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.

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/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/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/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/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
+}

beacon-chain/p2p/topics.go

@@ -34,6 +34,9 @@ const (
 	GossipLightClientFinalityUpdateMessage = "light_client_finality_update"
 	// GossipLightClientOptimisticUpdateMessage is the name for the light client optimistic update message type.
 	GossipLightClientOptimisticUpdateMessage = "light_client_optimistic_update"
+	// GossipDataColumnSidecarMessage is the name for the data column sidecar message type.
+	GossipDataColumnSidecarMessage = "data_column_sidecar"
+
 	// Topic Formats
 	//
 	// AttestationSubnetTopicFormat is the topic format for the attestation subnet.
@@ -60,4 +63,6 @@ const (
 	LightClientFinalityUpdateTopicFormat = GossipProtocolAndDigest + GossipLightClientFinalityUpdateMessage
 	// LightClientOptimisticUpdateTopicFormat is the topic format for the light client optimistic update subnet.
 	LightClientOptimisticUpdateTopicFormat = GossipProtocolAndDigest + GossipLightClientOptimisticUpdateMessage
+	// DataColumnSubnetTopicFormat is the topic format for the data column subnet.
+	DataColumnSubnetTopicFormat = GossipProtocolAndDigest + GossipDataColumnSidecarMessage + "_%d"
 )

beacon-chain/p2p/types/BUILD.bazel

@@ -41,6 +41,7 @@ go_test(
     ],
     embed = [":go_default_library"],
     deps = [
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",

beacon-chain/p2p/types/object_mapping.go

@@ -108,7 +108,7 @@ func InitializeDataMaps() {
 			return wrapper.WrappedMetadataV1(&ethpb.MetaDataV1{}), nil
 		},
 		bytesutil.ToBytes4(params.BeaconConfig().FuluForkVersion): func() (metadata.Metadata, error) {
-			return wrapper.WrappedMetadataV1(&ethpb.MetaDataV1{}), nil
+			return wrapper.WrappedMetadataV2(&ethpb.MetaDataV2{}), nil
 		},
 	}
 

beacon-chain/p2p/types/rpc_errors.go

@@ -9,10 +9,15 @@ var (
 	ErrInvalidSequenceNum     = errors.New("invalid sequence number provided")
 	ErrGeneric                = errors.New("internal service error")
 
-	ErrRateLimited         = errors.New("rate limited")
-	ErrIODeadline          = errors.New("i/o deadline exceeded")
-	ErrInvalidRequest      = errors.New("invalid range, step or count")
-	ErrBlobLTMinRequest    = errors.New("blob slot < minimum_request_epoch")
-	ErrMaxBlobReqExceeded  = errors.New("requested more than MAX_REQUEST_BLOB_SIDECARS")
+	ErrRateLimited      = errors.New("rate limited")
+	ErrIODeadline       = errors.New("i/o deadline exceeded")
+	ErrInvalidRequest   = errors.New("invalid range, step or count")
+	ErrBlobLTMinRequest = errors.New("blob epoch < minimum_request_epoch")
+
+	ErrDataColumnLTMinRequest   = errors.New("data column epoch < minimum_request_epoch")
+	ErrMaxBlobReqExceeded       = errors.New("requested more than MAX_REQUEST_BLOB_SIDECARS")
+	ErrMaxDataColumnReqExceeded = errors.New("requested more than MAX_REQUEST_DATA_COLUMN_SIDECARS")
+
 	ErrResourceUnavailable = errors.New("resource requested unavailable")
+	ErrInvalidColumnIndex  = errors.New("invalid column index requested")
 )

beacon-chain/p2p/types/types.go

@@ -5,6 +5,7 @@ package types
 
 import (
 	"bytes"
+	"encoding/binary"
 	"sort"
 
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -14,7 +15,10 @@ import (
 	ssz "github.com/prysmaticlabs/fastssz"
 )
 
-const maxErrorLength = 256
+const (
+	maxErrorLength       = 256
+	bytesPerLengthOffset = 4
+)
 
 // SSZBytes is a bytes slice that satisfies the fast-ssz interface.
 type SSZBytes []byte
@@ -182,31 +186,154 @@ func (b *BlobSidecarsByRootReq) UnmarshalSSZ(buf []byte) error {
 	return nil
 }
 
-var _ sort.Interface = BlobSidecarsByRootReq{}
+var _ sort.Interface = (*BlobSidecarsByRootReq)(nil)
 
 // Less reports whether the element with index i must sort before the element with index j.
 // BlobIdentifier will be sorted in lexicographic order by root, with Blob Index as tiebreaker for a given root.
-func (s BlobSidecarsByRootReq) Less(i, j int) bool {
-	rootCmp := bytes.Compare(s[i].BlockRoot, s[j].BlockRoot)
+func (s *BlobSidecarsByRootReq) Less(i, j int) bool {
+	rootCmp := bytes.Compare((*s)[i].BlockRoot, (*s)[j].BlockRoot)
 	if rootCmp != 0 {
 		// They aren't equal; return true if i < j, false if i > j.
 		return rootCmp < 0
 	}
 	// They are equal; blob index is the tie breaker.
-	return s[i].Index < s[j].Index
+	return (*s)[i].Index < (*s)[j].Index
 }
 
 // Swap swaps the elements with indexes i and j.
-func (s BlobSidecarsByRootReq) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
+func (s *BlobSidecarsByRootReq) Swap(i, j int) {
+	(*s)[i], (*s)[j] = (*s)[j], (*s)[i]
 }
 
 // Len is the number of elements in the collection.
-func (s BlobSidecarsByRootReq) Len() int {
-	return len(s)
+func (s *BlobSidecarsByRootReq) Len() int {
+	return len(*s)
+}
+
+// ===================================
+// DataColumnsByRootIdentifiers section
+// ===================================
+var _ ssz.Marshaler = (*DataColumnsByRootIdentifiers)(nil)
+var _ ssz.Unmarshaler = (*DataColumnsByRootIdentifiers)(nil)
+
+// DataColumnsByRootIdentifiers is used to specify a list of data column targets (root+index) in a DataColumnSidecarsByRoot RPC request.
+type DataColumnsByRootIdentifiers []*eth.DataColumnsByRootIdentifier
+
+// DataColumnIdentifier is a fixed size value, so we can compute its fixed size at start time (see init below)
+var dataColumnIdSize int
+
+// UnmarshalSSZ implements ssz.Unmarshaler. It unmarshals the provided bytes buffer into the DataColumnSidecarsByRootReq value.
+func (d *DataColumnsByRootIdentifiers) UnmarshalSSZ(buf []byte) error {
+	// Exit early if the buffer is too small.
+	if len(buf) < bytesPerLengthOffset {
+		return nil
+	}
+
+	// Get the size of the offsets.
+	offsetEnd := binary.LittleEndian.Uint32(buf[:bytesPerLengthOffset])
+	if offsetEnd%bytesPerLengthOffset != 0 {
+		return errors.Errorf("expected offsets size to be a multiple of %d but got %d", bytesPerLengthOffset, offsetEnd)
+	}
+
+	count := offsetEnd / bytesPerLengthOffset
+	if count < 1 {
+		return nil
+	}
+
+	maxSize := params.BeaconConfig().MaxRequestBlocksDeneb
+	if uint64(count) > maxSize {
+		return errors.Errorf("data column identifiers list exceeds max size: %d > %d", count, maxSize)
+	}
+
+	if offsetEnd > uint32(len(buf)) {
+		return errors.Errorf("offsets value %d larger than buffer %d", offsetEnd, len(buf))
+	}
+	valueStart := offsetEnd
+
+	// Decode the identifers.
+	*d = make([]*eth.DataColumnsByRootIdentifier, count)
+	var start uint32
+	end := uint32(len(buf))
+	for i := count; i > 0; i-- {
+		offsetEnd -= bytesPerLengthOffset
+		start = binary.LittleEndian.Uint32(buf[offsetEnd : offsetEnd+bytesPerLengthOffset])
+		if start > end {
+			return errors.Errorf("expected offset[%d] %d to be less than %d", i-1, start, end)
+		}
+		if start < valueStart {
+			return errors.Errorf("offset[%d] %d indexes before value section %d", i-1, start, valueStart)
+		}
+		// Decode the identifier.
+		ident := &eth.DataColumnsByRootIdentifier{}
+		if err := ident.UnmarshalSSZ(buf[start:end]); err != nil {
+			return err
+		}
+		(*d)[i-1] = ident
+		end = start
+	}
+
+	return nil
+}
+
+func (d *DataColumnsByRootIdentifiers) MarshalSSZ() ([]byte, error) {
+	var err error
+	count := len(*d)
+	maxSize := params.BeaconConfig().MaxRequestBlocksDeneb
+	if uint64(count) > maxSize {
+		return nil, errors.Errorf("data column identifiers list exceeds max size: %d > %d", count, maxSize)
+	}
+
+	if len(*d) == 0 {
+		return []byte{}, nil
+	}
+	sizes := make([]uint32, count)
+	valTotal := uint32(0)
+	for i, elem := range *d {
+		if elem == nil {
+			return nil, errors.New("nil item in DataColumnsByRootIdentifiers list")
+		}
+		sizes[i] = uint32(elem.SizeSSZ())
+		valTotal += sizes[i]
+	}
+	offSize := uint32(4 * len(*d))
+	out := make([]byte, offSize, offSize+valTotal)
+	for i := range sizes {
+		binary.LittleEndian.PutUint32(out[i*4:i*4+4], offSize)
+		offSize += sizes[i]
+	}
+	for _, elem := range *d {
+		out, err = elem.MarshalSSZTo(out)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return out, nil
+}
+
+// MarshalSSZTo implements ssz.Marshaler. It appends the serialized DataColumnSidecarsByRootReq value to the provided byte slice.
+func (d *DataColumnsByRootIdentifiers) MarshalSSZTo(dst []byte) ([]byte, error) {
+	obj, err := d.MarshalSSZ()
+	if err != nil {
+		return nil, err
+	}
+	return append(dst, obj...), nil
+}
+
+// SizeSSZ implements ssz.Marshaler. It returns the size of the serialized representation.
+func (d *DataColumnsByRootIdentifiers) SizeSSZ() int {
+	size := 0
+	for i := 0; i < len(*d); i++ {
+		size += 4
+		size += (*d)[i].SizeSSZ()
+	}
+	return size
 }
 
 func init() {
-	sizer := &eth.BlobIdentifier{}
-	blobIdSize = sizer.SizeSSZ()
+	blobSizer := &eth.BlobIdentifier{}
+	blobIdSize = blobSizer.SizeSSZ()
+
+	dataColumnSizer := &eth.DataColumnSidecarsByRangeRequest{}
+	dataColumnIdSize = dataColumnSizer.SizeSSZ()
 }

beacon-chain/p2p/types/types_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"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/encoding/bytesutil"
@@ -203,3 +204,152 @@ func hexDecodeOrDie(t *testing.T, str string) []byte {
 	require.NoError(t, err)
 	return decoded
 }
+
+// =====================================
+// DataColumnsByRootIdentifiers section
+// =====================================
+func generateDataColumnIdentifiers(n int) []*eth.DataColumnsByRootIdentifier {
+	r := make([]*eth.DataColumnsByRootIdentifier, n)
+	for i := 0; i < n; i++ {
+		r[i] = &eth.DataColumnsByRootIdentifier{
+			BlockRoot: bytesutil.PadTo([]byte{byte(i)}, 32),
+			Columns:   []uint64{uint64(i)},
+		}
+	}
+	return r
+}
+
+func TestDataColumnSidecarsByRootReq_Marshal(t *testing.T) {
+	/*
+		Python code to generate the expected value
+
+		# pip install eth2spec
+
+		from eth2spec.utils.ssz import ssz_typing
+
+		Container = ssz_typing.Container
+		List = ssz_typing.List
+
+		Root = ssz_typing.Bytes32
+		ColumnIndex = ssz_typing.uint64
+
+		NUMBER_OF_COLUMNS=128
+
+		class DataColumnsByRootIdentifier(Container):
+			block_root: Root
+			columns: List[ColumnIndex, NUMBER_OF_COLUMNS]
+
+		first = DataColumnsByRootIdentifier(block_root="0x0100000000000000000000000000000000000000000000000000000000000000", columns=[3,5,7])
+		second = DataColumnsByRootIdentifier(block_root="0x0200000000000000000000000000000000000000000000000000000000000000", columns=[])
+		third = DataColumnsByRootIdentifier(block_root="0x0300000000000000000000000000000000000000000000000000000000000000", columns=[6, 4])
+
+		expected = List[DataColumnsByRootIdentifier, 42](first, second, third).encode_bytes().hex()
+	*/
+
+	const expected = "0c000000480000006c00000001000000000000000000000000000000000000000000000000000000000000002400000003000000000000000500000000000000070000000000000002000000000000000000000000000000000000000000000000000000000000002400000003000000000000000000000000000000000000000000000000000000000000002400000006000000000000000400000000000000"
+	identifiers := &DataColumnsByRootIdentifiers{
+		{
+			BlockRoot: bytesutil.PadTo([]byte{1}, fieldparams.RootLength),
+			Columns:   []uint64{3, 5, 7},
+		},
+		{
+			BlockRoot: bytesutil.PadTo([]byte{2}, fieldparams.RootLength),
+			Columns:   []uint64{},
+		},
+		{
+			BlockRoot: bytesutil.PadTo([]byte{3}, fieldparams.RootLength),
+			Columns:   []uint64{6, 4},
+		},
+	}
+
+	marshalled, err := identifiers.MarshalSSZ()
+	require.NoError(t, err)
+
+	actual := hex.EncodeToString(marshalled)
+	require.Equal(t, expected, actual)
+}
+
+func TestDataColumnSidecarsByRootReq_MarshalUnmarshal(t *testing.T) {
+	cases := []struct {
+		name         string
+		ids          []*eth.DataColumnsByRootIdentifier
+		marshalErr   error
+		unmarshalErr string
+		unmarshalMod func([]byte) []byte
+	}{
+		{
+			name: "empty list",
+		},
+		{
+			name: "single item list",
+			ids:  generateDataColumnIdentifiers(1),
+		},
+		{
+			name: "10 item list",
+			ids:  generateDataColumnIdentifiers(10),
+		},
+		{
+			name: "wonky unmarshal size",
+			ids:  generateDataColumnIdentifiers(10),
+			unmarshalMod: func(in []byte) []byte {
+				in = append(in, byte(0))
+				return in
+			},
+			unmarshalErr: "a is not evenly divisble by b",
+		},
+		{
+			name: "size too big",
+			ids:  generateDataColumnIdentifiers(1),
+			unmarshalMod: func(in []byte) []byte {
+				maxLen := params.BeaconConfig().MaxRequestDataColumnSidecars * uint64(dataColumnIdSize)
+				add := make([]byte, maxLen)
+				in = append(in, add...)
+				return in
+			},
+			unmarshalErr: "a/b is greater than max",
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			req := DataColumnsByRootIdentifiers(c.ids)
+			bytes, err := req.MarshalSSZ()
+			if c.marshalErr != nil {
+				require.ErrorIs(t, err, c.marshalErr)
+				return
+			}
+
+			require.NoError(t, err)
+			if c.unmarshalMod != nil {
+				bytes = c.unmarshalMod(bytes)
+			}
+
+			got := &DataColumnsByRootIdentifiers{}
+			err = got.UnmarshalSSZ(bytes)
+			if c.unmarshalErr != "" {
+				require.ErrorContains(t, c.unmarshalErr, err)
+				return
+			}
+			require.NoError(t, err)
+
+			require.Equal(t, len(c.ids), len(*got))
+
+			for i, expected := range c.ids {
+				actual := (*got)[i]
+				require.DeepEqual(t, expected, actual)
+			}
+		})
+	}
+
+	// Test MarshalSSZTo
+	req := DataColumnsByRootIdentifiers(generateDataColumnIdentifiers(10))
+	buf := make([]byte, 0)
+	buf, err := req.MarshalSSZTo(buf)
+	require.NoError(t, err)
+	require.Equal(t, len(buf), int(req.SizeSSZ()))
+
+	var unmarshalled DataColumnsByRootIdentifiers
+	err = unmarshalled.UnmarshalSSZ(buf)
+	require.NoError(t, err)
+	require.DeepEqual(t, req, unmarshalled)
+}