(t, err)
+			jsonRequestString := string(enc)
 
+			reqArg, err := json.Marshal(pb.PayloadIDBytes(payloadId))
+			require.NoError(t, err)
+
+			// We expect the JSON string RPC request contains the right arguments.
+			require.Equal(t, true, strings.Contains(
+				jsonRequestString, string(reqArg),
+			))
+			resp := map[string]interface{}{
+				"jsonrpc": "2.0",
+				"id":      1,
+				"result":  want,
+			}
+			err = json.NewEncoder(w).Encode(resp)
+			require.NoError(t, err)
+		}))
+		defer srv.Close()
+
+		rpcClient, err := rpc.DialHTTP(srv.URL)
+		require.NoError(t, err)
+		defer rpcClient.Close()
+
+		client := &Service{}
+		client.rpcClient = rpcClient
+
+		// We call the RPC method via HTTP and expect a proper result.
+		resp, err := client.GetPayload(ctx, payloadId, 4*params.BeaconConfig().SlotsPerEpoch)
+		require.NoError(t, err)
+		_, ok = resp.BlobsBundler.(*pb.BlobsBundleV2)
+		if !ok {
+			t.Logf("resp.BlobsBundler has unexpected type: %T", resp.BlobsBundler)
+		}
+		require.Equal(t, ok, true)
+	})
 	t.Run(ForkchoiceUpdatedMethod+" VALID status", func(t *testing.T) {
 		forkChoiceState := &pb.ForkchoiceState{
 			HeadBlockHash:      []byte("head"),
@@ -1539,6 +1586,7 @@ func fixtures() map[string]interface{} {
 		"ExecutionPayloadCapellaWithValue":  s.ExecutionPayloadWithValueCapella,
 		"ExecutionPayloadDenebWithValue":    s.ExecutionPayloadWithValueDeneb,
 		"ExecutionBundleElectra":            s.ExecutionBundleElectra,
+		"ExecutionBundleFulu":               s.ExecutionBundleFulu,
 		"ValidPayloadStatus":                s.ValidPayloadStatus,
 		"InvalidBlockHashStatus":            s.InvalidBlockHashStatus,
 		"AcceptedStatus":                    s.AcceptedStatus,
@@ -1774,6 +1822,36 @@ func fixturesStruct() *payloadFixtures {
 			append([]byte{pb.WithdrawalRequestType}, withdrawalRequestBytes...),
 			append([]byte{pb.ConsolidationRequestType}, consolidationRequestBytes...)},
 	}
+	executionBundleFixtureFulu := &pb.GetPayloadV5ResponseJson{
+		ShouldOverrideBuilder: true,
+		ExecutionPayload: &pb.ExecutionPayloadDenebJSON{
+			ParentHash:    &common.Hash{'a'},
+			FeeRecipient:  &common.Address{'b'},
+			StateRoot:     &common.Hash{'c'},
+			ReceiptsRoot:  &common.Hash{'d'},
+			LogsBloom:     &hexutil.Bytes{'e'},
+			PrevRandao:    &common.Hash{'f'},
+			BaseFeePerGas: "0x123",
+			BlockHash:     &common.Hash{'g'},
+			Transactions:  []hexutil.Bytes{{'h'}},
+			Withdrawals:   []*pb.Withdrawal{},
+			BlockNumber:   &hexUint,
+			GasLimit:      &hexUint,
+			GasUsed:       &hexUint,
+			Timestamp:     &hexUint,
+			BlobGasUsed:   &bgu,
+			ExcessBlobGas: &ebg,
+		},
+		BlockValue: "0x11fffffffff",
+		BlobsBundle: &pb.BlobBundleV2JSON{
+			Commitments: []hexutil.Bytes{[]byte("commitment1"), []byte("commitment2")},
+			Proofs:      []hexutil.Bytes{[]byte("proof1"), []byte("proof2")},
+			Blobs:       []hexutil.Bytes{{'a'}, {'b'}},
+		},
+		ExecutionRequests: []hexutil.Bytes{append([]byte{pb.DepositRequestType}, depositRequestBytes...),
+			append([]byte{pb.WithdrawalRequestType}, withdrawalRequestBytes...),
+			append([]byte{pb.ConsolidationRequestType}, consolidationRequestBytes...)},
+	}
 	parent := bytesutil.PadTo([]byte("parentHash"), fieldparams.RootLength)
 	sha3Uncles := bytesutil.PadTo([]byte("sha3Uncles"), fieldparams.RootLength)
 	miner := bytesutil.PadTo([]byte("miner"), fieldparams.FeeRecipientLength)
@@ -1868,6 +1946,7 @@ func fixturesStruct() *payloadFixtures {
 		ExecutionPayloadWithValueCapella:  executionPayloadWithValueFixtureCapella,
 		ExecutionPayloadWithValueDeneb:    executionPayloadWithValueFixtureDeneb,
 		ExecutionBundleElectra:            executionBundleFixtureElectra,
+		ExecutionBundleFulu:               executionBundleFixtureFulu,
 		ValidPayloadStatus:                validStatus,
 		InvalidBlockHashStatus:            inValidBlockHashStatus,
 		AcceptedStatus:                    acceptedStatus,
@@ -1892,6 +1971,7 @@ type payloadFixtures struct {
 	ExecutionPayloadWithValueCapella  *pb.GetPayloadV2ResponseJson
 	ExecutionPayloadWithValueDeneb    *pb.GetPayloadV3ResponseJson
 	ExecutionBundleElectra            *pb.GetPayloadV4ResponseJson
+	ExecutionBundleFulu               *pb.GetPayloadV5ResponseJson
 	ValidPayloadStatus                *pb.PayloadStatus
 	InvalidBlockHashStatus            *pb.PayloadStatus
 	AcceptedStatus                    *pb.PayloadStatus
@@ -2424,7 +2504,7 @@ func TestReconstructBlobSidecars(t *testing.T) {
 	t.Run("get-blobs end point is not supported", func(t *testing.T) {
 		hi := mockSummary(t, []bool{true, true, true, true, true, false})
 		verifiedBlobs, err := client.ReconstructBlobSidecars(ctx, sb, r, hi)
-		require.NoError(t, err)
+		require.ErrorContains(t, "engine_getBlobsV1 is not supported", err)
 		require.Equal(t, 0, len(verifiedBlobs))
 	})
 
@@ -2476,6 +2556,76 @@ func TestReconstructBlobSidecars(t *testing.T) {
 	})
 }
 
+func TestReconstructDataColumnSidecars(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Setup right fork epoch
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.CapellaForkEpoch = 1
+	cfg.DenebForkEpoch = 2
+	cfg.ElectraForkEpoch = 3
+	cfg.FuluForkEpoch = 4
+	params.OverrideBeaconConfig(cfg)
+
+	client := &Service{capabilityCache: &capabilityCache{}}
+	b := util.NewBeaconBlockFulu()
+	b.Block.Slot = 4 * params.BeaconConfig().SlotsPerEpoch
+	kzgCommitments := createRandomKzgCommitments(t, 6)
+	b.Block.Body.BlobKzgCommitments = kzgCommitments
+	r, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	sb, err := blocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+
+	ctx := context.Background()
+
+	t.Run("GetBlobsV2 is not supported", func(t *testing.T) {
+		_, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.ErrorContains(t, "get blobs V2 for block", err)
+	})
+
+	t.Run("nothing received", func(t *testing.T) {
+		srv := createBlobServerV2(t, 0, []bool{})
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.NoError(t, err)
+		require.Equal(t, 0, len(dataColumns))
+	})
+
+	t.Run("receiving all blobs", func(t *testing.T) {
+		blobMasks := []bool{true, true, true, true, true, true}
+		srv := createBlobServerV2(t, 6, blobMasks)
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.NoError(t, err)
+		require.Equal(t, 128, len(dataColumns))
+	})
+
+	t.Run("missing some blobs", func(t *testing.T) {
+		blobMasks := []bool{false, true, true, true, true, true}
+		srv := createBlobServerV2(t, 6, blobMasks)
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		require.ErrorContains(t, errMissingBlobsAndProofsFromEL.Error(), err)
+		require.Equal(t, 0, len(dataColumns))
+	})
+}
+
 func createRandomKzgCommitments(t *testing.T, num int) [][]byte {
 	kzgCommitments := make([][]byte, num)
 	for i := range kzgCommitments {
@@ -2511,6 +2661,42 @@ func createBlobServer(t *testing.T, numBlobs int, callbackFuncs ...func()) *http
 	}))
 }
 
+func createBlobServerV2(t *testing.T, numBlobs int, blobMasks []bool) *httptest.Server {
+	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		defer func() {
+			require.NoError(t, r.Body.Close())
+		}()
+
+		require.Equal(t, len(blobMasks), numBlobs)
+
+		blobAndCellProofs := make([]*pb.BlobAndProofV2Json, numBlobs)
+		for i := range blobAndCellProofs {
+			if !blobMasks[i] {
+				continue
+			}
+
+			blobAndCellProofs[i] = &pb.BlobAndProofV2Json{
+				Blob:      []byte("0xblob"),
+				KzgProofs: []hexutil.Bytes{},
+			}
+			for j := 0; j < int(params.BeaconConfig().NumberOfColumns); j++ {
+				cellProof := make([]byte, 48)
+				blobAndCellProofs[i].KzgProofs = append(blobAndCellProofs[i].KzgProofs, cellProof)
+			}
+		}
+
+		respJSON := map[string]interface{}{
+			"jsonrpc": "2.0",
+			"id":      1,
+			"result":  blobAndCellProofs,
+		}
+
+		err := json.NewEncoder(w).Encode(respJSON)
+		require.NoError(t, err)
+	}))
+}
+
 func setupRpcClient(t *testing.T, url string, client *Service) (*rpc.Client, *Service) {
 	rpcClient, err := rpc.DialHTTP(url)
 	require.NoError(t, err)
@@ -2522,6 +2708,12 @@ func setupRpcClient(t *testing.T, url string, client *Service) (*rpc.Client, *Se
 	return rpcClient, client
 }
 
+func setupRpcClientV2(t *testing.T, url string, client *Service) (*rpc.Client, *Service) {
+	rpcClient, client := setupRpcClient(t, url, client)
+	client.capabilityCache = &capabilityCache{capabilities: map[string]interface{}{GetBlobsV2: nil}}
+	return rpcClient, client
+}
+
 func testNewBlobVerifier() verification.NewBlobVerifier {
 	return func(b blocks.ROBlob, reqs []verification.Requirement) verification.BlobVerifier {
 		return &verification.MockBlobVerifier{

beacon-chain/execution/log_processing_test.go

@@ -479,6 +479,93 @@ func TestProcessETH2GenesisLog_CorrectNumOfDeposits(t *testing.T) {
 	hook.Reset()
 }
 
+func TestProcessLogs_DepositRequestsStarted(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	hook := logTest.NewGlobal()
+	testAcc, err := mock.Setup()
+	require.NoError(t, err, "Unable to set up simulated backend")
+	kvStore := testDB.SetupDB(t)
+	depositCache, err := depositsnapshot.New()
+	require.NoError(t, err)
+	server, endpoint, err := mockExecution.SetupRPCServer()
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		server.Stop()
+	})
+
+	web3Service, err := NewService(context.Background(),
+		WithHttpEndpoint(endpoint),
+		WithDepositContractAddress(testAcc.ContractAddr),
+		WithDatabase(kvStore),
+		WithDepositCache(depositCache),
+	)
+	require.NoError(t, err, "unable to setup web3 ETH1.0 chain service")
+	web3Service = setDefaultMocks(web3Service)
+	web3Service.depositContractCaller, err = contracts.NewDepositContractCaller(testAcc.ContractAddr, testAcc.Backend.Client())
+	require.NoError(t, err)
+	web3Service.rpcClient = &mockExecution.RPCClient{Backend: testAcc.Backend}
+	web3Service.httpLogger = testAcc.Backend.Client()
+	web3Service.latestEth1Data.LastRequestedBlock = 0
+	block, err := testAcc.Backend.Client().BlockByNumber(context.Background(), nil)
+	require.NoError(t, err)
+	web3Service.latestEth1Data.BlockHeight = block.NumberU64()
+	web3Service.latestEth1Data.BlockTime = block.Time()
+	bConfig := params.MinimalSpecConfig().Copy()
+	bConfig.MinGenesisTime = 0
+	bConfig.SecondsPerETH1Block = 1
+	params.OverrideBeaconConfig(bConfig)
+	nConfig := params.BeaconNetworkConfig()
+	nConfig.ContractDeploymentBlock = 0
+	params.OverrideBeaconNetworkConfig(nConfig)
+
+	testAcc.Backend.Commit()
+
+	totalNumOfDeposits := depositsReqForChainStart + 30
+
+	deposits, _, err := util.DeterministicDepositsAndKeys(uint64(totalNumOfDeposits))
+	require.NoError(t, err)
+	_, depositRoots, err := util.DeterministicDepositTrie(len(deposits))
+	require.NoError(t, err)
+	depositOffset := 5
+
+	// 64 Validators are used as size required for beacon-chain to start. This number
+	// is defined in the deposit contract as the number required for the testnet. The actual number
+	// is 2**14
+	for i := 0; i < totalNumOfDeposits; i++ {
+		data := deposits[i].Data
+		testAcc.TxOpts.Value = mock.Amount32Eth()
+		testAcc.TxOpts.GasLimit = 1000000
+		_, err = testAcc.Contract.Deposit(testAcc.TxOpts, data.PublicKey, data.WithdrawalCredentials, data.Signature, depositRoots[i])
+		require.NoError(t, err, "Could not deposit to deposit contract")
+		// pack 8 deposits into a block with an offset of
+		// 5
+		if (i+1)%8 == depositOffset {
+			testAcc.Backend.Commit()
+		}
+	}
+	// Forward the chain to account for the follow distance
+	for i := uint64(0); i < params.BeaconConfig().Eth1FollowDistance; i++ {
+		testAcc.Backend.Commit()
+	}
+	b, err := testAcc.Backend.Client().BlockByNumber(context.Background(), nil)
+	require.NoError(t, err)
+	web3Service.latestEth1Data.BlockHeight = b.NumberU64()
+	web3Service.latestEth1Data.BlockTime = b.Time()
+
+	// Set up our subscriber now to listen for the chain started event.
+	stateChannel := make(chan *feed.Event, 1)
+	stateSub := web3Service.cfg.stateNotifier.StateFeed().Subscribe(stateChannel)
+	defer stateSub.Unsubscribe()
+
+	web3Service.depositRequestsStarted = true
+	web3Service.initPOWService()
+	require.NoError(t, err)
+
+	require.Equal(t, int64(-1), web3Service.lastReceivedMerkleIndex, "Processed deposit logs even when requests are active")
+
+	hook.Reset()
+}
+
 func TestProcessETH2GenesisLog_LargePeriodOfNoLogs(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	hook := logTest.NewGlobal()

beacon-chain/execution/service.go

@@ -16,6 +16,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution/types"
@@ -141,6 +142,7 @@ type config struct {
 type Service struct {
 	connectedETH1           bool
 	isRunning               bool
+	depositRequestsStarted  bool
 	processingLock          sync.RWMutex
 	latestEth1DataLock      sync.RWMutex
 	cfg                     *config
@@ -205,7 +207,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 			return nil, err
 		}
 	}
-
+	s.initDepositRequests()
 	eth1Data, err := s.validPowchainData(ctx)
 	if err != nil {
 		return nil, errors.Wrap(err, "unable to validate powchain data")
@@ -463,7 +465,9 @@ func safelyHandlePanic() {
 func (s *Service) handleETH1FollowDistance() {
 	defer safelyHandlePanic()
 	ctx := s.ctx
-
+	if s.depositRequestsStarted {
+		return
+	}
 	// use a 5 minutes timeout for block time, because the max mining time is 278 sec (block 7208027)
 	// (analyzed the time of the block from 2018-09-01 to 2019-02-13)
 	fiveMinutesTimeout := prysmTime.Now().Add(-5 * time.Minute)
@@ -530,25 +534,27 @@ func (s *Service) initPOWService() {
 			s.latestEth1Data.BlockTime = header.Time
 			s.latestEth1DataLock.Unlock()
 
-			if err := s.processPastLogs(ctx); err != nil {
-				err = errors.Wrap(err, "processPastLogs")
-				s.retryExecutionClientConnection(ctx, err)
-				errorLogger(
-					err,
-					"Unable to process past deposit contract logs, perhaps your execution client is not fully synced",
-				)
-				continue
-			}
-			// Cache eth1 headers from our voting period.
-			if err := s.cacheHeadersForEth1DataVote(ctx); err != nil {
-				err = errors.Wrap(err, "cacheHeadersForEth1DataVote")
-				s.retryExecutionClientConnection(ctx, err)
-				if errors.Is(err, errBlockTimeTooLate) {
-					log.WithError(err).Debug("Unable to cache headers for execution client votes")
-				} else {
-					errorLogger(err, "Unable to cache headers for execution client votes")
+			if !s.depositRequestsStarted {
+				if err := s.processPastLogs(ctx); err != nil {
+					err = errors.Wrap(err, "processPastLogs")
+					s.retryExecutionClientConnection(ctx, err)
+					errorLogger(
+						err,
+						"Unable to process past deposit contract logs, perhaps your execution client is not fully synced",
+					)
+					continue
+				}
+				// Cache eth1 headers from our voting period.
+				if err := s.cacheHeadersForEth1DataVote(ctx); err != nil {
+					err = errors.Wrap(err, "cacheHeadersForEth1DataVote")
+					s.retryExecutionClientConnection(ctx, err)
+					if errors.Is(err, errBlockTimeTooLate) {
+						log.WithError(err).Debug("Unable to cache headers for execution client votes")
+					} else {
+						errorLogger(err, "Unable to cache headers for execution client votes")
+					}
+					continue
 				}
-				continue
 			}
 			// Handle edge case with embedded genesis state by fetching genesis header to determine
 			// its height.
@@ -824,7 +830,7 @@ func (s *Service) validPowchainData(ctx context.Context) (*ethpb.ETH1ChainData,
 	if genState == nil || genState.IsNil() {
 		return eth1Data, nil
 	}
-	if eth1Data == nil || !eth1Data.ChainstartData.Chainstarted || !validateDepositContainers(eth1Data.DepositContainers) {
+	if s.depositRequestsStarted || eth1Data == nil || !eth1Data.ChainstartData.Chainstarted || !validateDepositContainers(eth1Data.DepositContainers) {
 		pbState, err := native.ProtobufBeaconStatePhase0(s.preGenesisState.ToProtoUnsafe())
 		if err != nil {
 			return nil, err
@@ -900,6 +906,15 @@ func (s *Service) removeStartupState() {
 	s.cfg.finalizedStateAtStartup = nil
 }
 
+func (s *Service) initDepositRequests() {
+	fState := s.cfg.finalizedStateAtStartup
+	isNil := fState == nil || fState.IsNil()
+	if isNil {
+		return
+	}
+	s.depositRequestsStarted = helpers.DepositRequestsStarted(fState)
+}
+
 func newBlobVerifierFromInitializer(ini *verification.Initializer) verification.NewBlobVerifier {
 	return func(b blocks.ROBlob, reqs []verification.Requirement) verification.BlobVerifier {
 		return ini.NewBlobVerifier(b, reqs)

beacon-chain/execution/testing/mock_engine_client.go

@@ -38,6 +38,8 @@ type EngineClient struct {
 	ErrGetPayload               error
 	BlobSidecars                []blocks.VerifiedROBlob
 	ErrorBlobSidecars           error
+	DataColumnSidecars          []blocks.VerifiedRODataColumn
+	ErrorDataColumnSidecars     error
 }
 
 // NewPayload --
@@ -113,6 +115,10 @@ func (e *EngineClient) ReconstructBlobSidecars(context.Context, interfaces.ReadO
 	return e.BlobSidecars, e.ErrorBlobSidecars
 }
 
+func (e *EngineClient) ReconstructDataColumnSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) ([]blocks.VerifiedRODataColumn, error) {
+	return e.DataColumnSidecars, e.ErrorDataColumnSidecars
+}
+
 // GetTerminalBlockHash --
 func (e *EngineClient) GetTerminalBlockHash(ctx context.Context, transitionTime uint64) ([]byte, bool, error) {
 	ttd := new(big.Int)

beacon-chain/node/BUILD.bazel

@@ -23,6 +23,7 @@ go_library(
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/db/kv:go_default_library",

beacon-chain/node/node.go

@@ -25,6 +25,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
@@ -86,44 +87,47 @@ type serviceFlagOpts struct {
 // full PoS node. It handles the lifecycle of the entire system and registers
 // services to a service registry.
 type BeaconNode struct {
-	cliCtx                  *cli.Context
-	ctx                     context.Context
-	cancel                  context.CancelFunc
-	services                *runtime.ServiceRegistry
-	lock                    sync.RWMutex
-	stop                    chan struct{} // Channel to wait for termination notifications.
-	db                      db.Database
-	slasherDB               db.SlasherDatabase
-	attestationCache        *cache.AttestationCache
-	attestationPool         attestations.Pool
-	exitPool                voluntaryexits.PoolManager
-	slashingsPool           slashings.PoolManager
-	syncCommitteePool       synccommittee.Pool
-	blsToExecPool           blstoexec.PoolManager
-	depositCache            cache.DepositCache
-	trackedValidatorsCache  *cache.TrackedValidatorsCache
-	payloadIDCache          *cache.PayloadIDCache
-	stateFeed               *event.Feed
-	blockFeed               *event.Feed
-	opFeed                  *event.Feed
-	stateGen                *stategen.State
-	collector               *bcnodeCollector
-	slasherBlockHeadersFeed *event.Feed
-	slasherAttestationsFeed *event.Feed
-	finalizedStateAtStartUp state.BeaconState
-	serviceFlagOpts         *serviceFlagOpts
-	GenesisInitializer      genesis.Initializer
-	CheckpointInitializer   checkpoint.Initializer
-	forkChoicer             forkchoice.ForkChoicer
-	clockWaiter             startup.ClockWaiter
-	BackfillOpts            []backfill.ServiceOption
-	initialSyncComplete     chan struct{}
-	BlobStorage             *filesystem.BlobStorage
-	BlobStorageOptions      []filesystem.BlobStorageOption
-	verifyInitWaiter        *verification.InitializerWaiter
-	syncChecker             *initialsync.SyncChecker
-	slasherEnabled          bool
-	lcStore                 *lightclient.Store
+	cliCtx                   *cli.Context
+	ctx                      context.Context
+	cancel                   context.CancelFunc
+	services                 *runtime.ServiceRegistry
+	lock                     sync.RWMutex
+	stop                     chan struct{} // Channel to wait for termination notifications.
+	db                       db.Database
+	slasherDB                db.SlasherDatabase
+	attestationCache         *cache.AttestationCache
+	attestationPool          attestations.Pool
+	exitPool                 voluntaryexits.PoolManager
+	slashingsPool            slashings.PoolManager
+	syncCommitteePool        synccommittee.Pool
+	blsToExecPool            blstoexec.PoolManager
+	depositCache             cache.DepositCache
+	trackedValidatorsCache   *cache.TrackedValidatorsCache
+	payloadIDCache           *cache.PayloadIDCache
+	stateFeed                *event.Feed
+	blockFeed                *event.Feed
+	opFeed                   *event.Feed
+	stateGen                 *stategen.State
+	collector                *bcnodeCollector
+	slasherBlockHeadersFeed  *event.Feed
+	slasherAttestationsFeed  *event.Feed
+	finalizedStateAtStartUp  state.BeaconState
+	serviceFlagOpts          *serviceFlagOpts
+	GenesisInitializer       genesis.Initializer
+	CheckpointInitializer    checkpoint.Initializer
+	forkChoicer              forkchoice.ForkChoicer
+	clockWaiter              startup.ClockWaiter
+	BackfillOpts             []backfill.ServiceOption
+	initialSyncComplete      chan struct{}
+	BlobStorage              *filesystem.BlobStorage
+	BlobStorageOptions       []filesystem.BlobStorageOption
+	DataColumnStorage        *filesystem.DataColumnStorage
+	DataColumnStorageOptions []filesystem.DataColumnStorageOption
+	custodyInfo              *peerdas.CustodyInfo
+	verifyInitWaiter         *verification.InitializerWaiter
+	syncChecker              *initialsync.SyncChecker
+	slasherEnabled           bool
+	lcStore                  *lightclient.Store
 }
 
 // New creates a new node instance, sets up configuration options, and registers
@@ -161,6 +165,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		serviceFlagOpts:         &serviceFlagOpts{},
 		initialSyncComplete:     make(chan struct{}),
 		syncChecker:             &initialsync.SyncChecker{},
+		custodyInfo:             &peerdas.CustodyInfo{},
 		slasherEnabled:          cliCtx.Bool(flags.SlasherFlag.Name),
 		lcStore:                 &lightclient.Store{},
 	}
@@ -190,6 +195,15 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		beacon.BlobStorage = blobs
 	}
 
+	if beacon.DataColumnStorage == nil {
+		dataColumnStorage, err := filesystem.NewDataColumnStorage(cliCtx.Context, beacon.DataColumnStorageOptions...)
+		if err != nil {
+			return nil, errors.Wrap(err, "new data column storage")
+		}
+
+		beacon.DataColumnStorage = dataColumnStorage
+	}
+
 	bfs, err := startBaseServices(cliCtx, beacon, depositAddress)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not start modules")
@@ -280,7 +294,9 @@ func startBaseServices(cliCtx *cli.Context, beacon *BeaconNode, depositAddress s
 	if err := beacon.startDB(cliCtx, depositAddress); err != nil {
 		return nil, errors.Wrap(err, "could not start DB")
 	}
+
 	beacon.BlobStorage.WarmCache()
+	beacon.DataColumnStorage.WarmCache()
 
 	log.Debugln("Starting Slashing DB")
 	if err := beacon.startSlasherDB(cliCtx); err != nil {
@@ -491,6 +507,10 @@ func (b *BeaconNode) clearDB(clearDB, forceClearDB bool, d *kv.Store, dbPath str
 			return nil, errors.Wrap(err, "could not clear blob storage")
 		}
 
+		if err := b.DataColumnStorage.Clear(); err != nil {
+			return nil, errors.Wrap(err, "could not clear data column storage")
+		}
+
 		d, err = kv.NewKVStore(b.ctx, dbPath)
 		if err != nil {
 			return nil, errors.Wrap(err, "could not create new database")
@@ -697,6 +717,7 @@ func (b *BeaconNode) registerP2P(cliCtx *cli.Context) error {
 		StateNotifier:        b,
 		DB:                   b.db,
 		ClockWaiter:          b.clockWaiter,
+		CustodyInfo:          b.custodyInfo,
 	})
 	if err != nil {
 		return err
@@ -775,9 +796,11 @@ func (b *BeaconNode) registerBlockchainService(fc forkchoice.ForkChoicer, gs *st
 		blockchain.WithClockSynchronizer(gs),
 		blockchain.WithSyncComplete(syncComplete),
 		blockchain.WithBlobStorage(b.BlobStorage),
+		blockchain.WithDataColumnStorage(b.DataColumnStorage),
 		blockchain.WithTrackedValidatorsCache(b.trackedValidatorsCache),
 		blockchain.WithPayloadIDCache(b.payloadIDCache),
 		blockchain.WithSyncChecker(b.syncChecker),
+		blockchain.WithCustodyInfo(b.custodyInfo),
 		blockchain.WithSlasherEnabled(b.slasherEnabled),
 		blockchain.WithLightClientStore(b.lcStore),
 	)
@@ -862,8 +885,11 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithInitialSyncComplete(initialSyncComplete),
 		regularsync.WithStateNotifier(b),
 		regularsync.WithBlobStorage(b.BlobStorage),
+		regularsync.WithDataColumnStorage(b.DataColumnStorage),
 		regularsync.WithVerifierWaiter(b.verifyInitWaiter),
 		regularsync.WithAvailableBlocker(bFillStore),
+		regularsync.WithTrackedValidatorsCache(b.trackedValidatorsCache),
+		regularsync.WithCustodyInfo(b.custodyInfo),
 		regularsync.WithSlasherEnabled(b.slasherEnabled),
 		regularsync.WithLightClientStore(b.lcStore),
 	)
@@ -889,6 +915,8 @@ func (b *BeaconNode) registerInitialSyncService(complete chan struct{}) error {
 		ClockWaiter:         b.clockWaiter,
 		InitialSyncComplete: complete,
 		BlobStorage:         b.BlobStorage,
+		DataColumnStorage:   b.DataColumnStorage,
+		CustodyInfo:         b.custodyInfo,
 	}, opts...)
 	return b.services.RegisterService(is)
 }
@@ -983,6 +1011,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		FinalizationFetcher:       chainService,
 		BlockReceiver:             chainService,
 		BlobReceiver:              chainService,
+		DataColumnReceiver:        chainService,
 		AttestationReceiver:       chainService,
 		GenesisTimeFetcher:        chainService,
 		GenesisFetcher:            chainService,
@@ -1010,6 +1039,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		Router:                    router,
 		ClockWaiter:               b.clockWaiter,
 		BlobStorage:               b.BlobStorage,
+		DataColumnStorage:         b.DataColumnStorage,
 		TrackedValidatorsCache:    b.trackedValidatorsCache,
 		PayloadIDCache:            b.payloadIDCache,
 		LCStore:                   b.lcStore,
@@ -1151,6 +1181,7 @@ func (b *BeaconNode) registerPrunerService(cliCtx *cli.Context) error {
 
 func (b *BeaconNode) RegisterBackfillService(cliCtx *cli.Context, bfs *backfill.Store) error {
 	pa := peers.NewAssigner(b.fetchP2P().Peers(), b.forkChoicer)
+	// TODO: Add backfill for data column storage
 	bf, err := backfill.NewService(cliCtx.Context, bfs, b.BlobStorage, b.clockWaiter, b.fetchP2P(), pa, b.BackfillOpts...)
 	if err != nil {
 		return errors.Wrap(err, "error initializing backfill service")

beacon-chain/node/node_test.go

@@ -54,7 +54,7 @@ func TestNodeClose_OK(t *testing.T) {
 	cmd.ValidatorMonitorIndicesFlag.Value.SetInt(1)
 	ctx, cancel := newCliContextWithCancel(&app, set)
 
-	node, err := New(ctx, cancel, WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
+	node, err := New(ctx, cancel, WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)))
 	require.NoError(t, err)
 
 	node.Close()
@@ -75,7 +75,7 @@ func TestNodeStart_Ok(t *testing.T) {
 	node, err := New(ctx, cancel, WithBlockchainFlagOptions([]blockchain.Option{}),
 		WithBuilderFlagOptions([]builder.Option{}),
 		WithExecutionChainOptions([]execution.Option{}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)))
 	require.NoError(t, err)
 	node.services = &runtime.ServiceRegistry{}
 	go func() {
@@ -99,7 +99,7 @@ func TestNodeStart_SyncChecker(t *testing.T) {
 	node, err := New(ctx, cancel, WithBlockchainFlagOptions([]blockchain.Option{}),
 		WithBuilderFlagOptions([]builder.Option{}),
 		WithExecutionChainOptions([]execution.Option{}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)))
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)))
 	require.NoError(t, err)
 	go func() {
 		node.Start()
@@ -130,7 +130,7 @@ func TestClearDB(t *testing.T) {
 	context, cancel := newCliContextWithCancel(&app, set)
 	options := []Option{
 		WithExecutionChainOptions([]execution.Option{execution.WithHttpEndpoint(endpoint)}),
-		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)), WithDataColumnStorage(filesystem.NewEphemeralDataColumnStorage(t)),
 	}
 	_, err = New(context, cancel, options...)
 	require.NoError(t, err)

beacon-chain/node/options.go

@@ -50,3 +50,20 @@ func WithBlobStorageOptions(opt ...filesystem.BlobStorageOption) Option {
 		return nil
 	}
 }
+
+// WithDataColumnStorage sets the DataColumnStorage backend for the BeaconNode
+func WithDataColumnStorage(bs *filesystem.DataColumnStorage) Option {
+	return func(bn *BeaconNode) error {
+		bn.DataColumnStorage = bs
+		return nil
+	}
+}
+
+// WithDataColumnStorageOptions appends 1 or more filesystem.DataColumnStorageOption on the beacon node,
+// to be used when initializing data column storage.
+func WithDataColumnStorageOptions(opt ...filesystem.DataColumnStorageOption) Option {
+	return func(bn *BeaconNode) error {
+		bn.DataColumnStorageOptions = append(bn.DataColumnStorageOptions, opt...)
+		return nil
+	}
+}

beacon-chain/p2p/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "broadcaster.go",
         "config.go",
         "connection_gater.go",
+        "custody.go",
         "dial_relay_node.go",
         "discovery.go",
         "doc.go",
@@ -45,6 +46,7 @@ go_library(
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",
@@ -55,6 +57,7 @@ go_library(
         "//beacon-chain/startup:go_default_library",
         "//cmd/beacon-chain/flags:go_default_library",
         "//config/features:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
@@ -117,6 +120,7 @@ go_test(
         "addr_factory_test.go",
         "broadcaster_test.go",
         "connection_gater_test.go",
+        "custody_test.go",
         "dial_relay_node_test.go",
         "discovery_test.go",
         "fork_test.go",
@@ -138,10 +142,12 @@ go_test(
     flaky = True,
     tags = ["requires-network"],
     deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",
@@ -154,6 +160,7 @@ go_test(
         "//cmd/beacon-chain/flags:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
@@ -165,6 +172,7 @@ go_test(
         "//network/forks:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/metadata:go_default_library",
         "//proto/testing:go_default_library",
         "//runtime/version:go_default_library",
         "//testing/assert:go_default_library",

beacon-chain/p2p/broadcaster.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/altair"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
@@ -98,7 +99,12 @@ func (s *Service) BroadcastSyncCommitteeMessage(ctx context.Context, subnet uint
 	return nil
 }
 
-func (s *Service) internalBroadcastAttestation(ctx context.Context, subnet uint64, att ethpb.Att, forkDigest [4]byte) {
+func (s *Service) internalBroadcastAttestation(
+	ctx context.Context,
+	subnet uint64,
+	att ethpb.Att,
+	forkDigest [fieldparams.VersionLength]byte,
+) {
 	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastAttestation")
 	defer span.End()
 	ctx = trace.NewContext(context.Background(), span) // clear parent context / deadline.
@@ -154,7 +160,7 @@ func (s *Service) internalBroadcastAttestation(ctx context.Context, subnet uint6
 	}
 }
 
-func (s *Service) broadcastSyncCommittee(ctx context.Context, subnet uint64, sMsg *ethpb.SyncCommitteeMessage, forkDigest [4]byte) {
+func (s *Service) broadcastSyncCommittee(ctx context.Context, subnet uint64, sMsg *ethpb.SyncCommitteeMessage, forkDigest [fieldparams.VersionLength]byte) {
 	_, span := trace.StartSpan(ctx, "p2p.broadcastSyncCommittee")
 	defer span.End()
 	ctx = trace.NewContext(context.Background(), span) // clear parent context / deadline.
@@ -230,7 +236,12 @@ func (s *Service) BroadcastBlob(ctx context.Context, subnet uint64, blob *ethpb.
 	return nil
 }
 
-func (s *Service) internalBroadcastBlob(ctx context.Context, subnet uint64, blobSidecar *ethpb.BlobSidecar, forkDigest [4]byte) {
+func (s *Service) internalBroadcastBlob(
+	ctx context.Context,
+	subnet uint64,
+	blobSidecar *ethpb.BlobSidecar,
+	forkDigest [fieldparams.VersionLength]byte,
+) {
 	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastBlob")
 	defer span.End()
 	ctx = trace.NewContext(context.Background(), span) // clear parent context / deadline.
@@ -245,7 +256,7 @@ func (s *Service) internalBroadcastBlob(ctx context.Context, subnet uint64, blob
 	s.subnetLocker(wrappedSubIdx).RUnlock()
 
 	if !hasPeer {
-		blobSidecarCommitteeBroadcastAttempts.Inc()
+		blobSidecarBroadcastAttempts.Inc()
 		if err := func() error {
 			s.subnetLocker(wrappedSubIdx).Lock()
 			defer s.subnetLocker(wrappedSubIdx).Unlock()
@@ -254,7 +265,7 @@ func (s *Service) internalBroadcastBlob(ctx context.Context, subnet uint64, blob
 				return err
 			}
 			if ok {
-				blobSidecarCommitteeBroadcasts.Inc()
+				blobSidecarBroadcasts.Inc()
 				return nil
 			}
 			return errors.New("failed to find peers for subnet")
@@ -322,6 +333,120 @@ func (s *Service) BroadcastLightClientFinalityUpdate(ctx context.Context, update
 	return nil
 }
 
+// BroadcastDataColumn broadcasts a data column to the p2p network, the message is assumed to be
+// broadcasted to the current fork and to the input column subnet.
+// TODO: Add tests
+func (s *Service) BroadcastDataColumn(
+	ctx context.Context,
+	root [fieldparams.RootLength]byte,
+	columnSubnet uint64,
+	dataColumnSidecar *ethpb.DataColumnSidecar,
+) error {
+	// Add tracing to the function.
+	ctx, span := trace.StartSpan(ctx, "p2p.BroadcastBlob")
+	defer span.End()
+
+	// Ensure the data column sidecar is not nil.
+	if dataColumnSidecar == nil {
+		return errors.Errorf("attempted to broadcast nil data column sidecar at subnet %d", columnSubnet)
+	}
+
+	// Retrieve the current fork digest.
+	forkDigest, err := s.currentForkDigest()
+	if err != nil {
+		err := errors.Wrap(err, "current fork digest")
+		tracing.AnnotateError(span, err)
+		return err
+	}
+
+	// Non-blocking broadcast, with attempts to discover a column subnet peer if none available.
+	go s.internalBroadcastDataColumn(ctx, root, columnSubnet, dataColumnSidecar, forkDigest)
+
+	return nil
+}
+
+func (s *Service) internalBroadcastDataColumn(
+	ctx context.Context,
+	root [fieldparams.RootLength]byte,
+	columnSubnet uint64,
+	dataColumnSidecar *ethpb.DataColumnSidecar,
+	forkDigest [fieldparams.VersionLength]byte,
+) {
+	// Add tracing to the function.
+	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastDataColumn")
+	defer span.End()
+
+	// Increase the number of broadcast attempts.
+	dataColumnSidecarBroadcastAttempts.Inc()
+
+	// Clear parent context / deadline.
+	ctx = trace.NewContext(context.Background(), span)
+
+	// Define a one-slot length context timeout.
+	oneSlot := time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
+	ctx, cancel := context.WithTimeout(ctx, oneSlot)
+	defer cancel()
+
+	// Build the topic corresponding to this column subnet and this fork digest.
+	topic := dataColumnSubnetToTopic(columnSubnet, forkDigest)
+
+	// Compute the wrapped subnet index.
+	wrappedSubIdx := columnSubnet + dataColumnSubnetVal
+
+	// Check if we have peers with this subnet.
+	hasPeer := func() bool {
+		s.subnetLocker(wrappedSubIdx).RLock()
+		defer s.subnetLocker(wrappedSubIdx).RUnlock()
+
+		return s.hasPeerWithSubnet(topic)
+	}()
+
+	// If no peers are found, attempt to find peers with this subnet.
+	if !hasPeer {
+		if err := func() error {
+			s.subnetLocker(wrappedSubIdx).Lock()
+			defer s.subnetLocker(wrappedSubIdx).Unlock()
+
+			ok, err := s.FindPeersWithSubnet(ctx, topic, columnSubnet, 1 /*threshold*/)
+			if err != nil {
+				return errors.Wrap(err, "find peers for subnet")
+			}
+
+			if ok {
+				return nil
+			}
+			return errors.New("failed to find peers for subnet")
+		}(); err != nil {
+			log.WithError(err).Error("Failed to find peers")
+			tracing.AnnotateError(span, err)
+		}
+	}
+
+	// Broadcast the data column sidecar to the network.
+	if err := s.broadcastObject(ctx, dataColumnSidecar, topic); err != nil {
+		log.WithError(err).Error("Failed to broadcast data column sidecar")
+		tracing.AnnotateError(span, err)
+	}
+
+	header := dataColumnSidecar.SignedBlockHeader.GetHeader()
+	slot := header.GetSlot()
+
+	slotStartTime, err := slots.ToTime(uint64(s.genesisTime.Unix()), slot)
+	if err != nil {
+		log.WithError(err).Error("Failed to convert slot to time")
+	}
+
+	log.WithFields(logrus.Fields{
+		"slot":               slot,
+		"timeSinceSlotStart": time.Since(slotStartTime),
+		"root":               fmt.Sprintf("%#x", root),
+		"columnSubnet":       columnSubnet,
+	}).Debug("Broadcasted data column sidecar")
+
+	// Increase the number of successful broadcasts.
+	dataColumnSidecarBroadcasts.Inc()
+}
+
 // method to broadcast messages to other peers in our gossip mesh.
 func (s *Service) broadcastObject(ctx context.Context, obj ssz.Marshaler, topic string) error {
 	ctx, span := trace.StartSpan(ctx, "p2p.broadcastObject")
@@ -351,15 +476,15 @@ func (s *Service) broadcastObject(ctx context.Context, obj ssz.Marshaler, topic
 	return nil
 }
 
-func attestationToTopic(subnet uint64, forkDigest [4]byte) string {
+func attestationToTopic(subnet uint64, forkDigest [fieldparams.VersionLength]byte) string {
 	return fmt.Sprintf(AttestationSubnetTopicFormat, forkDigest, subnet)
 }
 
-func syncCommitteeToTopic(subnet uint64, forkDigest [4]byte) string {
+func syncCommitteeToTopic(subnet uint64, forkDigest [fieldparams.VersionLength]byte) string {
 	return fmt.Sprintf(SyncCommitteeSubnetTopicFormat, forkDigest, subnet)
 }
 
-func blobSubnetToTopic(subnet uint64, forkDigest [4]byte) string {
+func blobSubnetToTopic(subnet uint64, forkDigest [fieldparams.VersionLength]byte) string {
 	return fmt.Sprintf(BlobSubnetTopicFormat, forkDigest, subnet)
 }
 
@@ -370,3 +495,7 @@ func lcOptimisticToTopic(forkDigest [4]byte) string {
 func lcFinalityToTopic(forkDigest [4]byte) string {
 	return fmt.Sprintf(LightClientFinalityUpdateTopicFormat, forkDigest)
 }
+
+func dataColumnSubnetToTopic(subnet uint64, forkDigest [fieldparams.VersionLength]byte) string {
+	return fmt.Sprintf(DataColumnSubnetTopicFormat, forkDigest, subnet)
+}

beacon-chain/p2p/broadcaster_test.go

@@ -9,12 +9,15 @@ import (
 	"testing"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -655,3 +658,88 @@ func TestService_BroadcastLightClientFinalityUpdate(t *testing.T) {
 		t.Error("Failed to receive pubsub within 1s")
 	}
 }
+
+func TestService_BroadcastDataColumn(t *testing.T) {
+	require.NoError(t, kzg.Start())
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
+	p1.Connect(p2)
+	require.NotEqual(t, 0, len(p1.BHost.Network().Peers()), "No peers")
+
+	p := &Service{
+		host:                  p1.BHost,
+		pubsub:                p1.PubSub(),
+		joinedTopics:          map[string]*pubsub.Topic{},
+		cfg:                   &Config{},
+		genesisTime:           time.Now(),
+		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		subnetsLock:           make(map[uint64]*sync.RWMutex),
+		subnetsLockLock:       sync.Mutex{},
+		peers: peers.NewStatus(context.Background(), &peers.StatusConfig{
+			ScorerParams: &scorers.Config{},
+		}),
+	}
+
+	var (
+		comts [][]byte
+		blobs []kzg.Blob
+	)
+	for i := int64(0); i < 6; i++ {
+		blob := kzg.Blob(util.GetRandBlob(i))
+		commitment, err := kzg.BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+		comts = append(comts, commitment[:])
+		blobs = append(blobs, blob)
+	}
+
+	b := util.NewBeaconBlockFulu()
+	b.Block.Body.BlobKzgCommitments = comts
+	sb, err := blocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	for i := range blobs {
+		blobs[i] = kzg.Blob(util.GetRandBlob(int64(i)))
+	}
+	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
+	sidecars, err := peerdas.DataColumnSidecars(sb, cellsAndProofs)
+	require.NoError(t, err)
+
+	sidecar := sidecars[0]
+	subnet := uint64(0)
+	topic := DataColumnSubnetTopicFormat
+	GossipTypeMapping[reflect.TypeOf(sidecar)] = topic
+	digest, err := p.currentForkDigest()
+	require.NoError(t, err)
+	topic = fmt.Sprintf(topic, digest, subnet)
+
+	// External peer subscribes to the topic.
+	topic += p.Encoding().ProtocolSuffix()
+	sub, err := p2.SubscribeToTopic(topic)
+	require.NoError(t, err)
+
+	time.Sleep(50 * time.Millisecond) // libp2p fails without this delay...
+
+	// Async listen for the pubsub, must be before the broadcast.
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func(tt *testing.T) {
+		defer wg.Done()
+		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+		defer cancel()
+
+		msg, err := sub.Next(ctx)
+		require.NoError(t, err)
+
+		result := &ethpb.DataColumnSidecar{}
+		require.NoError(t, p.Encoding().DecodeGossip(msg.Data, result))
+		require.DeepEqual(t, result, sidecar)
+	}(t)
+
+	// Attempt to broadcast nil object should fail.
+	ctx := context.Background()
+	var root [fieldparams.RootLength]byte
+	require.ErrorContains(t, "attempted to broadcast nil", p.BroadcastDataColumn(ctx, root, subnet, nil))
+
+	// Broadcast to peers and wait.
+	require.NoError(t, p.BroadcastDataColumn(ctx, root, subnet, sidecar))
+	require.Equal(t, false, util.WaitTimeout(&wg, 1*time.Second), "Failed to receive pubsub within 1s")
+}

beacon-chain/p2p/config.go

@@ -4,6 +4,7 @@ import (
 	"time"
 
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 )
@@ -38,6 +39,7 @@ type Config struct {
 	StateNotifier        statefeed.Notifier
 	DB                   db.ReadOnlyDatabase
 	ClockWaiter          startup.ClockWaiter
+	CustodyInfo          *peerdas.CustodyInfo
 }
 
 // validateConfig validates whether the values provided are accurate and will set

beacon-chain/p2p/custody.go

@@ -0,0 +1,74 @@
+package p2p
+
+import (
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/sirupsen/logrus"
+)
+
+var _ DataColumnsHandler = (*Service)(nil)
+
+// custodyGroupCountFromPeerENR retrieves the custody count from the peer ENR.
+// If the ENR is not available, it defaults to the minimum number of custody groups
+// an honest node custodies and serves samples from.
+func (s *Service) custodyGroupCountFromPeerENR(pid peer.ID) uint64 {
+	// By default, we assume the peer custodies the minimum number of groups.
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+
+	// Retrieve the ENR of the peer.
+	record, err := s.peers.ENR(pid)
+	if err != nil {
+		log.WithError(err).WithFields(logrus.Fields{
+			"peerID":       pid,
+			"defaultValue": custodyRequirement,
+		}).Debug("Failed to retrieve ENR for peer, defaulting to the default value")
+
+		return custodyRequirement
+	}
+
+	// Retrieve the custody group count from the ENR.
+	custodyGroupCount, err := peerdas.CustodyGroupCountFromRecord(record)
+	if err != nil {
+		log.WithError(err).WithFields(logrus.Fields{
+			"peerID":       pid,
+			"defaultValue": custodyRequirement,
+		}).Debug("Failed to retrieve custody group count from ENR for peer, defaulting to the default value")
+
+		return custodyRequirement
+	}
+
+	return custodyGroupCount
+}
+
+// CustodyGroupCountFromPeer retrieves custody group count from a peer.
+// It first tries to get the custody group count from the peer's metadata,
+// then falls back to the ENR value if the metadata is not available, then
+// falls back to the minimum number of custody groups an honest node should custodiy
+// and serve samples from if ENR is not available.
+func (s *Service) CustodyGroupCountFromPeer(pid peer.ID) uint64 {
+	// Try to get the custody group count from the peer's metadata.
+	metadata, err := s.peers.Metadata(pid)
+	if err != nil {
+		// On error, default to the ENR value.
+		log.WithError(err).WithField("peerID", pid).Debug("Failed to retrieve metadata for peer, defaulting to the ENR value")
+		return s.custodyGroupCountFromPeerENR(pid)
+	}
+
+	// If the metadata is nil, default to the ENR value.
+	if metadata == nil {
+		log.WithField("peerID", pid).Debug("Metadata is nil, defaulting to the ENR value")
+		return s.custodyGroupCountFromPeerENR(pid)
+	}
+
+	// Get the custody subnets count from the metadata.
+	custodyCount := metadata.CustodyGroupCount()
+
+	// If the custody count is null, default to the ENR value.
+	if custodyCount == 0 {
+		log.WithField("peerID", pid).Debug("The custody count extracted from the metadata equals to 0, defaulting to the ENR value")
+		return s.custodyGroupCountFromPeerENR(pid)
+	}
+
+	return custodyCount
+}

beacon-chain/p2p/custody_test.go

@@ -0,0 +1,112 @@
+package p2p
+
+import (
+	"context"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
+	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/libp2p/go-libp2p/core/network"
+)
+
+func TestCustodyGroupCountFromPeer(t *testing.T) {
+	const (
+		expectedENR      uint64 = 7
+		expectedMetadata uint64 = 8
+		pid                     = "test-id"
+	)
+
+	cgc := peerdas.Cgc(expectedENR)
+
+	// Define a nil record
+	var nilRecord *enr.Record = nil
+
+	// Define an empty record (record with non `cgc` entry)
+	emptyRecord := &enr.Record{}
+
+	// Define a nominal record
+	nominalRecord := &enr.Record{}
+	nominalRecord.Set(cgc)
+
+	// Define a metadata with zero custody.
+	zeroMetadata := wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		CustodyGroupCount: 0,
+	})
+
+	// Define a nominal metadata.
+	nominalMetadata := wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		CustodyGroupCount: expectedMetadata,
+	})
+
+	testCases := []struct {
+		name     string
+		record   *enr.Record
+		metadata metadata.Metadata
+		expected uint64
+	}{
+		{
+			name:     "No metadata - No ENR",
+			record:   nilRecord,
+			expected: params.BeaconConfig().CustodyRequirement,
+		},
+		{
+			name:     "No metadata - Empty ENR",
+			record:   emptyRecord,
+			expected: params.BeaconConfig().CustodyRequirement,
+		},
+		{
+			name:     "No Metadata - ENR",
+			record:   nominalRecord,
+			expected: expectedENR,
+		},
+		{
+			name:     "Metadata with 0 value - ENR",
+			record:   nominalRecord,
+			metadata: zeroMetadata,
+			expected: expectedENR,
+		},
+		{
+			name:     "Metadata - ENR",
+			record:   nominalRecord,
+			metadata: nominalMetadata,
+			expected: expectedMetadata,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Create peers status.
+			peers := peers.NewStatus(context.Background(), &peers.StatusConfig{
+				ScorerParams: &scorers.Config{},
+			})
+
+			// Set the metadata.
+			if tc.metadata != nil {
+				peers.SetMetadata(pid, tc.metadata)
+			}
+
+			// Add a new peer with the record.
+			peers.Add(tc.record, pid, nil, network.DirOutbound)
+
+			// Create a new service.
+			service := &Service{
+				peers:    peers,
+				metaData: tc.metadata,
+			}
+
+			// Retrieve the custody count from the remote peer.
+			actual := service.CustodyGroupCountFromPeer(pid)
+
+			// Verify the result.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+
+}

beacon-chain/p2p/discovery.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -187,7 +188,8 @@ func (s *Service) RefreshPersistentSubnets() {
 	// Compare current epoch with Altair fork epoch
 	altairForkEpoch := params.BeaconConfig().AltairForkEpoch
 
-	if currentEpoch < altairForkEpoch {
+	// We add `1` to the current epoch because we want to prepare one epoch before the Altair fork.
+	if currentEpoch+1 < altairForkEpoch {
 		// Phase 0 behaviour.
 		if isBitVUpToDate {
 			// Return early if bitfield hasn't changed.
@@ -220,18 +222,52 @@ func (s *Service) RefreshPersistentSubnets() {
 	// Get the sync subnet bitfield in our metadata.
 	currentBitSInMetadata := s.Metadata().SyncnetsBitfield()
 
-	// Is our sync bitvector record up to date?
 	isBitSUpToDate := bytes.Equal(bitS, inRecordBitS) && bytes.Equal(bitS, currentBitSInMetadata)
 
-	if metadataVersion == version.Altair && isBitVUpToDate && isBitSUpToDate {
+	// Compare current epoch with the Fulu fork epoch.
+	fuluForkEpoch := params.BeaconConfig().FuluForkEpoch
+
+	// We add `1` to the current epoch because we want to prepare one epoch before the Fulu fork.
+	if currentEpoch+1 < fuluForkEpoch {
+		// Altair behaviour.
+		if metadataVersion == version.Altair && isBitVUpToDate && isBitSUpToDate {
+			// Nothing to do, return early.
+			return
+		}
+
+		// Some data have changed, update our record and metadata.
+		s.updateSubnetRecordWithMetadataV2(bitV, bitS)
+
+		// Ping all peers to inform them of new metadata
+		s.pingPeersAndLogEnr()
+
+		return
+	}
+
+	// Get the current custody group count.
+	custodyGroupCount := s.cfg.CustodyInfo.ActualGroupCount()
+
+	// Get the custody group count we store in our record.
+	inRecordCustodyGroupCount, err := peerdas.CustodyGroupCountFromRecord(record)
+	if err != nil {
+		log.WithError(err).Error("Could not retrieve custody subnet count")
+		return
+	}
+
+	// Get the custody group count in our metadata.
+	inMetadataCustodyGroupCount := s.Metadata().CustodyGroupCount()
+
+	isCustodyGroupCountUpToDate := (custodyGroupCount == inRecordCustodyGroupCount && custodyGroupCount == inMetadataCustodyGroupCount)
+
+	if isBitVUpToDate && isBitSUpToDate && isCustodyGroupCountUpToDate {
 		// Nothing to do, return early.
 		return
 	}
 
-	// Some data have changed, update our record and metadata.
-	s.updateSubnetRecordWithMetadataV2(bitV, bitS)
+	// Some data changed. Update the record and the metadata.
+	s.updateSubnetRecordWithMetadataV3(bitV, bitS, custodyGroupCount)
 
-	// Ping all peers to inform them of new metadata
+	// Ping all peers.
 	s.pingPeersAndLogEnr()
 }
 
@@ -458,6 +494,11 @@ func (s *Service) createLocalNode(
 		localNode.Set(quicEntry)
 	}
 
+	if params.FuluEnabled() {
+		custodyGroupCount := s.cfg.CustodyInfo.ActualGroupCount()
+		localNode.Set(peerdas.Cgc(custodyGroupCount))
+	}
+
 	localNode.SetFallbackIP(ipAddr)
 	localNode.SetFallbackUDP(udpPort)
 

beacon-chain/p2p/discovery_test.go

@@ -16,6 +16,7 @@ import (
 
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/peerdata"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
@@ -140,6 +141,15 @@ func TestStartDiscV5_DiscoverAllPeers(t *testing.T) {
 
 func TestCreateLocalNode(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
+
+	// Set the fulu fork epoch to something other than the far future epoch.
+	initFuluForkEpoch := params.BeaconConfig().FuluForkEpoch
+	params.BeaconConfig().FuluForkEpoch = 42
+
+	defer func() {
+		params.BeaconConfig().FuluForkEpoch = initFuluForkEpoch
+	}()
+
 	testCases := []struct {
 		name          string
 		cfg           *Config
@@ -147,30 +157,31 @@ func TestCreateLocalNode(t *testing.T) {
 	}{
 		{
 			name:          "valid config",
-			cfg:           nil,
+			cfg:           &Config{CustodyInfo: &peerdas.CustodyInfo{}},
 			expectedError: false,
 		},
 		{
 			name:          "invalid host address",
-			cfg:           &Config{HostAddress: "invalid"},
+			cfg:           &Config{HostAddress: "invalid", CustodyInfo: &peerdas.CustodyInfo{}},
 			expectedError: true,
 		},
 		{
 			name:          "valid host address",
-			cfg:           &Config{HostAddress: "192.168.0.1"},
+			cfg:           &Config{HostAddress: "192.168.0.1", CustodyInfo: &peerdas.CustodyInfo{}},
 			expectedError: false,
 		},
 		{
 			name:          "invalid host DNS",
-			cfg:           &Config{HostDNS: "invalid"},
+			cfg:           &Config{HostDNS: "invalid", CustodyInfo: &peerdas.CustodyInfo{}},
 			expectedError: true,
 		},
 		{
 			name:          "valid host DNS",
-			cfg:           &Config{HostDNS: "www.google.com"},
+			cfg:           &Config{HostDNS: "www.google.com", CustodyInfo: &peerdas.CustodyInfo{}},
 			expectedError: false,
 		},
 	}
+
 	for _, tt := range testCases {
 		t.Run(tt.name, func(t *testing.T) {
 			// Define ports.
@@ -199,7 +210,7 @@ func TestCreateLocalNode(t *testing.T) {
 			require.NoError(t, err)
 
 			expectedAddress := address
-			if tt.cfg != nil && tt.cfg.HostAddress != "" {
+			if tt.cfg.HostAddress != "" {
 				expectedAddress = net.ParseIP(tt.cfg.HostAddress)
 			}
 
@@ -236,6 +247,11 @@ func TestCreateLocalNode(t *testing.T) {
 			syncSubnets := new([]byte)
 			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(syncCommsSubnetEnrKey, syncSubnets)))
 			require.DeepSSZEqual(t, []byte{0}, *syncSubnets)
+
+			// Check cgc config.
+			custodyGroupCount := new(uint64)
+			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(peerdas.CustodyGroupCountEnrKey, custodyGroupCount)))
+			require.Equal(t, params.BeaconConfig().CustodyRequirement, *custodyGroupCount)
 		})
 	}
 }
@@ -535,7 +551,7 @@ type check struct {
 	metadataSequenceNumber uint64
 	attestationSubnets     []uint64
 	syncSubnets            []uint64
-	custodySubnetCount     *uint64
+	custodyGroupCount      *uint64
 }
 
 func checkPingCountCacheMetadataRecord(
@@ -601,6 +617,18 @@ func checkPingCountCacheMetadataRecord(
 		actualBitSMetadata := service.metaData.SyncnetsBitfield()
 		require.DeepSSZEqual(t, expectedBitS, actualBitSMetadata)
 	}
+
+	if expected.custodyGroupCount != nil {
+		// Check custody subnet count in ENR.
+		var actualCustodyGroupCount uint64
+		err := service.dv5Listener.LocalNode().Node().Record().Load(enr.WithEntry(peerdas.CustodyGroupCountEnrKey, &actualCustodyGroupCount))
+		require.NoError(t, err)
+		require.Equal(t, *expected.custodyGroupCount, actualCustodyGroupCount)
+
+		// Check custody subnet count in metadata.
+		actualGroupCountMetadata := service.metaData.CustodyGroupCount()
+		require.Equal(t, *expected.custodyGroupCount, actualGroupCountMetadata)
+	}
 }
 
 func TestRefreshPersistentSubnets(t *testing.T) {
@@ -610,12 +638,18 @@ func TestRefreshPersistentSubnets(t *testing.T) {
 	defer cache.SubnetIDs.EmptyAllCaches()
 	defer cache.SyncSubnetIDs.EmptyAllCaches()
 
-	const altairForkEpoch = 5
+	const (
+		altairForkEpoch = 5
+		fuluForkEpoch   = 10
+	)
+
+	custodyGroupCount := params.BeaconConfig().CustodyRequirement
 
 	// Set up epochs.
 	defaultCfg := params.BeaconConfig()
 	cfg := defaultCfg.Copy()
 	cfg.AltairForkEpoch = altairForkEpoch
+	cfg.FuluForkEpoch = fuluForkEpoch
 	params.OverrideBeaconConfig(cfg)
 
 	// Compute the number of seconds per epoch.
@@ -684,6 +718,39 @@ func TestRefreshPersistentSubnets(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:              "Fulu",
+			epochSinceGenesis: fuluForkEpoch,
+			checks: []check{
+				{
+					pingCount:              0,
+					metadataSequenceNumber: 0,
+					attestationSubnets:     []uint64{},
+					syncSubnets:            nil,
+				},
+				{
+					pingCount:              1,
+					metadataSequenceNumber: 1,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            nil,
+					custodyGroupCount:      &custodyGroupCount,
+				},
+				{
+					pingCount:              2,
+					metadataSequenceNumber: 2,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            []uint64{1, 2},
+					custodyGroupCount:      &custodyGroupCount,
+				},
+				{
+					pingCount:              2,
+					metadataSequenceNumber: 2,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            []uint64{1, 2},
+					custodyGroupCount:      &custodyGroupCount,
+				},
+			},
+		},
 	}
 
 	for _, tc := range testCases {
@@ -717,7 +784,7 @@ func TestRefreshPersistentSubnets(t *testing.T) {
 					actualPingCount++
 					return nil
 				},
-				cfg:                   &Config{UDPPort: 2000},
+				cfg:                   &Config{UDPPort: 2000, CustodyInfo: &peerdas.CustodyInfo{}},
 				peers:                 p2p.Peers(),
 				genesisTime:           time.Now().Add(-time.Duration(tc.epochSinceGenesis*secondsPerEpoch) * time.Second),
 				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),

beacon-chain/p2p/gossip_scoring_params.go

@@ -127,7 +127,7 @@ func (s *Service) topicScoreParams(topic string) (*pubsub.TopicScoreParams, erro
 		return defaultAttesterSlashingTopicParams(), nil
 	case strings.Contains(topic, GossipBlsToExecutionChangeMessage):
 		return defaultBlsToExecutionChangeTopicParams(), nil
-	case strings.Contains(topic, GossipBlobSidecarMessage):
+	case strings.Contains(topic, GossipBlobSidecarMessage), strings.Contains(topic, GossipDataColumnSidecarMessage):
 		// TODO(Deneb): Using the default block scoring. But this should be updated.
 		return defaultBlockTopicParams(), nil
 	case strings.Contains(topic, GossipLightClientOptimisticUpdateMessage):

beacon-chain/p2p/gossip_topic_mappings.go

@@ -24,6 +24,7 @@ var gossipTopicMappings = map[string]func() proto.Message{
 	BlobSubnetTopicFormat:                     func() proto.Message { return &ethpb.BlobSidecar{} },
 	LightClientOptimisticUpdateTopicFormat:    func() proto.Message { return &ethpb.LightClientOptimisticUpdateAltair{} },
 	LightClientFinalityUpdateTopicFormat:      func() proto.Message { return &ethpb.LightClientFinalityUpdateAltair{} },
+	DataColumnSubnetTopicFormat:               func() proto.Message { return &ethpb.DataColumnSidecar{} },
 }
 
 // GossipTopicMappings is a function to return the assigned data type

beacon-chain/p2p/handshake.go

@@ -22,7 +22,9 @@ const (
 )
 
 func peerMultiaddrString(conn network.Conn) string {
-	return fmt.Sprintf("%s/p2p/%s", conn.RemoteMultiaddr().String(), conn.RemotePeer().String())
+	remoteMultiaddr := conn.RemoteMultiaddr().String()
+	remotePeerID := conn.RemotePeer().String()
+	return fmt.Sprintf("%s/p2p/%s", remoteMultiaddr, remotePeerID)
 }
 
 func (s *Service) connectToPeer(conn network.Conn) {

beacon-chain/p2p/interfaces.go

@@ -5,9 +5,11 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/connmgr"
@@ -29,6 +31,12 @@ type P2P interface {
 	ConnectionHandler
 	PeersProvider
 	MetadataProvider
+	DataColumnsHandler
+}
+
+type Acceser interface {
+	Broadcaster
+	PeerManager
 }
 
 // Broadcaster broadcasts messages to peers over the p2p pubsub protocol.
@@ -39,6 +47,7 @@ type Broadcaster interface {
 	BroadcastBlob(ctx context.Context, subnet uint64, blob *ethpb.BlobSidecar) error
 	BroadcastLightClientOptimisticUpdate(ctx context.Context, update interfaces.LightClientOptimisticUpdate) error
 	BroadcastLightClientFinalityUpdate(ctx context.Context, update interfaces.LightClientFinalityUpdate) error
+	BroadcastDataColumn(ctx context.Context, root [fieldparams.RootLength]byte, columnSubnet uint64, dataColumnSidecar *ethpb.DataColumnSidecar) error
 }
 
 // SetStreamHandler configures p2p to handle streams of a certain topic ID.
@@ -84,6 +93,7 @@ type PeerManager interface {
 	PeerID() peer.ID
 	Host() host.Host
 	ENR() *enr.Record
+	NodeID() enode.ID
 	DiscoveryAddresses() ([]multiaddr.Multiaddr, error)
 	RefreshPersistentSubnets()
 	FindPeersWithSubnet(ctx context.Context, topic string, subIndex uint64, threshold int) (bool, error)
@@ -105,3 +115,7 @@ type MetadataProvider interface {
 	Metadata() metadata.Metadata
 	MetadataSeq() uint64
 }
+
+type DataColumnsHandler interface {
+	CustodyGroupCountFromPeer(peer.ID) uint64
+}

beacon-chain/p2p/monitoring.go

@@ -60,17 +60,25 @@ var (
 			"the subnet. The beacon node increments this counter when the broadcast is blocked " +
 			"until a subnet peer can be found.",
 	})
-	blobSidecarCommitteeBroadcasts = promauto.NewCounter(prometheus.CounterOpts{
+	blobSidecarBroadcasts = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "p2p_blob_sidecar_committee_broadcasts",
-		Help: "The number of blob sidecar committee messages that were broadcast with no peer on.",
+		Help: "The number of blob sidecar messages that were broadcast with no peer on.",
 	})
 	syncCommitteeBroadcastAttempts = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "p2p_sync_committee_subnet_attempted_broadcasts",
 		Help: "The number of sync committee that were attempted to be broadcast.",
 	})
-	blobSidecarCommitteeBroadcastAttempts = promauto.NewCounter(prometheus.CounterOpts{
+	blobSidecarBroadcastAttempts = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "p2p_blob_sidecar_committee_attempted_broadcasts",
-		Help: "The number of blob sidecar committee messages that were attempted to be broadcast.",
+		Help: "The number of blob sidecar messages that were attempted to be broadcast.",
+	})
+	dataColumnSidecarBroadcasts = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "p2p_data_column_sidecar_broadcasts",
+		Help: "The number of data column sidecar messages that were broadcasted.",
+	})
+	dataColumnSidecarBroadcastAttempts = promauto.NewCounter(prometheus.CounterOpts{
+		Name: "p2p_data_column_sidecar_attempted_broadcasts",
+		Help: "The number of data column sidecar messages that were attempted to be broadcast.",
 	})
 
 	// Gossip Tracer Metrics

beacon-chain/p2p/peers/scorers/bad_responses.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/peerdata"
 	"github.com/libp2p/go-libp2p/core/peer"
-	"github.com/pkg/errors"
 )
 
 var _ Scorer = (*BadResponsesScorer)(nil)
@@ -129,13 +128,14 @@ func (s *BadResponsesScorer) IsBadPeer(pid peer.ID) error {
 
 // isBadPeerNoLock is lock-free version of IsBadPeer.
 func (s *BadResponsesScorer) isBadPeerNoLock(pid peer.ID) error {
-	if peerData, ok := s.store.PeerData(pid); ok {
-		if peerData.BadResponses >= s.config.Threshold {
-			return errors.Errorf("peer exceeded bad responses threshold: got %d, threshold %d", peerData.BadResponses, s.config.Threshold)
-		}
+	// if peerData, ok := s.store.PeerData(pid); ok {
+	// TODO: Remote this out of devnet
+	// if peerData.BadResponses >= s.config.Threshold {
+	// return errors.Errorf("peer exceeded bad responses threshold: got %d, threshold %d", peerData.BadResponses, s.config.Threshold)
+	// }
 
-		return nil
-	}
+	// return nil
+	// }
 
 	return nil
 }

beacon-chain/p2p/peers/scorers/bad_responses_test.go

@@ -2,7 +2,6 @@ package scorers_test
 
 import (
 	"context"
-	"sort"
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
@@ -14,40 +13,41 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 )
 
-func TestScorers_BadResponses_Score(t *testing.T) {
-	const pid = "peer1"
+// TODO: Uncomment when out of devnet
+// func TestScorers_BadResponses_Score(t *testing.T) {
+// 	const pid = "peer1"
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+// 	ctx, cancel := context.WithCancel(context.Background())
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: 4,
-			},
-		},
-	})
-	scorer := peerStatuses.Scorers().BadResponsesScorer()
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: 4,
+// 			},
+// 		},
+// 	})
+// 	scorer := peerStatuses.Scorers().BadResponsesScorer()
 
-	assert.Equal(t, 0., scorer.Score(pid), "Unexpected score for unregistered peer")
+// 	assert.Equal(t, 0., scorer.Score(pid), "Unexpected score for unregistered peer")
 
-	scorer.Increment(pid)
-	assert.NoError(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, -2.5, scorer.Score(pid))
+// 	scorer.Increment(pid)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, -2.5, scorer.Score(pid))
 
-	scorer.Increment(pid)
-	assert.NoError(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, float64(-5), scorer.Score(pid))
+// 	scorer.Increment(pid)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, float64(-5), scorer.Score(pid))
 
-	scorer.Increment(pid)
-	assert.NoError(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, float64(-7.5), scorer.Score(pid))
+// 	scorer.Increment(pid)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, float64(-7.5), scorer.Score(pid))
 
-	scorer.Increment(pid)
-	assert.NotNil(t, scorer.IsBadPeer(pid))
-	assert.Equal(t, -100.0, scorer.Score(pid))
-}
+// 	scorer.Increment(pid)
+// 	assert.NotNil(t, scorer.IsBadPeer(pid))
+// 	assert.Equal(t, -100.0, scorer.Score(pid))
+// }
 
 func TestScorers_BadResponses_ParamsThreshold(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
@@ -142,58 +142,60 @@ func TestScorers_BadResponses_Decay(t *testing.T) {
 	assert.Equal(t, 1, badResponses, "unexpected bad responses for pid3")
 }
 
-func TestScorers_BadResponses_IsBadPeer(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+// TODO: Uncomment when out of devnet
+// func TestScorers_BadResponses_IsBadPeer(t *testing.T) {
+// 	ctx, cancel := context.WithCancel(context.Background())
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit:    30,
-		ScorerParams: &scorers.Config{},
-	})
-	scorer := peerStatuses.Scorers().BadResponsesScorer()
-	pid := peer.ID("peer1")
-	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit:    30,
+// 		ScorerParams: &scorers.Config{},
+// 	})
+// 	scorer := peerStatuses.Scorers().BadResponsesScorer()
+// 	pid := peer.ID("peer1")
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
 
-	peerStatuses.Add(nil, pid, nil, network.DirUnknown)
-	assert.NoError(t, scorer.IsBadPeer(pid))
+// 	peerStatuses.Add(nil, pid, nil, network.DirUnknown)
+// 	assert.NoError(t, scorer.IsBadPeer(pid))
 
-	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
-		scorer.Increment(pid)
-		if i == scorers.DefaultBadResponsesThreshold-1 {
-			assert.NotNil(t, scorer.IsBadPeer(pid), "Unexpected peer status")
-		} else {
-			assert.NoError(t, scorer.IsBadPeer(pid), "Unexpected peer status")
-		}
-	}
-}
+// 	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
+// 		scorer.Increment(pid)
+// 		if i == scorers.DefaultBadResponsesThreshold-1 {
+// 			assert.NotNil(t, scorer.IsBadPeer(pid), "Unexpected peer status")
+// 		} else {
+// 			assert.NoError(t, scorer.IsBadPeer(pid), "Unexpected peer status")
+// 		}
+// 	}
+// }
 
-func TestScorers_BadResponses_BadPeers(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+// TODO: Uncomment when out of devnet
+// func TestScorers_BadResponses_BadPeers(t *testing.T) {
+// 	ctx, cancel := context.WithCancel(context.Background())
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit:    30,
-		ScorerParams: &scorers.Config{},
-	})
-	scorer := peerStatuses.Scorers().BadResponsesScorer()
-	pids := []peer.ID{peer.ID("peer1"), peer.ID("peer2"), peer.ID("peer3"), peer.ID("peer4"), peer.ID("peer5")}
-	for i := 0; i < len(pids); i++ {
-		peerStatuses.Add(nil, pids[i], nil, network.DirUnknown)
-	}
-	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
-		scorer.Increment(pids[1])
-		scorer.Increment(pids[2])
-		scorer.Increment(pids[4])
-	}
-	assert.NoError(t, scorer.IsBadPeer(pids[0]), "Invalid peer status")
-	assert.NotNil(t, scorer.IsBadPeer(pids[1]), "Invalid peer status")
-	assert.NotNil(t, scorer.IsBadPeer(pids[2]), "Invalid peer status")
-	assert.NoError(t, scorer.IsBadPeer(pids[3]), "Invalid peer status")
-	assert.NotNil(t, scorer.IsBadPeer(pids[4]), "Invalid peer status")
-	want := []peer.ID{pids[1], pids[2], pids[4]}
-	badPeers := scorer.BadPeers()
-	sort.Slice(badPeers, func(i, j int) bool {
-		return badPeers[i] < badPeers[j]
-	})
-	assert.DeepEqual(t, want, badPeers, "Unexpected list of bad peers")
-}
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit:    30,
+// 		ScorerParams: &scorers.Config{},
+// 	})
+// 	scorer := peerStatuses.Scorers().BadResponsesScorer()
+// 	pids := []peer.ID{peer.ID("peer1"), peer.ID("peer2"), peer.ID("peer3"), peer.ID("peer4"), peer.ID("peer5")}
+// 	for i := 0; i < len(pids); i++ {
+// 		peerStatuses.Add(nil, pids[i], nil, network.DirUnknown)
+// 	}
+// 	for i := 0; i < scorers.DefaultBadResponsesThreshold; i++ {
+// 		scorer.Increment(pids[1])
+// 		scorer.Increment(pids[2])
+// 		scorer.Increment(pids[4])
+// 	}
+// 	assert.NoError(t, scorer.IsBadPeer(pids[0]), "Invalid peer status")
+// 	assert.NotNil(t, scorer.IsBadPeer(pids[1]), "Invalid peer status")
+// 	assert.NotNil(t, scorer.IsBadPeer(pids[2]), "Invalid peer status")
+// 	assert.NoError(t, scorer.IsBadPeer(pids[3]), "Invalid peer status")
+// 	assert.NotNil(t, scorer.IsBadPeer(pids[4]), "Invalid peer status")
+// 	want := []peer.ID{pids[1], pids[2], pids[4]}
+// 	badPeers := scorer.BadPeers()
+// 	sort.Slice(badPeers, func(i, j int) bool {
+// 		return badPeers[i] < badPeers[j]
+// 	})
+// 	assert.DeepEqual(t, want, badPeers, "Unexpected list of bad peers")
+// }

beacon-chain/p2p/peers/scorers/gossip_scorer_test.go

@@ -44,7 +44,7 @@ func TestScorers_Gossip_Score(t *testing.T) {
 			},
 			check: func(scorer *scorers.GossipScorer) {
 				assert.Equal(t, 10.0, scorer.Score("peer1"), "Unexpected score")
-				assert.Equal(t, nil, scorer.IsBadPeer("peer1"), "Unexpected bad peer")
+				assert.NoError(t, scorer.IsBadPeer("peer1"), "Unexpected bad peer")
 				_, _, topicMap, err := scorer.GossipData("peer1")
 				assert.NoError(t, err)
 				assert.Equal(t, uint64(100), topicMap["a"].TimeInMesh, "incorrect time in mesh")

beacon-chain/p2p/peers/scorers/service_test.go

@@ -212,99 +212,102 @@ func TestScorers_Service_Score(t *testing.T) {
 	})
 }
 
-func TestScorers_Service_loop(t *testing.T) {
-	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
-	defer cancel()
+// TODO: Uncomment when out of devnet
+// func TestScorers_Service_loop(t *testing.T) {
+// 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+// 	defer cancel()
 
-	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold:     5,
-				DecayInterval: 50 * time.Millisecond,
-			},
-			BlockProviderScorerConfig: &scorers.BlockProviderScorerConfig{
-				DecayInterval: 25 * time.Millisecond,
-				Decay:         64,
-			},
-		},
-	})
-	s1 := peerStatuses.Scorers().BadResponsesScorer()
-	s2 := peerStatuses.Scorers().BlockProviderScorer()
+// 	peerStatuses := peers.NewStatus(ctx, &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold:     5,
+// 				DecayInterval: 50 * time.Millisecond,
+// 			},
+// 			BlockProviderScorerConfig: &scorers.BlockProviderScorerConfig{
+// 				DecayInterval: 25 * time.Millisecond,
+// 				Decay:         64,
+// 			},
+// 		},
+// 	})
+// 	s1 := peerStatuses.Scorers().BadResponsesScorer()
+// 	s2 := peerStatuses.Scorers().BlockProviderScorer()
 
-	pid1 := peer.ID("peer1")
-	peerStatuses.Add(nil, pid1, nil, network.DirUnknown)
-	for i := 0; i < s1.Params().Threshold+5; i++ {
-		s1.Increment(pid1)
-	}
-	assert.NotNil(t, s1.IsBadPeer(pid1), "Peer should be marked as bad")
+// 	pid1 := peer.ID("peer1")
+// 	peerStatuses.Add(nil, pid1, nil, network.DirUnknown)
+// 	for i := 0; i < s1.Params().Threshold+5; i++ {
+// 		s1.Increment(pid1)
+// 	}
+// 	assert.NotNil(t, s1.IsBadPeer(pid1), "Peer should be marked as bad")
 
-	s2.IncrementProcessedBlocks("peer1", 221)
-	assert.Equal(t, uint64(221), s2.ProcessedBlocks("peer1"))
+// 	s2.IncrementProcessedBlocks("peer1", 221)
+// 	assert.Equal(t, uint64(221), s2.ProcessedBlocks("peer1"))
 
-	done := make(chan struct{}, 1)
-	go func() {
-		defer func() {
-			done <- struct{}{}
-		}()
-		ticker := time.NewTicker(50 * time.Millisecond)
-		defer ticker.Stop()
-		for {
-			select {
-			case <-ticker.C:
-				if s1.IsBadPeer(pid1) == nil && s2.ProcessedBlocks("peer1") == 0 {
-					return
-				}
-			case <-ctx.Done():
-				t.Error("Timed out")
-				return
-			}
-		}
-	}()
+// 	done := make(chan struct{}, 1)
+// 	go func() {
+// 		defer func() {
+// 			done <- struct{}{}
+// 		}()
+// 		ticker := time.NewTicker(50 * time.Millisecond)
+// 		defer ticker.Stop()
+// 		for {
+// 			select {
+// 			case <-ticker.C:
+// 				if s1.IsBadPeer(pid1) == nil && s2.ProcessedBlocks("peer1") == 0 {
+// 					return
+// 				}
+// 			case <-ctx.Done():
+// 				t.Error("Timed out")
+// 				return
+// 			}
+// 		}
+// 	}()
 
-	<-done
-	assert.NoError(t, s1.IsBadPeer(pid1), "Peer should not be marked as bad")
-	assert.Equal(t, uint64(0), s2.ProcessedBlocks("peer1"), "No blocks are expected")
-}
+// 	<-done
+// 	assert.NoError(t, s1.IsBadPeer(pid1), "Peer should not be marked as bad")
+// 	assert.Equal(t, uint64(0), s2.ProcessedBlocks("peer1"), "No blocks are expected")
+// }
 
-func TestScorers_Service_IsBadPeer(t *testing.T) {
-	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold:     2,
-				DecayInterval: 50 * time.Second,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestScorers_Service_IsBadPeer(t *testing.T) {
+// 	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold:     2,
+// 				DecayInterval: 50 * time.Second,
+// 			},
+// 		},
+// 	})
 
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
-	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
-	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-}
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// 	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
+// 	peerStatuses.Scorers().BadResponsesScorer().Increment("peer1")
+// 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// }
 
-func TestScorers_Service_BadPeers(t *testing.T) {
-	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold:     2,
-				DecayInterval: 50 * time.Second,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestScorers_Service_BadPeers(t *testing.T) {
+// 	peerStatuses := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold:     2,
+// 				DecayInterval: 50 * time.Second,
+// 			},
+// 		},
+// 	})
 
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer3"))
-	assert.Equal(t, 0, len(peerStatuses.Scorers().BadPeers()))
-	for _, pid := range []peer.ID{"peer1", "peer3"} {
-		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
-		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
-	}
-	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
-	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
-	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer3"))
-	assert.Equal(t, 2, len(peerStatuses.Scorers().BadPeers()))
-}
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer3"))
+// 	assert.Equal(t, 0, len(peerStatuses.Scorers().BadPeers()))
+// 	for _, pid := range []peer.ID{"peer1", "peer3"} {
+// 		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
+// 		peerStatuses.Scorers().BadResponsesScorer().Increment(pid)
+// 	}
+// 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer1"))
+// 	assert.NoError(t, peerStatuses.Scorers().IsBadPeer("peer2"))
+// 	assert.NotNil(t, peerStatuses.Scorers().IsBadPeer("peer3"))
+// 	assert.Equal(t, 2, len(peerStatuses.Scorers().BadPeers()))
+// }

beacon-chain/p2p/peers/status.go

@@ -705,31 +705,47 @@ func (p *Status) deprecatedPrune() {
 	p.tallyIPTracker()
 }
 
-// BestFinalized returns the highest finalized epoch equal to or higher than ours that is agreed
-// upon by the majority of peers. This method may not return the absolute highest finalized, but
-// the finalized epoch in which most peers can serve blocks (plurality voting).
-// Ideally, all peers would be reporting the same finalized epoch but some may be behind due to their
-// own latency, or because of their finalized epoch at the time we queried them.
-// Returns epoch number and list of peers that are at or beyond that epoch.
+// BestFinalized returns the highest finalized epoch equal to or higher than `ourFinalizedEpoch`
+// that is agreed upon by the majority of peers, and the peers agreeing on this finalized epoch.
+// This method may not return the absolute highest finalized epoch, but the finalized epoch in which
+// most peers can serve blocks (plurality voting). Ideally, all peers would be reporting the same
+// finalized epoch but some may be behind due to their own latency, or because of their finalized
+// epoch at the time we queried them. Returns epoch number and list of peers that are at or beyond
+// that epoch.
 func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch) (primitives.Epoch, []peer.ID) {
+	// Retrieve all connected peers.
 	connected := p.Connected()
+
+	// key: finalized epoch, value: number of peers that support this finalized epoch.
 	finalizedEpochVotes := make(map[primitives.Epoch]uint64)
+
+	// key: peer ID, value: finalized epoch of the peer.
 	pidEpoch := make(map[peer.ID]primitives.Epoch, len(connected))
+
+	// key: peer ID, value: head slot of the peer.
 	pidHead := make(map[peer.ID]primitives.Slot, len(connected))
+
 	potentialPIDs := make([]peer.ID, 0, len(connected))
 	for _, pid := range connected {
 		peerChainState, err := p.ChainState(pid)
-		if err == nil && peerChainState != nil && peerChainState.FinalizedEpoch >= ourFinalizedEpoch {
-			finalizedEpochVotes[peerChainState.FinalizedEpoch]++
-			pidEpoch[pid] = peerChainState.FinalizedEpoch
-			potentialPIDs = append(potentialPIDs, pid)
-			pidHead[pid] = peerChainState.HeadSlot
+
+		// Skip if the peer's finalized epoch is not defined, or if the peer's finalized epoch is
+		// lower than ours.
+		if err != nil || peerChainState == nil || peerChainState.FinalizedEpoch < ourFinalizedEpoch {
+			continue
 		}
+
+		finalizedEpochVotes[peerChainState.FinalizedEpoch]++
+
+		pidEpoch[pid] = peerChainState.FinalizedEpoch
+		pidHead[pid] = peerChainState.HeadSlot
+
+		potentialPIDs = append(potentialPIDs, pid)
 	}
 
 	// Select the target epoch, which is the epoch most peers agree upon.
-	var targetEpoch primitives.Epoch
-	var mostVotes uint64
+	// If there is a tie, select the highest epoch.
+	targetEpoch, mostVotes := primitives.Epoch(0), uint64(0)
 	for epoch, count := range finalizedEpochVotes {
 		if count > mostVotes || (count == mostVotes && epoch > targetEpoch) {
 			mostVotes = count
@@ -737,11 +753,12 @@ func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch)
 		}
 	}
 
-	// Sort PIDs by finalized epoch, in decreasing order.
+	// Sort PIDs by finalized (epoch, head), in decreasing order.
 	sort.Slice(potentialPIDs, func(i, j int) bool {
 		if pidEpoch[potentialPIDs[i]] == pidEpoch[potentialPIDs[j]] {
 			return pidHead[potentialPIDs[i]] > pidHead[potentialPIDs[j]]
 		}
+
 		return pidEpoch[potentialPIDs[i]] > pidEpoch[potentialPIDs[j]]
 	})
 
@@ -764,26 +781,42 @@ func (p *Status) BestFinalized(maxPeers int, ourFinalizedEpoch primitives.Epoch)
 // BestNonFinalized returns the highest known epoch, higher than ours,
 // and is shared by at least minPeers.
 func (p *Status) BestNonFinalized(minPeers int, ourHeadEpoch primitives.Epoch) (primitives.Epoch, []peer.ID) {
+	// Retrieve all connected peers.
 	connected := p.Connected()
+
+	// Calculate our head slot.
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	ourHeadSlot := slotsPerEpoch.Mul(uint64(ourHeadEpoch))
+
+	// key: head epoch, value: number of peers that support this epoch.
 	epochVotes := make(map[primitives.Epoch]uint64)
+
+	// key: peer ID, value: head epoch of the peer.
 	pidEpoch := make(map[peer.ID]primitives.Epoch, len(connected))
+
+	// key: peer ID, value: head slot of the peer.
 	pidHead := make(map[peer.ID]primitives.Slot, len(connected))
+
 	potentialPIDs := make([]peer.ID, 0, len(connected))
 
-	ourHeadSlot := params.BeaconConfig().SlotsPerEpoch.Mul(uint64(ourHeadEpoch))
 	for _, pid := range connected {
 		peerChainState, err := p.ChainState(pid)
-		if err == nil && peerChainState != nil && peerChainState.HeadSlot > ourHeadSlot {
-			epoch := slots.ToEpoch(peerChainState.HeadSlot)
-			epochVotes[epoch]++
-			pidEpoch[pid] = epoch
-			pidHead[pid] = peerChainState.HeadSlot
-			potentialPIDs = append(potentialPIDs, pid)
+		// Skip if the peer's head epoch is not defined, or if the peer's head slot is
+		// lower or equal than ours.
+		if err != nil || peerChainState == nil || peerChainState.HeadSlot <= ourHeadSlot {
+			continue
 		}
+
+		epoch := slots.ToEpoch(peerChainState.HeadSlot)
+
+		epochVotes[epoch]++
+		pidEpoch[pid] = epoch
+		pidHead[pid] = peerChainState.HeadSlot
+		potentialPIDs = append(potentialPIDs, pid)
 	}
 
 	// Select the target epoch, which has enough peers' votes (>= minPeers).
-	var targetEpoch primitives.Epoch
+	targetEpoch := primitives.Epoch(0)
 	for epoch, votes := range epochVotes {
 		if votes >= uint64(minPeers) && targetEpoch < epoch {
 			targetEpoch = epoch
@@ -1012,16 +1045,23 @@ func (p *Status) isfromBadIP(pid peer.ID) error {
 		return nil
 	}
 
-	ip, err := manet.ToIP(peerData.Address)
-	if err != nil {
-		return errors.Wrap(err, "to ip")
-	}
+	// ip, err := manet.ToIP(peerData.Address)
+	// if err != nil {
+	// 	return errors.Wrap(err, "to ip")
+	// }
 
-	if val, ok := p.ipTracker[ip.String()]; ok {
-		if val > CollocationLimit {
-			return errors.Errorf("collocation limit exceeded: got %d - limit %d", val, CollocationLimit)
-		}
-	}
+	// if val, ok := p.ipTracker[ip.String()]; ok {
+	// if val > CollocationLimit {
+	// TODO: Remove this out of denvet.
+	// return errors.Errorf("colocation limit exceeded: got %d - limit %d", val, CollocationLimit)
+	// log.WithFields(logrus.Fields{
+	// 	"pid":             pid,
+	// 	"ip":              ip.String(),
+	// 	"colocationCount": val,
+	// 	"colocationLimit": CollocationLimit,
+	// }).Debug("Colocation limit exceeded. Peer should be banned.")
+	// }
+	// }
 
 	return nil
 }

beacon-chain/p2p/peers/status_test.go

@@ -3,7 +3,6 @@ package peers_test
 import (
 	"context"
 	"crypto/rand"
-	"strconv"
 	"testing"
 	"time"
 
@@ -329,55 +328,56 @@ func TestPeerWithNilChainState(t *testing.T) {
 	require.Equal(t, resChainState, nothing)
 }
 
-func TestPeerBadResponses(t *testing.T) {
-	maxBadResponses := 2
-	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: maxBadResponses,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestPeerBadResponses(t *testing.T) {
+// 	maxBadResponses := 2
+// 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: maxBadResponses,
+// 			},
+// 		},
+// 	})
 
-	id, err := peer.Decode("16Uiu2HAkyWZ4Ni1TpvDS8dPxsozmHY85KaiFjodQuV6Tz5tkHVeR")
-	require.NoError(t, err)
-	{
-		_, err := id.MarshalBinary()
-		require.NoError(t, err)
-	}
+// 	id, err := peer.Decode("16Uiu2HAkyWZ4Ni1TpvDS8dPxsozmHY85KaiFjodQuV6Tz5tkHVeR")
+// 	require.NoError(t, err)
+// 	{
+// 		_, err := id.MarshalBinary()
+// 		require.NoError(t, err)
+// 	}
 
-	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
+// 	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
 
-	address, err := ma.NewMultiaddr("/ip4/213.202.254.180/tcp/13000")
-	require.NoError(t, err, "Failed to create address")
-	direction := network.DirInbound
-	p.Add(new(enr.Record), id, address, direction)
+// 	address, err := ma.NewMultiaddr("/ip4/213.202.254.180/tcp/13000")
+// 	require.NoError(t, err, "Failed to create address")
+// 	direction := network.DirInbound
+// 	p.Add(new(enr.Record), id, address, direction)
 
-	scorer := p.Scorers().BadResponsesScorer()
-	resBadResponses, err := scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 0, resBadResponses, "Unexpected bad responses")
-	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
+// 	scorer := p.Scorers().BadResponsesScorer()
+// 	resBadResponses, err := scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 0, resBadResponses, "Unexpected bad responses")
+// 	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
 
-	scorer.Increment(id)
-	resBadResponses, err = scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 1, resBadResponses, "Unexpected bad responses")
-	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
+// 	scorer.Increment(id)
+// 	resBadResponses, err = scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 1, resBadResponses, "Unexpected bad responses")
+// 	assert.NoError(t, p.IsBad(id), "Peer marked as bad when should be good")
 
-	scorer.Increment(id)
-	resBadResponses, err = scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 2, resBadResponses, "Unexpected bad responses")
-	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
+// 	scorer.Increment(id)
+// 	resBadResponses, err = scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 2, resBadResponses, "Unexpected bad responses")
+// 	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
 
-	scorer.Increment(id)
-	resBadResponses, err = scorer.Count(id)
-	require.NoError(t, err)
-	assert.Equal(t, 3, resBadResponses, "Unexpected bad responses")
-	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
-}
+// 	scorer.Increment(id)
+// 	resBadResponses, err = scorer.Count(id)
+// 	require.NoError(t, err)
+// 	assert.Equal(t, 3, resBadResponses, "Unexpected bad responses")
+// 	assert.NotNil(t, p.IsBad(id), "Peer not marked as bad when it should be")
+// }
 
 func TestAddMetaData(t *testing.T) {
 	maxBadResponses := 2
@@ -496,100 +496,102 @@ func TestPeerValidTime(t *testing.T) {
 	assert.Equal(t, numPeersConnected, len(p.Connected()), "Unexpected number of connected peers")
 }
 
-func TestPrune(t *testing.T) {
-	maxBadResponses := 2
-	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: maxBadResponses,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestPrune(t *testing.T) {
+// 	maxBadResponses := 2
+// 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: maxBadResponses,
+// 			},
+// 		},
+// 	})
 
-	for i := 0; i < p.MaxPeerLimit()+100; i++ {
-		if i%7 == 0 {
-			// Peer added as disconnected.
-			_ = addPeer(t, p, peers.Disconnected)
-		}
-		// Peer added to peer handler.
-		_ = addPeer(t, p, peers.Connected)
-	}
+// 	for i := 0; i < p.MaxPeerLimit()+100; i++ {
+// 		if i%7 == 0 {
+// 			// Peer added as disconnected.
+// 			_ = addPeer(t, p, peers.PeerDisconnected)
+// 		}
+// 		// Peer added to peer handler.
+// 		_ = addPeer(t, p, peers.PeerConnected)
+// 	}
 
-	disPeers := p.Disconnected()
-	firstPID := disPeers[0]
-	secondPID := disPeers[1]
-	thirdPID := disPeers[2]
+// 	disPeers := p.Disconnected()
+// 	firstPID := disPeers[0]
+// 	secondPID := disPeers[1]
+// 	thirdPID := disPeers[2]
 
-	scorer := p.Scorers().BadResponsesScorer()
+// 	scorer := p.Scorers().BadResponsesScorer()
 
-	// Make first peer a bad peer
-	scorer.Increment(firstPID)
-	scorer.Increment(firstPID)
+// 	// Make first peer a bad peer
+// 	scorer.Increment(firstPID)
+// 	scorer.Increment(firstPID)
 
-	// Add bad response for p2.
-	scorer.Increment(secondPID)
+// 	// Add bad response for p2.
+// 	scorer.Increment(secondPID)
 
-	// Prune peers
-	p.Prune()
+// 	// Prune peers
+// 	p.Prune()
 
-	// Bad peer is expected to still be kept in handler.
-	badRes, err := scorer.Count(firstPID)
-	assert.NoError(t, err, "error is supposed to be  nil")
-	assert.Equal(t, 2, badRes, "Did not get expected amount")
+// 	// Bad peer is expected to still be kept in handler.
+// 	badRes, err := scorer.Count(firstPID)
+// 	assert.NoError(t, err, "error is supposed to be  nil")
+// 	assert.Equal(t, 2, badRes, "Did not get expected amount")
 
-	// Not so good peer is pruned away so that we can reduce the
-	// total size of the handler.
-	_, err = scorer.Count(secondPID)
-	assert.ErrorContains(t, "peer unknown", err)
+// 	// Not so good peer is pruned away so that we can reduce the
+// 	// total size of the handler.
+// 	_, err = scorer.Count(secondPID)
+// 	assert.ErrorContains(t, "peer unknown", err)
 
-	// Last peer has been removed.
-	_, err = scorer.Count(thirdPID)
-	assert.ErrorContains(t, "peer unknown", err)
-}
+// 	// Last peer has been removed.
+// 	_, err = scorer.Count(thirdPID)
+// 	assert.ErrorContains(t, "peer unknown", err)
+// }
 
-func TestPeerIPTracker(t *testing.T) {
-	resetCfg := features.InitWithReset(&features.Flags{
-		EnablePeerScorer: false,
-	})
-	defer resetCfg()
-	maxBadResponses := 2
-	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
-		PeerLimit: 30,
-		ScorerParams: &scorers.Config{
-			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
-				Threshold: maxBadResponses,
-			},
-		},
-	})
+// TODO: Uncomment when out of devnet
+// func TestPeerIPTracker(t *testing.T) {
+// 	resetCfg := features.InitWithReset(&features.Flags{
+// 		EnablePeerScorer: false,
+// 	})
+// 	defer resetCfg()
+// 	maxBadResponses := 2
+// 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 		PeerLimit: 30,
+// 		ScorerParams: &scorers.Config{
+// 			BadResponsesScorerConfig: &scorers.BadResponsesScorerConfig{
+// 				Threshold: maxBadResponses,
+// 			},
+// 		},
+// 	})
 
-	badIP := "211.227.218.116"
-	var badPeers []peer.ID
-	for i := 0; i < peers.CollocationLimit+10; i++ {
-		port := strconv.Itoa(3000 + i)
-		addr, err := ma.NewMultiaddr("/ip4/" + badIP + "/tcp/" + port)
-		if err != nil {
-			t.Fatal(err)
-		}
-		badPeers = append(badPeers, createPeer(t, p, addr, network.DirUnknown, peerdata.ConnectionState(ethpb.ConnectionState_DISCONNECTED)))
-	}
-	for _, pr := range badPeers {
-		assert.NotNil(t, p.IsBad(pr), "peer with bad ip is not bad")
-	}
+// 	badIP := "211.227.218.116"
+// 	var badPeers []peer.ID
+// 	for i := 0; i < peers.CollocationLimit+10; i++ {
+// 		port := strconv.Itoa(3000 + i)
+// 		addr, err := ma.NewMultiaddr("/ip4/" + badIP + "/tcp/" + port)
+// 		if err != nil {
+// 			t.Fatal(err)
+// 		}
+// 		badPeers = append(badPeers, createPeer(t, p, addr, network.DirUnknown, peerdata.PeerConnectionState(ethpb.ConnectionState_DISCONNECTED)))
+// 	}
+// 	for _, pr := range badPeers {
+// 		assert.NotNil(t, p.IsBad(pr), "peer with bad ip is not bad")
+// 	}
 
-	// Add in bad peers, so that our records are trimmed out
-	// from the peer store.
-	for i := 0; i < p.MaxPeerLimit()+100; i++ {
-		// Peer added to peer handler.
-		pid := addPeer(t, p, peers.Disconnected)
-		p.Scorers().BadResponsesScorer().Increment(pid)
-	}
-	p.Prune()
+// 	// Add in bad peers, so that our records are trimmed out
+// 	// from the peer store.
+// 	for i := 0; i < p.MaxPeerLimit()+100; i++ {
+// 		// Peer added to peer handler.
+// 		pid := addPeer(t, p, peers.PeerDisconnected)
+// 		p.Scorers().BadResponsesScorer().Increment(pid)
+// 	}
+// 	p.Prune()
 
-	for _, pr := range badPeers {
-		assert.NoError(t, p.IsBad(pr), "peer with good ip is regarded as bad")
-	}
-}
+// 	for _, pr := range badPeers {
+// 		assert.NoError(t, p.IsBad(pr), "peer with good ip is regarded as bad")
+// 	}
+// }
 
 func TestTrimmedOrderedPeers(t *testing.T) {
 	p := peers.NewStatus(context.Background(), &peers.StatusConfig{

beacon-chain/p2p/pubsub_filter.go

@@ -26,10 +26,11 @@ var _ pubsub.SubscriptionFilter = (*Service)(nil)
 // -> SyncContributionAndProof * 2 = 2
 // -> 4 SyncCommitteeSubnets   * 2 = 8
 // -> BlsToExecutionChange     * 2 = 2
-// -> 6 BlobSidecar            * 2 = 12
+// -> 128 DataColumnSidecar    * 2 = 256
 // -------------------------------------
-// TOTAL                           = 162
-const pubsubSubscriptionRequestLimit = 200
+// TOTAL                           = 406
+// (Note: BlobSidecar is not included in this list since it is superseded by DataColumnSidecar)
+const pubsubSubscriptionRequestLimit = 500
 
 // CanSubscribe returns true if the topic is of interest and we could subscribe to it.
 func (s *Service) CanSubscribe(topic string) bool {

beacon-chain/p2p/pubsub_filter_test.go

@@ -90,7 +90,7 @@ func TestService_CanSubscribe(t *testing.T) {
 		formatting := []interface{}{digest}
 
 		// Special case for attestation subnets which have a second formatting placeholder.
-		if topic == AttestationSubnetTopicFormat || topic == SyncCommitteeSubnetTopicFormat || topic == BlobSubnetTopicFormat {
+		if topic == AttestationSubnetTopicFormat || topic == SyncCommitteeSubnetTopicFormat || topic == BlobSubnetTopicFormat || topic == DataColumnSubnetTopicFormat {
 			formatting = append(formatting, 0 /* some subnet ID */)
 		}
 

beacon-chain/p2p/rpc_topic_mappings.go

@@ -10,11 +10,16 @@ import (
 	"github.com/pkg/errors"
 )
 
-// SchemaVersionV1 specifies the schema version for our rpc protocol ID.
-const SchemaVersionV1 = "/1"
+const (
+	// SchemaVersionV1 specifies the schema version for our rpc protocol ID.
+	SchemaVersionV1 = "/1"
 
-// SchemaVersionV2 specifies the next schema version for our rpc protocol ID.
-const SchemaVersionV2 = "/2"
+	// SchemaVersionV2 specifies the next schema version for our rpc protocol ID.
+	SchemaVersionV2 = "/2"
+
+	// SchemaVersionV3 specifies the next schema version for our rpc protocol ID.
+	SchemaVersionV3 = "/3"
+)
 
 // Specifies the protocol prefix for all our Req/Resp topics.
 const protocolPrefix = "/eth2/beacon_chain/req"
@@ -43,6 +48,12 @@ const BlobSidecarsByRangeName = "/blob_sidecars_by_range"
 // BlobSidecarsByRootName is the name for the BlobSidecarsByRoot v1 message topic.
 const BlobSidecarsByRootName = "/blob_sidecars_by_root"
 
+// DataColumnSidecarsByRootName is the name for the DataColumnSidecarsByRoot v1 message topic.
+const DataColumnSidecarsByRootName = "/data_column_sidecars_by_root"
+
+// DataColumnSidecarsByRangeName is the name for the DataColumnSidecarsByRange v1 message topic.
+const DataColumnSidecarsByRangeName = "/data_column_sidecars_by_range"
+
 const (
 	// V1 RPC Topics
 	// RPCStatusTopicV1 defines the v1 topic for the status rpc method.
@@ -60,11 +71,17 @@ const (
 
 	// RPCBlobSidecarsByRangeTopicV1 is a topic for requesting blob sidecars
 	// in the slot range [start_slot, start_slot + count), leading up to the current head block as selected by fork choice.
-	// Protocol ID: /eth2/beacon_chain/req/blob_sidecars_by_range/1/ - New in deneb.
+	// /eth2/beacon_chain/req/blob_sidecars_by_range/1/ - New in deneb.
 	RPCBlobSidecarsByRangeTopicV1 = protocolPrefix + BlobSidecarsByRangeName + SchemaVersionV1
-	// RPCBlobSidecarsByRootTopicV1 is a topic for requesting blob sidecars by their block root. New in deneb.
-	// /eth2/beacon_chain/req/blob_sidecars_by_root/1/
+	// RPCBlobSidecarsByRootTopicV1 is a topic for requesting blob sidecars by their block root.
+	// /eth2/beacon_chain/req/blob_sidecars_by_root/1/ - New in deneb.
 	RPCBlobSidecarsByRootTopicV1 = protocolPrefix + BlobSidecarsByRootName + SchemaVersionV1
+	// RPCDataColumnSidecarsByRootTopicV1 is a topic for requesting data column sidecars by their block root.
+	// /eth2/beacon_chain/req/data_column_sidecars_by_root/1 - New in Fulu.
+	RPCDataColumnSidecarsByRootTopicV1 = protocolPrefix + DataColumnSidecarsByRootName + SchemaVersionV1
+	// RPCDataColumnSidecarsByRangeTopicV1 is a topic for requesting data column sidecars by their slot.
+	// /eth2/beacon_chain/req/data_column_sidecars_by_range/1 - New in Fulu.
+	RPCDataColumnSidecarsByRangeTopicV1 = protocolPrefix + DataColumnSidecarsByRangeName + SchemaVersionV1
 
 	// V2 RPC Topics
 	// RPCBlocksByRangeTopicV2 defines v2 the topic for the blocks by range rpc method.
@@ -73,6 +90,10 @@ const (
 	RPCBlocksByRootTopicV2 = protocolPrefix + BeaconBlocksByRootsMessageName + SchemaVersionV2
 	// RPCMetaDataTopicV2 defines the v2 topic for the metadata rpc method.
 	RPCMetaDataTopicV2 = protocolPrefix + MetadataMessageName + SchemaVersionV2
+
+	// V3 RPC Topics
+	// RPCMetaDataTopicV3 defines the v3 topic for the metadata rpc method.
+	RPCMetaDataTopicV3 = protocolPrefix + MetadataMessageName + SchemaVersionV3
 )
 
 // RPC errors for topic parsing.
@@ -97,10 +118,15 @@ var RPCTopicMappings = map[string]interface{}{
 	// RPC Metadata Message
 	RPCMetaDataTopicV1: new(interface{}),
 	RPCMetaDataTopicV2: new(interface{}),
+	RPCMetaDataTopicV3: new(interface{}),
 	// BlobSidecarsByRange v1 Message
 	RPCBlobSidecarsByRangeTopicV1: new(pb.BlobSidecarsByRangeRequest),
 	// BlobSidecarsByRoot v1 Message
 	RPCBlobSidecarsByRootTopicV1: new(p2ptypes.BlobSidecarsByRootReq),
+	// DataColumnSidecarsByRange v1 Message
+	RPCDataColumnSidecarsByRangeTopicV1: new(pb.DataColumnSidecarsByRangeRequest),
+	// DataColumnSidecarsByRoot v1 Message
+	RPCDataColumnSidecarsByRootTopicV1: new(p2ptypes.DataColumnsByRootIdentifiers),
 }
 
 // Maps all registered protocol prefixes.
@@ -119,6 +145,8 @@ var messageMapping = map[string]bool{
 	MetadataMessageName:            true,
 	BlobSidecarsByRangeName:        true,
 	BlobSidecarsByRootName:         true,
+	DataColumnSidecarsByRootName:   true,
+	DataColumnSidecarsByRangeName:  true,
 }
 
 // Maps all the RPC messages which are to updated in altair.
@@ -128,9 +156,15 @@ var altairMapping = map[string]bool{
 	MetadataMessageName:            true,
 }
 
+// Maps all the RPC messages which are to updated in fulu.
+var fuluMapping = map[string]bool{
+	MetadataMessageName: true,
+}
+
 var versionMapping = map[string]bool{
 	SchemaVersionV1: true,
 	SchemaVersionV2: true,
+	SchemaVersionV3: true,
 }
 
 // OmitContextBytesV1 keeps track of which RPC methods do not write context bytes in their v1 incarnations.
@@ -258,13 +292,25 @@ func (r RPCTopic) Version() string {
 // TopicFromMessage constructs the rpc topic from the provided message
 // type and epoch.
 func TopicFromMessage(msg string, epoch primitives.Epoch) (string, error) {
+	// Check if the topic is known.
 	if !messageMapping[msg] {
 		return "", errors.Errorf("%s: %s", invalidRPCMessageType, msg)
 	}
+
+	// Base version is version 1.
 	version := SchemaVersionV1
+
+	// Check if the message is to be updated in altair.
 	isAltair := epoch >= params.BeaconConfig().AltairForkEpoch
 	if isAltair && altairMapping[msg] {
 		version = SchemaVersionV2
 	}
+
+	// Check if the message is to be updated in fulu.
+	isFulu := epoch >= params.BeaconConfig().FuluForkEpoch
+	if isFulu && fuluMapping[msg] {
+		version = SchemaVersionV3
+	}
+
 	return protocolPrefix + msg + version, nil
 }

beacon-chain/p2p/sender.go

@@ -42,7 +42,7 @@ func (s *Service) Send(ctx context.Context, message interface{}, baseTopic strin
 		return nil, err
 	}
 	// do not encode anything if we are sending a metadata request
-	if baseTopic != RPCMetaDataTopicV1 && baseTopic != RPCMetaDataTopicV2 {
+	if baseTopic != RPCMetaDataTopicV1 && baseTopic != RPCMetaDataTopicV2 && baseTopic != RPCMetaDataTopicV3 {
 		castedMsg, ok := message.(ssz.Marshaler)
 		if !ok {
 			return nil, errors.Errorf("%T does not support the ssz marshaller interface", message)

beacon-chain/p2p/service.go

@@ -363,6 +363,15 @@ func (s *Service) ENR() *enr.Record {
 	return s.dv5Listener.Self().Record()
 }
 
+// NodeID returns the local node's node ID
+// for discovery.
+func (s *Service) NodeID() enode.ID {
+	if s.dv5Listener == nil {
+		return [32]byte{}
+	}
+	return s.dv5Listener.Self().ID()
+}
+
 // DiscoveryAddresses represents our enr addresses as multiaddresses.
 func (s *Service) DiscoveryAddresses() ([]multiaddr.Multiaddr, error) {
 	if s.dv5Listener == nil {

beacon-chain/p2p/service_test.go

@@ -10,8 +10,6 @@ import (
 
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
@@ -358,48 +356,49 @@ func initializeStateWithForkDigest(_ context.Context, t *testing.T, gs startup.C
 	return fd
 }
 
-func TestService_connectWithPeer(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	tests := []struct {
-		name    string
-		peers   *peers.Status
-		info    peer.AddrInfo
-		wantErr string
-	}{
-		{
-			name: "bad peer",
-			peers: func() *peers.Status {
-				ps := peers.NewStatus(context.Background(), &peers.StatusConfig{
-					ScorerParams: &scorers.Config{},
-				})
-				for i := 0; i < 10; i++ {
-					ps.Scorers().BadResponsesScorer().Increment("bad")
-				}
-				return ps
-			}(),
-			info:    peer.AddrInfo{ID: "bad"},
-			wantErr: "refused to connect to bad peer",
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			h, _, _ := createHost(t, 34567)
-			defer func() {
-				if err := h.Close(); err != nil {
-					t.Fatal(err)
-				}
-			}()
-			ctx := context.Background()
-			s := &Service{
-				host:  h,
-				peers: tt.peers,
-			}
-			err := s.connectWithPeer(ctx, tt.info)
-			if len(tt.wantErr) > 0 {
-				require.ErrorContains(t, tt.wantErr, err)
-			} else {
-				require.NoError(t, err)
-			}
-		})
-	}
-}
+// TODO: Uncomment when out of devnet
+// func TestService_connectWithPeer(t *testing.T) {
+// 	params.SetupTestConfigCleanup(t)
+// 	tests := []struct {
+// 		name    string
+// 		peers   *peers.Status
+// 		info    peer.AddrInfo
+// 		wantErr string
+// 	}{
+// 		{
+// 			name: "bad peer",
+// 			peers: func() *peers.Status {
+// 				ps := peers.NewStatus(context.Background(), &peers.StatusConfig{
+// 					ScorerParams: &scorers.Config{},
+// 				})
+// 				for i := 0; i < 10; i++ {
+// 					ps.Scorers().BadResponsesScorer().Increment("bad")
+// 				}
+// 				return ps
+// 			}(),
+// 			info:    peer.AddrInfo{ID: "bad"},
+// 			wantErr: "refused to connect to bad peer",
+// 		},
+// 	}
+// 	for _, tt := range tests {
+// 		t.Run(tt.name, func(t *testing.T) {
+// 			h, _, _ := createHost(t, 34567)
+// 			defer func() {
+// 				if err := h.Close(); err != nil {
+// 					t.Fatal(err)
+// 				}
+// 			}()
+// 			ctx := context.Background()
+// 			s := &Service{
+// 				host:  h,
+// 				peers: tt.peers,
+// 			}
+// 			err := s.connectWithPeer(ctx, tt.info)
+// 			if len(tt.wantErr) > 0 {
+// 				require.ErrorContains(t, tt.wantErr, err)
+// 			} else {
+// 				require.NoError(t, err)
+// 			}
+// 		})
+// 	}
+// }

beacon-chain/p2p/subnets.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -29,8 +30,9 @@ var (
 	attestationSubnetCount = params.BeaconConfig().AttestationSubnetCount
 	syncCommsSubnetCount   = params.BeaconConfig().SyncCommitteeSubnetCount
 
-	attSubnetEnrKey       = params.BeaconNetworkConfig().AttSubnetKey
-	syncCommsSubnetEnrKey = params.BeaconNetworkConfig().SyncCommsSubnetKey
+	attSubnetEnrKey         = params.BeaconNetworkConfig().AttSubnetKey
+	syncCommsSubnetEnrKey   = params.BeaconNetworkConfig().SyncCommsSubnetKey
+	custodyGroupCountEnrKey = params.BeaconNetworkConfig().CustodyGroupCountKey
 )
 
 // The value used with the subnet, in order
@@ -47,7 +49,14 @@ const syncLockerVal = 100
 // chosen more than sync and attestation subnet combined.
 const blobSubnetLockerVal = 110
 
-// nodeFilter return a function that filters nodes based on the subnet topic and subnet index.
+// The value used with the data column sidecar subnet, in order
+// to create an appropriate key to retrieve
+// the relevant lock. This is used to differentiate
+// data column subnets from others. This is deliberately
+// chosen more than sync, attestation and blob subnet (6) combined.
+const dataColumnSubnetVal = 150
+
+// nodeFilter returns a function that filters nodes based on the subnet topic and subnet index.
 func (s *Service) nodeFilter(topic string, index uint64) (func(node *enode.Node) bool, error) {
 	switch {
 	case strings.Contains(topic, GossipAttestationMessage):
@@ -56,6 +65,8 @@ func (s *Service) nodeFilter(topic string, index uint64) (func(node *enode.Node)
 		return s.filterPeerForSyncSubnet(index), nil
 	case strings.Contains(topic, GossipBlobSidecarMessage):
 		return s.filterPeerForBlobSubnet(), nil
+	case strings.Contains(topic, GossipDataColumnSidecarMessage):
+		return s.filterPeerForDataColumnsSubnet(index), nil
 	default:
 		return nil, errors.Errorf("no subnet exists for provided topic: %s", topic)
 	}
@@ -276,6 +287,22 @@ func (s *Service) filterPeerForBlobSubnet() func(_ *enode.Node) bool {
 	}
 }
 
+// returns a method with filters peers specifically for a particular data column subnet.
+func (s *Service) filterPeerForDataColumnsSubnet(index uint64) func(node *enode.Node) bool {
+	return func(node *enode.Node) bool {
+		if !s.filterPeer(node) {
+			return false
+		}
+
+		subnets, err := dataColumnSubnets(node.ID(), node.Record())
+		if err != nil {
+			return false
+		}
+
+		return subnets[index]
+	}
+}
+
 // lower threshold to broadcast object compared to searching
 // for a subnet. So that even in the event of poor peer
 // connectivity, we can still broadcast an attestation.
@@ -321,6 +348,35 @@ func (s *Service) updateSubnetRecordWithMetadataV2(bitVAtt bitfield.Bitvector64,
 	})
 }
 
+// updateSubnetRecordWithMetadataV3 updates:
+// - attestation subnet tracked,
+// - sync subnets tracked, and
+// - custody subnet count
+// both in the node's record and in the node's metadata.
+func (s *Service) updateSubnetRecordWithMetadataV3(
+	bitVAtt bitfield.Bitvector64,
+	bitVSync bitfield.Bitvector4,
+	custodyGroupCount uint64,
+) {
+	attSubnetsEntry := enr.WithEntry(attSubnetEnrKey, &bitVAtt)
+	syncSubnetsEntry := enr.WithEntry(syncCommsSubnetEnrKey, &bitVSync)
+	custodyGroupCountEntry := enr.WithEntry(custodyGroupCountEnrKey, custodyGroupCount)
+
+	localNode := s.dv5Listener.LocalNode()
+	localNode.Set(attSubnetsEntry)
+	localNode.Set(syncSubnetsEntry)
+	localNode.Set(custodyGroupCountEntry)
+
+	newSeqNumber := s.metaData.SequenceNumber() + 1
+
+	s.metaData = wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		SeqNumber:         newSeqNumber,
+		Attnets:           bitVAtt,
+		Syncnets:          bitVSync,
+		CustodyGroupCount: custodyGroupCount,
+	})
+}
+
 func initializePersistentSubnets(id enode.ID, epoch primitives.Epoch) error {
 	_, ok, expTime := cache.SubnetIDs.GetPersistentSubnets()
 	if ok && expTime.After(time.Now()) {
@@ -458,6 +514,25 @@ func syncSubnets(record *enr.Record) ([]uint64, error) {
 	return committeeIdxs, nil
 }
 
+// Retrieve the data columns subnets from a node's ENR and node ID.
+// TODO: Add tests
+func dataColumnSubnets(nodeID enode.ID, record *enr.Record) (map[uint64]bool, error) {
+	// Retrieve the custody count from the ENR.
+	custodyGroupCount, err := peerdas.CustodyGroupCountFromRecord(record)
+	if err != nil {
+		return nil, errors.Wrap(err, "custody group count from record")
+	}
+
+	// Retrieve the peer info.
+	peerInfo, _, err := peerdas.Info(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "peer info")
+	}
+
+	// Get custody columns subnets from the columns.
+	return peerInfo.DataColumnsSubnets, nil
+}
+
 // Parses the attestation subnets ENR entry in a node and extracts its value
 // as a bitvector for further manipulation.
 func attBitvector(record *enr.Record) (bitfield.Bitvector64, error) {
@@ -487,6 +562,7 @@ func syncBitvector(record *enr.Record) (bitfield.Bitvector4, error) {
 // between both the attestation, sync and blob subnets.
 // Sync subnets are stored by (subnet+syncLockerVal).
 // Blob subnets are stored by (subnet+blobSubnetLockerVal).
+// Data column subnets are stored by (subnet+dataColumnSubnetVal).
 // This is to prevent conflicts while allowing subnets
 // to use a single locker.
 func (s *Service) subnetLocker(i uint64) *sync.RWMutex {

beacon-chain/p2p/testing/BUILD.bazel

@@ -17,9 +17,12 @@ go_library(
         "//beacon-chain:__subpackages__",
     ],
     deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",
         "//beacon-chain/p2p/peers:go_default_library",
         "//beacon-chain/p2p/peers/scorers:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/metadata:go_default_library",

beacon-chain/p2p/testing/fuzz_p2p.go

@@ -5,9 +5,11 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/control"
@@ -56,6 +58,11 @@ func (*FakeP2P) ENR() *enr.Record {
 	return new(enr.Record)
 }
 
+// NodeID returns the node id of the local peer.
+func (*FakeP2P) NodeID() enode.ID {
+	return [32]byte{}
+}
+
 // DiscoveryAddresses -- fake
 func (*FakeP2P) DiscoveryAddresses() ([]multiaddr.Multiaddr, error) {
 	return nil, nil
@@ -159,6 +166,11 @@ func (*FakeP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfac
 	return nil
 }
 
+// BroadcastDataColumn -- fake.
+func (*FakeP2P) BroadcastDataColumn(_ context.Context, _ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+	return nil
+}
+
 // InterceptPeerDial -- fake.
 func (*FakeP2P) InterceptPeerDial(peer.ID) (allow bool) {
 	return true
@@ -183,3 +195,7 @@ func (*FakeP2P) InterceptSecured(network.Direction, peer.ID, network.ConnMultiad
 func (*FakeP2P) InterceptUpgraded(network.Conn) (allow bool, reason control.DisconnectReason) {
 	return true, 0
 }
+
+func (*FakeP2P) CustodyGroupCountFromPeer(peer.ID) uint64 {
+	return 0
+}

beacon-chain/p2p/testing/mock_broadcaster.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"sync/atomic"
 
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"google.golang.org/protobuf/proto"
@@ -61,6 +62,12 @@ func (m *MockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
+// BroadcastDataColumn broadcasts a data column for mock.
+func (m *MockBroadcaster) BroadcastDataColumn(context.Context, [fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar) error {
+	m.BroadcastCalled.Store(true)
+	return nil
+}
+
 // NumMessages returns the number of messages broadcasted.
 func (m *MockBroadcaster) NumMessages() int {
 	m.msgLock.Lock()

beacon-chain/p2p/testing/mock_peermanager.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/peer"
@@ -39,6 +40,11 @@ func (m *MockPeerManager) ENR() *enr.Record {
 	return m.Enr
 }
 
+// NodeID .
+func (m MockPeerManager) NodeID() enode.ID {
+	return [32]byte{}
+}
+
 // DiscoveryAddresses .
 func (m *MockPeerManager) DiscoveryAddresses() ([]multiaddr.Multiaddr, error) {
 	if m.FailDiscoveryAddr {

beacon-chain/p2p/testing/p2p.go

@@ -10,9 +10,12 @@ import (
 	"testing"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1/metadata"
@@ -220,6 +223,12 @@ func (p *TestP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interf
 	return nil
 }
 
+// BroadcastDataColumn broadcasts a data column for mock.
+func (p *TestP2P) BroadcastDataColumn(context.Context, [fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar) error {
+	p.BroadcastCalled.Store(true)
+	return nil
+}
+
 // SetStreamHandler for RPC.
 func (p *TestP2P) SetStreamHandler(topic string, handler network.StreamHandler) {
 	p.BHost.SetStreamHandler(protocol.ID(topic), handler)
@@ -451,3 +460,22 @@ func (*TestP2P) InterceptSecured(network.Direction, peer.ID, network.ConnMultiad
 func (*TestP2P) InterceptUpgraded(network.Conn) (allow bool, reason control.DisconnectReason) {
 	return true, 0
 }
+
+func (s *TestP2P) CustodyGroupCountFromPeer(pid peer.ID) uint64 {
+	// By default, we assume the peer custodies the minimum number of groups.
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+
+	// Retrieve the ENR of the peer.
+	record, err := s.peers.ENR(pid)
+	if err != nil {
+		return custodyRequirement
+	}
+
+	// Retrieve the custody subnets count from the ENR.
+	custodyGroupCount, err := peerdas.CustodyGroupCountFromRecord(record)
+	if err != nil {
+		return custodyRequirement
+	}
+
+	return custodyGroupCount
+}