Change Custody Count to Uint8 (#14386)

* Add Changes for Uint8 Csc

* Fix Build

* Fix Build for Sync

* Fix Discovery Test

.bazelrc

@@ -22,6 +22,7 @@ coverage --define=coverage_enabled=1
 build --workspace_status_command=./hack/workspace_status.sh
 
 build --define blst_disabled=false
+build --compilation_mode=opt
 run --define blst_disabled=false
 
 build:blst_disabled --define blst_disabled=true

.github/PULL_REQUEST_TEMPLATE.md

@@ -10,6 +10,7 @@
    in review.
 4. Note that PRs updating dependencies and new Go versions are not accepted.
    Please file an issue instead.
+5. A changelog entry is required for user facing issues.
 -->
 
 **What type of PR is this?**
@@ -28,3 +29,9 @@
 Fixes #
 
 **Other notes for review**
+
+**Acknowledgements**
+
+- [ ] I have read [CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
+- [ ] I have made an appropriate entry to [CHANGELOG.md](https://github.com/prysmaticlabs/prysm/blob/develop/CHANGELOG.md).
+- [ ] I have added a description to this PR with sufficient context for reviewers to understand this PR.

.github/workflows/changelog.yml

@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - develop
+
+jobs:
+  changed_files:
+    runs-on: ubuntu-latest 
+    name: Check CHANGELOG.md
+    steps:
+      - uses: actions/checkout@v4
+      - name: changelog modified
+        id: changelog-modified
+        uses: tj-actions/changed-files@v45
+        with:
+          files: CHANGELOG.md
+
+      - name: List all changed files
+        env:
+          ALL_CHANGED_FILES: ${{ steps.changelog-modified.outputs.all_changed_files }}
+        run: |
+          if [[ ${ALL_CHANGED_FILES[*]} =~ (^|[[:space:]])"CHANGELOG.md"($|[[:space:]]) ]];
+          then
+            echo "CHANGELOG.md was modified.";
+            exit 0;
+          else
+            echo "CHANGELOG.md was not modified.";
+            echo "Please see CHANGELOG.md and follow the instructions to add your changes to that file."
+            echo "In some rare scenarios, a changelog entry is not required and this CI check can be ignored."
+            exit 1;
+          fi

.github/workflows/go.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Go mod tidy checker
         id: gomodtidy
@@ -27,11 +27,11 @@ jobs:
       GO111MODULE: on
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Set up Go 1.22
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
-          go-version: '1.22.3'
+          go-version: '1.22.6'
       - name: Run Gosec Security Scanner
         run: | # https://github.com/securego/gosec/issues/469
           export PATH=$PATH:$(go env GOPATH)/bin
@@ -43,18 +43,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Set up Go 1.22
-        uses: actions/setup-go@v3
+        uses: actions/setup-go@v4
         with:
-          go-version: '1.22.3'
+          go-version: '1.22.6'
           id: go
 
       - name: Golangci-lint
-        uses: golangci/golangci-lint-action@v3
+        uses: golangci/golangci-lint-action@v5
         with:
-          version: v1.55.2
+          version: v1.56.1
           args: --config=.golangci.yml --out-${NO_FUTURE}format colored-line-number
 
   build:
@@ -62,13 +62,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Set up Go 1.x
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v4
         with:
-          go-version: '1.22.3'
+          go-version: '1.22.6'
         id: go
 
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Get dependencies
         run: |

.golangci.yml

@@ -6,7 +6,7 @@ run:
     - proto
     - tools/analyzers
   timeout: 10m
-  go: '1.22.3'
+  go: '1.22.6'
 
 linters:
   enable-all: true
@@ -73,6 +73,7 @@ linters:
     - promlinter
     - protogetter
     - revive
+    - spancheck
     - staticcheck
     - stylecheck
     - tagalign

CONTRIBUTING.md

@@ -6,6 +6,9 @@ Excited by our work and want to get involved in building out our sharding releas
 
 You can explore our [Open Issues](https://github.com/prysmaticlabs/prysm/issues) in-the works for our different releases. Feel free to fork our repo and start creating PR’s after assigning yourself to an issue of interest. We are always chatting on [Discord](https://discord.gg/CTYGPUJ) drop us a line there if you want to get more involved or have any questions on our implementation!
 
+> [!IMPORTANT] 
+> Please, **do not send pull requests for trivial changes**, such as typos, these will be rejected. These types of pull requests incur a cost to reviewers and do not provide much value to the project. If you are unsure, please open an issue first to discuss the change.
+
 ## Contribution Steps
 
 **1. Set up Prysm following the instructions in README.md.**
@@ -120,15 +123,19 @@ $ git push myrepo feature-in-progress-branch
 
 Navigate to your fork of the repo on GitHub. On the upper left where the current branch is listed, change the branch to your feature-in-progress-branch. Open the files that you have worked on and check to make sure they include your changes.
 
-**16. Create a pull request.**
+**16. Add an entry to CHANGELOG.md.**
 
-Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base master”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls.
+If your change is user facing, you must include a CHANGELOG.md entry. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
 
-**17. Respond to comments by Core Contributors.**
+**17. Create a pull request.**
+
+Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base master”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
+
+**18. Respond to comments by Core Contributors.**
 
 Core Contributors may ask questions and request that you make edits. If you set notifications at the top of the page to “not watching,” you will still be notified by email whenever someone comments on the page of a pull request you have created. If you are asked to modify your pull request, repeat steps 8 through 15, then leave a comment to notify the Core Contributors that the pull request is ready for further review.
 
-**18. If the number of commits becomes excessive, you may be asked to squash your commits.**
+**19. If the number of commits becomes excessive, you may be asked to squash your commits.**
 
  You can do this with an interactive rebase. Start by running the following command to determine the commit that is the base of your branch...
 
@@ -136,7 +143,7 @@ Core Contributors may ask questions and request that you make edits. If you set
 $ git merge-base feature-in-progress-branch prysm/master
 ```
 
-**19. The previous command will return a commit-hash that you should use in the following command.**
+**20. The previous command will return a commit-hash that you should use in the following command.**
 
 ```
 $ git rebase -i commit-hash
@@ -160,13 +167,30 @@ squash  hash 	add a feature
 
 Save and close the file, then a commit command will appear in the terminal that squashes the smaller commits into one. Check to be sure the commit message accurately reflects your changes and then hit enter to execute it.
 
-**20. Update your pull request with the following command.**
+**21. Update your pull request with the following command.**
 
 ```
 $ git push myrepo feature-in-progress-branch -f
 ```
 
-**21.  Finally, again leave a comment to the Core Contributors on the pull request to let them know that the pull request has been updated.**
+**22.  Finally, again leave a comment to the Core Contributors on the pull request to let them know that the pull request has been updated.**
+
+## Maintaining CHANGELOG.md
+
+This project follows the changelog guidelines from [keepachangelog.com](https://keepachangelog.com/en/1.1.0/).
+
+All PRs with user facing changes should have an entry in the CHANGELOG.md file and the change should be categorized in the appropriate category within the "Unreleased" section. The categories are:
+
+-  `Added` for new features.
+-  `Changed` for changes in existing functionality.
+-  `Deprecated` for soon-to-be removed features.
+-  `Removed` for now removed features.
+-  `Fixed` for any bug fixes.
+-  `Security` in case of vulnerabilities. Please see the [Security Policy](SECURITY.md) for responsible disclosure before adding a change with this category.
+
+### Releasing
+
+When a new release is made, the "Unreleased" section should be moved to a new section with the release version and the current date. Then a new "Unreleased" section is made at the top of the file with the categories listed above.
 
 ## Contributor Responsibilities
 

WORKSPACE

@@ -227,7 +227,7 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.5.0-alpha.4"
+consensus_spec_version = "v1.5.0-alpha.5"
 
 bls_test_version = "v0.1.1"
 
@@ -243,7 +243,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-sSw6c9IR/ZiWjyk1cbfVGC/aUkId4r7+eSl3haWsq0E=",
+    integrity = "sha256-R9vG5HEL5eGMOAmbkKfJ2jfelNqL5V0xBUPiXOiGM6U=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )
 
@@ -259,7 +259,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-OGlKhbA6TjTP0p1ojXVCJPzLEHJzewKkhAa+PQggoiU=",
+    integrity = "sha256-AEIiEOlf1XuxoRMCsN+kgJMo4LrS05+biTA1p/7Ro00=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )
 
@@ -275,7 +275,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-ah2Gj4ci5hw5vQgpUWkNjEQutoBCepg5jcpTi0DKVB0=",
+    integrity = "sha256-LH/Xr20yrJRYnbpjRGupMWTIOWt3cpxZJWXgThwVDsk=",
     url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )
 
@@ -290,7 +290,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-I+llAsIF6lPP8RUtZ2DFsJqtCs4UPh+st3hFs12FWpY=",
+    integrity = "sha256-mlytz4MPjKh0DwV7FMiAtnRbJw9B6o78/x66/vmnYc8=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )

api/client/builder/BUILD.bazel

@@ -21,6 +21,7 @@ go_library(
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
@@ -28,7 +29,6 @@ go_library(
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )

api/client/builder/client.go

@@ -19,11 +19,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	log "github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 const (

api/server/structs/endpoints_lightclient.go

@@ -1,12 +1,16 @@
 package structs
 
+type LightClientHeader struct {
+	Beacon *BeaconBlockHeader `json:"beacon"`
+}
+
 type LightClientBootstrapResponse struct {
 	Version string                `json:"version"`
 	Data    *LightClientBootstrap `json:"data"`
 }
 
 type LightClientBootstrap struct {
-	Header                     *BeaconBlockHeader `json:"header"`
+	Header                     *LightClientHeader `json:"header"`
 	CurrentSyncCommittee       *SyncCommittee     `json:"current_sync_committee"`
 	CurrentSyncCommitteeBranch []string           `json:"current_sync_committee_branch"`
 }

beacon-chain/blockchain/BUILD.bazel

@@ -13,7 +13,6 @@ go_library(
         "head.go",
         "head_sync_committee_info.go",
         "init_sync_process_block.go",
-        "lightclient.go",
         "log.go",
         "merge_ascii_art.go",
         "metrics.go",
@@ -26,6 +25,7 @@ go_library(
         "receive_attestation.go",
         "receive_blob.go",
         "receive_block.go",
+        "receive_data_column.go",
         "service.go",
         "tracked_proposer.go",
         "weak_subjectivity_checks.go",
@@ -48,6 +48,8 @@ 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/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",
@@ -81,10 +83,10 @@ go_library(
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/eth/v2:go_default_library",
-        "//proto/migration:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",
         "//runtime/version:go_default_library",
@@ -117,7 +119,6 @@ go_test(
         "head_test.go",
         "init_sync_process_block_test.go",
         "init_test.go",
-        "lightclient_test.go",
         "log_test.go",
         "metrics_test.go",
         "mock_test.go",
@@ -159,6 +160,7 @@ go_test(
         "//beacon-chain/operations/slashings:go_default_library",
         "//beacon-chain/operations/voluntaryexits:go_default_library",
         "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/startup:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
@@ -174,7 +176,6 @@ go_test(
         "//encoding/bytesutil:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
-        "//proto/eth/v2:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "//testing/assert:go_default_library",

beacon-chain/blockchain/chain_info.go

@@ -16,9 +16,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
-	"go.opencensus.io/trace"
 )
 
 // ChainInfoFetcher defines a common interface for methods in blockchain service which

beacon-chain/blockchain/error.go

@@ -33,6 +33,7 @@ var (
 )
 
 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")
+var errMaxDataColumnsExceeded = errors.New("Expected data columns for node exceeds NUMBER_OF_COLUMNS")
 
 // 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.

beacon-chain/blockchain/execution_engine.go

@@ -21,11 +21,11 @@ import (
 	payloadattribute "github.com/prysmaticlabs/prysm/v5/consensus-types/payload-attribute"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 const blobCommitmentVersionKZG uint8 = 0x01

beacon-chain/blockchain/head.go

@@ -18,11 +18,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/math"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 // UpdateAndSaveHeadWithBalances updates the beacon state head after getting justified balanced from cache.

beacon-chain/blockchain/kzg/BUILD.bazel

@@ -3,6 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "kzg.go",
         "trusted_setup.go",
         "validation.go",
     ],
@@ -12,6 +13,9 @@ go_library(
     deps = [
         "//consensus-types/blocks:go_default_library",
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_ethereum_c_kzg_4844//bindings/go:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//crypto/kzg4844:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/blockchain/kzg/kzg.go

@@ -0,0 +1,109 @@
+package kzg
+
+import (
+	"errors"
+
+	ckzg4844 "github.com/ethereum/c-kzg-4844/bindings/go"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+)
+
+// BytesPerBlob is the number of bytes in a single blob.
+const BytesPerBlob = ckzg4844.BytesPerBlob
+
+// Blob represents a serialized chunk of data.
+type Blob [BytesPerBlob]byte
+
+// BytesPerCell is the number of bytes in a single cell.
+const BytesPerCell = ckzg4844.BytesPerCell
+
+// Cell represents a chunk of an encoded Blob.
+type Cell [BytesPerCell]byte
+
+// Commitment represent a KZG commitment to a Blob.
+type Commitment [48]byte
+
+// Proof represents a KZG proof that attests to the validity of a Blob or parts of it.
+type Proof [48]byte
+
+// Bytes48 is a 48-byte array.
+type Bytes48 = ckzg4844.Bytes48
+
+// Bytes32 is a 32-byte array.
+type Bytes32 = ckzg4844.Bytes32
+
+// CellsAndProofs represents the Cells and Proofs corresponding to
+// a single blob.
+type CellsAndProofs struct {
+	Cells  []Cell
+	Proofs []Proof
+}
+
+func BlobToKZGCommitment(blob *Blob) (Commitment, error) {
+	comm, err := kzg4844.BlobToCommitment(kzg4844.Blob(*blob))
+	if err != nil {
+		return Commitment{}, err
+	}
+	return Commitment(comm), nil
+}
+
+func ComputeBlobKZGProof(blob *Blob, commitment Commitment) (Proof, error) {
+	proof, err := kzg4844.ComputeBlobProof(kzg4844.Blob(*blob), kzg4844.Commitment(commitment))
+	if err != nil {
+		return [48]byte{}, err
+	}
+	return Proof(proof), nil
+}
+
+func ComputeCellsAndKZGProofs(blob *Blob) (CellsAndProofs, error) {
+	ckzgBlob := (*ckzg4844.Blob)(blob)
+	ckzgCells, ckzgProofs, err := ckzg4844.ComputeCellsAndKZGProofs(ckzgBlob)
+	if err != nil {
+		return CellsAndProofs{}, err
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+func VerifyCellKZGProofBatch(commitmentsBytes []Bytes48, cellIndices []uint64, cells []Cell, proofsBytes []Bytes48) (bool, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgCells := make([]ckzg4844.Cell, len(cells))
+	for i := range cells {
+		ckzgCells[i] = ckzg4844.Cell(cells[i])
+	}
+
+	return ckzg4844.VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, ckzgCells, proofsBytes)
+}
+
+func RecoverCellsAndKZGProofs(cellIndices []uint64, partialCells []Cell) (CellsAndProofs, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgPartialCells := make([]ckzg4844.Cell, len(partialCells))
+	for i := range partialCells {
+		ckzgPartialCells[i] = ckzg4844.Cell(partialCells[i])
+	}
+
+	ckzgCells, ckzgProofs, err := ckzg4844.RecoverCellsAndKZGProofs(cellIndices, ckzgPartialCells)
+	if err != nil {
+		return CellsAndProofs{}, err
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+// Convert cells/proofs to the CellsAndProofs type defined in this package.
+func makeCellsAndProofs(ckzgCells []ckzg4844.Cell, ckzgProofs []ckzg4844.KZGProof) (CellsAndProofs, error) {
+	if len(ckzgCells) != len(ckzgProofs) {
+		return CellsAndProofs{}, errors.New("different number of cells/proofs")
+	}
+
+	var cells []Cell
+	var proofs []Proof
+	for i := range ckzgCells {
+		cells = append(cells, Cell(ckzgCells[i]))
+		proofs = append(proofs, Proof(ckzgProofs[i]))
+	}
+
+	return CellsAndProofs{
+		Cells:  cells,
+		Proofs: proofs,
+	}, nil
+}

beacon-chain/blockchain/kzg/trusted_setup.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	CKZG "github.com/ethereum/c-kzg-4844/bindings/go"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 )
 
@@ -12,17 +14,53 @@ var (
 	//go:embed trusted_setup.json
 	embeddedTrustedSetup []byte // 1.2Mb
 	kzgContext           *GoKZG.Context
+	kzgLoaded            bool
 )
 
+type TrustedSetup struct {
+	G1Monomial [GoKZG.ScalarsPerBlob]GoKZG.G1CompressedHexStr `json:"g1_monomial"`
+	G1Lagrange [GoKZG.ScalarsPerBlob]GoKZG.G1CompressedHexStr `json:"g1_lagrange"`
+	G2Monomial [65]GoKZG.G2CompressedHexStr                   `json:"g2_monomial"`
+}
+
 func Start() error {
-	parsedSetup := GoKZG.JSONTrustedSetup{}
-	err := json.Unmarshal(embeddedTrustedSetup, &parsedSetup)
+	trustedSetup := &TrustedSetup{}
+	err := json.Unmarshal(embeddedTrustedSetup, trustedSetup)
 	if err != nil {
 		return errors.Wrap(err, "could not parse trusted setup JSON")
 	}
-	kzgContext, err = GoKZG.NewContext4096(&parsedSetup)
+	kzgContext, err = GoKZG.NewContext4096(&GoKZG.JSONTrustedSetup{
+		SetupG2:         trustedSetup.G2Monomial[:],
+		SetupG1Lagrange: trustedSetup.G1Lagrange})
 	if err != nil {
 		return errors.Wrap(err, "could not initialize go-kzg context")
 	}
+
+	// Length of a G1 point, converted from hex to binary.
+	g1MonomialBytes := make([]byte, len(trustedSetup.G1Monomial)*(len(trustedSetup.G1Monomial[0])-2)/2)
+	for i, g1 := range &trustedSetup.G1Monomial {
+		copy(g1MonomialBytes[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
+	}
+	// Length of a G1 point, converted from hex to binary.
+	g1LagrangeBytes := make([]byte, len(trustedSetup.G1Lagrange)*(len(trustedSetup.G1Lagrange[0])-2)/2)
+	for i, g1 := range &trustedSetup.G1Lagrange {
+		copy(g1LagrangeBytes[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
+	}
+	// Length of a G2 point, converted from hex to binary.
+	g2MonomialBytes := make([]byte, len(trustedSetup.G2Monomial)*(len(trustedSetup.G2Monomial[0])-2)/2)
+	for i, g2 := range &trustedSetup.G2Monomial {
+		copy(g2MonomialBytes[i*(len(g2)-2)/2:], hexutil.MustDecode(g2))
+	}
+	if !kzgLoaded {
+		// TODO: Provide a configuration option for this.
+		var precompute uint = 0
+
+		// Free the current trusted setup before running this method. CKZG
+		// panics if the same setup is run multiple times.
+		if err = CKZG.LoadTrustedSetup(g1MonomialBytes, g1LagrangeBytes, g2MonomialBytes, precompute); err != nil {
+			panic(err)
+		}
+	}
+	kzgLoaded = true
 	return nil
 }

beacon-chain/blockchain/lightclient_test.go

@@ -1,160 +0,0 @@
-package blockchain
-
-import (
-	"context"
-	"testing"
-
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	v1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
-	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
-)
-
-type testlc struct {
-	t              *testing.T
-	ctx            context.Context
-	state          state.BeaconState
-	block          interfaces.ReadOnlySignedBeaconBlock
-	attestedState  state.BeaconState
-	attestedHeader *ethpb.BeaconBlockHeader
-}
-
-func newTestLc(t *testing.T) *testlc {
-	return &testlc{t: t}
-}
-
-func (l *testlc) setupTest() *testlc {
-	ctx := context.Background()
-
-	slot := primitives.Slot(params.BeaconConfig().AltairForkEpoch * primitives.Epoch(params.BeaconConfig().SlotsPerEpoch)).Add(1)
-
-	attestedState, err := util.NewBeaconStateCapella()
-	require.NoError(l.t, err)
-	err = attestedState.SetSlot(slot)
-	require.NoError(l.t, err)
-
-	parent := util.NewBeaconBlockCapella()
-	parent.Block.Slot = slot
-
-	signedParent, err := blocks.NewSignedBeaconBlock(parent)
-	require.NoError(l.t, err)
-
-	parentHeader, err := signedParent.Header()
-	require.NoError(l.t, err)
-	attestedHeader := parentHeader.Header
-
-	err = attestedState.SetLatestBlockHeader(attestedHeader)
-	require.NoError(l.t, err)
-	attestedStateRoot, err := attestedState.HashTreeRoot(ctx)
-	require.NoError(l.t, err)
-
-	// get a new signed block so the root is updated with the new state root
-	parent.Block.StateRoot = attestedStateRoot[:]
-	signedParent, err = blocks.NewSignedBeaconBlock(parent)
-	require.NoError(l.t, err)
-
-	state, err := util.NewBeaconStateCapella()
-	require.NoError(l.t, err)
-	err = state.SetSlot(slot)
-	require.NoError(l.t, err)
-
-	parentRoot, err := signedParent.Block().HashTreeRoot()
-	require.NoError(l.t, err)
-
-	block := util.NewBeaconBlockCapella()
-	block.Block.Slot = slot
-	block.Block.ParentRoot = parentRoot[:]
-
-	for i := uint64(0); i < params.BeaconConfig().MinSyncCommitteeParticipants; i++ {
-		block.Block.Body.SyncAggregate.SyncCommitteeBits.SetBitAt(i, true)
-	}
-
-	signedBlock, err := blocks.NewSignedBeaconBlock(block)
-	require.NoError(l.t, err)
-
-	h, err := signedBlock.Header()
-	require.NoError(l.t, err)
-
-	err = state.SetLatestBlockHeader(h.Header)
-	require.NoError(l.t, err)
-	stateRoot, err := state.HashTreeRoot(ctx)
-	require.NoError(l.t, err)
-
-	// get a new signed block so the root is updated with the new state root
-	block.Block.StateRoot = stateRoot[:]
-	signedBlock, err = blocks.NewSignedBeaconBlock(block)
-	require.NoError(l.t, err)
-
-	l.state = state
-	l.attestedState = attestedState
-	l.attestedHeader = attestedHeader
-	l.block = signedBlock
-	l.ctx = ctx
-
-	return l
-}
-
-func (l *testlc) checkAttestedHeader(update *ethpbv2.LightClientUpdate) {
-	require.Equal(l.t, l.attestedHeader.Slot, update.AttestedHeader.Slot, "Attested header slot is not equal")
-	require.Equal(l.t, l.attestedHeader.ProposerIndex, update.AttestedHeader.ProposerIndex, "Attested header proposer index is not equal")
-	require.DeepSSZEqual(l.t, l.attestedHeader.ParentRoot, update.AttestedHeader.ParentRoot, "Attested header parent root is not equal")
-	require.DeepSSZEqual(l.t, l.attestedHeader.BodyRoot, update.AttestedHeader.BodyRoot, "Attested header body root is not equal")
-
-	attestedStateRoot, err := l.attestedState.HashTreeRoot(l.ctx)
-	require.NoError(l.t, err)
-	require.DeepSSZEqual(l.t, attestedStateRoot[:], update.AttestedHeader.StateRoot, "Attested header state root is not equal")
-}
-
-func (l *testlc) checkSyncAggregate(update *ethpbv2.LightClientUpdate) {
-	syncAggregate, err := l.block.Block().Body().SyncAggregate()
-	require.NoError(l.t, err)
-	require.DeepSSZEqual(l.t, syncAggregate.SyncCommitteeBits, update.SyncAggregate.SyncCommitteeBits, "SyncAggregate bits is not equal")
-	require.DeepSSZEqual(l.t, syncAggregate.SyncCommitteeSignature, update.SyncAggregate.SyncCommitteeSignature, "SyncAggregate signature is not equal")
-}
-
-func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T) {
-	l := newTestLc(t).setupTest()
-
-	update, err := NewLightClientOptimisticUpdateFromBeaconState(l.ctx, l.state, l.block, l.attestedState)
-	require.NoError(t, err)
-	require.NotNil(t, update, "update is nil")
-
-	require.Equal(t, l.block.Block().Slot(), update.SignatureSlot, "Signature slot is not equal")
-
-	l.checkSyncAggregate(update)
-	l.checkAttestedHeader(update)
-
-	require.Equal(t, (*v1.BeaconBlockHeader)(nil), update.FinalizedHeader, "Finalized header is not nil")
-	require.DeepSSZEqual(t, ([][]byte)(nil), update.FinalityBranch, "Finality branch is not nil")
-}
-
-func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
-	l := newTestLc(t).setupTest()
-
-	update, err := NewLightClientFinalityUpdateFromBeaconState(l.ctx, l.state, l.block, l.attestedState, nil)
-	require.NoError(t, err)
-	require.NotNil(t, update, "update is nil")
-
-	require.Equal(t, l.block.Block().Slot(), update.SignatureSlot, "Signature slot is not equal")
-
-	l.checkSyncAggregate(update)
-	l.checkAttestedHeader(update)
-
-	zeroHash := params.BeaconConfig().ZeroHash[:]
-	require.NotNil(t, update.FinalizedHeader, "Finalized header is nil")
-	require.Equal(t, primitives.Slot(0), update.FinalizedHeader.Slot, "Finalized header slot is not zero")
-	require.Equal(t, primitives.ValidatorIndex(0), update.FinalizedHeader.ProposerIndex, "Finalized header proposer index is not zero")
-	require.DeepSSZEqual(t, zeroHash, update.FinalizedHeader.ParentRoot, "Finalized header parent root is not zero")
-	require.DeepSSZEqual(t, zeroHash, update.FinalizedHeader.StateRoot, "Finalized header state root is not zero")
-	require.DeepSSZEqual(t, zeroHash, update.FinalizedHeader.BodyRoot, "Finalized header body root is not zero")
-	require.Equal(t, FinalityBranchNumOfLeaves, len(update.FinalityBranch), "Invalid finality branch leaves")
-	for _, leaf := range update.FinalityBranch {
-		require.DeepSSZEqual(t, zeroHash, leaf, "Leaf is not zero")
-	}
-}

beacon-chain/blockchain/options.go

@@ -118,9 +118,9 @@ 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
 	}
 }

beacon-chain/blockchain/process_block.go

@@ -10,6 +10,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
 	coreTime "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
@@ -25,12 +26,12 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 // A custom slot deadline for processing state slots in our cache.
@@ -499,7 +500,7 @@ func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte
 	}
 	indices, err := bs.Indices(root)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "indices")
 	}
 	missing := make(map[uint64]struct{}, len(expected))
 	for i := range expected {
@@ -513,12 +514,39 @@ func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte
 	return missing, nil
 }
 
+func missingDataColumns(bs *filesystem.BlobStorage, root [32]byte, expected map[uint64]bool) (map[uint64]bool, error) {
+	if len(expected) == 0 {
+		return nil, nil
+	}
+
+	if len(expected) > int(params.BeaconConfig().NumberOfColumns) {
+		return nil, errMaxDataColumnsExceeded
+	}
+
+	indices, err := bs.ColumnIndices(root)
+	if err != nil {
+		return nil, err
+	}
+
+	missing := make(map[uint64]bool, len(expected))
+	for col := range expected {
+		if !indices[col] {
+			missing[col] = true
+		}
+	}
+
+	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 coreTime.PeerDASIsActive(signed.Block().Slot()) {
+		return s.isDataColumnsAvailable(ctx, root, signed)
+	}
 	if signed.Version() < version.Deneb {
 		return nil
 	}
@@ -548,7 +576,7 @@ 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)
 	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 {
@@ -567,8 +595,13 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 			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":          signed.Block().Slot(),
+				"root":          fmt.Sprintf("%#x", root),
+				"blobsExpected": expected,
+				"blobsWaiting":  len(missing),
+			}).Error("Still waiting for blobs DA check at slot end.")
 		})
 		defer nst.Stop()
 	}
@@ -590,12 +623,130 @@ 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,
+func (s *Service) isDataColumnsAvailable(ctx context.Context, root [32]byte, signed interfaces.ReadOnlySignedBeaconBlock) error {
+	if signed.Version() < version.Deneb {
+		return nil
+	}
+
+	block := signed.Block()
+	if block == nil {
+		return errors.New("invalid nil beacon block")
+	}
+	// 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
+	}
+
+	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
+	}
+
+	colMap, err := peerdas.CustodyColumns(s.cfg.P2P.NodeID(), peerdas.CustodySubnetCount())
+	if err != nil {
+		return errors.Wrap(err, "custody columns")
+	}
+
+	// Expected is the number of custody data columnns a node is expected to have.
+	expected := len(colMap)
+	if expected == 0 {
+		return nil
+	}
+
+	// Subscribe to newsly data columns stored in the database.
+	rootIndexChan := make(chan filesystem.RootIndexPair)
+	subscription := s.blobStorage.DataColumnFeed.Subscribe(rootIndexChan)
+	defer subscription.Unsubscribe()
+
+	// Get the count of data columns we already have in the store.
+	retrievedDataColumns, err := s.blobStorage.ColumnIndices(root)
+	if err != nil {
+		return errors.Wrap(err, "column indices")
+	}
+
+	retrievedDataColumnsCount := uint64(len(retrievedDataColumns))
+
+	// 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 peerdas.CanSelfReconstruct(retrievedDataColumnsCount) {
+		return nil
+	}
+
+	// Get a map of data column indices that are not currently available.
+	missing, err := missingDataColumns(s.blobStorage, root, colMap)
+	if err != nil {
+		return err
+	}
+
+	// If there are no missing indices, all data column sidecars are available.
+	// This is the happy path.
+	if len(missing) == 0 {
+		return nil
+	}
+
+	// Log for DA checks that cross over into the next slot; helpful for debugging.
+	nextSlot := slots.BeginsAt(signed.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(logrus.Fields{
+				"slot":            signed.Block().Slot(),
+				"root":            fmt.Sprintf("%#x", root),
+				"columnsExpected": expected,
+				"columnsWaiting":  len(missing),
+			}).Error("Still waiting for data columns DA check at slot end.")
+		})
+		defer nst.Stop()
+	}
+
+	for {
+		select {
+		case rootIndex := <-rootIndexChan:
+			if rootIndex.Root != root {
+				// This is not the root we are looking for.
+				continue
+			}
+
+			// This is a data column we are expecting.
+			if _, ok := missing[rootIndex.Index]; ok {
+				retrievedDataColumnsCount++
+			}
+
+			// 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 peerdas.CanSelfReconstruct(retrievedDataColumnsCount) {
+				return nil
+			}
+
+			// Remove the index from the missing map.
+			delete(missing, rootIndex.Index)
+
+			// Exit if there is no more missing data columns.
+			if len(missing) == 0 {
+				return nil
+			}
+		case <-ctx.Done():
+			missingIndexes := make([]uint64, 0, len(missing))
+			for val := range missing {
+				copiedVal := val
+				missingIndexes = append(missingIndexes, copiedVal)
+			}
+			return errors.Wrapf(ctx.Err(), "context deadline waiting for data column sidecars slot: %d, BlockRoot: %#x, missing %v", block.Slot(), root, missingIndexes)
+		}
 	}
 }
 
@@ -678,7 +829,7 @@ 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

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"time"
 
+	lightclient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
@@ -20,11 +22,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	mathutil "github.com/prysmaticlabs/prysm/v5/math"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 // CurrentSlot returns the current slot based on time.
@@ -176,7 +178,7 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 		}
 	}
 
-	update, err := NewLightClientFinalityUpdateFromBeaconState(
+	update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
 		ctx,
 		postState,
 		signed,
@@ -191,7 +193,7 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 	// Return the result
 	result := &ethpbv2.LightClientFinalityUpdateWithVersion{
 		Version: ethpbv2.Version(signed.Version()),
-		Data:    CreateLightClientFinalityUpdate(update),
+		Data:    lightclient.CreateLightClientFinalityUpdate(update),
 	}
 
 	// Send event
@@ -211,7 +213,7 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 		return 0, errors.Wrap(err, "could not get attested state")
 	}
 
-	update, err := NewLightClientOptimisticUpdateFromBeaconState(
+	update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
 		ctx,
 		postState,
 		signed,
@@ -225,7 +227,7 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 	// Return the result
 	result := &ethpbv2.LightClientOptimisticUpdateWithVersion{
 		Version: ethpbv2.Version(signed.Version()),
-		Data:    CreateLightClientOptimisticUpdate(update),
+		Data:    lightclient.CreateLightClientOptimisticUpdate(update),
 	}
 
 	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{

beacon-chain/blockchain/receive_attestation.go

@@ -12,11 +12,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 // reorgLateBlockCountAttestations is the time until the end of the slot in which we count

beacon-chain/blockchain/receive_block.go

@@ -21,12 +21,12 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
-	"go.opencensus.io/trace"
 	"golang.org/x/sync/errgroup"
 )
 
@@ -51,6 +51,12 @@ 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
+}
+
 // 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)

beacon-chain/blockchain/receive_data_column.go

@@ -0,0 +1,14 @@
+package blockchain
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+)
+
+func (s *Service) ReceiveDataColumn(ds blocks.VerifiedRODataColumn) error {
+	if err := s.blobStorage.SaveDataColumn(ds); err != nil {
+		return errors.Wrap(err, "save data column")
+	}
+
+	return nil
+}

beacon-chain/blockchain/service.go

@@ -39,10 +39,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	prysmTime "github.com/prysmaticlabs/prysm/v5/time"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
-	"go.opencensus.io/trace"
 )
 
 // Service represents a service that handles the internal
@@ -81,7 +81,7 @@ 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
@@ -106,15 +106,17 @@ var ErrMissingClockSetter = errors.New("blockchain Service initialized without a
 type blobNotifierMap struct {
 	sync.RWMutex
 	notifiers map[[32]byte]chan uint64
-	seenIndex map[[32]byte][fieldparams.MaxBlobsPerBlock]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) {
-	if idx >= fieldparams.MaxBlobsPerBlock {
-		return
-	}
+	// TODO: Separate Data Columns from blobs
+	/*
+		if idx >= fieldparams.MaxBlobsPerBlock {
+			return
+		}*/
 
 	bn.Lock()
 	seen := bn.seenIndex[root]
@@ -128,7 +130,7 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	// Retrieve or create the notifier channel for the given root.
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 
@@ -142,7 +144,7 @@ func (bn *blobNotifierMap) forRoot(root [32]byte) chan uint64 {
 	defer bn.Unlock()
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 	return c
@@ -168,7 +170,7 @@ 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][fieldparams.MaxBlobsPerBlock]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),
@@ -579,7 +579,7 @@ func (s *MockClockSetter) SetClock(g *startup.Clock) error {
 func TestNotifyIndex(t *testing.T) {
 	// Initialize a blobNotifierMap
 	bn := &blobNotifierMap{
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 		notifiers: make(map[[32]byte]chan uint64),
 	}
 

beacon-chain/blockchain/setup_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/blstoexec"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p"
+	p2pTesting "github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/testing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -45,6 +46,11 @@ 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
@@ -65,6 +71,11 @@ func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.B
 	return nil
 }
 
+func (mb *mockBroadcaster) BroadcastDataColumn(_ context.Context, _ uint64, _ *ethpb.DataColumnSidecar) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }
 

beacon-chain/blockchain/testing/mock.go

@@ -628,6 +628,11 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 	return nil
 }
 
+// ReceiveDataColumn implements the same method in chain service
+func (*ChainService) ReceiveDataColumn(_ blocks.VerifiedRODataColumn) error {
+	return nil
+}
+
 // TargetRootForEpoch mocks the same method in the chain service
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil

beacon-chain/cache/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "attestation_data.go",
         "balance_cache_key.go",
         "checkpoint_state.go",
+        "column_subnet_ids.go",
         "committee.go",
         "committee_disabled.go",  # keep
         "committees.go",

beacon-chain/cache/column_subnet_ids.go

@@ -0,0 +1,70 @@
+package cache
+
+import (
+	"sync"
+	"time"
+
+	"github.com/patrickmn/go-cache"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+)
+
+type columnSubnetIDs struct {
+	colSubCache *cache.Cache
+	colSubLock  sync.RWMutex
+}
+
+// ColumnSubnetIDs for column subnet participants
+var ColumnSubnetIDs = newColumnSubnetIDs()
+
+const columnKey = "columns"
+
+func newColumnSubnetIDs() *columnSubnetIDs {
+	secondsPerSlot := params.BeaconConfig().SecondsPerSlot
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	epochDuration := time.Duration(slotsPerEpoch.Mul(secondsPerSlot))
+
+	// Set the default duration of a column subnet subscription as the column expiry period.
+	minEpochsForDataColumnSidecarsRequest := time.Duration(params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest)
+	subLength := epochDuration * minEpochsForDataColumnSidecarsRequest
+
+	persistentCache := cache.New(subLength*time.Second, epochDuration*time.Second)
+	return &columnSubnetIDs{colSubCache: persistentCache}
+}
+
+// GetColumnSubnets retrieves the data column subnets.
+func (s *columnSubnetIDs) GetColumnSubnets() ([]uint64, bool, time.Time) {
+	s.colSubLock.RLock()
+	defer s.colSubLock.RUnlock()
+
+	id, duration, ok := s.colSubCache.GetWithExpiration(columnKey)
+	if !ok {
+		return nil, false, time.Time{}
+	}
+	// Retrieve indices from the cache.
+	idxs, ok := id.([]uint64)
+	if !ok {
+		return nil, false, time.Time{}
+	}
+
+	return idxs, ok, duration
+}
+
+// AddColumnSubnets adds the relevant data column subnets.
+func (s *columnSubnetIDs) AddColumnSubnets(colIdx []uint64) {
+	s.colSubLock.Lock()
+	defer s.colSubLock.Unlock()
+
+	s.colSubCache.Set(columnKey, colIdx, 0)
+}
+
+// EmptyAllCaches empties out all the related caches and flushes any stored
+// entries on them. This should only ever be used for testing, in normal
+// production, handling of the relevant subnets for each role is done
+// separately.
+func (s *columnSubnetIDs) EmptyAllCaches() {
+	// Clear the cache.
+	s.colSubLock.Lock()
+	defer s.colSubLock.Unlock()
+
+	s.colSubCache.Flush()
+}

beacon-chain/core/altair/BUILD.bazel

@@ -34,13 +34,13 @@ go_library(
         "//crypto/hash:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
     ],
 )
 

beacon-chain/core/altair/attestation.go

@@ -14,9 +14,9 @@ import (
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
-	"go.opencensus.io/trace"
 )
 
 // ProcessAttestationsNoVerifySignature applies processing operations to a block's inner attestation

beacon-chain/core/altair/epoch_precompute.go

@@ -10,7 +10,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/math"
-	"go.opencensus.io/trace"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 )
 
 // AttDelta contains rewards and penalties for a single attestation.

beacon-chain/core/altair/transition.go

@@ -7,7 +7,7 @@ import (
 	e "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epoch"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epoch/precompute"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"go.opencensus.io/trace"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 )
 
 // ProcessEpoch describes the per epoch operations that are performed on the beacon state.

beacon-chain/core/blocks/BUILD.bazel

@@ -40,6 +40,7 @@ go_library(
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
         "//math:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//network/forks:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
@@ -49,7 +50,6 @@ go_library(
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )

beacon-chain/core/blocks/attestation.go

@@ -14,10 +14,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"go.opencensus.io/trace"
 )
 
 // ProcessAttestationsNoVerifySignature applies processing operations to a block's inner attestation

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/epoch/precompute/BUILD.bazel

@@ -24,6 +24,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",
         "//runtime/version:go_default_library",

beacon-chain/core/epoch/precompute/attestation.go

@@ -11,10 +11,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"go.opencensus.io/trace"
 )
 
 // ProcessAttestations process the attestations in state and update individual validator's pre computes,

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

@@ -32,6 +32,9 @@ const (
 
 	// AttesterSlashingReceived is sent after an attester slashing is received from gossip or rpc
 	AttesterSlashingReceived = 8
+
+	// DataColumnSidecarReceived is sent after a data column sidecar is received from gossip or rpc.
+	DataColumnSidecarReceived = 9
 )
 
 // UnAggregatedAttReceivedData is the data sent with UnaggregatedAttReceived events.
@@ -77,3 +80,7 @@ type ProposerSlashingReceivedData struct {
 type AttesterSlashingReceivedData struct {
 	AttesterSlashing ethpb.AttSlashing
 }
+
+type DataColumnSidecarReceivedData struct {
+	DataColumn *blocks.VerifiedRODataColumn
+}

beacon-chain/core/helpers/BUILD.bazel

@@ -33,6 +33,7 @@ go_library(
         "//crypto/hash:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "//time:go_default_library",
@@ -42,7 +43,6 @@ go_library(
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
     ],
 )
 

beacon-chain/core/helpers/sync_committee_test.go

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

beacon-chain/core/helpers/validators.go

@@ -16,11 +16,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	log "github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 var (

beacon-chain/core/light-client/BUILD.bazel

@@ -0,0 +1,31 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["lightclient.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/state:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/eth/v1:go_default_library",
+        "//proto/eth/v2:go_default_library",
+        "//proto/migration:go_default_library",
+        "//time/slots:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["lightclient_test.go"],
+    deps = [
+        ":go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//proto/eth/v1:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+    ],
+)

beacon-chain/core/light-client/lightclient.go

@@ -1,18 +1,20 @@
-package blockchain
+package light_client
 
 import (
 	"bytes"
-	"context"
 	"fmt"
 
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
 	"github.com/prysmaticlabs/prysm/v5/proto/migration"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
+
+	"context"
+
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 )
 
 const (

beacon-chain/core/light-client/lightclient_test.go

@@ -0,0 +1,54 @@
+package light_client_test
+
+import (
+	"testing"
+
+	lightClient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+
+	v1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
+)
+
+func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T) {
+	l := util.NewTestLightClient(t).SetupTest()
+
+	update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState)
+	require.NoError(t, err)
+	require.NotNil(t, update, "update is nil")
+
+	require.Equal(t, l.Block.Block().Slot(), update.SignatureSlot, "Signature slot is not equal")
+
+	l.CheckSyncAggregate(update)
+	l.CheckAttestedHeader(update)
+
+	require.Equal(t, (*v1.BeaconBlockHeader)(nil), update.FinalizedHeader, "Finalized header is not nil")
+	require.DeepSSZEqual(t, ([][]byte)(nil), update.FinalityBranch, "Finality branch is not nil")
+}
+
+func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
+	l := util.NewTestLightClient(t).SetupTest()
+
+	update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, nil)
+	require.NoError(t, err)
+	require.NotNil(t, update, "update is nil")
+
+	require.Equal(t, l.Block.Block().Slot(), update.SignatureSlot, "Signature slot is not equal")
+
+	l.CheckSyncAggregate(update)
+	l.CheckAttestedHeader(update)
+
+	zeroHash := params.BeaconConfig().ZeroHash[:]
+	require.NotNil(t, update.FinalizedHeader, "Finalized header is nil")
+	require.Equal(t, primitives.Slot(0), update.FinalizedHeader.Slot, "Finalized header slot is not zero")
+	require.Equal(t, primitives.ValidatorIndex(0), update.FinalizedHeader.ProposerIndex, "Finalized header proposer index is not zero")
+	require.DeepSSZEqual(t, zeroHash, update.FinalizedHeader.ParentRoot, "Finalized header parent root is not zero")
+	require.DeepSSZEqual(t, zeroHash, update.FinalizedHeader.StateRoot, "Finalized header state root is not zero")
+	require.DeepSSZEqual(t, zeroHash, update.FinalizedHeader.BodyRoot, "Finalized header body root is not zero")
+	require.Equal(t, lightClient.FinalityBranchNumOfLeaves, len(update.FinalityBranch), "Invalid finality branch leaves")
+	for _, leaf := range update.FinalityBranch {
+		require.DeepSSZEqual(t, zeroHash, leaf, "Leaf is not zero")
+	}
+}

beacon-chain/core/peerdas/BUILD.bazel

@@ -0,0 +1,48 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "helpers.go",
+        "log.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/blockchain/kzg: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/interfaces:go_default_library",
+        "//crypto/hash:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_holiman_uint256//: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",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["helpers_test.go"],
+    deps = [
+        ":go_default_library",
+        "//beacon-chain/blockchain/kzg: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",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
+)

beacon-chain/core/peerdas/helpers.go

@@ -0,0 +1,587 @@
+package peerdas
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+	"math/big"
+	"slices"
+	"time"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sync/errgroup"
+
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/holiman/uint256"
+	errors "github.com/pkg/errors"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/kzg"
+
+	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+const (
+	CustodySubnetCountEnrKey = "csc"
+)
+
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/_features/eip7594/p2p-interface.md#the-discovery-domain-discv5
+type Csc uint8
+
+func (Csc) ENRKey() string { return CustodySubnetCountEnrKey }
+
+var (
+	// Custom errors
+	errCustodySubnetCountTooLarge   = errors.New("custody subnet count larger than data column sidecar subnet count")
+	errIndexTooLarge                = errors.New("column index is larger than the specified columns count")
+	errMismatchLength               = errors.New("mismatch in the length of the commitments and proofs")
+	errRecordNil                    = errors.New("record is nil")
+	errCannotLoadCustodySubnetCount = errors.New("cannot load the custody subnet count from peer")
+
+	// maxUint256 is the maximum value of a uint256.
+	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
+)
+
+// CustodyColumnSubnets computes the subnets the node should participate in for custody.
+func CustodyColumnSubnets(nodeId enode.ID, custodySubnetCount uint64) (map[uint64]bool, error) {
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+
+	// Check if the custody subnet count is larger than the data column sidecar subnet count.
+	if custodySubnetCount > dataColumnSidecarSubnetCount {
+		return nil, errCustodySubnetCountTooLarge
+	}
+
+	// First, compute the subnet IDs that the node should participate in.
+	subnetIds := make(map[uint64]bool, custodySubnetCount)
+
+	one := uint256.NewInt(1)
+
+	for currentId := new(uint256.Int).SetBytes(nodeId.Bytes()); uint64(len(subnetIds)) < custodySubnetCount; currentId.Add(currentId, one) {
+		// Convert to big endian bytes.
+		currentIdBytesBigEndian := currentId.Bytes32()
+
+		// Convert to little endian.
+		currentIdBytesLittleEndian := bytesutil.ReverseByteOrder(currentIdBytesBigEndian[:])
+
+		// Hash the result.
+		hashedCurrentId := hash.Hash(currentIdBytesLittleEndian)
+
+		// Get the subnet ID.
+		subnetId := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % dataColumnSidecarSubnetCount
+
+		// Add the subnet to the map.
+		subnetIds[subnetId] = true
+
+		// Overflow prevention.
+		if currentId.Cmp(maxUint256) == 0 {
+			currentId = uint256.NewInt(0)
+		}
+	}
+
+	return subnetIds, nil
+}
+
+// CustodyColumns computes the columns the node should custody.
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/_features/eip7594/das-core.md#helper-functions
+func CustodyColumns(nodeId enode.ID, custodySubnetCount uint64) (map[uint64]bool, error) {
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+
+	// Compute the custodied subnets.
+	subnetIds, err := CustodyColumnSubnets(nodeId, custodySubnetCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "custody subnets")
+	}
+
+	columnsPerSubnet := fieldparams.NumberOfColumns / dataColumnSidecarSubnetCount
+
+	// Knowing the subnet ID and the number of columns per subnet, select all the columns the node should custody.
+	// Columns belonging to the same subnet are contiguous.
+	columnIndices := make(map[uint64]bool, custodySubnetCount*columnsPerSubnet)
+	for i := uint64(0); i < columnsPerSubnet; i++ {
+		for subnetId := range subnetIds {
+			columnIndex := dataColumnSidecarSubnetCount*i + subnetId
+			columnIndices[columnIndex] = true
+		}
+	}
+
+	return columnIndices, nil
+}
+
+// DataColumnSidecars computes the data column sidecars from the signed block and blobs.
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/_features/eip7594/das-core.md#recover_matrix
+func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, blobs []kzg.Blob) ([]*ethpb.DataColumnSidecar, error) {
+	blobsCount := len(blobs)
+	if blobsCount == 0 {
+		return nil, nil
+	}
+
+	// Get the signed block header.
+	signedBlockHeader, err := signedBlock.Header()
+	if err != nil {
+		return nil, errors.Wrap(err, "signed block header")
+	}
+
+	// Get the block body.
+	block := signedBlock.Block()
+	blockBody := block.Body()
+
+	// Get the blob KZG commitments.
+	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// Compute the KZG commitments inclusion proof.
+	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
+	if err != nil {
+		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
+	}
+
+	// Compute cells and proofs.
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobsCount)
+
+	for i := range blobs {
+		blob := &blobs[i]
+		blobCellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(blob)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute cells and KZG proofs")
+		}
+
+		cellsAndProofs = append(cellsAndProofs, blobCellsAndProofs)
+	}
+
+	// Get the column sidecars.
+	sidecars := make([]*ethpb.DataColumnSidecar, 0, fieldparams.NumberOfColumns)
+	for columnIndex := uint64(0); columnIndex < fieldparams.NumberOfColumns; columnIndex++ {
+		column := make([]kzg.Cell, 0, blobsCount)
+		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
+
+		for rowIndex := 0; rowIndex < blobsCount; rowIndex++ {
+			cellsForRow := cellsAndProofs[rowIndex].Cells
+			proofsForRow := cellsAndProofs[rowIndex].Proofs
+
+			cell := cellsForRow[columnIndex]
+			column = append(column, cell)
+
+			kzgProof := proofsForRow[columnIndex]
+			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
+		}
+
+		columnBytes := make([][]byte, 0, blobsCount)
+		for i := range column {
+			columnBytes = append(columnBytes, column[i][:])
+		}
+
+		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
+		for _, kzgProof := range kzgProofOfColumn {
+			copiedProof := kzgProof
+			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, copiedProof[:])
+		}
+
+		sidecar := &ethpb.DataColumnSidecar{
+			ColumnIndex:                  columnIndex,
+			DataColumn:                   columnBytes,
+			KzgCommitments:               blobKzgCommitments,
+			KzgProof:                     kzgProofOfColumnBytes,
+			SignedBlockHeader:            signedBlockHeader,
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+
+		sidecars = append(sidecars, sidecar)
+	}
+
+	return sidecars, 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.
+	filteredIndices := make(map[uint64]bool, len(indices))
+	for i := range indices {
+		if i < blobCount {
+			filteredIndices[i] = true
+		}
+	}
+
+	// Transform set to slice.
+	indicesSlice := make([]uint64, 0, len(filteredIndices))
+	for i := range filteredIndices {
+		indicesSlice = append(indicesSlice, i)
+	}
+
+	// Sort the indices.
+	slices.Sort[[]uint64](indicesSlice)
+
+	return indicesSlice
+}
+
+// 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) {
+	columnCount := fieldparams.NumberOfColumns
+
+	neededColumnCount := columnCount / 2
+
+	// Check if all needed columns are present.
+	sliceIndexFromColumnIndex := make(map[uint64]int, len(dataColumnsSidecar))
+	for i := range dataColumnsSidecar {
+		dataColumnSideCar := dataColumnsSidecar[i]
+		columnIndex := dataColumnSideCar.ColumnIndex
+
+		if columnIndex < uint64(neededColumnCount) {
+			sliceIndexFromColumnIndex[columnIndex] = i
+		}
+	}
+
+	actualColumnCount := len(sliceIndexFromColumnIndex)
+
+	// Get missing columns.
+	if actualColumnCount < neededColumnCount {
+		missingColumns := make(map[int]bool, neededColumnCount-actualColumnCount)
+		for i := range neededColumnCount {
+			if _, ok := sliceIndexFromColumnIndex[uint64(i)]; !ok {
+				missingColumns[i] = true
+			}
+		}
+
+		missingColumnsSlice := make([]int, 0, len(missingColumns))
+		for i := range missingColumns {
+			missingColumnsSlice = append(missingColumnsSlice, i)
+		}
+
+		slices.Sort[[]int](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.DataColumn))
+
+	// Check all colums have te same length.
+	for i := range dataColumnsSidecar {
+		if uint64(len(dataColumnsSidecar[i].DataColumn)) != blobCount {
+			return nil, errors.Errorf("mismatch in the length of the data columns, expected %d, got %d", blobCount, len(dataColumnsSidecar[i].DataColumn))
+		}
+	}
+
+	// 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[uint64(columnIndex)]
+			if !ok {
+				return nil, errors.Errorf("missing column %d, this should never happen", columnIndex)
+			}
+
+			dataColumnSideCar := dataColumnsSidecar[sliceIndex]
+			cell := dataColumnSideCar.DataColumn[blobIndex]
+
+			for i := 0; i < len(cell); i++ {
+				blob[columnIndex*kzg.BytesPerCell+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
+}
+
+// DataColumnSidecarsForReconstruct is a TEMPORARY function until there is an official specification for it.
+// It is scheduled for deletion.
+func DataColumnSidecarsForReconstruct(
+	blobKzgCommitments [][]byte,
+	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
+	kzgCommitmentsInclusionProof [][]byte,
+	cellsAndProofs []kzg.CellsAndProofs,
+) ([]*ethpb.DataColumnSidecar, error) {
+	// Each CellsAndProofs corresponds to a Blob
+	// So we can get the BlobCount by checking the length of CellsAndProofs
+	blobsCount := len(cellsAndProofs)
+	if blobsCount == 0 {
+		return nil, nil
+	}
+
+	// Get the column sidecars.
+	sidecars := make([]*ethpb.DataColumnSidecar, 0, fieldparams.NumberOfColumns)
+	for columnIndex := uint64(0); columnIndex < fieldparams.NumberOfColumns; columnIndex++ {
+		column := make([]kzg.Cell, 0, blobsCount)
+		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
+
+		for rowIndex := 0; rowIndex < blobsCount; rowIndex++ {
+			cellsForRow := cellsAndProofs[rowIndex].Cells
+			proofsForRow := cellsAndProofs[rowIndex].Proofs
+
+			cell := cellsForRow[columnIndex]
+			column = append(column, cell)
+
+			kzgProof := proofsForRow[columnIndex]
+			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
+		}
+
+		columnBytes := make([][]byte, 0, blobsCount)
+		for i := range column {
+			columnBytes = append(columnBytes, column[i][:])
+		}
+
+		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
+		for _, kzgProof := range kzgProofOfColumn {
+			copiedProof := kzgProof
+			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, copiedProof[:])
+		}
+
+		sidecar := &ethpb.DataColumnSidecar{
+			ColumnIndex:                  columnIndex,
+			DataColumn:                   columnBytes,
+			KzgCommitments:               blobKzgCommitments,
+			KzgProof:                     kzgProofOfColumnBytes,
+			SignedBlockHeader:            signedBlockHeader,
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+
+		sidecars = append(sidecars, sidecar)
+	}
+
+	return sidecars, nil
+}
+
+// VerifyDataColumnSidecarKZGProofs verifies the provided KZG Proofs for the particular
+// data column.
+func VerifyDataColumnSidecarKZGProofs(sc blocks.RODataColumn) (bool, error) {
+	if sc.ColumnIndex >= params.BeaconConfig().NumberOfColumns {
+		return false, errIndexTooLarge
+	}
+	if len(sc.DataColumn) != len(sc.KzgCommitments) || len(sc.KzgCommitments) != len(sc.KzgProof) {
+		return false, errMismatchLength
+	}
+
+	var commitments []kzg.Bytes48
+	var indices []uint64
+	var cells []kzg.Cell
+	var proofs []kzg.Bytes48
+	for i := range sc.DataColumn {
+		commitments = append(commitments, kzg.Bytes48(sc.KzgCommitments[i]))
+		indices = append(indices, sc.ColumnIndex)
+		cells = append(cells, kzg.Cell(sc.DataColumn[i]))
+		proofs = append(proofs, kzg.Bytes48(sc.KzgProof[i]))
+	}
+
+	return kzg.VerifyCellKZGProofBatch(commitments, indices, cells, proofs)
+}
+
+// CustodySubnetCount returns the number of subnets the node should participate in for custody.
+func CustodySubnetCount() uint64 {
+	count := params.BeaconConfig().CustodyRequirement
+	if flags.Get().SubscribeToAllSubnets {
+		count = params.BeaconConfig().DataColumnSidecarSubnetCount
+	}
+	return count
+}
+
+// CustodyColumnCount returns the number of columns the node should custody.
+func CustodyColumnCount() uint64 {
+	// Get the number of subnets.
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+
+	// Compute the number of columns per subnet.
+	columnsPerSubnet := fieldparams.NumberOfColumns / dataColumnSidecarSubnetCount
+
+	// Get the number of subnets we custody
+	custodySubnetCount := CustodySubnetCount()
+
+	// Finally, compute the number of columns we should custody.
+	custodyColumnCount := custodySubnetCount * columnsPerSubnet
+
+	return custodyColumnCount
+}
+
+// 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
+}
+
+// ExtendedSampleCount computes, for a given number of samples per slot and allowed failures the
+// number of samples we should actually query from peers.
+// TODO: Add link to the specification once it is available.
+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
+}
+
+func CustodyCountFromRecord(record *enr.Record) (uint64, error) {
+	// By default, we assume the peer custodies the minimum number of subnets.
+	if record == nil {
+		return 0, errRecordNil
+	}
+
+	// Load the `custody_subnet_count`
+	var csc Csc
+	if err := record.Load(&csc); err != nil {
+		return 0, errCannotLoadCustodySubnetCount
+	}
+
+	return uint64(csc), nil
+}
+
+func CanSelfReconstruct(numCol uint64) bool {
+	total := params.BeaconConfig().NumberOfColumns
+	// 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
+	columnsNeeded := total/2 + total%2
+	return numCol >= columnsNeeded
+}
+
+// RecoverCellsAndProofs recovers the cells and proofs from the data column sidecars.
+func RecoverCellsAndProofs(
+	dataColumnSideCars []*ethpb.DataColumnSidecar,
+	blockRoot [fieldparams.RootLength]byte,
+) ([]kzg.CellsAndProofs, error) {
+	var wg errgroup.Group
+
+	dataColumnSideCarsCount := len(dataColumnSideCars)
+
+	if dataColumnSideCarsCount == 0 {
+		return nil, errors.New("no data column sidecars")
+	}
+
+	// Check if all columns have the same length.
+	blobCount := len(dataColumnSideCars[0].DataColumn)
+	for _, sidecar := range dataColumnSideCars {
+		length := len(sidecar.DataColumn)
+
+		if length != blobCount {
+			return nil, errors.New("columns do not have the same length")
+		}
+	}
+
+	// Recover cells and compute proofs in parallel.
+	recoveredCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+
+	for blobIndex := 0; blobIndex < blobCount; blobIndex++ {
+		bIndex := blobIndex
+		wg.Go(func() error {
+			start := time.Now()
+
+			cellsIndices := make([]uint64, 0, dataColumnSideCarsCount)
+			cells := make([]kzg.Cell, 0, dataColumnSideCarsCount)
+
+			for _, sidecar := range dataColumnSideCars {
+				// Build the cell indices.
+				cellsIndices = append(cellsIndices, sidecar.ColumnIndex)
+
+				// Get the cell.
+				column := sidecar.DataColumn
+				cell := column[bIndex]
+
+				cells = append(cells, kzg.Cell(cell))
+			}
+
+			// Recover the cells and proofs for the corresponding blob
+			cellsAndProofs, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
+
+			if err != nil {
+				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", bIndex)
+			}
+
+			recoveredCellsAndProofs[bIndex] = cellsAndProofs
+			log.WithFields(logrus.Fields{
+				"elapsed": time.Since(start),
+				"index":   bIndex,
+				"root":    fmt.Sprintf("%x", blockRoot),
+			}).Debug("Recovered cells and proofs")
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, err
+	}
+
+	return recoveredCellsAndProofs, nil
+}

beacon-chain/core/peerdas/helpers_test.go

@@ -0,0 +1,544 @@
+package peerdas_test
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/kzg"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
+	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/sirupsen/logrus"
+)
+
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func GetRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// Returns a random blob using the passed seed as entropy
+func GetRandBlob(seed int64) kzg.Blob {
+	var blob kzg.Blob
+	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
+		fieldElementBytes := GetRandFieldElement(seed + int64(i))
+		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
+	}
+	return blob
+}
+
+func GenerateCommitmentAndProof(blob *kzg.Blob) (*kzg.Commitment, *kzg.Proof, error) {
+	commitment, err := kzg.BlobToKZGCommitment(blob)
+	if err != nil {
+		return nil, nil, err
+	}
+	proof, err := kzg.ComputeBlobKZGProof(blob, commitment)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &commitment, &proof, err
+}
+
+func TestVerifyDataColumnSidecarKZGProofs(t *testing.T) {
+	dbBlock := util.NewBeaconBlockDeneb()
+	require.NoError(t, kzg.Start())
+
+	var (
+		comms [][]byte
+		blobs []kzg.Blob
+	)
+	for i := int64(0); i < 6; i++ {
+		blob := GetRandBlob(i)
+		commitment, _, err := GenerateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+		comms = append(comms, commitment[:])
+		blobs = append(blobs, blob)
+	}
+
+	dbBlock.Block.Body.BlobKzgCommitments = comms
+	sBlock, err := blocks.NewSignedBeaconBlock(dbBlock)
+	require.NoError(t, err)
+	sCars, err := peerdas.DataColumnSidecars(sBlock, blobs)
+	require.NoError(t, err)
+
+	for i, sidecar := range sCars {
+		roCol, err := blocks.NewRODataColumn(sidecar)
+		require.NoError(t, err)
+		verified, err := peerdas.VerifyDataColumnSidecarKZGProofs(roCol)
+		require.NoError(t, err)
+		require.Equal(t, true, verified, fmt.Sprintf("sidecar %d failed", i))
+	}
+}
+
+func TestDataColumnSidecars(t *testing.T) {
+	var expected []*ethpb.DataColumnSidecar = nil
+	actual, err := peerdas.DataColumnSidecars(nil, []kzg.Blob{})
+	require.NoError(t, err)
+
+	require.DeepSSZEqual(t, expected, actual)
+}
+
+func TestBlobs(t *testing.T) {
+	blobsIndice := map[uint64]bool{}
+
+	almostAllColumns := make([]*ethpb.DataColumnSidecar, 0, fieldparams.NumberOfColumns/2)
+	for i := 2; i < fieldparams.NumberOfColumns/2+2; i++ {
+		almostAllColumns = append(almostAllColumns, &ethpb.DataColumnSidecar{
+			ColumnIndex: uint64(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.
+	dataColumnsSidecar, err := peerdas.DataColumnSidecars(signedBeaconBlock, blobs)
+	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 TestCustodySubnetCount(t *testing.T) {
+	testCases := []struct {
+		name                  string
+		subscribeToAllSubnets bool
+		expected              uint64
+	}{
+		{
+			name:                  "subscribeToAllSubnets=false",
+			subscribeToAllSubnets: false,
+			expected:              params.BeaconConfig().CustodyRequirement,
+		},
+		{
+			name:                  "subscribeToAllSubnets=true",
+			subscribeToAllSubnets: true,
+			expected:              params.BeaconConfig().DataColumnSidecarSubnetCount,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Set flags.
+			resetFlags := flags.Get()
+			defer func() {
+				flags.Init(resetFlags)
+			}()
+
+			params.SetupTestConfigCleanup(t)
+			gFlags := new(flags.GlobalFlags)
+			gFlags.SubscribeToAllSubnets = tc.subscribeToAllSubnets
+			flags.Init(gFlags)
+
+			// Get the custody subnet count.
+			actual := peerdas.CustodySubnetCount()
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestCustodyColumnCount(t *testing.T) {
+	const expected uint64 = 8
+
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig().Copy()
+	config.DataColumnSidecarSubnetCount = 32
+	config.CustodyRequirement = 2
+	params.OverrideBeaconConfig(config)
+
+	actual := peerdas.CustodyColumnCount()
+	require.Equal(t, expected, actual)
+}
+
+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)
+}
+
+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 TestCustodyCountFromRecord(t *testing.T) {
+	const expected uint64 = 7
+
+	// Create an Ethereum record.
+	record := &enr.Record{}
+	record.Set(peerdas.Csc(expected))
+
+	actual, err := peerdas.CustodyCountFromRecord(record)
+	require.NoError(t, err)
+	require.Equal(t, expected, actual)
+}
+
+func TestCanSelfReconstruct(t *testing.T) {
+	testCases := []struct {
+		name                   string
+		totalNumberOfColumns   uint64
+		custodyNumberOfColumns uint64
+		expected               bool
+	}{
+		{
+			name:                   "totalNumberOfColumns=64, custodyNumberOfColumns=31",
+			totalNumberOfColumns:   64,
+			custodyNumberOfColumns: 31,
+			expected:               false,
+		},
+		{
+			name:                   "totalNumberOfColumns=64, custodyNumberOfColumns=32",
+			totalNumberOfColumns:   64,
+			custodyNumberOfColumns: 32,
+			expected:               true,
+		},
+		{
+			name:                   "totalNumberOfColumns=65, custodyNumberOfColumns=32",
+			totalNumberOfColumns:   65,
+			custodyNumberOfColumns: 32,
+			expected:               false,
+		},
+		{
+			name:                   "totalNumberOfColumns=63, custodyNumberOfColumns=33",
+			totalNumberOfColumns:   65,
+			custodyNumberOfColumns: 33,
+			expected:               true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Set the total number of columns.
+			params.SetupTestConfigCleanup(t)
+			cfg := params.BeaconConfig().Copy()
+			cfg.NumberOfColumns = tc.totalNumberOfColumns
+			params.OverrideBeaconConfig(cfg)
+
+			// Check if reconstuction is possible.
+			actual := peerdas.CanSelfReconstruct(tc.custodyNumberOfColumns)
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestReconstructionRoundTrip(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+
+	const blobCount = 5
+
+	var blockRoot [fieldparams.RootLength]byte
+
+	signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+	require.NoError(t, kzg.Start())
+
+	// Generate random blobs and their corresponding commitments.
+	var (
+		blobsKzgCommitments [][]byte
+		blobs               []kzg.Blob
+	)
+	for i := range blobCount {
+		blob := GetRandBlob(int64(i))
+		commitment, _, err := GenerateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+
+		blobsKzgCommitments = append(blobsKzgCommitments, commitment[:])
+		blobs = append(blobs, blob)
+	}
+
+	// Generate a signed beacon block.
+	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = blobsKzgCommitments
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+	require.NoError(t, err)
+
+	// Get the signed beacon block header.
+	signedBeaconBlockHeader, err := signedBeaconBlock.Header()
+	require.NoError(t, err)
+
+	// Convert data columns sidecars from signed block and blobs.
+	dataColumnSidecars, err := peerdas.DataColumnSidecars(signedBeaconBlock, blobs)
+	require.NoError(t, err)
+
+	// Create verified RO data columns.
+	verifiedRoDataColumns := make([]*blocks.VerifiedRODataColumn, 0, blobCount)
+	for _, dataColumnSidecar := range dataColumnSidecars {
+		roDataColumn, err := blocks.NewRODataColumn(dataColumnSidecar)
+		require.NoError(t, err)
+
+		verifiedRoDataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRoDataColumns = append(verifiedRoDataColumns, &verifiedRoDataColumn)
+	}
+
+	verifiedRoDataColumn := verifiedRoDataColumns[0]
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	var noDataColumns []*ethpb.DataColumnSidecar
+	dataColumnsWithDifferentLengths := []*ethpb.DataColumnSidecar{
+		{DataColumn: [][]byte{{}, {}}},
+		{DataColumn: [][]byte{{}}},
+	}
+	notEnoughDataColumns := dataColumnSidecars[:numberOfColumns/2-1]
+	originalDataColumns := dataColumnSidecars[:numberOfColumns/2]
+	extendedDataColumns := dataColumnSidecars[numberOfColumns/2:]
+	evenDataColumns := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns/2)
+	oddDataColumns := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns/2)
+	allDataColumns := dataColumnSidecars
+
+	for i, dataColumn := range dataColumnSidecars {
+		if i%2 == 0 {
+			evenDataColumns = append(evenDataColumns, dataColumn)
+		} else {
+			oddDataColumns = append(oddDataColumns, dataColumn)
+		}
+	}
+
+	testCases := []struct {
+		name               string
+		dataColumnsSidecar []*ethpb.DataColumnSidecar
+		isError            bool
+	}{
+		{
+			name:               "No data columns sidecars",
+			dataColumnsSidecar: noDataColumns,
+			isError:            true,
+		},
+		{
+			name:               "Data columns sidecar with different lengths",
+			dataColumnsSidecar: dataColumnsWithDifferentLengths,
+			isError:            true,
+		},
+		{
+			name:               "All columns are present (no actual need to reconstruct)",
+			dataColumnsSidecar: allDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only original columns are present",
+			dataColumnsSidecar: originalDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only extended columns are present",
+			dataColumnsSidecar: extendedDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only even columns are present",
+			dataColumnsSidecar: evenDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only odd columns are present",
+			dataColumnsSidecar: oddDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Not enough columns to reconstruct",
+			dataColumnsSidecar: notEnoughDataColumns,
+			isError:            true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Recover cells and proofs from available data columns sidecars.
+			cellsAndProofs, err := peerdas.RecoverCellsAndProofs(tc.dataColumnsSidecar, blockRoot)
+			isError := (err != nil)
+			require.Equal(t, tc.isError, isError)
+
+			if isError {
+				return
+			}
+
+			// Recover all data columns sidecars from cells and proofs.
+			reconstructedDataColumnsSideCars, err := peerdas.DataColumnSidecarsForReconstruct(
+				blobsKzgCommitments,
+				signedBeaconBlockHeader,
+				verifiedRoDataColumn.KzgCommitmentsInclusionProof,
+				cellsAndProofs,
+			)
+
+			require.NoError(t, err)
+
+			expected := dataColumnSidecars
+			actual := reconstructedDataColumnsSideCars
+			require.DeepSSZEqual(t, expected, actual)
+		})
+	}
+}

beacon-chain/core/peerdas/log.go

@@ -0,0 +1,5 @@
+package peerdas
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "peerdas")

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.PeerDASEnabled() && slots.ToEpoch(slot) >= params.BeaconConfig().Eip7594ForkEpoch
+}
+
 // 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/core/transition/BUILD.bazel

@@ -41,6 +41,7 @@ go_library(
         "//crypto/hash:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",

beacon-chain/core/transition/transition.go

@@ -25,8 +25,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"go.opencensus.io/trace"
+	goTrace "go.opencensus.io/trace"
 )
 
 type customProcessingFn func(context.Context, state.BeaconState) error
@@ -258,7 +259,7 @@ func cacheBestBeaconStateOnErrFn(highestSlot primitives.Slot, key [32]byte) cust
 //	      if (state.slot + 1) % SLOTS_PER_EPOCH == 0:
 //	          process_epoch(state)
 //	      state.slot = Slot(state.slot + 1)
-func ProcessSlotsCore(ctx context.Context, span *trace.Span, state state.BeaconState, slot primitives.Slot, fn customProcessingFn) (state.BeaconState, error) {
+func ProcessSlotsCore(ctx context.Context, span *goTrace.Span, state state.BeaconState, slot primitives.Slot, fn customProcessingFn) (state.BeaconState, error) {
 	var err error
 	for state.Slot() < slot {
 		if fn != nil {

beacon-chain/core/transition/transition_no_verify_sig.go

@@ -16,8 +16,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"go.opencensus.io/trace"
 )
 
 // ExecuteStateTransitionNoVerifyAnySig defines the procedure for a state transition function.

beacon-chain/das/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "availability.go",
+        "availability_columns.go",
         "cache.go",
         "iface.go",
         "mock.go",
@@ -20,6 +21,7 @@ go_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",
     ],

beacon-chain/das/availability_columns.go

@@ -0,0 +1,152 @@
+package das
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	errors "github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	log "github.com/sirupsen/logrus"
+)
+
+// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
+// This implementation will hold any blobs 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.BlobStorage
+	cache    *cache
+	verifier ColumnBatchVerifier
+	nodeID   enode.ID
+}
+
+type ColumnBatchVerifier interface {
+	VerifiedRODataColumns(ctx context.Context, blk blocks.ROBlock, sc []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error)
+}
+
+func NewLazilyPersistentStoreColumn(store *filesystem.BlobStorage, verifier ColumnBatchVerifier, id enode.ID) *LazilyPersistentStoreColumn {
+	return &LazilyPersistentStoreColumn{
+		store:    store,
+		cache:    newCache(),
+		verifier: verifier,
+		nodeID:   id,
+	}
+}
+
+// Persist do nothing at the moment.
+// TODO: Very Ugly, change interface to allow for columns and blobs
+func (*LazilyPersistentStoreColumn) Persist(_ primitives.Slot, _ ...blocks.ROBlob) error {
+	return nil
+}
+
+// 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 blobs referenced
+// by the given block are guaranteed to be persisted for the remainder of the retention period.
+func (s *LazilyPersistentStoreColumn) PersistColumns(current primitives.Slot, sc ...blocks.RODataColumn) error {
+	if len(sc) == 0 {
+		return nil
+	}
+	if len(sc) > 1 {
+		first := sc[0].BlockRoot()
+		for i := 1; i < len(sc); i++ {
+			if first != sc[i].BlockRoot() {
+				return errMixedRoots
+			}
+		}
+	}
+	if !params.WithinDAPeriod(slots.ToEpoch(sc[0].Slot()), slots.ToEpoch(current)) {
+		return nil
+	}
+	key := keyFromColumn(sc[0])
+	entry := s.cache.ensure(key)
+	for i := range sc {
+		if err := entry.stashColumns(&sc[i]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
+// BlobSidecars already in the db are assumed to have been previously verified against the block.
+func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error {
+	blockCommitments, err := fullCommitmentsToCheck(b, current)
+	if err != nil {
+		return errors.Wrapf(err, "could check data availability for block %#x", b.Root())
+	}
+	// Return early for blocks that are pre-deneb or which do not have any commitments.
+	if blockCommitments.count() == 0 {
+		return nil
+	}
+
+	key := keyFromBlock(b)
+	entry := s.cache.ensure(key)
+	defer s.cache.delete(key)
+	root := b.Root()
+	sumz, err := s.store.WaitForSummarizer(ctx)
+	if err != nil {
+		log.WithField("root", fmt.Sprintf("%#x", b.Root())).
+			WithError(err).
+			Debug("Failed to receive BlobStorageSummarizer within IsDataAvailable")
+	} else {
+		entry.setDiskSummary(sumz.Summary(root))
+	}
+
+	// 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.
+	sidecars, err := entry.filterColumns(root, &blockCommitments)
+	if err != nil {
+		return errors.Wrap(err, "incomplete BlobSidecar batch")
+	}
+	// Do thorough verifications of each BlobSidecar for the block.
+	// Same as above, we don't save BlobSidecars if there are any problems with the batch.
+	vscs, err := s.verifier.VerifiedRODataColumns(ctx, b, sidecars)
+	if err != nil {
+		var me verification.VerificationMultiError
+		ok := errors.As(err, &me)
+		if ok {
+			fails := me.Failures()
+			lf := make(log.Fields, len(fails))
+			for i := range fails {
+				lf[fmt.Sprintf("fail_%d", i)] = fails[i].Error()
+			}
+			log.WithFields(lf).
+				Debug("invalid ColumnSidecars received")
+		}
+		return errors.Wrapf(err, "invalid ColumnSidecars received for block %#x", root)
+	}
+	// Ensure that each column sidecar is written to disk.
+	for i := range vscs {
+		if err := s.store.SaveDataColumn(vscs[i]); err != nil {
+			return errors.Wrapf(err, "failed to save ColumnSidecar index %d for block %#x", vscs[i].ColumnIndex, root)
+		}
+	}
+	// All ColumnSidecars are persisted - da check succeeds.
+	return nil
+}
+
+func fullCommitmentsToCheck(b blocks.ROBlock, current primitives.Slot) (safeCommitmentsArray, error) {
+	var ar safeCommitmentsArray
+	if b.Version() < version.Deneb {
+		return ar, nil
+	}
+	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS
+	if !params.WithinDAPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(current)) {
+		return ar, nil
+	}
+	kc, err := b.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return ar, err
+	}
+	for i := range ar {
+		copy(ar[i], kc)
+	}
+	return ar, nil
+}

beacon-chain/das/cache.go

@@ -2,6 +2,7 @@ package das
 
 import (
 	"bytes"
+	"reflect"
 
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
@@ -38,6 +39,10 @@ func keyFromSidecar(sc blocks.ROBlob) cacheKey {
 	return cacheKey{slot: sc.Slot(), root: sc.BlockRoot()}
 }
 
+func keyFromColumn(sc blocks.RODataColumn) cacheKey {
+	return cacheKey{slot: sc.Slot(), root: sc.BlockRoot()}
+}
+
 // keyFromBlock is a convenience method for constructing a cacheKey from a ROBlock value.
 func keyFromBlock(b blocks.ROBlock) cacheKey {
 	return cacheKey{slot: b.Block().Slot(), root: b.Root()}
@@ -61,6 +66,7 @@ func (c *cache) delete(key cacheKey) {
 // cacheEntry holds a fixed-length cache of BlobSidecars.
 type cacheEntry struct {
 	scs         [fieldparams.MaxBlobsPerBlock]*blocks.ROBlob
+	colScs      [fieldparams.NumberOfColumns]*blocks.RODataColumn
 	diskSummary filesystem.BlobStorageSummary
 }
 
@@ -82,6 +88,17 @@ func (e *cacheEntry) stash(sc *blocks.ROBlob) error {
 	return nil
 }
 
+func (e *cacheEntry) stashColumns(sc *blocks.RODataColumn) error {
+	if sc.ColumnIndex >= fieldparams.NumberOfColumns {
+		return errors.Wrapf(errIndexOutOfBounds, "index=%d", sc.ColumnIndex)
+	}
+	if e.colScs[sc.ColumnIndex] != nil {
+		return errors.Wrapf(ErrDuplicateSidecar, "root=%#x, index=%d, commitment=%#x", sc.BlockRoot(), sc.ColumnIndex, sc.KzgCommitments)
+	}
+	e.colScs[sc.ColumnIndex] = sc
+	return nil
+}
+
 // filter evicts sidecars that are not committed to by the block and returns custom
 // errors if the cache is missing any of the commitments, or if the commitments in
 // the cache do not match those found in the block. If err is nil, then all expected
@@ -117,6 +134,35 @@ func (e *cacheEntry) filter(root [32]byte, kc safeCommitmentArray) ([]blocks.ROB
 	return scs, nil
 }
 
+func (e *cacheEntry) filterColumns(root [32]byte, kc *safeCommitmentsArray) ([]blocks.RODataColumn, error) {
+	if e.diskSummary.AllAvailable(kc.count()) {
+		return nil, nil
+	}
+	scs := make([]blocks.RODataColumn, 0, kc.count())
+	for i := uint64(0); i < fieldparams.NumberOfColumns; i++ {
+		// We already have this blob, we don't need to write it or validate it.
+		if e.diskSummary.HasIndex(i) {
+			continue
+		}
+		if kc[i] == nil {
+			if e.colScs[i] != nil {
+				return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, no block commitment", root, i, e.scs[i].KzgCommitment)
+			}
+			continue
+		}
+
+		if e.colScs[i] == nil {
+			return nil, errors.Wrapf(errMissingSidecar, "root=%#x, index=%#x", root, i)
+		}
+		if !reflect.DeepEqual(kc[i], e.colScs[i].KzgCommitments) {
+			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, e.colScs[i].KzgCommitments, kc[i])
+		}
+		scs = append(scs, *e.colScs[i])
+	}
+
+	return scs, nil
+}
+
 // safeCommitmentArray is a fixed size array of commitment byte slices. This is helpful for avoiding
 // gratuitous bounds checks.
 type safeCommitmentArray [fieldparams.MaxBlobsPerBlock][]byte
@@ -129,3 +175,14 @@ func (s safeCommitmentArray) count() int {
 	}
 	return fieldparams.MaxBlobsPerBlock
 }
+
+type safeCommitmentsArray [fieldparams.NumberOfColumns][][]byte
+
+func (s *safeCommitmentsArray) count() int {
+	for i := range s {
+		if s[i] == nil {
+			return i
+		}
+	}
+	return fieldparams.NumberOfColumns
+}

beacon-chain/db/filesystem/BUILD.bazel

@@ -13,6 +13,7 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem",
     visibility = ["//visibility:public"],
     deps = [
+        "//async/event:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",

beacon-chain/db/filesystem/blob.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/async/event"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -39,8 +40,15 @@ const (
 	directoryPermissions = 0700
 )
 
-// BlobStorageOption is a functional option for configuring a BlobStorage.
-type BlobStorageOption func(*BlobStorage) error
+type (
+	// BlobStorageOption is a functional option for configuring a BlobStorage.
+	BlobStorageOption func(*BlobStorage) error
+
+	RootIndexPair struct {
+		Root  [fieldparams.RootLength]byte
+		Index uint64
+	}
+)
 
 // WithBasePath is a required option that sets the base path of blob storage.
 func WithBasePath(base string) BlobStorageOption {
@@ -70,7 +78,10 @@ func WithSaveFsync(fsync bool) BlobStorageOption {
 // attempt to hold a file lock to guarantee exclusive control of the blob storage directory, so this should only be
 // initialized once per beacon node.
 func NewBlobStorage(opts ...BlobStorageOption) (*BlobStorage, error) {
-	b := &BlobStorage{}
+	b := &BlobStorage{
+		DataColumnFeed: new(event.Feed),
+	}
+
 	for _, o := range opts {
 		if err := o(b); err != nil {
 			return nil, errors.Wrap(err, "failed to create blob storage")
@@ -99,6 +110,7 @@ type BlobStorage struct {
 	fsync           bool
 	fs              afero.Fs
 	pruner          *blobPruner
+	DataColumnFeed  *event.Feed
 }
 
 // WarmCache runs the prune routine with an expiration of slot of 0, so nothing will be pruned, but the pruner's cache
@@ -221,6 +233,112 @@ func (bs *BlobStorage) Save(sidecar blocks.VerifiedROBlob) error {
 	return nil
 }
 
+// SaveDataColumn saves a data column to our local filesystem.
+func (bs *BlobStorage) SaveDataColumn(column blocks.VerifiedRODataColumn) error {
+	startTime := time.Now()
+	fname := namerForDataColumn(column)
+	sszPath := fname.path()
+	exists, err := afero.Exists(bs.fs, sszPath)
+	if err != nil {
+		return err
+	}
+
+	if exists {
+		log.Trace("Ignoring a duplicate data column sidecar save attempt")
+		return nil
+	}
+
+	if bs.pruner != nil {
+		hRoot, err := column.SignedBlockHeader.Header.HashTreeRoot()
+		if err != nil {
+			return err
+		}
+		if err := bs.pruner.notify(hRoot, column.SignedBlockHeader.Header.Slot, column.ColumnIndex); err != nil {
+			return errors.Wrapf(err, "problem maintaining pruning cache/metrics for sidecar with root=%#x", hRoot)
+		}
+	}
+
+	// Serialize the ethpb.DataColumnSidecar to binary data using SSZ.
+	sidecarData, err := column.MarshalSSZ()
+	if err != nil {
+		return errors.Wrap(err, "failed to serialize sidecar data")
+	} else if len(sidecarData) == 0 {
+		return errSidecarEmptySSZData
+	}
+
+	if err := bs.fs.MkdirAll(fname.dir(), directoryPermissions); err != nil {
+		return err
+	}
+	partPath := fname.partPath(fmt.Sprintf("%p", sidecarData))
+
+	partialMoved := false
+	// Ensure the partial file is deleted.
+	defer func() {
+		if partialMoved {
+			return
+		}
+		// It's expected to error if the save is successful.
+		err = bs.fs.Remove(partPath)
+		if err == nil {
+			log.WithFields(logrus.Fields{
+				"partPath": partPath,
+			}).Debugf("Removed partial file")
+		}
+	}()
+
+	// Create a partial file and write the serialized data to it.
+	partialFile, err := bs.fs.Create(partPath)
+	if err != nil {
+		return errors.Wrap(err, "failed to create partial file")
+	}
+
+	n, err := partialFile.Write(sidecarData)
+	if err != nil {
+		closeErr := partialFile.Close()
+		if closeErr != nil {
+			return closeErr
+		}
+		return errors.Wrap(err, "failed to write to partial file")
+	}
+	if bs.fsync {
+		if err := partialFile.Sync(); err != nil {
+			return err
+		}
+	}
+
+	if err := partialFile.Close(); err != nil {
+		return err
+	}
+
+	if n != len(sidecarData) {
+		return fmt.Errorf("failed to write the full bytes of sidecarData, wrote only %d of %d bytes", n, len(sidecarData))
+	}
+
+	if n == 0 {
+		return errEmptyBlobWritten
+	}
+
+	// Atomically rename the partial file to its final name.
+	err = bs.fs.Rename(partPath, sszPath)
+	if err != nil {
+		return errors.Wrap(err, "failed to rename partial file to final name")
+	}
+	partialMoved = true
+
+	// Notify the data column notifier that a new data column has been saved.
+	if bs.DataColumnFeed != nil {
+		bs.DataColumnFeed.Send(RootIndexPair{
+			Root:  column.BlockRoot(),
+			Index: column.ColumnIndex,
+		})
+	}
+
+	// TODO: Use new metrics for data columns
+	blobsWrittenCounter.Inc()
+	blobSaveLatency.Observe(float64(time.Since(startTime).Milliseconds()))
+	return nil
+}
+
 // Get retrieves a single BlobSidecar by its root and index.
 // Since BlobStorage only writes blobs that have undergone full verification, the return
 // value is always a VerifiedROBlob.
@@ -246,6 +364,20 @@ func (bs *BlobStorage) Get(root [32]byte, idx uint64) (blocks.VerifiedROBlob, er
 	return verification.BlobSidecarNoop(ro)
 }
 
+// GetColumn retrieves a single DataColumnSidecar by its root and index.
+func (bs *BlobStorage) GetColumn(root [32]byte, idx uint64) (*ethpb.DataColumnSidecar, error) {
+	expected := blobNamer{root: root, index: idx}
+	encoded, err := afero.ReadFile(bs.fs, expected.path())
+	if err != nil {
+		return nil, err
+	}
+	s := &ethpb.DataColumnSidecar{}
+	if err := s.UnmarshalSSZ(encoded); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
 // Remove removes all blobs for a given root.
 func (bs *BlobStorage) Remove(root [32]byte) error {
 	rootDir := blobNamer{root: root}.dir()
@@ -289,6 +421,61 @@ func (bs *BlobStorage) Indices(root [32]byte) ([fieldparams.MaxBlobsPerBlock]boo
 	return mask, nil
 }
 
+// ColumnIndices retrieve the stored column indexes from our filesystem.
+func (bs *BlobStorage) ColumnIndices(root [32]byte) (map[uint64]bool, error) {
+	custody := make(map[uint64]bool, fieldparams.NumberOfColumns)
+
+	// Get all the files in the directory.
+	rootDir := blobNamer{root: root}.dir()
+	entries, err := afero.ReadDir(bs.fs, rootDir)
+	if err != nil {
+		// If the directory does not exist, we do not custody any columns.
+		if os.IsNotExist(err) {
+			return nil, nil
+		}
+
+		return nil, errors.Wrap(err, "read directory")
+	}
+
+	// Iterate over all the entries in the directory.
+	for _, entry := range entries {
+		// If the entry is a directory, skip it.
+		if entry.IsDir() {
+			continue
+		}
+
+		// If the entry does not have the correct extension, skip it.
+		name := entry.Name()
+		if !strings.HasSuffix(name, sszExt) {
+			continue
+		}
+
+		// The file should be in the `<index>.<extension>` format.
+		// Skip the file if it does not match the format.
+		parts := strings.Split(name, ".")
+		if len(parts) != 2 {
+			continue
+		}
+
+		// Get the column index from the file name.
+		columnIndexStr := parts[0]
+		columnIndex, err := strconv.ParseUint(columnIndexStr, 10, 64)
+		if err != nil {
+			return nil, errors.Wrapf(err, "unexpected directory entry breaks listing, %s", parts[0])
+		}
+
+		// If the column index is out of bounds, return an error.
+		if columnIndex >= fieldparams.NumberOfColumns {
+			return nil, errors.Wrapf(errIndexOutOfBounds, "invalid index %d", columnIndex)
+		}
+
+		// Mark the column index as in custody.
+		custody[columnIndex] = true
+	}
+
+	return custody, nil
+}
+
 // Clear deletes all files on the filesystem.
 func (bs *BlobStorage) Clear() error {
 	dirs, err := listDir(bs.fs, ".")
@@ -321,6 +508,10 @@ func namerForSidecar(sc blocks.VerifiedROBlob) blobNamer {
 	return blobNamer{root: sc.BlockRoot(), index: sc.Index}
 }
 
+func namerForDataColumn(col blocks.VerifiedRODataColumn) blobNamer {
+	return blobNamer{root: col.BlockRoot(), index: col.ColumnIndex}
+}
+
 func (p blobNamer) dir() string {
 	return rootString(p.root)
 }

beacon-chain/db/filesystem/cache.go

@@ -9,7 +9,7 @@ import (
 )
 
 // blobIndexMask is a bitmask representing the set of blob indices that are currently set.
-type blobIndexMask [fieldparams.MaxBlobsPerBlock]bool
+type blobIndexMask [fieldparams.NumberOfColumns]bool
 
 // BlobStorageSummary represents cached information about the BlobSidecars on disk for each root the cache knows about.
 type BlobStorageSummary struct {
@@ -26,6 +26,15 @@ func (s BlobStorageSummary) HasIndex(idx uint64) bool {
 	return s.mask[idx]
 }
 
+// HasDataColumnIndex true if the DataColumnSidecar at the given index is available in the filesystem.
+func (s BlobStorageSummary) HasDataColumnIndex(idx uint64) bool {
+	// Protect from panic, but assume callers are sophisticated enough to not need an error telling them they have an invalid idx.
+	if idx >= fieldparams.NumberOfColumns {
+		return false
+	}
+	return s.mask[idx]
+}
+
 // AllAvailable returns true if we have all blobs for all indices from 0 to count-1.
 func (s BlobStorageSummary) AllAvailable(count int) bool {
 	if count > fieldparams.MaxBlobsPerBlock {
@@ -39,6 +48,21 @@ func (s BlobStorageSummary) AllAvailable(count int) bool {
 	return true
 }
 
+// AllDataColumnsAvailable returns true if we have all datacolumns for corresponding indices.
+func (s BlobStorageSummary) AllDataColumnsAvailable(indices map[uint64]bool) bool {
+	if uint64(len(indices)) > fieldparams.NumberOfColumns {
+		return false
+	}
+
+	for indice := range indices {
+		if !s.mask[indice] {
+			return false
+		}
+	}
+
+	return true
+}
+
 // BlobStorageSummarizer can be used to receive a summary of metadata about blobs on disk for a given root.
 // The BlobStorageSummary can be used to check which indices (if any) are available for a given block by root.
 type BlobStorageSummarizer interface {
@@ -68,9 +92,12 @@ func (s *blobStorageCache) Summary(root [32]byte) BlobStorageSummary {
 }
 
 func (s *blobStorageCache) ensure(key [32]byte, slot primitives.Slot, idx uint64) error {
-	if idx >= fieldparams.MaxBlobsPerBlock {
-		return errIndexOutOfBounds
-	}
+	// TODO: Separate blob index checks from data column index checks
+	/*
+		if idx >= fieldparams.MaxBlobsPerBlock {
+			return errIndexOutOfBounds
+		}
+	*/
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	v := s.cache[key]

beacon-chain/db/filesystem/cache_test.go

@@ -9,6 +9,7 @@ import (
 )
 
 func TestSlotByRoot_Summary(t *testing.T) {
+	t.Skip("Use new test for data columns")
 	var noneSet, allSet, firstSet, lastSet, oneSet blobIndexMask
 	firstSet[0] = true
 	lastSet[len(lastSet)-1] = true
@@ -148,3 +149,108 @@ func TestAllAvailable(t *testing.T) {
 		})
 	}
 }
+
+func TestHasDataColumnIndex(t *testing.T) {
+	storedIndices := map[uint64]bool{
+		1: true,
+		3: true,
+		5: true,
+	}
+
+	cases := []struct {
+		name     string
+		idx      uint64
+		expected bool
+	}{
+		{
+			name:     "index is too high",
+			idx:      fieldparams.NumberOfColumns,
+			expected: false,
+		},
+		{
+			name:     "non existing index",
+			idx:      2,
+			expected: false,
+		},
+		{
+			name:     "existing index",
+			idx:      3,
+			expected: true,
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			var mask blobIndexMask
+
+			for idx := range storedIndices {
+				mask[idx] = true
+			}
+
+			sum := BlobStorageSummary{mask: mask}
+			require.Equal(t, c.expected, sum.HasDataColumnIndex(c.idx))
+		})
+	}
+}
+
+func TestAllDataColumnAvailable(t *testing.T) {
+	tooManyColumns := make(map[uint64]bool, fieldparams.NumberOfColumns+1)
+	for i := uint64(0); i < fieldparams.NumberOfColumns+1; i++ {
+		tooManyColumns[i] = true
+	}
+
+	columns346 := map[uint64]bool{
+		3: true,
+		4: true,
+		6: true,
+	}
+
+	columns36 := map[uint64]bool{
+		3: true,
+		6: true,
+	}
+
+	cases := []struct {
+		name          string
+		storedIndices map[uint64]bool
+		testedIndices map[uint64]bool
+		expected      bool
+	}{
+		{
+			name:          "no tested indices",
+			storedIndices: columns346,
+			testedIndices: map[uint64]bool{},
+			expected:      true,
+		},
+		{
+			name:          "too many tested indices",
+			storedIndices: columns346,
+			testedIndices: tooManyColumns,
+			expected:      false,
+		},
+		{
+			name:          "not all tested indices are stored",
+			storedIndices: columns36,
+			testedIndices: columns346,
+			expected:      false,
+		},
+		{
+			name:          "all tested indices are stored",
+			storedIndices: columns346,
+			testedIndices: columns36,
+			expected:      true,
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			var mask blobIndexMask
+
+			for idx := range c.storedIndices {
+				mask[idx] = true
+			}
+
+			sum := BlobStorageSummary{mask: mask}
+			require.Equal(t, c.expected, sum.AllDataColumnsAvailable(c.testedIndices))
+		})
+	}
+}

beacon-chain/db/iface/BUILD.bazel

@@ -18,6 +18,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//monitoring/backup:go_default_library",
         "//proto/dbval:go_default_library",
+        "//proto/eth/v2:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
     ],

beacon-chain/db/iface/interface.go

@@ -7,6 +7,8 @@ import (
 	"context"
 	"io"
 
+	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filters"
 	slashertypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/slasher/types"
@@ -56,6 +58,9 @@ type ReadOnlyDatabase interface {
 	// Fee recipients operations.
 	FeeRecipientByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (common.Address, error)
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
+	// light client operations
+	LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]*ethpbv2.LightClientUpdateWithVersion, error)
+	LightClientUpdate(ctx context.Context, period uint64) (*ethpbv2.LightClientUpdateWithVersion, error)
 
 	// origin checkpoint sync support
 	OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
@@ -92,6 +97,8 @@ type NoHeadAccessDatabase interface {
 	// Fee recipients operations.
 	SaveFeeRecipientsByValidatorIDs(ctx context.Context, ids []primitives.ValidatorIndex, addrs []common.Address) error
 	SaveRegistrationsByValidatorIDs(ctx context.Context, ids []primitives.ValidatorIndex, regs []*ethpb.ValidatorRegistrationV1) error
+	// light client operations
+	SaveLightClientUpdate(ctx context.Context, period uint64, update *ethpbv2.LightClientUpdateWithVersion) error
 
 	CleanUpDirtyStates(ctx context.Context, slotsPerArchivedPoint primitives.Slot) error
 }

beacon-chain/db/kv/BUILD.bazel

@@ -16,6 +16,7 @@ go_library(
         "genesis.go",
         "key.go",
         "kv.go",
+        "lightclient.go",
         "log.go",
         "migration.go",
         "migration_archived_index.go",
@@ -50,7 +51,9 @@ go_library(
         "//io/file:go_default_library",
         "//monitoring/progress:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/dbval:go_default_library",
+        "//proto/eth/v2:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "//time:go_default_library",
@@ -87,6 +90,7 @@ go_test(
         "genesis_test.go",
         "init_test.go",
         "kv_test.go",
+        "lightclient_test.go",
         "migration_archived_index_test.go",
         "migration_block_slot_index_test.go",
         "migration_state_validators_test.go",
@@ -113,6 +117,7 @@ go_test(
         "//encoding/bytesutil:go_default_library",
         "//proto/dbval:go_default_library",
         "//proto/engine/v1:go_default_library",
+        "//proto/eth/v2:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/testing:go_default_library",
         "//runtime/version:go_default_library",

beacon-chain/db/kv/backup.go

@@ -8,8 +8,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/io/file"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
 const backupsDirectoryName = "backups"

beacon-chain/db/kv/blocks.go

@@ -16,17 +16,17 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/container/slice"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
-// used to represent errors for inconsistent slot ranges.
+// Used to represent errors for inconsistent slot ranges.
 var errInvalidSlotRange = errors.New("invalid end slot and start slot provided")
 
-// Block retrieval by root.
+// Block retrieval by root. Return nil if block is not found.
 func (s *Store) Block(ctx context.Context, blockRoot [32]byte) (interfaces.ReadOnlySignedBeaconBlock, error) {
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.Block")
 	defer span.End()

beacon-chain/db/kv/checkpoint.go

@@ -8,9 +8,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
 var errMissingStateForCheckpoint = errors.New("missing state summary for checkpoint root")

beacon-chain/db/kv/execution_chain.go

@@ -5,9 +5,9 @@ import (
 	"errors"
 
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	v2 "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 	"google.golang.org/protobuf/proto"
 )
 

beacon-chain/db/kv/finalized_block_roots.go

@@ -10,9 +10,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
 var previousFinalizedCheckpointKey = []byte("previous-finalized-checkpoint")

beacon-chain/db/kv/kv.go

@@ -107,6 +107,7 @@ var Buckets = [][]byte{
 	powchainBucket,
 	stateSummaryBucket,
 	stateValidatorsBucket,
+	lightClientUpdatesBucket,
 	// Indices buckets.
 	blockSlotIndicesBucket,
 	stateSlotIndicesBucket,

beacon-chain/db/kv/lightclient.go

@@ -0,0 +1,79 @@
+package kv
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
+	bolt "go.etcd.io/bbolt"
+	"go.opencensus.io/trace"
+)
+
+func (s *Store) SaveLightClientUpdate(ctx context.Context, period uint64, update *ethpbv2.LightClientUpdateWithVersion) error {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.saveLightClientUpdate")
+	defer span.End()
+
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(lightClientUpdatesBucket)
+		updateMarshalled, err := encode(ctx, update)
+		if err != nil {
+			return err
+		}
+		return bkt.Put(bytesutil.Uint64ToBytesBigEndian(period), updateMarshalled)
+	})
+}
+
+func (s *Store) LightClientUpdates(ctx context.Context, startPeriod, endPeriod uint64) (map[uint64]*ethpbv2.LightClientUpdateWithVersion, error) {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.LightClientUpdates")
+	defer span.End()
+
+	if startPeriod > endPeriod {
+		return nil, fmt.Errorf("start period %d is greater than end period %d", startPeriod, endPeriod)
+	}
+
+	updates := make(map[uint64]*ethpbv2.LightClientUpdateWithVersion)
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(lightClientUpdatesBucket)
+		c := bkt.Cursor()
+
+		firstPeriodInDb, _ := c.First()
+		if firstPeriodInDb == nil {
+			return nil
+		}
+
+		for k, v := c.Seek(bytesutil.Uint64ToBytesBigEndian(startPeriod)); k != nil && binary.BigEndian.Uint64(k) <= endPeriod; k, v = c.Next() {
+			currentPeriod := binary.BigEndian.Uint64(k)
+
+			var update ethpbv2.LightClientUpdateWithVersion
+			if err := decode(ctx, v, &update); err != nil {
+				return err
+			}
+			updates[currentPeriod] = &update
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+	return updates, err
+}
+
+func (s *Store) LightClientUpdate(ctx context.Context, period uint64) (*ethpbv2.LightClientUpdateWithVersion, error) {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.LightClientUpdate")
+	defer span.End()
+
+	var update ethpbv2.LightClientUpdateWithVersion
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(lightClientUpdatesBucket)
+		updateBytes := bkt.Get(bytesutil.Uint64ToBytesBigEndian(period))
+		if updateBytes == nil {
+			return nil
+		}
+		return decode(ctx, updateBytes, &update)
+	})
+	return &update, err
+}

beacon-chain/db/kv/lightclient_test.go

@@ -0,0 +1,648 @@
+package kv
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestStore_LightclientUpdate_CanSaveRetrieve(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	update := &ethpbv2.LightClientUpdate{
+		AttestedHeader:          nil,
+		NextSyncCommittee:       nil,
+		NextSyncCommitteeBranch: nil,
+		FinalizedHeader:         nil,
+		FinalityBranch:          nil,
+		SyncAggregate:           nil,
+		SignatureSlot:           7,
+	}
+
+	period := uint64(1)
+	err := db.SaveLightClientUpdate(ctx, period, &ethpbv2.LightClientUpdateWithVersion{
+		Version: 1,
+		Data:    update,
+	})
+	require.NoError(t, err)
+
+	// Retrieve the update
+	retrievedUpdate, err := db.LightClientUpdate(ctx, period)
+	require.NoError(t, err)
+	require.Equal(t, update.SignatureSlot, retrievedUpdate.Data.SignatureSlot, "retrieved update does not match saved update")
+
+}
+
+func TestStore_LightclientUpdates_canRetrieveRange(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           9,
+			},
+		},
+	}
+
+	for i, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(i+1), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdatesMap, err := db.LightClientUpdates(ctx, 1, 3)
+	require.NoError(t, err)
+	require.Equal(t, len(updates), len(retrievedUpdatesMap), "retrieved updates do not match saved updates")
+	for i, update := range updates {
+		require.Equal(t, update.Data.SignatureSlot, retrievedUpdatesMap[uint64(i+1)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+
+}
+
+func TestStore_LightClientUpdate_EndPeriodSmallerThanStartPeriod(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           9,
+			},
+		},
+	}
+
+	for i, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(i+1), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 3, 1)
+	require.NotNil(t, err)
+	require.Equal(t, err.Error(), "start period 3 is greater than end period 1")
+	require.IsNil(t, retrievedUpdates)
+
+}
+
+func TestStore_LightClientUpdate_EndPeriodEqualToStartPeriod(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           9,
+			},
+		},
+	}
+
+	for i, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(i+1), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 2, 2)
+	require.NoError(t, err)
+	require.Equal(t, 1, len(retrievedUpdates))
+	require.Equal(t, updates[1].Data.SignatureSlot, retrievedUpdates[2].Data.SignatureSlot, "retrieved update does not match saved update")
+}
+
+func TestStore_LightClientUpdate_StartPeriodBeforeFirstUpdate(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           9,
+			},
+		},
+	}
+
+	for i, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(i+2), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 0, 4)
+	require.NoError(t, err)
+	require.Equal(t, 3, len(retrievedUpdates))
+	for i, update := range updates {
+		require.Equal(t, update.Data.SignatureSlot, retrievedUpdates[uint64(i+2)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_EndPeriodAfterLastUpdate(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           9,
+			},
+		},
+	}
+
+	for i, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(i+1), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 1, 6)
+	require.NoError(t, err)
+	require.Equal(t, 3, len(retrievedUpdates))
+	for i, update := range updates {
+		require.Equal(t, update.Data.SignatureSlot, retrievedUpdates[uint64(i+1)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_PartialUpdates(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           9,
+			},
+		},
+	}
+
+	for i, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(i+1), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 1, 2)
+	require.NoError(t, err)
+	require.Equal(t, 2, len(retrievedUpdates))
+	for i, update := range updates[:2] {
+		require.Equal(t, update.Data.SignatureSlot, retrievedUpdates[uint64(i+1)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_MissingPeriods_SimpleData(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	updates := []*ethpbv2.LightClientUpdateWithVersion{
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           7,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           8,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           11,
+			},
+		},
+		{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           12,
+			},
+		},
+	}
+
+	for _, update := range updates {
+		err := db.SaveLightClientUpdate(ctx, uint64(update.Data.SignatureSlot), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 7, 12)
+	require.NoError(t, err)
+	require.Equal(t, 4, len(retrievedUpdates))
+	for _, update := range updates {
+		require.Equal(t, update.Data.SignatureSlot, retrievedUpdates[uint64(update.Data.SignatureSlot)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+
+	// Retrieve the updates from the middle
+	retrievedUpdates, err = db.LightClientUpdates(ctx, 8, 12)
+	require.NoError(t, err)
+	require.Equal(t, 3, len(retrievedUpdates))
+	require.Equal(t, updates[1].Data.SignatureSlot, retrievedUpdates[8].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, updates[2].Data.SignatureSlot, retrievedUpdates[11].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, updates[3].Data.SignatureSlot, retrievedUpdates[12].Data.SignatureSlot, "retrieved update does not match saved update")
+
+	// Retrieve the updates from after the missing period
+	retrievedUpdates, err = db.LightClientUpdates(ctx, 11, 12)
+	require.NoError(t, err)
+	require.Equal(t, 2, len(retrievedUpdates))
+	require.Equal(t, updates[2].Data.SignatureSlot, retrievedUpdates[11].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, updates[3].Data.SignatureSlot, retrievedUpdates[12].Data.SignatureSlot, "retrieved update does not match saved update")
+
+	//retrieve the updates from before the missing period to after the missing period
+	retrievedUpdates, err = db.LightClientUpdates(ctx, 3, 15)
+	require.NoError(t, err)
+	require.Equal(t, 4, len(retrievedUpdates))
+	require.Equal(t, updates[0].Data.SignatureSlot, retrievedUpdates[7].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, updates[1].Data.SignatureSlot, retrievedUpdates[8].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, updates[2].Data.SignatureSlot, retrievedUpdates[11].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, updates[3].Data.SignatureSlot, retrievedUpdates[12].Data.SignatureSlot, "retrieved update does not match saved update")
+}
+
+func TestStore_LightClientUpdate_EmptyDB(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+
+	// Retrieve the updates
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 1, 3)
+	require.IsNil(t, err)
+	require.Equal(t, 0, len(retrievedUpdates))
+}
+
+func TestStore_LightClientUpdate_MissingPeriodsAtTheEnd_SimpleData(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+
+	for i := 1; i < 4; i++ {
+		update := &ethpbv2.LightClientUpdateWithVersion{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           primitives.Slot(uint64(i)),
+			},
+		}
+		err := db.SaveLightClientUpdate(ctx, uint64(i), update)
+		require.NoError(t, err)
+	}
+	for i := 7; i < 10; i++ {
+		update := &ethpbv2.LightClientUpdateWithVersion{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           primitives.Slot(uint64(i)),
+			},
+		}
+		err := db.SaveLightClientUpdate(ctx, uint64(i), update)
+		require.NoError(t, err)
+	}
+
+	// Retrieve the updates from 1 to 5
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 1, 5)
+	require.NoError(t, err)
+	require.Equal(t, 3, len(retrievedUpdates))
+	require.Equal(t, primitives.Slot(1), retrievedUpdates[1].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, primitives.Slot(2), retrievedUpdates[2].Data.SignatureSlot, "retrieved update does not match saved update")
+	require.Equal(t, primitives.Slot(3), retrievedUpdates[3].Data.SignatureSlot, "retrieved update does not match saved update")
+
+}
+
+func setupLightClientTestDB(t *testing.T) (*Store, context.Context) {
+	db := setupDB(t)
+	ctx := context.Background()
+
+	for i := 10; i < 101; i++ { // 10 to 100
+		update := &ethpbv2.LightClientUpdateWithVersion{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           primitives.Slot(uint64(i)),
+			},
+		}
+		err := db.SaveLightClientUpdate(ctx, uint64(i), update)
+		require.NoError(t, err)
+	}
+
+	for i := 110; i < 201; i++ { // 110 to 200
+		update := &ethpbv2.LightClientUpdateWithVersion{
+			Version: 1,
+			Data: &ethpbv2.LightClientUpdate{
+				AttestedHeader:          nil,
+				NextSyncCommittee:       nil,
+				NextSyncCommitteeBranch: nil,
+				FinalizedHeader:         nil,
+				FinalityBranch:          nil,
+				SyncAggregate:           nil,
+				SignatureSlot:           primitives.Slot(uint64(i)),
+			},
+		}
+		err := db.SaveLightClientUpdate(ctx, uint64(i), update)
+		require.NoError(t, err)
+	}
+
+	return db, ctx
+}
+
+func TestStore_LightClientUpdate_MissingPeriodsInTheMiddleDistributed(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// Retrieve the updates - should fail because of missing periods in the middle
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 1, 300)
+	require.NoError(t, err)
+	require.Equal(t, 91*2, len(retrievedUpdates))
+	for i := 10; i < 101; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+	for i := 110; i < 201; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+
+}
+
+func TestStore_LightClientUpdate_RetrieveValidRangeFromStart(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// retrieve 1 to 100 - should work because all periods are present after the firstPeriodInDB > startPeriod
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 1, 100)
+	require.NoError(t, err)
+	require.Equal(t, 91, len(retrievedUpdates))
+	for i := 10; i < 101; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_RetrieveValidRangeInTheMiddle(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// retrieve 110 to 200 - should work because all periods are present
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 110, 200)
+	require.NoError(t, err)
+	require.Equal(t, 91, len(retrievedUpdates))
+	for i := 110; i < 201; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_MissingPeriodInTheMiddleConcentrated(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// retrieve 100 to 200
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 100, 200)
+	require.NoError(t, err)
+	require.Equal(t, 92, len(retrievedUpdates))
+	require.Equal(t, primitives.Slot(100), retrievedUpdates[100].Data.SignatureSlot, "retrieved update does not match saved update")
+	for i := 110; i < 201; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_MissingPeriodsAtTheEnd(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// retrieve 10 to 109
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 10, 109)
+	require.NoError(t, err)
+	require.Equal(t, 91, len(retrievedUpdates))
+	for i := 10; i < 101; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_MissingPeriodsAtTheBeginning(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// retrieve 105 to 200
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 105, 200)
+	require.NoError(t, err)
+	require.Equal(t, 91, len(retrievedUpdates))
+	for i := 110; i < 201; i++ {
+		require.Equal(t, primitives.Slot(uint64(i)), retrievedUpdates[uint64(i)].Data.SignatureSlot, "retrieved update does not match saved update")
+	}
+}
+
+func TestStore_LightClientUpdate_StartPeriodGreaterThanLastPeriod(t *testing.T) {
+	db, ctx := setupLightClientTestDB(t)
+
+	// retrieve 300 to 400
+	retrievedUpdates, err := db.LightClientUpdates(ctx, 300, 400)
+	require.NoError(t, err)
+	require.Equal(t, 0, len(retrievedUpdates))
+
+}

beacon-chain/db/kv/schema.go

@@ -17,6 +17,9 @@ var (
 	feeRecipientBucket    = []byte("fee-recipient")
 	registrationBucket    = []byte("registration")
 
+	// Light Client Updates Bucket
+	lightClientUpdatesBucket = []byte("light-client-updates")
+
 	// Deprecated: This bucket was migrated in PR 6461. Do not use, except for migrations.
 	slotsHasObjectBucket = []byte("slots-has-objects")
 	// Deprecated: This bucket was migrated in PR 6461. Do not use, except for migrations.

beacon-chain/db/kv/state_summary.go

@@ -4,9 +4,9 @@ import (
 	"context"
 
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
 // SaveStateSummary saves a state summary object to the DB.

beacon-chain/db/kv/utils.go

@@ -6,8 +6,8 @@ import (
 
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
 // lookupValuesForIndices takes in a list of indices and looks up

beacon-chain/db/kv/validated_checkpoint.go

@@ -3,9 +3,9 @@ package kv
 import (
 	"context"
 
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	bolt "go.etcd.io/bbolt"
-	"go.opencensus.io/trace"
 )
 
 // LastValidatedCheckpoint returns the latest fully validated checkpoint in beacon chain.

beacon-chain/execution/BUILD.bazel

@@ -50,6 +50,7 @@ go_library(
         "//io/logs:go_default_library",
         "//monitoring/clientstats:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//network:go_default_library",
         "//network/authorization:go_default_library",
         "//proto/engine/v1:go_default_library",
@@ -70,7 +71,6 @@ go_library(
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@io_k8s_client_go//tools/cache:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )

beacon-chain/execution/block_reader.go

@@ -10,7 +10,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution/types"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
-	"go.opencensus.io/trace"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 )
 
 // searchThreshold to apply for when searching for blocks of a particular time. If the buffer

beacon-chain/execution/engine_client.go

@@ -21,11 +21,11 @@ import (
 	payloadattribute "github.com/prysmaticlabs/prysm/v5/consensus-types/payload-attribute"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	pb "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 	"google.golang.org/protobuf/proto"
 )
 

beacon-chain/forkchoice/doubly-linked-tree/BUILD.bazel

@@ -33,6 +33,7 @@ go_library(
         "//consensus-types/forkchoice:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
@@ -40,7 +41,6 @@ go_library(
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_opencensus_go//trace:go_default_library",
     ],
 )
 

beacon-chain/forkchoice/doubly-linked-tree/forkchoice.go

@@ -15,11 +15,11 @@ import (
 	forkchoice2 "github.com/prysmaticlabs/prysm/v5/consensus-types/forkchoice"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 // New initializes a new fork choice store.

beacon-chain/forkchoice/doubly-linked-tree/store.go

@@ -9,8 +9,8 @@ import (
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
-	"go.opencensus.io/trace"
 )
 
 // head starts from justified root and then follows the best descendant links

beacon-chain/node/config.go

@@ -132,7 +132,7 @@ func configureEth1Config(cliCtx *cli.Context) error {
 }
 
 func configureNetwork(cliCtx *cli.Context) {
-	if len(cliCtx.StringSlice(cmd.BootstrapNode.Name)) > 0 {
+	if cliCtx.IsSet(cmd.BootstrapNode.Name) {
 		c := params.BeaconNetworkConfig()
 		c.BootstrapNodes = cliCtx.StringSlice(cmd.BootstrapNode.Name)
 		params.OverrideBeaconNetworkConfig(c)

beacon-chain/node/node.go

@@ -988,6 +988,7 @@ func (b *BeaconNode) registerRPCService(router *mux.Router) error {
 		FinalizationFetcher:           chainService,
 		BlockReceiver:                 chainService,
 		BlobReceiver:                  chainService,
+		DataColumnReceiver:            chainService,
 		AttestationReceiver:           chainService,
 		GenesisTimeFetcher:            chainService,
 		GenesisFetcher:                chainService,

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",
@@ -46,6 +47,7 @@ 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",
@@ -56,6 +58,7 @@ 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/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
@@ -66,6 +69,7 @@ go_library(
         "//io/file:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//monitoring/tracing/trace:go_default_library",
         "//network:go_default_library",
         "//network/forks:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
@@ -74,6 +78,8 @@ go_library(
         "//runtime/version:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_btcsuite_btcd_btcec_v2//:go_default_library",
+        "@com_github_ethereum_go_ethereum//crypto:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/discover:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
@@ -115,6 +121,7 @@ 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",
@@ -136,9 +143,11 @@ 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/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",
@@ -151,6 +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/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
         "//container/leaky-bucket:go_default_library",
@@ -161,13 +171,12 @@ 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",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time:go_default_library",
-        "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//crypto:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/discover:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",

beacon-chain/p2p/broadcaster.go

@@ -11,13 +11,14 @@ import (
 	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/altair"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -96,7 +97,12 @@ 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.
@@ -152,7 +158,7 @@ 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.
@@ -228,7 +234,12 @@ 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.
@@ -243,7 +254,7 @@ 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()
@@ -252,7 +263,7 @@ 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")
@@ -268,6 +279,99 @@ func (s *Service) internalBroadcastBlob(ctx context.Context, subnet uint64, blob
 	}
 }
 
+// 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, 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, columnSubnet, dataColumnSidecar, forkDigest)
+
+	return nil
+}
+
+func (s *Service) internalBroadcastDataColumn(
+	ctx context.Context,
+	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)
+	}
+
+	// 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")
@@ -297,14 +401,18 @@ 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)
 }
+
+func dataColumnSubnetToTopic(subnet uint64, forkDigest [fieldparams.VersionLength]byte) string {
+	return fmt.Sprintf(DataColumnSubnetTopicFormat, forkDigest, subnet)
+}

beacon-chain/p2p/broadcaster_test.go

@@ -13,11 +13,16 @@ import (
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/prysmaticlabs/go-bitfield"
+	"google.golang.org/protobuf/proto"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/kzg"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers/scorers"
 	p2ptest "github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/testing"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/wrapper"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -25,7 +30,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
-	"google.golang.org/protobuf/proto"
 )
 
 func TestService_Broadcast(t *testing.T) {
@@ -520,3 +524,70 @@ func TestService_BroadcastBlob(t *testing.T) {
 	require.NoError(t, p.BroadcastBlob(ctx, subnet, blobSidecar))
 	require.Equal(t, false, util.WaitTimeout(&wg, 1*time.Second), "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{},
+		}),
+	}
+
+	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockElectra())
+	require.NoError(t, err)
+	blobs := make([]kzg.Blob, fieldparams.MaxBlobsPerBlock)
+	sidecars, err := peerdas.DataColumnSidecars(b, blobs)
+	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()
+	require.ErrorContains(t, "attempted to broadcast nil", p.BroadcastDataColumn(ctx, subnet, nil))
+
+	// Broadcast to peers and wait.
+	require.NoError(t, p.BroadcastDataColumn(ctx, subnet, sidecar))
+	require.Equal(t, false, util.WaitTimeout(&wg, 1*time.Second), "Failed to receive pubsub within 1s")
+}

beacon-chain/p2p/custody.go

@@ -0,0 +1,118 @@
+package p2p
+
+import (
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+)
+
+// GetValidCustodyPeers returns a list of peers that custody a super set of the local node's custody columns.
+func (s *Service) GetValidCustodyPeers(peers []peer.ID) ([]peer.ID, error) {
+	// Get the total number of columns.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	localCustodySubnetCount := peerdas.CustodySubnetCount()
+	localCustodyColumns, err := peerdas.CustodyColumns(s.NodeID(), localCustodySubnetCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "custody columns for local node")
+	}
+
+	localCustotyColumnsCount := uint64(len(localCustodyColumns))
+
+	// Find the valid peers.
+	validPeers := make([]peer.ID, 0, len(peers))
+
+loop:
+	for _, pid := range peers {
+		// Get the custody subnets count of the remote peer.
+		remoteCustodySubnetCount := s.CustodyCountFromRemotePeer(pid)
+
+		// Get the remote node ID from the peer ID.
+		remoteNodeID, err := ConvertPeerIDToNodeID(pid)
+		if err != nil {
+			return nil, errors.Wrap(err, "convert peer ID to node ID")
+		}
+
+		// Get the custody columns of the remote peer.
+		remoteCustodyColumns, err := peerdas.CustodyColumns(remoteNodeID, remoteCustodySubnetCount)
+		if err != nil {
+			return nil, errors.Wrap(err, "custody columns")
+		}
+
+		remoteCustodyColumnsCount := uint64(len(remoteCustodyColumns))
+
+		// If the remote peer custodies less columns than the local node, skip it.
+		if remoteCustodyColumnsCount < localCustotyColumnsCount {
+			continue
+		}
+
+		// If the remote peers custodies all the possible columns, add it to the list.
+		if remoteCustodyColumnsCount == numberOfColumns {
+			copiedId := pid
+			validPeers = append(validPeers, copiedId)
+			continue
+		}
+
+		// Filter out invalid peers.
+		for c := range localCustodyColumns {
+			if !remoteCustodyColumns[c] {
+				continue loop
+			}
+		}
+
+		copiedId := pid
+
+		// Add valid peer to list
+		validPeers = append(validPeers, copiedId)
+	}
+
+	return validPeers, nil
+}
+
+// CustodyCountFromRemotePeer retrieves the custody count from a remote peer.
+func (s *Service) CustodyCountFromRemotePeer(pid peer.ID) uint64 {
+	// By default, we assume the peer custodies the minimum number of subnets.
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+
+	// First, try to get the custody count from the peer's metadata.
+	metadata, err := s.peers.Metadata(pid)
+	if err != nil {
+		log.WithError(err).WithField("peerID", pid).Debug("Failed to retrieve metadata for peer, defaulting to the ENR value")
+	}
+
+	if metadata != nil {
+		custodyCount := metadata.CustodySubnetCount()
+		if custodyCount > 0 {
+			return uint64(custodyCount)
+		}
+	}
+
+	log.WithField("peerID", pid).Debug("Failed to retrieve custody count from metadata for peer, defaulting to the ENR value")
+
+	// 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 subnets count from the ENR.
+	custodyCount, err := peerdas.CustodyCountFromRecord(record)
+	if err != nil {
+		log.WithError(err).WithFields(logrus.Fields{
+			"peerID":       pid,
+			"defaultValue": custodyRequirement,
+		}).Debug("Failed to retrieve custody count from ENR for peer, defaulting to the default value")
+
+		return custodyRequirement
+	}
+
+	return custodyCount
+}

beacon-chain/p2p/custody_test.go

@@ -0,0 +1,196 @@
+package p2p
+
+import (
+	"context"
+	"crypto/ecdsa"
+	"net"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/network"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers/scorers"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/wrapper"
+	ecdsaprysm "github.com/prysmaticlabs/prysm/v5/crypto/ecdsa"
+	prysmNetwork "github.com/prysmaticlabs/prysm/v5/network"
+	pb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/metadata"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func createPeer(t *testing.T, privateKeyOffset int, custodyCount uint64) (*enr.Record, peer.ID, *ecdsa.PrivateKey) {
+	privateKeyBytes := make([]byte, 32)
+	for i := 0; i < 32; i++ {
+		privateKeyBytes[i] = byte(privateKeyOffset + i)
+	}
+
+	unmarshalledPrivateKey, err := crypto.UnmarshalSecp256k1PrivateKey(privateKeyBytes)
+	require.NoError(t, err)
+
+	privateKey, err := ecdsaprysm.ConvertFromInterfacePrivKey(unmarshalledPrivateKey)
+	require.NoError(t, err)
+
+	peerID, err := peer.IDFromPrivateKey(unmarshalledPrivateKey)
+	require.NoError(t, err)
+
+	record := &enr.Record{}
+	record.Set(peerdas.Csc(custodyCount))
+	record.Set(enode.Secp256k1(privateKey.PublicKey))
+
+	return record, peerID, privateKey
+}
+
+func TestGetValidCustodyPeers(t *testing.T) {
+	genesisValidatorRoot := make([]byte, 32)
+
+	for i := 0; i < 32; i++ {
+		genesisValidatorRoot[i] = byte(i)
+	}
+
+	service := &Service{
+		cfg:                   &Config{},
+		genesisTime:           time.Now(),
+		genesisValidatorsRoot: genesisValidatorRoot,
+		peers: peers.NewStatus(context.Background(), &peers.StatusConfig{
+			ScorerParams: &scorers.Config{},
+		}),
+	}
+
+	ipAddrString, err := prysmNetwork.ExternalIPv4()
+	require.NoError(t, err)
+	ipAddr := net.ParseIP(ipAddrString)
+
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+
+	// Peer 1 custodies exactly the same columns than us.
+	// (We use the same keys pair than ours for simplicity)
+	peer1Record, peer1ID, localPrivateKey := createPeer(t, 1, custodyRequirement)
+
+	// Peer 2 custodies all the columns.
+	peer2Record, peer2ID, _ := createPeer(t, 2, dataColumnSidecarSubnetCount)
+
+	// Peer 3 custodies different columns than us (but the same count).
+	// (We use the same public key than peer 2 for simplicity)
+	peer3Record, peer3ID, _ := createPeer(t, 3, custodyRequirement)
+
+	// Peer 4 custodies less columns than us.
+	peer4Record, peer4ID, _ := createPeer(t, 4, custodyRequirement-1)
+
+	listener, err := service.createListener(ipAddr, localPrivateKey)
+	require.NoError(t, err)
+
+	service.dv5Listener = listener
+
+	service.peers.Add(peer1Record, peer1ID, nil, network.DirOutbound)
+	service.peers.Add(peer2Record, peer2ID, nil, network.DirOutbound)
+	service.peers.Add(peer3Record, peer3ID, nil, network.DirOutbound)
+	service.peers.Add(peer4Record, peer4ID, nil, network.DirOutbound)
+
+	actual, err := service.GetValidCustodyPeers([]peer.ID{peer1ID, peer2ID, peer3ID, peer4ID})
+	require.NoError(t, err)
+
+	expected := []peer.ID{peer1ID, peer2ID}
+	require.DeepSSZEqual(t, expected, actual)
+}
+
+func TestCustodyCountFromRemotePeer(t *testing.T) {
+	const (
+		expectedENR      uint64 = 7
+		expectedMetadata uint64 = 8
+		pid                     = "test-id"
+	)
+
+	csc := peerdas.Csc(expectedENR)
+
+	// Define a nil record
+	var nilRecord *enr.Record = nil
+
+	// Define an empty record (record with non `csc` entry)
+	emptyRecord := &enr.Record{}
+
+	// Define a nominal record
+	nominalRecord := &enr.Record{}
+	nominalRecord.Set(csc)
+
+	// Define a metadata with zero custody.
+	zeroMetadata := wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		CustodySubnetCount: []byte{0},
+	})
+
+	// Define a nominal metadata.
+	nominalMetadata := wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		CustodySubnetCount: []byte{uint8(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.CustodyCountFromRemotePeer(pid)
+
+			// Verify the result.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+
+}

beacon-chain/p2p/discovery.go

@@ -15,7 +15,9 @@ import (
 	ma "github.com/multiformats/go-multiaddr"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/go-bitfield"
+
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
 	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
@@ -42,67 +44,148 @@ const (
 	udp6
 )
 
+const quickProtocolEnrKey = "quic"
+
 type quicProtocol uint16
 
 // quicProtocol is the "quic" key, which holds the QUIC port of the node.
-func (quicProtocol) ENRKey() string { return "quic" }
+func (quicProtocol) ENRKey() string { return quickProtocolEnrKey }
 
-// RefreshENR uses an epoch to refresh the enr entry for our node
-// with the tracked committee ids for the epoch, allowing our node
-// to be dynamically discoverable by others given our tracked committee ids.
-func (s *Service) RefreshENR() {
-	// return early if discv5 isn't running
+// RefreshPersistentSubnets checks that we are tracking our local persistent subnets for a variety of gossip topics.
+// This routine checks for our attestation, sync committee and data column subnets and updates them if they have
+// been rotated.
+func (s *Service) RefreshPersistentSubnets() {
+	// Return early if discv5 service isn't running.
 	if s.dv5Listener == nil || !s.isInitialized() {
 		return
 	}
-	currEpoch := slots.ToEpoch(slots.CurrentSlot(uint64(s.genesisTime.Unix())))
-	if err := initializePersistentSubnets(s.dv5Listener.LocalNode().ID(), currEpoch); err != nil {
+
+	// Get the current epoch.
+	currentSlot := slots.CurrentSlot(uint64(s.genesisTime.Unix()))
+	currentEpoch := slots.ToEpoch(currentSlot)
+
+	// Get our node ID.
+	nodeID := s.dv5Listener.LocalNode().ID()
+
+	// Get our node record.
+	record := s.dv5Listener.Self().Record()
+
+	// Get the version of our metadata.
+	metadataVersion := s.Metadata().Version()
+
+	// Initialize persistent subnets.
+	if err := initializePersistentSubnets(nodeID, currentEpoch); err != nil {
 		log.WithError(err).Error("Could not initialize persistent subnets")
 		return
 	}
 
+	// Initialize persistent column subnets.
+	if err := initializePersistentColumnSubnets(nodeID); err != nil {
+		log.WithError(err).Error("Could not initialize persistent column subnets")
+		return
+	}
+
+	// Get the current attestation subnet bitfield.
 	bitV := bitfield.NewBitvector64()
-	committees := cache.SubnetIDs.GetAllSubnets()
-	for _, idx := range committees {
+	attestationCommittees := cache.SubnetIDs.GetAllSubnets()
+	for _, idx := range attestationCommittees {
 		bitV.SetBitAt(idx, true)
 	}
-	currentBitV, err := attBitvector(s.dv5Listener.Self().Record())
+
+	// Get the attestation subnet bitfield we store in our record.
+	inRecordBitV, err := attBitvector(record)
 	if err != nil {
 		log.WithError(err).Error("Could not retrieve att bitfield")
 		return
 	}
 
-	// Compare current epoch with our fork epochs
+	// Get the attestation subnet bitfield in our metadata.
+	inMetadataBitV := s.Metadata().AttnetsBitfield()
+
+	// Is our attestation bitvector record up to date?
+	isBitVUpToDate := bytes.Equal(bitV, inRecordBitV) && bytes.Equal(bitV, inMetadataBitV)
+
+	// Compare current epoch with Altair fork epoch
 	altairForkEpoch := params.BeaconConfig().AltairForkEpoch
-	switch {
-	case currEpoch < altairForkEpoch:
+
+	if currentEpoch < altairForkEpoch {
 		// Phase 0 behaviour.
-		if bytes.Equal(bitV, currentBitV) {
-			// return early if bitfield hasn't changed
+		if isBitVUpToDate {
+			// Return early if bitfield hasn't changed.
 			return
 		}
+
+		// Some data changed. Update the record and the metadata.
 		s.updateSubnetRecordWithMetadata(bitV)
-	default:
-		// Retrieve sync subnets from application level
-		// cache.
-		bitS := bitfield.Bitvector4{byte(0x00)}
-		committees = cache.SyncSubnetIDs.GetAllSubnets(currEpoch)
-		for _, idx := range committees {
-			bitS.SetBitAt(idx, true)
-		}
-		currentBitS, err := syncBitvector(s.dv5Listener.Self().Record())
-		if err != nil {
-			log.WithError(err).Error("Could not retrieve sync bitfield")
-			return
-		}
-		if bytes.Equal(bitV, currentBitV) && bytes.Equal(bitS, currentBitS) &&
-			s.Metadata().Version() == version.Altair {
-			// return early if bitfields haven't changed
-			return
-		}
-		s.updateSubnetRecordWithMetadataV2(bitV, bitS)
+
+		// Ping all peers.
+		s.pingPeers()
+
+		return
 	}
-	// ping all peers to inform them of new metadata
+
+	// Get the current sync subnet bitfield.
+	bitS := bitfield.Bitvector4{byte(0x00)}
+	syncCommittees := cache.SyncSubnetIDs.GetAllSubnets(currentEpoch)
+	for _, idx := range syncCommittees {
+		bitS.SetBitAt(idx, true)
+	}
+
+	// Get the sync subnet bitfield we store in our record.
+	inRecordBitS, err := syncBitvector(record)
+	if err != nil {
+		log.WithError(err).Error("Could not retrieve sync bitfield")
+		return
+	}
+
+	// Get the sync subnet bitfield in our metadata.
+	currentBitSInMetadata := s.Metadata().SyncnetsBitfield()
+
+	isBitSUpToDate := bytes.Equal(bitS, inRecordBitS) && bytes.Equal(bitS, currentBitSInMetadata)
+
+	// Compare current epoch with EIP-7594 fork epoch.
+	eip7594ForkEpoch := params.BeaconConfig().Eip7594ForkEpoch
+
+	if currentEpoch < eip7594ForkEpoch {
+		// 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.pingPeers()
+
+		return
+	}
+
+	// Get the current custody subnet count.
+	custodySubnetCount := peerdas.CustodySubnetCount()
+
+	// Get the custody subnet count we store in our record.
+	inRecordCustodySubnetCount, err := peerdas.CustodyCountFromRecord(record)
+	if err != nil {
+		log.WithError(err).Error("Could not retrieve custody subnet count")
+		return
+	}
+
+	// Get the custody subnet count in our metadata.
+	inMetadataCustodySubnetCount := s.Metadata().CustodySubnetCount()
+
+	isCustodySubnetCountUpToDate := custodySubnetCount == inRecordCustodySubnetCount && custodySubnetCount == uint64(inMetadataCustodySubnetCount)
+
+	if isBitVUpToDate && isBitSUpToDate && isCustodySubnetCountUpToDate {
+		// Nothing to do, return early.
+		return
+	}
+
+	// Some data changed. Update the record and the metadata.
+	s.updateSubnetRecordWithMetadataV3(bitV, bitS, custodySubnetCount)
+
+	// Ping all peers.
 	s.pingPeers()
 }
 
@@ -258,6 +341,10 @@ func (s *Service) createLocalNode(
 		localNode.Set(quicEntry)
 	}
 
+	if params.PeerDASEnabled() {
+		localNode.Set(peerdas.Csc(peerdas.CustodySubnetCount()))
+	}
+
 	localNode.SetFallbackIP(ipAddr)
 	localNode.SetFallbackUDP(udpPort)
 
@@ -346,6 +433,8 @@ func (s *Service) filterPeer(node *enode.Node) bool {
 
 	// Ignore nodes that are already active.
 	if s.peers.IsActive(peerData.ID) {
+		// Constantly update enr for known peers
+		s.peers.UpdateENR(node.Record(), peerData.ID)
 		return false
 	}
 

beacon-chain/p2p/discovery_test.go

@@ -16,12 +16,15 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/libp2p/go-libp2p/core/crypto"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/libp2p/go-libp2p/core/peer"
+	swarmt "github.com/libp2p/go-libp2p/p2p/net/swarm/testing"
 	"github.com/prysmaticlabs/go-bitfield"
 	mock "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/testing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers/peerdata"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers/scorers"
@@ -30,13 +33,12 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/wrapper"
 	leakybucket "github.com/prysmaticlabs/prysm/v5/container/leaky-bucket"
+	ecdsaprysm "github.com/prysmaticlabs/prysm/v5/crypto/ecdsa"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	prysmNetwork "github.com/prysmaticlabs/prysm/v5/network"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 )
 
@@ -131,6 +133,10 @@ func TestStartDiscV5_DiscoverAllPeers(t *testing.T) {
 }
 
 func TestCreateLocalNode(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig()
+	cfg.Eip7594ForkEpoch = 1
+	params.OverrideBeaconConfig(cfg)
 	testCases := []struct {
 		name          string
 		cfg           *Config
@@ -227,6 +233,11 @@ 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 custody_subnet_count config.
+			custodySubnetCount := new(uint64)
+			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(peerdas.CustodySubnetCountEnrKey, custodySubnetCount)))
+			require.Equal(t, params.BeaconConfig().CustodyRequirement, *custodySubnetCount)
 		})
 	}
 }
@@ -435,177 +446,314 @@ func addPeer(t *testing.T, p *peers.Status, state peerdata.PeerConnectionState)
 	return id
 }
 
-func TestRefreshENR_ForkBoundaries(t *testing.T) {
+func createAndConnectPeer(t *testing.T, p2pService *testp2p.TestP2P, offset int) {
+	// Create the private key.
+	privateKeyBytes := make([]byte, 32)
+	for i := 0; i < 32; i++ {
+		privateKeyBytes[i] = byte(offset + i)
+	}
+
+	privateKey, err := crypto.UnmarshalSecp256k1PrivateKey(privateKeyBytes)
+	require.NoError(t, err)
+
+	// Create the peer.
+	peer := testp2p.NewTestP2P(t, swarmt.OptPeerPrivateKey(privateKey))
+
+	// Add the peer and connect it.
+	p2pService.Peers().Add(&enr.Record{}, peer.PeerID(), nil, network.DirOutbound)
+	p2pService.Peers().SetConnectionState(peer.PeerID(), peers.PeerConnected)
+	p2pService.Connect(peer)
+}
+
+// Define the ping count.
+var actualPingCount int
+
+type check struct {
+	pingCount              int
+	metadataSequenceNumber uint64
+	attestationSubnets     []uint64
+	syncSubnets            []uint64
+	custodySubnetCount     *uint8
+}
+
+func checkPingCountCacheMetadataRecord(
+	t *testing.T,
+	service *Service,
+	expected check,
+) {
+	// Check the ping count.
+	require.Equal(t, expected.pingCount, actualPingCount)
+
+	// Check the attestation subnets in the cache.
+	actualAttestationSubnets := cache.SubnetIDs.GetAllSubnets()
+	require.DeepSSZEqual(t, expected.attestationSubnets, actualAttestationSubnets)
+
+	// Check the metadata sequence number.
+	actualMetadataSequenceNumber := service.metaData.SequenceNumber()
+	require.Equal(t, expected.metadataSequenceNumber, actualMetadataSequenceNumber)
+
+	// Compute expected attestation subnets bits.
+	expectedBitV := bitfield.NewBitvector64()
+	exists := false
+
+	for _, idx := range expected.attestationSubnets {
+		exists = true
+		expectedBitV.SetBitAt(idx, true)
+	}
+
+	// Check attnets in ENR.
+	var actualBitVENR bitfield.Bitvector64
+	err := service.dv5Listener.LocalNode().Node().Record().Load(enr.WithEntry(attSubnetEnrKey, &actualBitVENR))
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, expectedBitV, actualBitVENR)
+
+	// Check attnets in metadata.
+	if !exists {
+		expectedBitV = nil
+	}
+
+	actualBitVMetadata := service.metaData.AttnetsBitfield()
+	require.DeepSSZEqual(t, expectedBitV, actualBitVMetadata)
+
+	if expected.syncSubnets != nil {
+		// Compute expected sync subnets bits.
+		expectedBitS := bitfield.NewBitvector4()
+		exists = false
+
+		for _, idx := range expected.syncSubnets {
+			exists = true
+			expectedBitS.SetBitAt(idx, true)
+		}
+
+		// Check syncnets in ENR.
+		var actualBitSENR bitfield.Bitvector4
+		err := service.dv5Listener.LocalNode().Node().Record().Load(enr.WithEntry(syncCommsSubnetEnrKey, &actualBitSENR))
+		require.NoError(t, err)
+		require.DeepSSZEqual(t, expectedBitS, actualBitSENR)
+
+		// Check syncnets in metadata.
+		if !exists {
+			expectedBitS = nil
+		}
+
+		actualBitSMetadata := service.metaData.SyncnetsBitfield()
+		require.DeepSSZEqual(t, expectedBitS, actualBitSMetadata)
+	}
+
+	if expected.custodySubnetCount != nil {
+		// Check custody subnet count in ENR.
+		var actualCustodySubnetCount uint8
+		err := service.dv5Listener.LocalNode().Node().Record().Load(enr.WithEntry(peerdas.CustodySubnetCountEnrKey, &actualCustodySubnetCount))
+		require.NoError(t, err)
+		require.Equal(t, *expected.custodySubnetCount, actualCustodySubnetCount)
+
+		// Check custody subnet count in metadata.
+		actualCustodySubnetCountMetadata := service.metaData.CustodySubnetCount()
+		require.Equal(t, *expected.custodySubnetCount, actualCustodySubnetCountMetadata)
+	}
+}
+
+func TestRefreshPersistentSubnets(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
+
 	// Clean up caches after usage.
 	defer cache.SubnetIDs.EmptyAllCaches()
+	defer cache.SyncSubnetIDs.EmptyAllCaches()
 
-	tests := []struct {
-		name           string
-		svcBuilder     func(t *testing.T) *Service
-		postValidation func(t *testing.T, s *Service)
+	const (
+		altairForkEpoch  = 5
+		eip7594ForkEpoch = 10
+	)
+
+	custodySubnetCount := uint8(params.BeaconConfig().CustodyRequirement)
+
+	// Set up epochs.
+	defaultCfg := params.BeaconConfig()
+	cfg := defaultCfg.Copy()
+	cfg.AltairForkEpoch = altairForkEpoch
+	cfg.Eip7594ForkEpoch = eip7594ForkEpoch
+	params.OverrideBeaconConfig(cfg)
+
+	// Compute the number of seconds per epoch.
+	secondsPerSlot := params.BeaconConfig().SecondsPerSlot
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	secondsPerEpoch := secondsPerSlot * uint64(slotsPerEpoch)
+
+	testCases := []struct {
+		name              string
+		epochSinceGenesis uint64
+		checks            []check
 	}{
 		{
-			name: "metadata no change",
-			svcBuilder: func(t *testing.T) *Service {
-				port := 2000
-				ipAddr, pkey := createAddrAndPrivKey(t)
-				s := &Service{
-					genesisTime:           time.Now(),
-					genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
-					cfg:                   &Config{UDPPort: uint(port)},
-				}
-				listener, err := s.createListener(ipAddr, pkey)
-				assert.NoError(t, err)
-				s.dv5Listener = listener
-				s.metaData = wrapper.WrappedMetadataV0(new(ethpb.MetaDataV0))
-				s.updateSubnetRecordWithMetadata([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})
-				return s
-			},
-			postValidation: func(t *testing.T, s *Service) {
-				currEpoch := slots.ToEpoch(slots.CurrentSlot(uint64(s.genesisTime.Unix())))
-				subs, err := computeSubscribedSubnets(s.dv5Listener.LocalNode().ID(), currEpoch)
-				assert.NoError(t, err)
-
-				bitV := bitfield.NewBitvector64()
-				for _, idx := range subs {
-					bitV.SetBitAt(idx, true)
-				}
-				assert.DeepEqual(t, bitV, s.metaData.AttnetsBitfield())
+			name:              "Phase0",
+			epochSinceGenesis: 0,
+			checks: []check{
+				{
+					pingCount:              0,
+					metadataSequenceNumber: 0,
+					attestationSubnets:     []uint64{},
+				},
+				{
+					pingCount:              1,
+					metadataSequenceNumber: 1,
+					attestationSubnets:     []uint64{40, 41},
+				},
+				{
+					pingCount:              1,
+					metadataSequenceNumber: 1,
+					attestationSubnets:     []uint64{40, 41},
+				},
+				{
+					pingCount:              1,
+					metadataSequenceNumber: 1,
+					attestationSubnets:     []uint64{40, 41},
+				},
 			},
 		},
 		{
-			name: "metadata updated",
-			svcBuilder: func(t *testing.T) *Service {
-				port := 2000
-				ipAddr, pkey := createAddrAndPrivKey(t)
-				s := &Service{
-					genesisTime:           time.Now(),
-					genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
-					cfg:                   &Config{UDPPort: uint(port)},
-				}
-				listener, err := s.createListener(ipAddr, pkey)
-				assert.NoError(t, err)
-				s.dv5Listener = listener
-				s.metaData = wrapper.WrappedMetadataV0(new(ethpb.MetaDataV0))
-				s.updateSubnetRecordWithMetadata([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})
-				cache.SubnetIDs.AddPersistentCommittee([]uint64{1, 2, 3, 23}, 0)
-				return s
-			},
-			postValidation: func(t *testing.T, s *Service) {
-				assert.DeepEqual(t, bitfield.Bitvector64{0xe, 0x0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0}, s.metaData.AttnetsBitfield())
+			name:              "Altair",
+			epochSinceGenesis: altairForkEpoch,
+			checks: []check{
+				{
+					pingCount:              0,
+					metadataSequenceNumber: 0,
+					attestationSubnets:     []uint64{},
+					syncSubnets:            nil,
+				},
+				{
+					pingCount:              1,
+					metadataSequenceNumber: 1,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            nil,
+				},
+				{
+					pingCount:              2,
+					metadataSequenceNumber: 2,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            []uint64{1, 2},
+				},
+				{
+					pingCount:              2,
+					metadataSequenceNumber: 2,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            []uint64{1, 2},
+				},
 			},
 		},
 		{
-			name: "metadata updated at fork epoch",
-			svcBuilder: func(t *testing.T) *Service {
-				port := 2000
-				ipAddr, pkey := createAddrAndPrivKey(t)
-				s := &Service{
-					genesisTime:           time.Now().Add(-5 * oneEpochDuration()),
-					genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
-					cfg:                   &Config{UDPPort: uint(port)},
-				}
-				listener, err := s.createListener(ipAddr, pkey)
-				assert.NoError(t, err)
-
-				// Update params
-				cfg := params.BeaconConfig().Copy()
-				cfg.AltairForkEpoch = 5
-				params.OverrideBeaconConfig(cfg)
-				params.BeaconConfig().InitializeForkSchedule()
-
-				s.dv5Listener = listener
-				s.metaData = wrapper.WrappedMetadataV0(new(ethpb.MetaDataV0))
-				s.updateSubnetRecordWithMetadata([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01})
-				cache.SubnetIDs.AddPersistentCommittee([]uint64{1, 2, 3, 23}, 0)
-				return s
-			},
-			postValidation: func(t *testing.T, s *Service) {
-				assert.Equal(t, version.Altair, s.metaData.Version())
-				assert.DeepEqual(t, bitfield.Bitvector4{0x00}, s.metaData.MetadataObjV1().Syncnets)
-				assert.DeepEqual(t, bitfield.Bitvector64{0xe, 0x0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0}, s.metaData.AttnetsBitfield())
-			},
-		},
-		{
-			name: "metadata updated at fork epoch with no bitfield",
-			svcBuilder: func(t *testing.T) *Service {
-				port := 2000
-				ipAddr, pkey := createAddrAndPrivKey(t)
-				s := &Service{
-					genesisTime:           time.Now().Add(-5 * oneEpochDuration()),
-					genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
-					cfg:                   &Config{UDPPort: uint(port)},
-				}
-				listener, err := s.createListener(ipAddr, pkey)
-				assert.NoError(t, err)
-
-				// Update params
-				cfg := params.BeaconConfig().Copy()
-				cfg.AltairForkEpoch = 5
-				params.OverrideBeaconConfig(cfg)
-				params.BeaconConfig().InitializeForkSchedule()
-
-				s.dv5Listener = listener
-				s.metaData = wrapper.WrappedMetadataV0(new(ethpb.MetaDataV0))
-				s.updateSubnetRecordWithMetadata([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})
-				return s
-			},
-			postValidation: func(t *testing.T, s *Service) {
-				assert.Equal(t, version.Altair, s.metaData.Version())
-				assert.DeepEqual(t, bitfield.Bitvector4{0x00}, s.metaData.MetadataObjV1().Syncnets)
-				currEpoch := slots.ToEpoch(slots.CurrentSlot(uint64(s.genesisTime.Unix())))
-				subs, err := computeSubscribedSubnets(s.dv5Listener.LocalNode().ID(), currEpoch)
-				assert.NoError(t, err)
-
-				bitV := bitfield.NewBitvector64()
-				for _, idx := range subs {
-					bitV.SetBitAt(idx, true)
-				}
-				assert.DeepEqual(t, bitV, s.metaData.AttnetsBitfield())
-			},
-		},
-		{
-			name: "metadata updated past fork epoch with bitfields",
-			svcBuilder: func(t *testing.T) *Service {
-				port := 2000
-				ipAddr, pkey := createAddrAndPrivKey(t)
-				s := &Service{
-					genesisTime:           time.Now().Add(-6 * oneEpochDuration()),
-					genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
-					cfg:                   &Config{UDPPort: uint(port)},
-				}
-				listener, err := s.createListener(ipAddr, pkey)
-				assert.NoError(t, err)
-
-				// Update params
-				cfg := params.BeaconConfig().Copy()
-				cfg.AltairForkEpoch = 5
-				params.OverrideBeaconConfig(cfg)
-				params.BeaconConfig().InitializeForkSchedule()
-
-				s.dv5Listener = listener
-				s.metaData = wrapper.WrappedMetadataV0(new(ethpb.MetaDataV0))
-				s.updateSubnetRecordWithMetadata([]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})
-				cache.SubnetIDs.AddPersistentCommittee([]uint64{1, 2, 3, 23}, 0)
-				cache.SyncSubnetIDs.AddSyncCommitteeSubnets([]byte{'A'}, 0, []uint64{0, 1}, 0)
-				return s
-			},
-			postValidation: func(t *testing.T, s *Service) {
-				assert.Equal(t, version.Altair, s.metaData.Version())
-				assert.DeepEqual(t, bitfield.Bitvector4{0x03}, s.metaData.MetadataObjV1().Syncnets)
-				assert.DeepEqual(t, bitfield.Bitvector64{0xe, 0x0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0}, s.metaData.AttnetsBitfield())
+			name:              "PeerDAS",
+			epochSinceGenesis: eip7594ForkEpoch,
+			checks: []check{
+				{
+					pingCount:              0,
+					metadataSequenceNumber: 0,
+					attestationSubnets:     []uint64{},
+					syncSubnets:            nil,
+				},
+				{
+					pingCount:              1,
+					metadataSequenceNumber: 1,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            nil,
+					custodySubnetCount:     &custodySubnetCount,
+				},
+				{
+					pingCount:              2,
+					metadataSequenceNumber: 2,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            []uint64{1, 2},
+					custodySubnetCount:     &custodySubnetCount,
+				},
+				{
+					pingCount:              2,
+					metadataSequenceNumber: 2,
+					attestationSubnets:     []uint64{40, 41},
+					syncSubnets:            []uint64{1, 2},
+					custodySubnetCount:     &custodySubnetCount,
+				},
 			},
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			s := tt.svcBuilder(t)
-			s.RefreshENR()
-			tt.postValidation(t, s)
-			s.dv5Listener.Close()
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			const peerOffset = 1
+
+			// Initialize the ping count.
+			actualPingCount = 0
+
+			// Create the private key.
+			privateKeyBytes := make([]byte, 32)
+			for i := 0; i < 32; i++ {
+				privateKeyBytes[i] = byte(i)
+			}
+
+			unmarshalledPrivateKey, err := crypto.UnmarshalSecp256k1PrivateKey(privateKeyBytes)
+			require.NoError(t, err)
+
+			privateKey, err := ecdsaprysm.ConvertFromInterfacePrivKey(unmarshalledPrivateKey)
+			require.NoError(t, err)
+
+			// Create a p2p service.
+			p2p := testp2p.NewTestP2P(t)
+
+			// Create and connect a peer.
+			createAndConnectPeer(t, p2p, peerOffset)
+
+			// Create a service.
+			service := &Service{
+				pingMethod: func(_ context.Context, _ peer.ID) error {
+					actualPingCount++
+					return nil
+				},
+				cfg:                   &Config{UDPPort: 2000},
+				peers:                 p2p.Peers(),
+				genesisTime:           time.Now().Add(-time.Duration(tc.epochSinceGenesis*secondsPerEpoch) * time.Second),
+				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+			}
+
+			// Create a listener.
+			listener, err := service.createListener(nil, privateKey)
+			require.NoError(t, err)
+
+			// Set the listener and the metadata.
+			service.dv5Listener = listener
+			service.metaData = wrapper.WrappedMetadataV0(new(ethpb.MetaDataV0))
+
+			// Run a check.
+			checkPingCountCacheMetadataRecord(t, service, tc.checks[0])
+
+			// Refresh the persistent subnets.
+			service.RefreshPersistentSubnets()
+			time.Sleep(10 * time.Millisecond)
+
+			// Run a check.
+			checkPingCountCacheMetadataRecord(t, service, tc.checks[1])
+
+			// Add a sync committee subnet.
+			cache.SyncSubnetIDs.AddSyncCommitteeSubnets([]byte{'a'}, altairForkEpoch, []uint64{1, 2}, 1*time.Hour)
+
+			// Refresh the persistent subnets.
+			service.RefreshPersistentSubnets()
+			time.Sleep(10 * time.Millisecond)
+
+			// Run a check.
+			checkPingCountCacheMetadataRecord(t, service, tc.checks[2])
+
+			// Refresh the persistent subnets.
+			service.RefreshPersistentSubnets()
+			time.Sleep(10 * time.Millisecond)
+
+			// Run a check.
+			checkPingCountCacheMetadataRecord(t, service, tc.checks[3])
+
+			// Clean the test.
+			service.dv5Listener.Close()
 			cache.SubnetIDs.EmptyAllCaches()
 			cache.SyncSubnetIDs.EmptyAllCaches()
 		})
 	}
+
+	// Reset the config.
+	params.OverrideBeaconConfig(defaultCfg)
 }

beacon-chain/p2p/gossip_scoring_params.go

@@ -121,7 +121,7 @@ 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
 	default:

beacon-chain/p2p/gossip_topic_mappings.go

@@ -22,6 +22,7 @@ var gossipTopicMappings = map[string]func() proto.Message{
 	SyncCommitteeSubnetTopicFormat:            func() proto.Message { return &ethpb.SyncCommitteeMessage{} },
 	BlsToExecutionChangeSubnetTopicFormat:     func() proto.Message { return &ethpb.SignedBLSToExecutionChange{} },
 	BlobSubnetTopicFormat:                     func() proto.Message { return &ethpb.BlobSidecar{} },
+	DataColumnSubnetTopicFormat:               func() proto.Message { return &ethpb.DataColumnSidecar{} },
 }
 
 // GossipTopicMappings is a function to return the assigned data type

beacon-chain/p2p/interfaces.go

@@ -3,6 +3,7 @@ package p2p
 import (
 	"context"
 
+	"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"
@@ -28,6 +29,12 @@ type P2P interface {
 	ConnectionHandler
 	PeersProvider
 	MetadataProvider
+	CustodyHandler
+}
+
+type Acceser interface {
+	Broadcaster
+	PeerManager
 }
 
 // Broadcaster broadcasts messages to peers over the p2p pubsub protocol.
@@ -36,6 +43,7 @@ type Broadcaster interface {
 	BroadcastAttestation(ctx context.Context, subnet uint64, att ethpb.Att) error
 	BroadcastSyncCommitteeMessage(ctx context.Context, subnet uint64, sMsg *ethpb.SyncCommitteeMessage) error
 	BroadcastBlob(ctx context.Context, subnet uint64, blob *ethpb.BlobSidecar) error
+	BroadcastDataColumn(ctx context.Context, columnSubnet uint64, dataColumnSidecar *ethpb.DataColumnSidecar) error
 }
 
 // SetStreamHandler configures p2p to handle streams of a certain topic ID.
@@ -81,8 +89,9 @@ type PeerManager interface {
 	PeerID() peer.ID
 	Host() host.Host
 	ENR() *enr.Record
+	NodeID() enode.ID
 	DiscoveryAddresses() ([]multiaddr.Multiaddr, error)
-	RefreshENR()
+	RefreshPersistentSubnets()
 	FindPeersWithSubnet(ctx context.Context, topic string, subIndex uint64, threshold int) (bool, error)
 	AddPingMethod(reqFunc func(ctx context.Context, id peer.ID) error)
 }
@@ -102,3 +111,8 @@ type MetadataProvider interface {
 	Metadata() metadata.Metadata
 	MetadataSeq() uint64
 }
+
+type CustodyHandler interface {
+	CustodyCountFromRemotePeer(peer.ID) uint64
+	GetValidCustodyPeers([]peer.ID) ([]peer.ID, error)
+}

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/status.go

@@ -159,6 +159,14 @@ func (p *Status) Add(record *enr.Record, pid peer.ID, address ma.Multiaddr, dire
 	p.addIpToTracker(pid)
 }
 
+func (p *Status) UpdateENR(record *enr.Record, pid peer.ID) {
+	p.store.Lock()
+	defer p.store.Unlock()
+	if peerData, ok := p.store.PeerData(pid); ok {
+		peerData.Enr = record
+	}
+}
+
 // Address returns the multiaddress of the given remote peer.
 // This will error if the peer does not exist.
 func (p *Status) Address(pid peer.ID) (ma.Multiaddr, error) {

beacon-chain/p2p/pubsub.go

@@ -165,14 +165,14 @@ func (s *Service) pubsubOptions() []pubsub.Option {
 func parsePeersEnr(peers []string) ([]peer.AddrInfo, error) {
 	addrs, err := PeersFromStringAddrs(peers)
 	if err != nil {
-		return nil, fmt.Errorf("Cannot convert peers raw ENRs into multiaddresses: %w", err)
+		return nil, fmt.Errorf("cannot convert peers raw ENRs into multiaddresses: %w", err)
 	}
 	if len(addrs) == 0 {
-		return nil, fmt.Errorf("Converting peers raw ENRs into multiaddresses resulted in an empty list")
+		return nil, fmt.Errorf("converting peers raw ENRs into multiaddresses resulted in an empty list")
 	}
 	directAddrInfos, err := peer.AddrInfosFromP2pAddrs(addrs...)
 	if err != nil {
-		return nil, fmt.Errorf("Cannot convert peers multiaddresses into AddrInfos: %w", err)
+		return nil, fmt.Errorf("cannot convert peers multiaddresses into AddrInfos: %w", err)
 	}
 	return directAddrInfos, nil
 }