Fork digest to consider blob schedule for fulu

* files changed

* added changelog file

* added tests and formatting changes

* fixed bugs

* fixed formatting

.github/workflows/changelog.yml

@@ -18,7 +18,7 @@ jobs:
         uses: dsaltares/fetch-gh-release-asset@aa2ab1243d6e0d5b405b973c89fa4d06a2d0fff7 # 1.1.2
         with:
           repo: OffchainLabs/unclog
-          version: "tags/v0.1.3"
+          version: "tags/v0.1.5"
           file: "unclog"
 
       - name: Get new changelog files

CHANGELOG.md

@@ -4,6 +4,166 @@ All notable changes to this project will be documented in this file.
 
 The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.
 
+## [v6.0.3](https://github.com/prysmaticlabs/prysm/compare/v6.0.2...v6.0.3) - 2025-05-21
+
+This release has important bugfixes for users of the [Beacon API](https://ethereum.github.io/beacon-APIs/). These fixes include:
+- Fixed pending consolidations endpoint to return the correct response.
+- Fixed incorrect field name from pending partial withdrawals response.
+- Fixed attester slashing to return an empty array instead of nil/null. 
+- Fixed validator participation and active set changes endpoints to accept a `{state_id}` parameter. 
+
+Other improvements include:
+- Disabled deposit log processing routine for Electra and beyond.
+
+Operators are encouraged to update at their own convenience.
+
+### Added
+
+- ssz static spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15279)
+- finality and merkle proof spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15286)
+- sanity and rewards spec tests for fulu. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15285)
+
+### Changed
+
+- Added more tracing spans to various helpers related to GetDuties. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15271)
+- Disable log processing after deposit requests are activated. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15274)
+
+### Fixed
+
+- fixed wrong handler for get pending consolidations endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15290)
+- Fixed /eth/v2/beacon/pool/attester_slashings no slashings returns empty array instead of nil. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15291)
+- Fix Prysm endpoints `/prysm/v1/validators/{state_id}/participation` and `/prysm/v1/validators/{state_id}/active_set_changes` to properly handle `{state_id}`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15245)
+
+## [v6.0.2](https://github.com/prysmaticlabs/prysm/compare/v6.0.1...v6.0.2) - 2025-05-12
+
+This is a patch release to fix a few important bugs. Most importantly, we have adjusted the index limit for field tries in the beacon state to better support Pectra states. This should alleviate memory issues that clients are seeing since Pectra mainnet fork.
+
+### Added
+
+- Enable light client gossip for optimistic and finality updates. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15220)
+- Implement peerDAS core functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15192)
+- Force duties start on received blocks. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15251)
+- Added additional tracing spans for the GetDuties routine. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15258)
+
+### Changed
+
+- Use otelgrpc for tracing grpc server and client. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15237)
+- Upgraded ristretto to v2.2.0, for RISC-V support. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15170)
+- Update spec to v1.5.0 compliance which changes minimal execution requests size. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15256)
+- Increase indices limit in field trie rebuilding. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15252)
+- Increase sepolia gas limit to 60M. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15253)
+
+### Fixed
+
+- Fixed wrong field name in pending partial withdrawals was returned on state json representation, described in https://github.com/ethereum/consensus-specs/blob/dev/specs/electra/beacon-chain.md#pendingpartialwithdrawal. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15254)
+- Fixed gocognit on propose block rest path. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15147)
+
+## [v6.0.1](https://github.com/prysmaticlabs/prysm/compare/v6.0.0...v6.0.1) - 2025-05-02
+
+This release fixes two bugs related to the `payload_attributes` [event stream](https://ethereum.github.io/beacon-APIs/#/Events/eventstream). If you are using or planning to use this endpoint, upgrading to version 6.0.1 is mandatory.  
+Also, a reminder: like other Beacon API endpoints, when a node is syncing, it may return historical data as `finalized` or `head`. Until the node is fully synced to the head of the chain, you should avoid using this data, depending on your application's needs.
+
+We currently recommend against using the `--enable-beacon-rest-api` flag on Mainnet. As you may have noticed, we put a deprecation notice on our gRPC code, in particular on gRPC-related flags. The reason for this is that we want to eventually remove gRPC and have REST HTTP as the standard way of communication between the validator client and the beacon node. That being said, the REST option is still unstable and thus marked as experimental in the flag's description (the flag is `--enable-beacon-rest-api`). Therefore we encourage everyone to keep using gRPC, which is currently the default. It is fine to test the REST option on testnets, but doing it on Mainnet can lead to missing attestations and even missing blocks.
+
+**Updating to v6.0.0 or later is required for Pectra Mainnet!**
+
+This patch release has a few important fixes from v6.0.0. Updating to this release is encouraged.
+
+### Added
+
+- `UpgradeToFulu` spectests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15190)
+- PeerDAS related KZG wrappers. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15186)
+- Add light client p2p broadcaster functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15175)
+- Added immediate broadcasting of proposer slashings when equivocating blocks are detected during block processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14693)
+- Added 2 new errors: `HeadStateErr` and `ErrCouldNotVerifyBlockHeader`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14693)
+- Implement pending consolidations Beacon API endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15219)
+- PeerDAS: Add needed proto files and corresponding generated code. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15187)
+- Add light client p2p validator and subscriber functions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15214)
+
+### Changed
+
+- Refactored internal function `reValidateSubscriptions` to `pruneSubscriptions` in `beacon-chain/sync/subscriber.go` for improved clarity, addressing a TODO comment. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15160)
+- Updated geth to v1.15.9. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15216)
+- Removed the slot from `UpdateDuties`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15223)
+- Update hoodie bootnodes. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15240)
+
+### Fixed
+
+- avoid nondeterministic default fork value when generate genesis. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15151)
+- `UpgradeToFulu`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15190)
+- fixed underflow with balances in leaking edge case with expected withdrawals. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15191)
+- Fixes our generated ssz files to have the correct package name. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15199)
+- Fixes our blob sidecar by root request lists for electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15209)
+- Ensure that the `payload_attributes` event has a consistent view of the head state by passing the head block in the event and using stategen to retrieve the corresponding state. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15213)
+- Pass parent context to update duties when dependent roots change. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15221)
+- Process slots across epoch for payload attribute event. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15228)
+- extend the payload attribute computation deadline to the beginning of the proposal slot. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15230)
+
+### Security
+
+- Fix CVE-2025-22869. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-22870. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-22872. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+- Fix CVE-2025-30204. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15204)
+
+## [v6.0.0](https://github.com/prysmaticlabs/prysm/compare/v5.3.2...v6.0.0) - 2025-04-21
+
+This release introduces Mainnet support for the upcoming Electra + Prague (Pectra) fork. The fork is scheduled for mainnet epoch 364032 (May 7, 2025, 10:05:11 UTC). You MUST update Prysm Beacon Node, Prysm Validator Client, and your execution layer client to the Pectra ready release prior to the fork to stay on the correct chain.
+
+Besides Pectra, we have more light client API support, cleanups, and a few bugfixes. Please review the changelog below and update your client as soon as practical before May 7.
+
+This release is **mandatory** for all operators before May 7.
+
+### Added
+
+- Implemented validator identities Beacon API endpoint. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15086)
+- Add SSZ support to light client updates by range API. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15082)
+- Add light client ssz types to the spec test. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15097)
+- Added the ability for execution requests to be tested in e2e with electra. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14971)
+- Add warning messages for gas limit ranges that might be problematic. Low gas limits (≤10% of default) may cause transactions to fail, while high gas limits (>150% of default) could lead to block propagation issues. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15078)
+- Add light client store object to the beacon node object. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15120)
+- prysmctl option in wrapper script to generate devnet ssz. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15145)
+- Add support for Electra fork epoch. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15132)
+
+### Changed
+
+- The validator client will no longer use the full list of committee values but instead use the committee length and validator committee index. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15039)
+- Remove the header `Content-Disposition` from the `httputil.WriteSSZ` function. No `filename` parameter is needed anymore. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15092)
+- Sort attestations in proposer block by reward. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15093)
+- More efficient query method for stategen to retrieve blocks between a given state and the replay target block. This avoids attempting to look up blocks that are not needed for head replay queries, which may be missing due to a previous rollback bug. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15063)
+- removed old web3signer metrics in favor for a universal one. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14920)
+- Deprecated everything related with the gRPC API. [[PR]](https://github.com/prysmaticlabs/prysm/pull/14944)
+- Migrate Prysm repo to Offchain Labs organization ahead of Pectra upgrade v6. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15140)
+
+### Deprecated
+
+- deprecates and removes usage of the `--trace` flag and`--cpuprofile` flag in favor of just using `--pprof`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15083)
+
+### Removed
+
+- Remove /eth/v1/beacon/states/head/committees call when getting duties. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15039)
+- Removed unused hack scripts. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15157)
+- Remove `disable-committee-aware-packing` flag. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15162)
+- Remove deprecated flags for the major release. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15165)
+- Removed Beacon API endpoints which have been deprecated at the Deneb fork. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15166)
+
+### Fixed
+
+- The `--rpc` flag will now properly enable the keymanager APIs without web. The `--web` will enable both validator api endpoints and web. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15080)
+- Use latest state to pack attestation. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15113)
+- Clean up dangling block index entries for blocks that were previously deleted by incomplete cleanup code. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15040)
+- Fixed to use io stream instead of stream read. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15089)
+- When using a DV, send all aggregations for a slot and committee. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15110)
+- Fixed a bug in consolidation request processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15122)
+- Fix State Getter for pending withdrawal balance. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15123)
+- Fixed a bug in checking for attestation lengths in our block. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15134)
+- Fix Committee Index Check For Aggregates. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15146)
+- Fix filtering by committee index post-Electra in `ListAttestationsV2`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15148)
+- Peers giving invalid data in range syncing are now downscored. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15149)
+- Adding fork guard to attestation api endpoints so that it doesn't accidentally include wrong attestation types in the pool. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15161)
+- fixed underflow with balances in leaking edge case with expected withdrawals. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15191)
+- Attribute block and blob issues to correct peers during range syncing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15173)
+
 ## [v5.3.2](https://github.com/prysmaticlabs/prysm/compare/v5.3.1...v5.3.2) - 2025-03-25
 
 This release introduces support for the `Hoodi` testnet.
@@ -3255,4 +3415,4 @@ There are no security updates in this release.
 
 # Older than v2.0.0
 
-For changelog history for releases older than v2.0.0, please refer to https://github.com/prysmaticlabs/prysm/releases
+For changelog history for releases older than v2.0.0, please refer to https://github.com/prysmaticlabs/prysm/releases

CONTRIBUTING.md

@@ -4,7 +4,7 @@ Note: The latest and most up-to-date documentation can be found on our [docs por
 
 Excited by our work and want to get involved in building out our sharding releases? Or maybe you haven't learned as much about the Ethereum protocol but are a savvy developer? 
 
-You can explore our [Open Issues](https://github.com/OffchainLabs/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!
+You can explore our [Open Issues](https://github.com/OffchainLabs/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/prysm) 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.

README.md

@@ -6,7 +6,7 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/OffchainLabs/prysm)](https://goreportcard.com/report/github.com/OffchainLabs/prysm)
 [![Consensus_Spec_Version 1.4.0](https://img.shields.io/badge/Consensus%20Spec%20Version-v1.4.0-blue.svg)](https://github.com/ethereum/consensus-specs/tree/v1.4.0)
 [![Execution_API_Version 1.0.0-beta.2](https://img.shields.io/badge/Execution%20API%20Version-v1.0.0.beta.2-blue.svg)](https://github.com/ethereum/execution-apis/tree/v1.0.0-beta.2/src/engine)
-[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/OffchainLabs)
+[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysm)
 [![GitPOAP Badge](https://public-api.gitpoap.io/v1/repo/OffchainLabs/prysm/badge)](https://www.gitpoap.io/gh/OffchainLabs/prysm)
 
 </div>
@@ -25,7 +25,7 @@ See the [Changelog](https://github.com/OffchainLabs/prysm/releases) for details
 
 A detailed set of installation and usage instructions as well as breakdowns of each individual component are available in the **[official documentation portal](https://docs.prylabs.network)**.
 
-💬 **Need help?** Join our **[Discord Community](https://discord.gg/OffchainLabs)** for support.
+💬 **Need help?** Join our **[Discord Community](https://discord.gg/prysm)** for support.
 
 ---
 

WORKSPACE

@@ -255,56 +255,18 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.5.0-beta.5"
+consensus_spec_version = "v1.6.0-alpha.0"
 
-bls_test_version = "v0.1.1"
+load("@prysm//tools:download_spectests.bzl", "consensus_spec_tests")
 
-http_archive(
-    name = "consensus_spec_tests_general",
-    build_file_content = """
-filegroup(
-    name = "test_data",
-    srcs = glob([
-        "**/*.ssz_snappy",
-        "**/*.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    integrity = "sha256-H+Pt4z+HCVDnEBAv814yvsjR7f5l1IpumjFoTj2XnLE=",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
-)
-
-http_archive(
-    name = "consensus_spec_tests_minimal",
-    build_file_content = """
-filegroup(
-    name = "test_data",
-    srcs = glob([
-        "**/*.ssz_snappy",
-        "**/*.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    integrity = "sha256-Dqiwf5BG7yYyURGf+i87AIdArAyztvcgjoi2kSxrGvo=",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
-)
-
-http_archive(
-    name = "consensus_spec_tests_mainnet",
-    build_file_content = """
-filegroup(
-    name = "test_data",
-    srcs = glob([
-        "**/*.ssz_snappy",
-        "**/*.yaml",
-    ]),
-    visibility = ["//visibility:public"],
-)
-    """,
-    integrity = "sha256-xrmsFF243pzXHAjh1EQYKS9gtcwmtHK3wRZDSLlVVRk=",
-    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
+consensus_spec_tests(
+    name = "consensus_spec_tests",
+    flavors = {
+        "general": "sha256-W7oKvoM0nAkyitykRxAw6kmCvjYC01IqiNJy0AmCnMM=",
+        "minimal": "sha256-ig7/zxomjv6buBWMom4IxAJh3lFJ9+JnY44E7c8ZNP8=",
+        "mainnet": "sha256-mjx+MkXtPhCNv4c4knLYLIkvIdpF7WTjx/ElvGPQzSo=",
+    },
+    version = consensus_spec_version,
 )
 
 http_archive(
@@ -318,11 +280,13 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-c+gGapqifCvFtmtxfhOwieBDO2Syxp13GECWEpWM/Ho=",
+    integrity = "sha256-u0RkIZIeGttb3sInR31mO64aBSwxALqO5SYIPlqEvPo=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
 
+bls_test_version = "v0.1.1"
+
 http_archive(
     name = "bls_spec_tests",
     build_file_content = """

api/client/builder/BUILD.bazel

@@ -13,7 +13,6 @@ go_library(
     deps = [
         "//api:go_default_library",
         "//api/client:go_default_library",
-        "//api/server:go_default_library",
         "//api/server/structs:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -28,7 +27,6 @@ go_library(
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
-        "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",

api/client/builder/client.go

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

api/client/builder/client_test.go

@@ -532,7 +532,7 @@ func TestClient_GetHeader(t *testing.T) {
 				require.Equal(t, expectedPath, r.URL.Path)
 				epr := &ExecHeaderResponseElectra{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleHeaderResponseElectra), epr))
-				pro, err := epr.ToProto()
+				pro, err := epr.ToProto(100)
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)
@@ -640,9 +640,9 @@ func TestSubmitBlindedBlock(t *testing.T) {
 				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
 				epr := &ExecutionPayloadResponse{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
-				ep := &ExecutionPayload{}
+				ep := &structs.ExecutionPayload{}
 				require.NoError(t, json.Unmarshal(epr.Data, ep))
-				pro, err := ep.ToProto()
+				pro, err := ep.ToConsensus()
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)
@@ -710,9 +710,9 @@ func TestSubmitBlindedBlock(t *testing.T) {
 				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
 				epr := &ExecutionPayloadResponse{}
 				require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadCapella), epr))
-				ep := &ExecutionPayloadCapella{}
+				ep := &structs.ExecutionPayloadCapella{}
 				require.NoError(t, json.Unmarshal(epr.Data, ep))
-				pro, err := ep.ToProto()
+				pro, err := ep.ToConsensus()
 				require.NoError(t, err)
 				ssz, err := pro.MarshalSSZ()
 				require.NoError(t, err)

api/client/builder/types_test.go

@@ -328,72 +328,72 @@ func TestExecutionHeaderResponseUnmarshal(t *testing.T) {
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ParentHash),
+			actual:   hr.Data.Message.Header.ParentHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(hr.Data.Message.Header.FeeRecipient),
+			actual:   hr.Data.Message.Header.FeeRecipient,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.StateRoot),
+			actual:   hr.Data.Message.Header.StateRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ReceiptsRoot),
+			actual:   hr.Data.Message.Header.ReceiptsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(hr.Data.Message.Header.LogsBloom),
+			actual:   hr.Data.Message.Header.LogsBloom,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.PrevRandao),
+			actual:   hr.Data.Message.Header.PrevRandao,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BlockNumber),
+			actual:   hr.Data.Message.Header.BlockNumber,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasLimit),
+			actual:   hr.Data.Message.Header.GasLimit,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasUsed),
+			actual:   hr.Data.Message.Header.GasUsed,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.Timestamp),
+			actual:   hr.Data.Message.Header.Timestamp,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ExtraData),
+			actual:   hr.Data.Message.Header.ExtraData,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BaseFeePerGas),
+			actual:   hr.Data.Message.Header.BaseFeePerGas,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.BlockHash),
+			actual:   hr.Data.Message.Header.BlockHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockHash",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.TransactionsRoot),
+			actual:   hr.Data.Message.Header.TransactionsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.TransactionsRoot",
 		},
 	}
@@ -427,77 +427,77 @@ func TestExecutionHeaderResponseCapellaUnmarshal(t *testing.T) {
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ParentHash),
+			actual:   hr.Data.Message.Header.ParentHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(hr.Data.Message.Header.FeeRecipient),
+			actual:   hr.Data.Message.Header.FeeRecipient,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.StateRoot),
+			actual:   hr.Data.Message.Header.StateRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ReceiptsRoot),
+			actual:   hr.Data.Message.Header.ReceiptsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(hr.Data.Message.Header.LogsBloom),
+			actual:   hr.Data.Message.Header.LogsBloom,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.PrevRandao),
+			actual:   hr.Data.Message.Header.PrevRandao,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BlockNumber),
+			actual:   hr.Data.Message.Header.BlockNumber,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasLimit),
+			actual:   hr.Data.Message.Header.GasLimit,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.GasUsed),
+			actual:   hr.Data.Message.Header.GasUsed,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.Timestamp),
+			actual:   hr.Data.Message.Header.Timestamp,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.ExtraData),
+			actual:   hr.Data.Message.Header.ExtraData,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", hr.Data.Message.Header.BaseFeePerGas),
+			actual:   hr.Data.Message.Header.BaseFeePerGas,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.BlockHash),
+			actual:   hr.Data.Message.Header.BlockHash,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.BlockHash",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.TransactionsRoot),
+			actual:   hr.Data.Message.Header.TransactionsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.TransactionsRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(hr.Data.Message.Header.WithdrawalsRoot),
+			actual:   hr.Data.Message.Header.WithdrawalsRoot,
 			name:     "ExecHeaderResponse.ExecutionPayloadHeader.WithdrawalsRoot",
 		},
 	}
@@ -867,88 +867,6 @@ var testExampleExecutionPayloadDenebDifferentProofCount = fmt.Sprintf(`{
   }
 }`, hexutil.Encode(make([]byte, fieldparams.BlobLength)))
 
-func TestExecutionPayloadResponseUnmarshal(t *testing.T) {
-	epr := &ExecPayloadResponse{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), epr))
-	cases := []struct {
-		expected string
-		actual   string
-		name     string
-	}{
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ParentHash),
-			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
-		},
-		{
-			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(epr.Data.FeeRecipient),
-			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.StateRoot),
-			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ReceiptsRoot),
-			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
-		},
-		{
-			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(epr.Data.LogsBloom),
-			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.PrevRandao),
-			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.BlockNumber),
-			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasLimit),
-			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasUsed),
-			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
-		},
-		{
-			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.Timestamp),
-			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExtraData),
-			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
-		},
-		{
-			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", epr.Data.BaseFeePerGas),
-			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
-		},
-		{
-			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.BlockHash),
-			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
-		},
-	}
-	for _, c := range cases {
-		require.Equal(t, c.expected, c.actual, fmt.Sprintf("unexpected value for field %s", c.name))
-	}
-	require.Equal(t, 1, len(epr.Data.Transactions))
-	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-	require.Equal(t, txHash, hexutil.Encode(epr.Data.Transactions[0]))
-}
-
 func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	epr := &ExecPayloadResponseCapella{}
 	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayloadCapella), epr))
@@ -959,67 +877,67 @@ func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	}{
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ParentHash),
+			actual:   epr.Data.ParentHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(epr.Data.FeeRecipient),
+			actual:   epr.Data.FeeRecipient,
 			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.StateRoot),
+			actual:   epr.Data.StateRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ReceiptsRoot),
+			actual:   epr.Data.ReceiptsRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(epr.Data.LogsBloom),
+			actual:   epr.Data.LogsBloom,
 			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.PrevRandao),
+			actual:   epr.Data.PrevRandao,
 			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.BlockNumber),
+			actual:   epr.Data.BlockNumber,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasLimit),
+			actual:   epr.Data.GasLimit,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.GasUsed),
+			actual:   epr.Data.GasUsed,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.Timestamp),
+			actual:   epr.Data.Timestamp,
 			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExtraData),
+			actual:   epr.Data.ExtraData,
 			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", epr.Data.BaseFeePerGas),
+			actual:   epr.Data.BaseFeePerGas,
 			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.BlockHash),
+			actual:   epr.Data.BlockHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
 		},
 	}
@@ -1028,14 +946,14 @@ func TestExecutionPayloadResponseCapellaUnmarshal(t *testing.T) {
 	}
 	require.Equal(t, 1, len(epr.Data.Transactions))
 	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-	require.Equal(t, txHash, hexutil.Encode(epr.Data.Transactions[0]))
+	require.Equal(t, txHash, epr.Data.Transactions[0])
 
 	require.Equal(t, 1, len(epr.Data.Withdrawals))
 	w := epr.Data.Withdrawals[0]
-	assert.Equal(t, uint64(1), w.Index.Uint64())
-	assert.Equal(t, uint64(1), w.ValidatorIndex.Uint64())
-	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.Address.String())
-	assert.Equal(t, uint64(1), w.Amount.Uint64())
+	assert.Equal(t, "1", w.WithdrawalIndex)
+	assert.Equal(t, "1", w.ValidatorIndex)
+	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.ExecutionAddress)
+	assert.Equal(t, "1", w.Amount)
 }
 
 func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
@@ -1048,77 +966,77 @@ func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
 	}{
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ParentHash),
+			actual:   epr.Data.ExecutionPayload.ParentHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.ParentHash",
 		},
 		{
 			expected: "0xabcf8e0d4e9587369b2301d0790347320302cc09",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.FeeRecipient),
+			actual:   epr.Data.ExecutionPayload.FeeRecipient,
 			name:     "ExecPayloadResponse.ExecutionPayload.FeeRecipient",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.StateRoot),
+			actual:   epr.Data.ExecutionPayload.StateRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.StateRoot",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ReceiptsRoot),
+			actual:   epr.Data.ExecutionPayload.ReceiptsRoot,
 			name:     "ExecPayloadResponse.ExecutionPayload.ReceiptsRoot",
 		},
 		{
 			expected: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.LogsBloom),
+			actual:   epr.Data.ExecutionPayload.LogsBloom,
 			name:     "ExecPayloadResponse.ExecutionPayload.LogsBloom",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.PrevRandao),
+			actual:   epr.Data.ExecutionPayload.PrevRandao,
 			name:     "ExecPayloadResponse.ExecutionPayload.PrevRandao",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BlockNumber),
+			actual:   epr.Data.ExecutionPayload.BlockNumber,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockNumber",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.GasLimit),
+			actual:   epr.Data.ExecutionPayload.GasLimit,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasLimit",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.GasUsed),
+			actual:   epr.Data.ExecutionPayload.GasUsed,
 			name:     "ExecPayloadResponse.ExecutionPayload.GasUsed",
 		},
 		{
 			expected: "1",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.Timestamp),
+			actual:   epr.Data.ExecutionPayload.Timestamp,
 			name:     "ExecPayloadResponse.ExecutionPayload.Timestamp",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.ExtraData),
+			actual:   epr.Data.ExecutionPayload.ExtraData,
 			name:     "ExecPayloadResponse.ExecutionPayload.ExtraData",
 		},
 		{
 			expected: "452312848583266388373324160190187140051835877600158453279131187530910662656",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BaseFeePerGas),
+			actual:   epr.Data.ExecutionPayload.BaseFeePerGas,
 			name:     "ExecPayloadResponse.ExecutionPayload.BaseFeePerGas",
 		},
 		{
 			expected: "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
-			actual:   hexutil.Encode(epr.Data.ExecutionPayload.BlockHash),
+			actual:   epr.Data.ExecutionPayload.BlockHash,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlockHash",
 		},
 		{
 			expected: "2",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.BlobGasUsed),
+			actual:   epr.Data.ExecutionPayload.BlobGasUsed,
 			name:     "ExecPayloadResponse.ExecutionPayload.BlobGasUsed",
 		},
 		{
 			expected: "3",
-			actual:   fmt.Sprintf("%d", epr.Data.ExecutionPayload.ExcessBlobGas),
+			actual:   epr.Data.ExecutionPayload.ExcessBlobGas,
 			name:     "ExecPayloadResponse.ExecutionPayload.ExcessBlobGas",
 		},
 	}
@@ -1127,64 +1045,16 @@ func TestExecutionPayloadResponseDenebUnmarshal(t *testing.T) {
 	}
 	require.Equal(t, 1, len(epr.Data.ExecutionPayload.Transactions))
 	txHash := "0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86"
-	require.Equal(t, txHash, hexutil.Encode(epr.Data.ExecutionPayload.Transactions[0]))
+	require.Equal(t, txHash, epr.Data.ExecutionPayload.Transactions[0])
 
 	require.Equal(t, 1, len(epr.Data.ExecutionPayload.Withdrawals))
 	w := epr.Data.ExecutionPayload.Withdrawals[0]
-	assert.Equal(t, uint64(1), w.Index.Uint64())
-	assert.Equal(t, uint64(1), w.ValidatorIndex.Uint64())
-	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.Address.String())
-	assert.Equal(t, uint64(1), w.Amount.Uint64())
-	assert.Equal(t, uint64(2), uint64(epr.Data.ExecutionPayload.BlobGasUsed))
-	assert.Equal(t, uint64(3), uint64(epr.Data.ExecutionPayload.ExcessBlobGas))
-}
-
-func TestExecutionPayloadResponseToProto(t *testing.T) {
-	hr := &ExecPayloadResponse{}
-	require.NoError(t, json.Unmarshal([]byte(testExampleExecutionPayload), hr))
-	p, err := hr.ToProto()
-	require.NoError(t, err)
-
-	parentHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	feeRecipient, err := hexutil.Decode("0xabcf8e0d4e9587369b2301d0790347320302cc09")
-	require.NoError(t, err)
-	stateRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	receiptsRoot, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	logsBloom, err := hexutil.Decode("0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000")
-	require.NoError(t, err)
-	prevRandao, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	extraData, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-	blockHash, err := hexutil.Decode("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
-	require.NoError(t, err)
-
-	tx, err := hexutil.Decode("0x02f878831469668303f51d843b9ac9f9843b9aca0082520894c93269b73096998db66be0441e836d873535cb9c8894a19041886f000080c001a031cc29234036afbf9a1fb9476b463367cb1f957ac0b919b69bbc798436e604aaa018c4e9c3914eb27aadd0b91e10b18655739fcf8c1fc398763a9f1beecb8ddc86")
-	require.NoError(t, err)
-	txList := [][]byte{tx}
-
-	bfpg, err := stringToUint256("452312848583266388373324160190187140051835877600158453279131187530910662656")
-	require.NoError(t, err)
-	expected := &v1.ExecutionPayload{
-		ParentHash:    parentHash,
-		FeeRecipient:  feeRecipient,
-		StateRoot:     stateRoot,
-		ReceiptsRoot:  receiptsRoot,
-		LogsBloom:     logsBloom,
-		PrevRandao:    prevRandao,
-		BlockNumber:   1,
-		GasLimit:      1,
-		GasUsed:       1,
-		Timestamp:     1,
-		ExtraData:     extraData,
-		BaseFeePerGas: bfpg.SSZBytes(),
-		BlockHash:     blockHash,
-		Transactions:  txList,
-	}
-	require.DeepEqual(t, expected, p)
+	assert.Equal(t, "1", w.WithdrawalIndex)
+	assert.Equal(t, "1", w.ValidatorIndex)
+	assert.DeepEqual(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943", w.ExecutionAddress)
+	assert.Equal(t, "1", w.Amount)
+	assert.Equal(t, "2", epr.Data.ExecutionPayload.BlobGasUsed)
+	assert.Equal(t, "3", epr.Data.ExecutionPayload.ExcessBlobGas)
 }
 
 func TestExecutionPayloadResponseCapellaToProto(t *testing.T) {
@@ -1352,16 +1222,6 @@ func pbEth1Data() *eth.Eth1Data {
 	}
 }
 
-func TestEth1DataMarshal(t *testing.T) {
-	ed := &Eth1Data{
-		Eth1Data: pbEth1Data(),
-	}
-	b, err := json.Marshal(ed)
-	require.NoError(t, err)
-	expected := `{"deposit_root":"0x0000000000000000000000000000000000000000000000000000000000000000","deposit_count":"23","block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbSyncAggregate() *eth.SyncAggregate {
 	return &eth.SyncAggregate{
 		SyncCommitteeSignature: make([]byte, 48),
@@ -1369,14 +1229,6 @@ func pbSyncAggregate() *eth.SyncAggregate {
 	}
 }
 
-func TestSyncAggregate_MarshalJSON(t *testing.T) {
-	sa := &SyncAggregate{pbSyncAggregate()}
-	b, err := json.Marshal(sa)
-	require.NoError(t, err)
-	expected := `{"sync_committee_bits":"0x01","sync_committee_signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbDeposit(t *testing.T) *eth.Deposit {
 	return &eth.Deposit{
 		Proof: [][]byte{ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")},
@@ -1389,16 +1241,6 @@ func pbDeposit(t *testing.T) *eth.Deposit {
 	}
 }
 
-func TestDeposit_MarshalJSON(t *testing.T) {
-	d := &Deposit{
-		Deposit: pbDeposit(t),
-	}
-	b, err := json.Marshal(d)
-	require.NoError(t, err)
-	expected := `{"proof":["0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"],"data":{"pubkey":"0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a","withdrawal_credentials":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","amount":"1","signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbSignedVoluntaryExit(t *testing.T) *eth.SignedVoluntaryExit {
 	return &eth.SignedVoluntaryExit{
 		Exit: &eth.VoluntaryExit{
@@ -1409,16 +1251,6 @@ func pbSignedVoluntaryExit(t *testing.T) *eth.SignedVoluntaryExit {
 	}
 }
 
-func TestVoluntaryExit(t *testing.T) {
-	ve := &SignedVoluntaryExit{
-		SignedVoluntaryExit: pbSignedVoluntaryExit(t),
-	}
-	b, err := json.Marshal(ve)
-	require.NoError(t, err)
-	expected := `{"message":{"epoch":"1","validator_index":"1"},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbAttestation(t *testing.T) *eth.Attestation {
 	return &eth.Attestation{
 		AggregationBits: bitfield.Bitlist{0x01},
@@ -1439,16 +1271,6 @@ func pbAttestation(t *testing.T) *eth.Attestation {
 	}
 }
 
-func TestAttestationMarshal(t *testing.T) {
-	a := &Attestation{
-		Attestation: pbAttestation(t),
-	}
-	b, err := json.Marshal(a)
-	require.NoError(t, err)
-	expected := `{"aggregation_bits":"0x01","data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}`
-	require.Equal(t, expected, string(b))
-}
-
 func pbAttesterSlashing(t *testing.T) *eth.AttesterSlashing {
 	return &eth.AttesterSlashing{
 		Attestation_1: &eth.IndexedAttestation{
@@ -1489,9 +1311,7 @@ func pbAttesterSlashing(t *testing.T) *eth.AttesterSlashing {
 }
 
 func TestAttesterSlashing_MarshalJSON(t *testing.T) {
-	as := &AttesterSlashing{
-		AttesterSlashing: pbAttesterSlashing(t),
-	}
+	as := structs.AttesterSlashingFromConsensus(pbAttesterSlashing(t))
 	b, err := json.Marshal(as)
 	require.NoError(t, err)
 	expected := `{"attestation_1":{"attesting_indices":["1"],"data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"},"attestation_2":{"attesting_indices":["1"],"data":{"slot":"1","index":"1","beacon_block_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","source":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"},"target":{"epoch":"1","root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}},"signature":"0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"}}`
@@ -1599,9 +1419,8 @@ func pbExecutionPayloadHeaderDeneb(t *testing.T) *v1.ExecutionPayloadHeaderDeneb
 }
 
 func TestExecutionPayloadHeader_MarshalJSON(t *testing.T) {
-	h := &ExecutionPayloadHeader{
-		ExecutionPayloadHeader: pbExecutionPayloadHeader(t),
-	}
+	h, err := structs.ExecutionPayloadHeaderFromConsensus(pbExecutionPayloadHeader(t))
+	require.NoError(t, err)
 	b, err := json.Marshal(h)
 	require.NoError(t, err)
 	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}`
@@ -1609,9 +1428,9 @@ func TestExecutionPayloadHeader_MarshalJSON(t *testing.T) {
 }
 
 func TestExecutionPayloadHeaderCapella_MarshalJSON(t *testing.T) {
-	h := &ExecutionPayloadHeaderCapella{
-		ExecutionPayloadHeaderCapella: pbExecutionPayloadHeaderCapella(t),
-	}
+	h, err := structs.ExecutionPayloadHeaderCapellaFromConsensus(pbExecutionPayloadHeaderCapella(t))
+	require.NoError(t, err)
+	require.NoError(t, err)
 	b, err := json.Marshal(h)
 	require.NoError(t, err)
 	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","withdrawals_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"}`
@@ -1619,9 +1438,8 @@ func TestExecutionPayloadHeaderCapella_MarshalJSON(t *testing.T) {
 }
 
 func TestExecutionPayloadHeaderDeneb_MarshalJSON(t *testing.T) {
-	h := &ExecutionPayloadHeaderDeneb{
-		ExecutionPayloadHeaderDeneb: pbExecutionPayloadHeaderDeneb(t),
-	}
+	h, err := structs.ExecutionPayloadHeaderDenebFromConsensus(pbExecutionPayloadHeaderDeneb(t))
+	require.NoError(t, err)
 	b, err := json.Marshal(h)
 	require.NoError(t, err)
 	expected := `{"parent_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","fee_recipient":"0xabcf8e0d4e9587369b2301d0790347320302cc09","state_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","receipts_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","logs_bloom":"0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000","prev_randao":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","block_number":"1","gas_limit":"1","gas_used":"1","timestamp":"1","extra_data":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","base_fee_per_gas":"452312848583266388373324160190187140051835877600158453279131187530910662656","block_hash":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","transactions_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","withdrawals_root":"0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2","blob_gas_used":"1","excess_blob_gas":"2"}`
@@ -1850,12 +1668,13 @@ func TestRoundTripUint256(t *testing.T) {
 func TestRoundTripProtoUint256(t *testing.T) {
 	h := pbExecutionPayloadHeader(t)
 	h.BaseFeePerGas = []byte{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}
-	hm := &ExecutionPayloadHeader{ExecutionPayloadHeader: h}
+	hm, err := structs.ExecutionPayloadHeaderFromConsensus(h)
+	require.NoError(t, err)
 	m, err := json.Marshal(hm)
 	require.NoError(t, err)
-	hu := &ExecutionPayloadHeader{}
+	hu := &structs.ExecutionPayloadHeader{}
 	require.NoError(t, json.Unmarshal(m, hu))
-	hp, err := hu.ToProto()
+	hp, err := hu.ToConsensus()
 	require.NoError(t, err)
 	require.DeepEqual(t, h.BaseFeePerGas, hp.BaseFeePerGas)
 }
@@ -1863,7 +1682,7 @@ func TestRoundTripProtoUint256(t *testing.T) {
 func TestExecutionPayloadHeaderRoundtrip(t *testing.T) {
 	expected, err := os.ReadFile("testdata/execution-payload.json")
 	require.NoError(t, err)
-	hu := &ExecutionPayloadHeader{}
+	hu := &structs.ExecutionPayloadHeader{}
 	require.NoError(t, json.Unmarshal(expected, hu))
 	m, err := json.Marshal(hu)
 	require.NoError(t, err)
@@ -1873,7 +1692,7 @@ func TestExecutionPayloadHeaderRoundtrip(t *testing.T) {
 func TestExecutionPayloadHeaderCapellaRoundtrip(t *testing.T) {
 	expected, err := os.ReadFile("testdata/execution-payload-capella.json")
 	require.NoError(t, err)
-	hu := &ExecutionPayloadHeaderCapella{}
+	hu := &structs.ExecutionPayloadHeaderCapella{}
 	require.NoError(t, json.Unmarshal(expected, hu))
 	m, err := json.Marshal(hu)
 	require.NoError(t, err)
@@ -1994,11 +1813,9 @@ func TestEmptyResponseBody(t *testing.T) {
 			epr := &ExecutionPayloadResponse{}
 			require.NoError(t, json.Unmarshal(encoded, epr))
 			pp, err := epr.ParsePayload()
-			require.NoError(t, err)
-			pb, err := pp.PayloadProto()
 			if err == nil {
 				require.NoError(t, err)
-				require.Equal(t, false, pb == nil)
+				require.Equal(t, false, pp == nil)
 			} else {
 				require.ErrorIs(t, err, consensusblocks.ErrNilObject)
 			}

api/client/event/event_stream.go

@@ -14,22 +14,10 @@ import (
 )
 
 const (
-	EventHead                        = "head"
-	EventBlock                       = "block"
-	EventAttestation                 = "attestation"
-	EventVoluntaryExit               = "voluntary_exit"
-	EventBlsToExecutionChange        = "bls_to_execution_change"
-	EventProposerSlashing            = "proposer_slashing"
-	EventAttesterSlashing            = "attester_slashing"
-	EventFinalizedCheckpoint         = "finalized_checkpoint"
-	EventChainReorg                  = "chain_reorg"
-	EventContributionAndProof        = "contribution_and_proof"
-	EventLightClientFinalityUpdate   = "light_client_finality_update"
-	EventLightClientOptimisticUpdate = "light_client_optimistic_update"
-	EventPayloadAttributes           = "payload_attributes"
-	EventBlobSidecar                 = "blob_sidecar"
-	EventError                       = "error"
-	EventConnectionError             = "connection_error"
+	EventHead = "head"
+
+	EventError           = "error"
+	EventConnectionError = "connection_error"
 )
 
 var (

api/client/event/event_stream_test.go

@@ -83,8 +83,7 @@ func TestEventStream(t *testing.T) {
 func TestEventStreamRequestError(t *testing.T) {
 	topics := []string{"head"}
 	eventsChannel := make(chan *Event, 1)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	// use valid url that will result in failed request with nil body
 	stream, err := NewEventStream(ctx, http.DefaultClient, "http://badhost:1234", topics)

api/server/structs/BUILD.bazel

@@ -31,6 +31,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
@@ -44,6 +45,7 @@ go_library(
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )
 
@@ -57,6 +59,7 @@ go_test(
     deps = [
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",

api/server/structs/conversions_block_execution.go

@@ -7,12 +7,15 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	consensusblocks "github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
+	"google.golang.org/protobuf/proto"
 )
 
 // ----------------------------------------------------------------------------
@@ -132,6 +135,13 @@ func (e *ExecutionPayload) ToConsensus() (*enginev1.ExecutionPayload, error) {
 	}, nil
 }
 
+func (r *ExecutionPayload) PayloadProto() (proto.Message, error) {
+	if r == nil {
+		return nil, errors.Wrap(consensusblocks.ErrNilObject, "nil execution payload")
+	}
+	return r.ToConsensus()
+}
+
 func ExecutionPayloadHeaderFromConsensus(payload *enginev1.ExecutionPayloadHeader) (*ExecutionPayloadHeader, error) {
 	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
 	if err != nil {
@@ -383,6 +393,13 @@ func (e *ExecutionPayloadCapella) ToConsensus() (*enginev1.ExecutionPayloadCapel
 	}, nil
 }
 
+func (p *ExecutionPayloadCapella) PayloadProto() (proto.Message, error) {
+	if p == nil {
+		return nil, errors.Wrap(consensusblocks.ErrNilObject, "nil capella execution payload")
+	}
+	return p.ToConsensus()
+}
+
 func ExecutionPayloadHeaderCapellaFromConsensus(payload *enginev1.ExecutionPayloadHeaderCapella) (*ExecutionPayloadHeaderCapella, error) {
 	baseFeePerGas, err := sszBytesToUint256String(payload.BaseFeePerGas)
 	if err != nil {

api/server/structs/conversions_state.go

@@ -26,10 +26,7 @@ func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error)
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -116,10 +113,7 @@ func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAlt
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -225,10 +219,7 @@ func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconState
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -347,10 +338,7 @@ func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCa
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -488,10 +476,7 @@ func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDene
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -629,10 +614,7 @@ func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateEl
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)
@@ -815,10 +797,7 @@ func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu,
 	for i, r := range srcSr {
 		sr[i] = hexutil.Encode(r)
 	}
-	srcHr, err := st.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
+	srcHr := st.HistoricalRoots()
 	hr := make([]string, len(srcHr))
 	for i, r := range srcHr {
 		hr[i] = hexutil.Encode(r)

api/server/structs/conversions_test.go

@@ -4,7 +4,9 @@ import (
 	"testing"
 
 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
 func TestDepositSnapshotFromConsensus(t *testing.T) {
@@ -102,12 +104,266 @@ func TestProposerSlashing_ToConsensus(t *testing.T) {
 	require.ErrorContains(t, errNilValue.Error(), err)
 }
 
+func TestProposerSlashing_FromConsensus(t *testing.T) {
+	input := []*eth.ProposerSlashing{
+		{
+			Header_1: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          1,
+					ProposerIndex: 2,
+					ParentRoot:    []byte{3},
+					StateRoot:     []byte{4},
+					BodyRoot:      []byte{5},
+				},
+				Signature: []byte{6},
+			},
+			Header_2: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          7,
+					ProposerIndex: 8,
+					ParentRoot:    []byte{9},
+					StateRoot:     []byte{10},
+					BodyRoot:      []byte{11},
+				},
+				Signature: []byte{12},
+			},
+		},
+		{
+			Header_1: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          13,
+					ProposerIndex: 14,
+					ParentRoot:    []byte{15},
+					StateRoot:     []byte{16},
+					BodyRoot:      []byte{17},
+				},
+				Signature: []byte{18},
+			},
+			Header_2: &eth.SignedBeaconBlockHeader{
+				Header: &eth.BeaconBlockHeader{
+					Slot:          19,
+					ProposerIndex: 20,
+					ParentRoot:    []byte{21},
+					StateRoot:     []byte{22},
+					BodyRoot:      []byte{23},
+				},
+				Signature: []byte{24},
+			},
+		},
+	}
+
+	expectedResult := []*ProposerSlashing{
+		{
+			SignedHeader1: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "1",
+					ProposerIndex: "2",
+					ParentRoot:    hexutil.Encode([]byte{3}),
+					StateRoot:     hexutil.Encode([]byte{4}),
+					BodyRoot:      hexutil.Encode([]byte{5}),
+				},
+				Signature: hexutil.Encode([]byte{6}),
+			},
+			SignedHeader2: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "7",
+					ProposerIndex: "8",
+					ParentRoot:    hexutil.Encode([]byte{9}),
+					StateRoot:     hexutil.Encode([]byte{10}),
+					BodyRoot:      hexutil.Encode([]byte{11}),
+				},
+				Signature: hexutil.Encode([]byte{12}),
+			},
+		},
+		{
+			SignedHeader1: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "13",
+					ProposerIndex: "14",
+					ParentRoot:    hexutil.Encode([]byte{15}),
+					StateRoot:     hexutil.Encode([]byte{16}),
+					BodyRoot:      hexutil.Encode([]byte{17}),
+				},
+				Signature: hexutil.Encode([]byte{18}),
+			},
+			SignedHeader2: &SignedBeaconBlockHeader{
+				Message: &BeaconBlockHeader{
+					Slot:          "19",
+					ProposerIndex: "20",
+					ParentRoot:    hexutil.Encode([]byte{21}),
+					StateRoot:     hexutil.Encode([]byte{22}),
+					BodyRoot:      hexutil.Encode([]byte{23}),
+				},
+				Signature: hexutil.Encode([]byte{24}),
+			},
+		},
+	}
+
+	result := ProposerSlashingsFromConsensus(input)
+	assert.DeepEqual(t, expectedResult, result)
+}
+
 func TestAttesterSlashing_ToConsensus(t *testing.T) {
 	a := &AttesterSlashing{Attestation1: nil, Attestation2: nil}
 	_, err := a.ToConsensus()
 	require.ErrorContains(t, errNilValue.Error(), err)
 }
 
+func TestAttesterSlashing_FromConsensus(t *testing.T) {
+	input := []*eth.AttesterSlashing{
+		{
+			Attestation_1: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{1, 2},
+				Data: &eth.AttestationData{
+					Slot:            3,
+					CommitteeIndex:  4,
+					BeaconBlockRoot: []byte{5},
+					Source: &eth.Checkpoint{
+						Epoch: 6,
+						Root:  []byte{7},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 8,
+						Root:  []byte{9},
+					},
+				},
+				Signature: []byte{10},
+			},
+			Attestation_2: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{11, 12},
+				Data: &eth.AttestationData{
+					Slot:            13,
+					CommitteeIndex:  14,
+					BeaconBlockRoot: []byte{15},
+					Source: &eth.Checkpoint{
+						Epoch: 16,
+						Root:  []byte{17},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 18,
+						Root:  []byte{19},
+					},
+				},
+				Signature: []byte{20},
+			},
+		},
+		{
+			Attestation_1: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{21, 22},
+				Data: &eth.AttestationData{
+					Slot:            23,
+					CommitteeIndex:  24,
+					BeaconBlockRoot: []byte{25},
+					Source: &eth.Checkpoint{
+						Epoch: 26,
+						Root:  []byte{27},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 28,
+						Root:  []byte{29},
+					},
+				},
+				Signature: []byte{30},
+			},
+			Attestation_2: &eth.IndexedAttestation{
+				AttestingIndices: []uint64{31, 32},
+				Data: &eth.AttestationData{
+					Slot:            33,
+					CommitteeIndex:  34,
+					BeaconBlockRoot: []byte{35},
+					Source: &eth.Checkpoint{
+						Epoch: 36,
+						Root:  []byte{37},
+					},
+					Target: &eth.Checkpoint{
+						Epoch: 38,
+						Root:  []byte{39},
+					},
+				},
+				Signature: []byte{40},
+			},
+		},
+	}
+
+	expectedResult := []*AttesterSlashing{
+		{
+			Attestation1: &IndexedAttestation{
+				AttestingIndices: []string{"1", "2"},
+				Data: &AttestationData{
+					Slot:            "3",
+					CommitteeIndex:  "4",
+					BeaconBlockRoot: hexutil.Encode([]byte{5}),
+					Source: &Checkpoint{
+						Epoch: "6",
+						Root:  hexutil.Encode([]byte{7}),
+					},
+					Target: &Checkpoint{
+						Epoch: "8",
+						Root:  hexutil.Encode([]byte{9}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{10}),
+			},
+			Attestation2: &IndexedAttestation{
+				AttestingIndices: []string{"11", "12"},
+				Data: &AttestationData{
+					Slot:            "13",
+					CommitteeIndex:  "14",
+					BeaconBlockRoot: hexutil.Encode([]byte{15}),
+					Source: &Checkpoint{
+						Epoch: "16",
+						Root:  hexutil.Encode([]byte{17}),
+					},
+					Target: &Checkpoint{
+						Epoch: "18",
+						Root:  hexutil.Encode([]byte{19}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{20}),
+			},
+		},
+		{
+			Attestation1: &IndexedAttestation{
+				AttestingIndices: []string{"21", "22"},
+				Data: &AttestationData{
+					Slot:            "23",
+					CommitteeIndex:  "24",
+					BeaconBlockRoot: hexutil.Encode([]byte{25}),
+					Source: &Checkpoint{
+						Epoch: "26",
+						Root:  hexutil.Encode([]byte{27}),
+					},
+					Target: &Checkpoint{
+						Epoch: "28",
+						Root:  hexutil.Encode([]byte{29}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{30}),
+			},
+			Attestation2: &IndexedAttestation{
+				AttestingIndices: []string{"31", "32"},
+				Data: &AttestationData{
+					Slot:            "33",
+					CommitteeIndex:  "34",
+					BeaconBlockRoot: hexutil.Encode([]byte{35}),
+					Source: &Checkpoint{
+						Epoch: "36",
+						Root:  hexutil.Encode([]byte{37}),
+					},
+					Target: &Checkpoint{
+						Epoch: "38",
+						Root:  hexutil.Encode([]byte{39}),
+					},
+				},
+				Signature: hexutil.Encode([]byte{40}),
+			},
+		},
+	}
+
+	result := AttesterSlashingsFromConsensus(input)
+	assert.DeepEqual(t, expectedResult, result)
+}
+
 func TestIndexedAttestation_ToConsensus(t *testing.T) {
 	a := &IndexedAttestation{
 		AttestingIndices: []string{"1"},

api/server/structs/endpoints_beacon.go

@@ -263,6 +263,13 @@ type ChainHead struct {
 	OptimisticStatus           bool   `json:"optimistic_status"`
 }
 
+type GetPendingConsolidationsResponse struct {
+	Version             string                  `json:"version"`
+	ExecutionOptimistic bool                    `json:"execution_optimistic"`
+	Finalized           bool                    `json:"finalized"`
+	Data                []*PendingConsolidation `json:"data"`
+}
+
 type GetPendingDepositsResponse struct {
 	Version             string            `json:"version"`
 	ExecutionOptimistic bool              `json:"execution_optimistic"`

api/server/structs/other.go

@@ -253,7 +253,7 @@ type PendingDeposit struct {
 }
 
 type PendingPartialWithdrawal struct {
-	Index             string `json:"index"`
+	Index             string `json:"validator_index"`
 	Amount            string `json:"amount"`
 	WithdrawableEpoch string `json:"withdrawable_epoch"`
 }

beacon-chain/README.md

@@ -4,6 +4,6 @@ This is the main project folder for the beacon chain implementation of Ethereum
 
 You can also read our main [README](https://github.com/prysmaticlabs/prysm/blob/master/README.md) and join our active chat room on Discord.
 
-[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/CTYGPUJ)
+[![Discord](https://user-images.githubusercontent.com/7288322/34471967-1df7808a-efbb-11e7-9088-ed0b04151291.png)](https://discord.gg/prysm)
 
 Also, read the official beacon chain [specification](https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/beacon-chain.md), this design spec serves as a source of truth for the beacon chain implementation we follow at Prysmatic Labs.

beacon-chain/blockchain/BUILD.bazel

@@ -163,6 +163,7 @@ 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",

beacon-chain/blockchain/chain_info.go

@@ -51,6 +51,7 @@ type ForkchoiceFetcher interface {
 	ProposerBoost() [32]byte
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 	IsCanonical(ctx context.Context, blockRoot [32]byte) (bool, error)
+	DependentRoot(primitives.Epoch) ([32]byte, error)
 }
 
 // TimeFetcher retrieves the Ethereum consensus data that's related to time.

beacon-chain/blockchain/execution_engine.go

@@ -184,13 +184,17 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 	return payloadID, nil
 }
 
-func firePayloadAttributesEvent(_ context.Context, f event.SubscriberSender, nextSlot primitives.Slot) {
+func (s *Service) firePayloadAttributesEvent(f event.SubscriberSender, block interfaces.ReadOnlySignedBeaconBlock, root [32]byte, nextSlot primitives.Slot) {
+	// If we're syncing a block in the past and init-sync is still running, we shouldn't fire this event.
+	if !s.cfg.SyncChecker.Synced() {
+		return
+	}
 	// the fcu args have differing amounts of completeness based on the code path,
 	// and there is work we only want to do if a client is actually listening to the events beacon api endpoint.
 	// temporary solution: just fire a blank event and fill in the details in the api handler.
 	f.Send(&feed.Event{
 		Type: statefeed.PayloadAttributes,
-		Data: payloadattribute.EventData{ProposalSlot: nextSlot},
+		Data: payloadattribute.EventData{HeadBlock: block, HeadRoot: root, ProposalSlot: nextSlot},
 	})
 }
 

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -102,7 +102,7 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 		log.WithError(err).Error("could not save head")
 	}
 
-	go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
+	go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), args.headBlock, args.headRoot, s.CurrentSlot()+1)
 
 	// Only need to prune attestations from pool if the head has changed.
 	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)

beacon-chain/blockchain/kzg/BUILD.bazel

@@ -3,15 +3,19 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "kzg.go",
         "trusted_setup.go",
         "validation.go",
     ],
-    embedsrcs = ["trusted_setup.json"],
+    embedsrcs = ["trusted_setup_4096.json"],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg",
     visibility = ["//visibility:public"],
     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",
     ],
 )
@@ -25,8 +29,8 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//consensus-types/blocks:go_default_library",
+        "//crypto/random:go_default_library",
         "//testing/require:go_default_library",
-        "//testing/util:go_default_library",
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
     ],
 )

beacon-chain/blockchain/kzg/kzg.go

@@ -0,0 +1,143 @@
+package kzg
+
+import (
+	"github.com/pkg/errors"
+
+	ckzg4844 "github.com/ethereum/c-kzg-4844/v2/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
+}
+
+// BlobToKZGCommitment computes a KZG commitment from a given blob.
+func BlobToKZGCommitment(blob *Blob) (Commitment, error) {
+	var kzgBlob kzg4844.Blob
+	copy(kzgBlob[:], blob[:])
+
+	commitment, err := kzg4844.BlobToCommitment(&kzgBlob)
+	if err != nil {
+		return Commitment{}, err
+	}
+
+	return Commitment(commitment), nil
+}
+
+// ComputeCells computes the (extended) cells from a given blob.
+func ComputeCells(blob *Blob) ([]Cell, error) {
+	var ckzgBlob ckzg4844.Blob
+	copy(ckzgBlob[:], blob[:])
+
+	ckzgCells, err := ckzg4844.ComputeCells(&ckzgBlob)
+	if err != nil {
+		return nil, errors.Wrap(err, "compute cells")
+	}
+
+	cells := make([]Cell, len(ckzgCells))
+	for i := range ckzgCells {
+		cells[i] = Cell(ckzgCells[i])
+	}
+
+	return cells, nil
+}
+
+// ComputeBlobKZGProof computes the blob KZG proof from a given blob and its commitment.
+func ComputeBlobKZGProof(blob *Blob, commitment Commitment) (Proof, error) {
+	var kzgBlob kzg4844.Blob
+	copy(kzgBlob[:], blob[:])
+
+	proof, err := kzg4844.ComputeBlobProof(&kzgBlob, kzg4844.Commitment(commitment))
+	if err != nil {
+		return [48]byte{}, err
+	}
+	return Proof(proof), nil
+}
+
+// ComputeCellsAndKZGProofs computes the cells and cells KZG proofs from a given blob.
+func ComputeCellsAndKZGProofs(blob *Blob) (CellsAndProofs, error) {
+	var ckzgBlob ckzg4844.Blob
+	copy(ckzgBlob[:], blob[:])
+
+	ckzgCells, ckzgProofs, err := ckzg4844.ComputeCellsAndKZGProofs(&ckzgBlob)
+	if err != nil {
+		return CellsAndProofs{}, err
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+// VerifyCellKZGProofBatch verifies the KZG proofs for a given slice of commitments, cells indices, cells and proofs.
+// Note: It is way more efficient to call once this function with big slices than calling it multiple times with small slices.
+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)
+}
+
+// RecoverCellsAndKZGProofs recovers the complete cells and KZG proofs from a given set of cell indices and partial cells.
+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{}, errors.Wrap(err, "recover cells and KZG proofs")
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+// makeCellsAndProofs converts 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")
+	}
+
+	cells := make([]Cell, 0, len(ckzgCells))
+	proofs := make([]Proof, 0, len(ckzgProofs))
+
+	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

@@ -5,24 +5,69 @@ import (
 	"encoding/json"
 
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	CKZG "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 )
 
 var (
-	//go:embed trusted_setup.json
+	// https://github.com/ethereum/consensus-specs/blob/dev/presets/mainnet/trusted_setups/trusted_setup_4096.json
+	//go:embed trusted_setup_4096.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 {
+		const precompute uint = 8
+
+		kzgLoaded = true
+
+		// 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 {
+			return errors.Wrap(err, "load trust setup")
+		}
+	}
+
 	return nil
 }

beacon-chain/blockchain/kzg/validation_test.go

@@ -4,8 +4,8 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/crypto/random"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 )
 
@@ -37,7 +37,7 @@ func TestBytesToAny(t *testing.T) {
 }
 
 func TestGenerateCommitmentAndProof(t *testing.T) {
-	blob := util.GetRandBlob(123)
+	blob := random.GetRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
 	expectedCommitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}

beacon-chain/blockchain/mock_test.go

@@ -20,6 +20,7 @@ func testServiceOptsWithDB(t *testing.T) []Option {
 		WithForkChoiceStore(fcs),
 		WithClockSynchronizer(cs),
 		WithStateNotifier(&mock.MockStateNotifier{RecordEvents: true}),
+		WithSyncChecker(&mock.MockSyncChecker{}),
 	}
 }
 

beacon-chain/blockchain/options.go

@@ -4,6 +4,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution"
@@ -220,3 +221,10 @@ func WithSlasherEnabled(enabled bool) Option {
 		return nil
 	}
 }
+
+func WithLightClientStore(lcs *lightclient.Store) Option {
+	return func(s *Service) error {
+		s.lcStore = lcs
+		return nil
+	}
+}

beacon-chain/blockchain/process_block.go

@@ -729,9 +729,13 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
 	// return early if we are not proposing next slot
 	if attribute.IsEmpty() {
+		headBlock, err := s.headBlock()
+		if err != nil {
+			log.WithError(err).WithField("head_root", headRoot).Error("unable to retrieve head block to fire payload attributes event")
+		}
 		// notifyForkchoiceUpdate fires the payload attribute event. But in this case, we won't
 		// call notifyForkchoiceUpdate, so the event is fired here.
-		go firePayloadAttributesEvent(ctx, s.cfg.StateNotifier.StateFeed(), s.CurrentSlot()+1)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), headBlock, headRoot, s.CurrentSlot()+1)
 		return
 	}
 

beacon-chain/blockchain/process_block_helpers.go

@@ -103,15 +103,29 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 		log.WithError(err).Debug("Could not check if block is optimistic")
 		optimistic = true
 	}
+	currEpoch := slots.ToEpoch(s.CurrentSlot())
+	currDependenRoot, err := s.cfg.ForkChoiceStore.DependentRoot(currEpoch)
+	if err != nil {
+		log.WithError(err).Debug("Could not get dependent root")
+	}
+	prevDependentRoot := [32]byte{}
+	if currEpoch > 0 {
+		prevDependentRoot, err = s.cfg.ForkChoiceStore.DependentRoot(currEpoch - 1)
+		if err != nil {
+			log.WithError(err).Debug("Could not get previous dependent root")
+		}
+	}
 	// Send notification of the processed block to the state feed.
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.BlockProcessed,
 		Data: &statefeed.BlockProcessedData{
-			Slot:        cfg.roblock.Block().Slot(),
-			BlockRoot:   cfg.roblock.Root(),
-			SignedBlock: cfg.roblock,
-			Verified:    true,
-			Optimistic:  optimistic,
+			Slot:              cfg.roblock.Block().Slot(),
+			BlockRoot:         cfg.roblock.Root(),
+			SignedBlock:       cfg.roblock,
+			CurrDependentRoot: currDependenRoot,
+			PrevDependentRoot: prevDependentRoot,
+			Verified:          true,
+			Optimistic:        optimistic,
 		},
 	})
 }
@@ -254,7 +268,7 @@ func (s *Service) processLightClientFinalityUpdate(
 		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
 	}
 
-	update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
+	newUpdate, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
 		ctx,
 		postState.Slot(),
 		postState,
@@ -268,10 +282,38 @@ func (s *Service) processLightClientFinalityUpdate(
 		return errors.Wrap(err, "could not create light client finality update")
 	}
 
+	lastUpdate := s.lcStore.LastFinalityUpdate()
+	if lastUpdate != nil {
+		// The finalized_header.beacon.lastUpdateSlot is greater than that of all previously forwarded finality_updates,
+		// or it matches the highest previously forwarded lastUpdateSlot and also has a sync_aggregate indicating supermajority (> 2/3)
+		// sync committee participation while the previously forwarded finality_update for that lastUpdateSlot did not indicate supermajority
+		newUpdateSlot := newUpdate.FinalizedHeader().Beacon().Slot
+		newHasSupermajority := lightclient.UpdateHasSupermajority(newUpdate.SyncAggregate())
+
+		lastUpdateSlot := lastUpdate.FinalizedHeader().Beacon().Slot
+		lastHasSupermajority := lightclient.UpdateHasSupermajority(lastUpdate.SyncAggregate())
+
+		if newUpdateSlot < lastUpdateSlot {
+			log.Debug("Skip saving light client finality newUpdate: Older than local newUpdate")
+			return nil
+		}
+		if newUpdateSlot == lastUpdateSlot && (lastHasSupermajority || !newHasSupermajority) {
+			log.Debug("Skip saving light client finality update: No supermajority advantage")
+			return nil
+		}
+	}
+	log.Debug("Saving new light client finality update")
+	s.lcStore.SetLastFinalityUpdate(newUpdate)
+
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.LightClientFinalityUpdate,
-		Data: update,
+		Data: newUpdate,
 	})
+
+	if err = s.cfg.P2p.BroadcastLightClientFinalityUpdate(ctx, newUpdate); err != nil {
+		return errors.Wrap(err, "could not broadcast light client finality update")
+	}
+
 	return nil
 }
 
@@ -287,7 +329,7 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}
 
-	update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
+	newUpdate, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
 		ctx,
 		postState.Slot(),
 		postState,
@@ -304,11 +346,27 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return errors.Wrap(err, "could not create light client optimistic update")
 	}
 
+	lastUpdate := s.lcStore.LastOptimisticUpdate()
+	if lastUpdate != nil {
+		// The attested_header.beacon.slot is greater than that of all previously forwarded optimistic updates
+		if newUpdate.AttestedHeader().Beacon().Slot <= lastUpdate.AttestedHeader().Beacon().Slot {
+			log.Debug("Skip saving light client optimistic update: Older than local update")
+			return nil
+		}
+	}
+
+	log.Debug("Saving new light client optimistic update")
+	s.lcStore.SetLastOptimisticUpdate(newUpdate)
+
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.LightClientOptimisticUpdate,
-		Data: update,
+		Data: newUpdate,
 	})
 
+	if err = s.cfg.P2p.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
+		return errors.Wrap(err, "could not broadcast light client optimistic update")
+	}
+
 	return nil
 }
 

beacon-chain/blockchain/process_block_test.go

@@ -24,6 +24,7 @@ import (
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations/kv"
+	mockp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -2653,7 +2654,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 
 	t.Run("Altair", func(t *testing.T) {
 		t.Run("No old update", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+			l := util.NewTestLightClient(t, version.Altair)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -2699,7 +2700,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 		})
 
 		t.Run("New update is better", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+			l := util.NewTestLightClient(t, version.Altair)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -2751,7 +2752,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 		})
 
 		t.Run("Old update is better", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestAltair(0, false)
+			l := util.NewTestLightClient(t, version.Altair)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -2812,7 +2813,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 
 	t.Run("Capella", func(t *testing.T) {
 		t.Run("No old update", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+			l := util.NewTestLightClient(t, version.Capella)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -2857,7 +2858,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 		})
 
 		t.Run("New update is better", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+			l := util.NewTestLightClient(t, version.Capella)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -2909,7 +2910,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 		})
 
 		t.Run("Old update is better", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(false, 0, false)
+			l := util.NewTestLightClient(t, version.Capella)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -2970,7 +2971,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 
 	t.Run("Deneb", func(t *testing.T) {
 		t.Run("No old update", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+			l := util.NewTestLightClient(t, version.Deneb)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -3015,7 +3016,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 		})
 
 		t.Run("New update is better", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+			l := util.NewTestLightClient(t, version.Deneb)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -3067,7 +3068,7 @@ func TestSaveLightClientUpdate(t *testing.T) {
 		})
 
 		t.Run("Old update is better", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, false)
+			l := util.NewTestLightClient(t, version.Deneb)
 
 			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -3138,7 +3139,7 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 	ctx := tr.ctx
 
 	t.Run("Altair", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+		l := util.NewTestLightClient(t, version.Altair)
 
 		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -3173,7 +3174,7 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 	})
 
 	t.Run("Capella", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+		l := util.NewTestLightClient(t, version.Capella)
 
 		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -3208,7 +3209,7 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 	})
 
 	t.Run("Deneb", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+		l := util.NewTestLightClient(t, version.Deneb)
 
 		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
 
@@ -3244,3 +3245,340 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 
 	reset()
 }
+
+func setupLightClientTestRequirements(ctx context.Context, t *testing.T, s *Service, v int, options ...util.LightClientOption) (*util.TestLightClient, *postBlockProcessConfig) {
+	var l *util.TestLightClient
+	switch v {
+	case version.Altair:
+		l = util.NewTestLightClient(t, version.Altair, options...)
+	case version.Bellatrix:
+		l = util.NewTestLightClient(t, version.Bellatrix, options...)
+	case version.Capella:
+		l = util.NewTestLightClient(t, version.Capella, options...)
+	case version.Deneb:
+		l = util.NewTestLightClient(t, version.Deneb, options...)
+	case version.Electra:
+		l = util.NewTestLightClient(t, version.Electra, options...)
+	default:
+		t.Errorf("Unsupported fork version %s", version.String(v))
+		return nil, nil
+	}
+
+	err := s.cfg.BeaconDB.SaveBlock(ctx, l.AttestedBlock)
+	require.NoError(t, err)
+	attestedBlockRoot, err := l.AttestedBlock.Block().HashTreeRoot()
+	require.NoError(t, err)
+	err = s.cfg.BeaconDB.SaveState(ctx, l.AttestedState, attestedBlockRoot)
+	require.NoError(t, err)
+
+	currentBlockRoot, err := l.Block.Block().HashTreeRoot()
+	require.NoError(t, err)
+	roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
+	require.NoError(t, err)
+
+	err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
+	require.NoError(t, err)
+	err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
+	require.NoError(t, err)
+
+	err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
+	require.NoError(t, err)
+
+	cfg := &postBlockProcessConfig{
+		ctx:            ctx,
+		roblock:        roblock,
+		postState:      l.State,
+		isValidPayload: true,
+	}
+
+	return l, cfg
+}
+
+func TestProcessLightClientOptimisticUpdate(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+	defer reset()
+
+	params.SetupTestConfigCleanup(t)
+	beaconCfg := params.BeaconConfig()
+	beaconCfg.AltairForkEpoch = 1
+	beaconCfg.BellatrixForkEpoch = 2
+	beaconCfg.CapellaForkEpoch = 3
+	beaconCfg.DenebForkEpoch = 4
+	beaconCfg.ElectraForkEpoch = 5
+	params.OverrideBeaconConfig(beaconCfg)
+
+	s, tr := minimalTestService(t)
+	s.cfg.P2p = &mockp2p.FakeP2P{}
+	ctx := tr.ctx
+
+	testCases := []struct {
+		name          string
+		oldOptions    []util.LightClientOption
+		newOptions    []util.LightClientOption
+		expectReplace bool
+	}{
+		{
+			name:          "No old update",
+			oldOptions:    nil,
+			newOptions:    []util.LightClientOption{},
+			expectReplace: true,
+		},
+		{
+			name:          "Same age",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithSupermajority()}, // supermajority does not matter here and is only added to result in two different updates
+			expectReplace: false,
+		},
+		{
+			name:          "Old update is better - age",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
+			newOptions:    []util.LightClientOption{},
+			expectReplace: false,
+		},
+		{
+			name:          "New update is better - age",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
+			expectReplace: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		for testVersion := 1; testVersion < 6; testVersion++ { // test all forks
+			var forkEpoch uint64
+			var expectedVersion int
+
+			switch testVersion {
+			case 1:
+				forkEpoch = uint64(params.BeaconConfig().AltairForkEpoch)
+				expectedVersion = version.Altair
+			case 2:
+				forkEpoch = uint64(params.BeaconConfig().BellatrixForkEpoch)
+				expectedVersion = version.Altair
+			case 3:
+				forkEpoch = uint64(params.BeaconConfig().CapellaForkEpoch)
+				expectedVersion = version.Capella
+			case 4:
+				forkEpoch = uint64(params.BeaconConfig().DenebForkEpoch)
+				expectedVersion = version.Deneb
+			case 5:
+				forkEpoch = uint64(params.BeaconConfig().ElectraForkEpoch)
+				expectedVersion = version.Deneb
+			default:
+				t.Errorf("Unsupported fork version %s", version.String(testVersion))
+			}
+
+			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
+				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+				s.lcStore = &lightClient.Store{}
+
+				var oldActualUpdate interfaces.LightClientOptimisticUpdate
+				var err error
+				if tc.oldOptions != nil {
+					// config for old update
+					lOld, cfgOld := setupLightClientTestRequirements(ctx, t, s, testVersion, tc.oldOptions...)
+					require.NoError(t, s.processLightClientOptimisticUpdate(cfgOld.ctx, cfgOld.roblock, cfgOld.postState))
+
+					oldActualUpdate, err = lightClient.NewLightClientOptimisticUpdateFromBeaconState(
+						lOld.Ctx,
+						lOld.State.Slot(),
+						lOld.State,
+						lOld.Block,
+						lOld.AttestedState,
+						lOld.AttestedBlock,
+					)
+					require.NoError(t, err)
+
+					// check that the old update is saved
+					oldUpdate := s.lcStore.LastOptimisticUpdate()
+					require.NotNil(t, oldUpdate)
+
+					require.DeepEqual(t, oldUpdate, oldActualUpdate, "old update should be saved")
+				}
+
+				// config for new update
+				lNew, cfgNew := setupLightClientTestRequirements(ctx, t, s, testVersion, tc.newOptions...)
+				require.NoError(t, s.processLightClientOptimisticUpdate(cfgNew.ctx, cfgNew.roblock, cfgNew.postState))
+
+				newActualUpdate, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(
+					lNew.Ctx,
+					lNew.State.Slot(),
+					lNew.State,
+					lNew.Block,
+					lNew.AttestedState,
+					lNew.AttestedBlock,
+				)
+				require.NoError(t, err)
+
+				require.DeepNotEqual(t, newActualUpdate, oldActualUpdate, "new update should not be equal to old update")
+
+				// check that the new update is saved or skipped
+				newUpdate := s.lcStore.LastOptimisticUpdate()
+				require.NotNil(t, newUpdate)
+
+				if tc.expectReplace {
+					require.DeepEqual(t, newActualUpdate, newUpdate)
+					require.Equal(t, expectedVersion, newUpdate.Version())
+				} else {
+					require.DeepEqual(t, oldActualUpdate, newUpdate)
+					require.Equal(t, expectedVersion, newUpdate.Version())
+				}
+			})
+		}
+	}
+}
+
+func TestProcessLightClientFinalityUpdate(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+	defer reset()
+
+	params.SetupTestConfigCleanup(t)
+	beaconCfg := params.BeaconConfig()
+	beaconCfg.AltairForkEpoch = 1
+	beaconCfg.BellatrixForkEpoch = 2
+	beaconCfg.CapellaForkEpoch = 3
+	beaconCfg.DenebForkEpoch = 4
+	beaconCfg.ElectraForkEpoch = 5
+	params.OverrideBeaconConfig(beaconCfg)
+
+	s, tr := minimalTestService(t)
+	s.cfg.P2p = &mockp2p.FakeP2P{}
+	ctx := tr.ctx
+
+	testCases := []struct {
+		name          string
+		oldOptions    []util.LightClientOption
+		newOptions    []util.LightClientOption
+		expectReplace bool
+	}{
+		{
+			name:          "No old update",
+			oldOptions:    nil,
+			newOptions:    []util.LightClientOption{},
+			expectReplace: true,
+		},
+		{
+			name:          "Old update is better - age - no supermajority",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
+			newOptions:    []util.LightClientOption{},
+			expectReplace: false,
+		},
+		{
+			name:          "Old update is better - age - both supermajority",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
+			newOptions:    []util.LightClientOption{util.WithSupermajority()},
+			expectReplace: false,
+		},
+		{
+			name:          "Old update is better - supermajority",
+			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
+			newOptions:    []util.LightClientOption{},
+			expectReplace: false,
+		},
+		{
+			name:          "New update is better - age - both supermajority",
+			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
+			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
+			expectReplace: true,
+		},
+		{
+			name:          "New update is better - age - no supermajority",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
+			expectReplace: true,
+		},
+		{
+			name:          "New update is better - supermajority",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithSupermajority()},
+			expectReplace: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		for testVersion := 1; testVersion < 6; testVersion++ { // test all forks
+			var forkEpoch uint64
+			var expectedVersion int
+
+			switch testVersion {
+			case 1:
+				forkEpoch = uint64(params.BeaconConfig().AltairForkEpoch)
+				expectedVersion = version.Altair
+			case 2:
+				forkEpoch = uint64(params.BeaconConfig().BellatrixForkEpoch)
+				expectedVersion = version.Altair
+			case 3:
+				forkEpoch = uint64(params.BeaconConfig().CapellaForkEpoch)
+				expectedVersion = version.Capella
+			case 4:
+				forkEpoch = uint64(params.BeaconConfig().DenebForkEpoch)
+				expectedVersion = version.Deneb
+			case 5:
+				forkEpoch = uint64(params.BeaconConfig().ElectraForkEpoch)
+				expectedVersion = version.Electra
+			default:
+				t.Errorf("Unsupported fork version %s", version.String(testVersion))
+			}
+
+			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
+				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+				s.lcStore = &lightClient.Store{}
+
+				var actualOldUpdate, actualNewUpdate interfaces.LightClientFinalityUpdate
+				var err error
+
+				if tc.oldOptions != nil {
+					// config for old update
+					lOld, cfgOld := setupLightClientTestRequirements(ctx, t, s, testVersion, tc.oldOptions...)
+					require.NoError(t, s.processLightClientFinalityUpdate(cfgOld.ctx, cfgOld.roblock, cfgOld.postState))
+
+					// check that the old update is saved
+					actualOldUpdate, err = lightClient.NewLightClientFinalityUpdateFromBeaconState(
+						ctx,
+						cfgOld.postState.Slot(),
+						cfgOld.postState,
+						cfgOld.roblock,
+						lOld.AttestedState,
+						lOld.AttestedBlock,
+						lOld.FinalizedBlock,
+					)
+					require.NoError(t, err)
+					oldUpdate := s.lcStore.LastFinalityUpdate()
+					require.DeepEqual(t, actualOldUpdate, oldUpdate)
+				}
+
+				// config for new update
+				lNew, cfgNew := setupLightClientTestRequirements(ctx, t, s, testVersion, tc.newOptions...)
+				require.NoError(t, s.processLightClientFinalityUpdate(cfgNew.ctx, cfgNew.roblock, cfgNew.postState))
+
+				// check that the actual old update and the actual new update are different
+				actualNewUpdate, err = lightClient.NewLightClientFinalityUpdateFromBeaconState(
+					ctx,
+					cfgNew.postState.Slot(),
+					cfgNew.postState,
+					cfgNew.roblock,
+					lNew.AttestedState,
+					lNew.AttestedBlock,
+					lNew.FinalizedBlock,
+				)
+				require.NoError(t, err)
+				require.DeepNotEqual(t, actualOldUpdate, actualNewUpdate)
+
+				// check that the new update is saved or skipped
+				newUpdate := s.lcStore.LastFinalityUpdate()
+
+				if tc.expectReplace {
+					require.DeepEqual(t, actualNewUpdate, newUpdate)
+					require.Equal(t, expectedVersion, newUpdate.Version())
+				} else {
+					require.DeepEqual(t, actualOldUpdate, newUpdate)
+					require.Equal(t, expectedVersion, newUpdate.Version())
+				}
+			})
+		}
+	}
+}

beacon-chain/blockchain/service.go

@@ -15,6 +15,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
@@ -64,6 +65,7 @@ type Service struct {
 	blockBeingSynced     *currentlySyncingBlock
 	blobStorage          *filesystem.BlobStorage
 	slasherEnabled       bool
+	lcStore              *lightClient.Store
 }
 
 // config options for the service.

beacon-chain/blockchain/setup_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
+	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
@@ -19,8 +20,11 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/attestations"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/blstoexec"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"google.golang.org/protobuf/proto"
@@ -45,6 +49,11 @@ type mockBroadcaster struct {
 	broadcastCalled bool
 }
 
+type mockAccesser struct {
+	mockBroadcaster
+	p2pTesting.MockPeerManager
+}
+
 func (mb *mockBroadcaster) Broadcast(_ context.Context, _ proto.Message) error {
 	mb.broadcastCalled = true
 	return nil
@@ -65,6 +74,21 @@ func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.B
 	return nil
 }
 
+func (mb *mockBroadcaster) BroadcastLightClientOptimisticUpdate(_ context.Context, _ interfaces.LightClientOptimisticUpdate) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
+func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfaces.LightClientFinalityUpdate) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
+func (mb *mockBroadcaster) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar, _ ...chan<- bool) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }
 
@@ -122,6 +146,8 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
 		WithSyncChecker(mock.MockChecker{}),
 		WithExecutionEngineCaller(&mockExecution.EngineClient{}),
+		WithP2PBroadcaster(&mockAccesser{}),
+		WithLightClientStore(&lightclient.Store{}),
 	}
 	// append the variadic opts so they override the defaults by being processed afterwards
 	opts = append(defOpts, opts...)

beacon-chain/blockchain/testing/mock.go

@@ -53,6 +53,7 @@ type ChainService struct {
 	InitSyncBlockRoots          map[[32]byte]bool
 	DB                          db.Database
 	State                       state.BeaconState
+	HeadStateErr                error
 	Block                       interfaces.ReadOnlySignedBeaconBlock
 	VerifyBlkDescendantErr      error
 	stateNotifier               statefeed.Notifier
@@ -364,6 +365,9 @@ func (s *ChainService) HeadState(context.Context) (state.BeaconState, error) {
 
 // HeadStateReadOnly mocks HeadStateReadOnly method in chain service.
 func (s *ChainService) HeadStateReadOnly(context.Context) (state.ReadOnlyBeaconState, error) {
+	if s.HeadStateErr != nil {
+		return nil, s.HeadStateErr
+	}
 	return s.State, nil
 }
 
@@ -448,6 +452,11 @@ func (s *ChainService) IsCanonical(_ context.Context, r [32]byte) (bool, error)
 	return true, nil
 }
 
+// DependentRoot mocks the base method in the chain service.
+func (*ChainService) DependentRoot(_ primitives.Epoch) ([32]byte, error) {
+	return [32]byte{}, nil
+}
+
 // HasBlock mocks the same method in the chain service.
 func (s *ChainService) HasBlock(ctx context.Context, rt [32]byte) bool {
 	if s.DB == nil {
@@ -710,3 +719,14 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil
 }
+
+// MockSyncChecker is a mock implementation of blockchain.Checker.
+// We can't make an assertion here that this is true because that would create a circular dependency.
+type MockSyncChecker struct {
+	synced bool
+}
+
+// Synced satisfies the blockchain.Checker interface.
+func (m *MockSyncChecker) Synced() bool {
+	return m.synced
+}

beacon-chain/cache/committee.go

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

beacon-chain/core/altair/upgrade.go

@@ -67,10 +67,6 @@ func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.Beacon
 	epoch := time.CurrentEpoch(state)
 
 	numValidators := state.NumValidators()
-	hrs, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	s := &ethpb.BeaconStateAltair{
 		GenesisTime:           state.GenesisTime(),
 		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
@@ -83,7 +79,7 @@ func UpgradeToAltair(ctx context.Context, state state.BeaconState) (state.Beacon
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             hrs,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/altair/upgrade_test.go

@@ -82,10 +82,8 @@ func TestUpgradeToAltair(t *testing.T) {
 	require.DeepSSZEqual(t, preForkState.LatestBlockHeader(), aState.LatestBlockHeader())
 	require.DeepSSZEqual(t, preForkState.BlockRoots(), aState.BlockRoots())
 	require.DeepSSZEqual(t, preForkState.StateRoots(), aState.StateRoots())
-	r1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	r2, err := aState.HistoricalRoots()
-	require.NoError(t, err)
+	r1 := preForkState.HistoricalRoots()
+	r2 := aState.HistoricalRoots()
 	require.DeepSSZEqual(t, r1, r2)
 	require.DeepSSZEqual(t, preForkState.Eth1Data(), aState.Eth1Data())
 	require.DeepSSZEqual(t, preForkState.Eth1DataVotes(), aState.Eth1DataVotes())

beacon-chain/core/blocks/attestation.go

@@ -106,7 +106,7 @@ func VerifyAttestationNoVerifySignature(
 	if err != nil {
 		return err
 	}
-	c := helpers.SlotCommitteeCount(activeValidatorCount)
+	committeeCount := helpers.SlotCommitteeCount(activeValidatorCount)
 
 	var indexedAtt ethpb.IndexedAtt
 
@@ -115,13 +115,14 @@ func VerifyAttestationNoVerifySignature(
 			return errors.New("committee index must be 0 post-Electra")
 		}
 
+		aggBits := att.GetAggregationBits()
 		committeeIndices := att.CommitteeBitsVal().BitIndices()
 		committees := make([][]primitives.ValidatorIndex, len(committeeIndices))
 		participantsCount := 0
 		var err error
 		for i, ci := range committeeIndices {
-			if uint64(ci) >= c {
-				return fmt.Errorf("committee index %d >= committee count %d", ci, c)
+			if uint64(ci) >= committeeCount {
+				return fmt.Errorf("committee index %d >= committee count %d", ci, committeeCount)
 			}
 			committees[i], err = helpers.BeaconCommitteeFromState(ctx, beaconState, att.GetData().Slot, primitives.CommitteeIndex(ci))
 			if err != nil {
@@ -129,16 +130,32 @@ func VerifyAttestationNoVerifySignature(
 			}
 			participantsCount += len(committees[i])
 		}
-		if att.GetAggregationBits().Len() != uint64(participantsCount) {
+		if aggBits.Len() != uint64(participantsCount) {
 			return fmt.Errorf("aggregation bits count %d is different than participant count %d", att.GetAggregationBits().Len(), participantsCount)
 		}
+
+		committeeOffset := 0
+		for ci, c := range committees {
+			attesterFound := false
+			for i := range c {
+				if aggBits.BitAt(uint64(committeeOffset + i)) {
+					attesterFound = true
+					break
+				}
+			}
+			if !attesterFound {
+				return fmt.Errorf("no attesting indices found for committee index %d", ci)
+			}
+			committeeOffset += len(c)
+		}
+
 		indexedAtt, err = attestation.ConvertToIndexed(ctx, att, committees...)
 		if err != nil {
 			return err
 		}
 	} else {
-		if uint64(att.GetData().CommitteeIndex) >= c {
-			return fmt.Errorf("committee index %d >= committee count %d", att.GetData().CommitteeIndex, c)
+		if uint64(att.GetData().CommitteeIndex) >= committeeCount {
+			return fmt.Errorf("committee index %d >= committee count %d", att.GetData().CommitteeIndex, committeeCount)
 		}
 
 		// Verify attesting indices are correct.

beacon-chain/core/blocks/attestation_test.go

@@ -296,6 +296,22 @@ func TestVerifyAttestationNoVerifySignature_Electra(t *testing.T) {
 		err = blocks.VerifyAttestationNoVerifySignature(context.TODO(), beaconState, att)
 		assert.ErrorContains(t, "aggregation bits count 123 is different than participant count 3", err)
 	})
+	t.Run("no attester in committee", func(t *testing.T) {
+		aggBits := bitfield.NewBitlist(3)
+		committeeBits := bitfield.NewBitvector64()
+		committeeBits.SetBitAt(0, true)
+		att := &ethpb.AttestationElectra{
+			Data: &ethpb.AttestationData{
+				Source: &ethpb.Checkpoint{Epoch: 0, Root: mockRoot[:]},
+				Target: &ethpb.Checkpoint{Epoch: 0, Root: make([]byte, 32)},
+			},
+			AggregationBits: aggBits,
+			CommitteeBits:   committeeBits,
+		}
+		att.Signature = zeroSig[:]
+		err = blocks.VerifyAttestationNoVerifySignature(context.TODO(), beaconState, att)
+		assert.ErrorContains(t, "no attesting indices found for committee index 0", err)
+	})
 }
 
 func TestConvertToIndexed_OK(t *testing.T) {

beacon-chain/core/blocks/payload.go

@@ -12,7 +12,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
@@ -240,16 +239,3 @@ func verifyBlobCommitmentCount(slot primitives.Slot, body interfaces.ReadOnlyBea
 	}
 	return nil
 }
-
-// GetBlockPayloadHash returns the hash of the execution payload of the block
-func GetBlockPayloadHash(blk interfaces.ReadOnlyBeaconBlock) ([32]byte, error) {
-	var payloadHash [32]byte
-	if IsPreBellatrixVersion(blk.Version()) {
-		return payloadHash, nil
-	}
-	payload, err := blk.Body().Execution()
-	if err != nil {
-		return payloadHash, err
-	}
-	return bytesutil.ToBytes32(payload.BlockHash()), nil
-}

beacon-chain/core/blocks/proposer_slashing.go

@@ -16,6 +16,9 @@ import (
 	"google.golang.org/protobuf/proto"
 )
 
+// ErrCouldNotVerifyBlockHeader is returned when a block header's signature cannot be verified.
+var ErrCouldNotVerifyBlockHeader = errors.New("could not verify beacon block header")
+
 type slashValidatorFunc func(
 	ctx context.Context,
 	st state.BeaconState,
@@ -114,7 +117,7 @@ func VerifyProposerSlashing(
 	for _, header := range headers {
 		if err := signing.ComputeDomainVerifySigningRoot(beaconState, pIdx, slots.ToEpoch(hSlot),
 			header.Header, params.BeaconConfig().DomainBeaconProposer, header.Signature); err != nil {
-			return errors.Wrap(err, "could not verify beacon block header")
+			return errors.Wrap(ErrCouldNotVerifyBlockHeader, err.Error())
 		}
 	}
 	return nil

beacon-chain/core/capella/upgrade.go

@@ -42,10 +42,6 @@ func UpgradeToCapella(state state.BeaconState) (state.BeaconState, error) {
 		return nil, err
 	}
 
-	hrs, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	s := &ethpb.BeaconStateCapella{
 		GenesisTime:           state.GenesisTime(),
 		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
@@ -58,7 +54,7 @@ func UpgradeToCapella(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             hrs,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/deneb/upgrade.go

@@ -57,10 +57,6 @@ func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
 	if err != nil {
 		return nil, err
 	}
-	historicalRoots, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 
 	s := &ethpb.BeaconStateDeneb{
 		GenesisTime:           state.GenesisTime(),
@@ -74,7 +70,7 @@ func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             historicalRoots,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/deneb/upgrade_test.go

@@ -47,10 +47,8 @@ func TestUpgradeToDeneb(t *testing.T) {
 	require.NoError(t, err)
 	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
 
-	hr1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	hr2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	hr1 := preForkState.HistoricalRoots()
+	hr2 := mSt.HistoricalRoots()
 	require.DeepEqual(t, hr1, hr2)
 
 	f := mSt.Fork()

beacon-chain/core/electra/upgrade.go

@@ -170,10 +170,6 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 	if err != nil {
 		return nil, err
 	}
-	historicalRoots, err := beaconState.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	excessBlobGas, err := payloadHeader.ExcessBlobGas()
 	if err != nil {
 		return nil, err
@@ -223,7 +219,7 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 		LatestBlockHeader:           beaconState.LatestBlockHeader(),
 		BlockRoots:                  beaconState.BlockRoots(),
 		StateRoots:                  beaconState.StateRoots(),
-		HistoricalRoots:             historicalRoots,
+		HistoricalRoots:             beaconState.HistoricalRoots(),
 		Eth1Data:                    beaconState.Eth1Data(),
 		Eth1DataVotes:               beaconState.Eth1DataVotes(),
 		Eth1DepositIndex:            beaconState.Eth1DepositIndex(),

beacon-chain/core/electra/upgrade_test.go

@@ -77,10 +77,8 @@ func TestUpgradeToElectra(t *testing.T) {
 	require.NoError(t, err)
 	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
 
-	hr1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	hr2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	hr1 := preForkState.HistoricalRoots()
+	hr2 := mSt.HistoricalRoots()
 	require.DeepEqual(t, hr1, hr2)
 
 	f := mSt.Fork()

beacon-chain/core/epoch/epoch_processing_test.go

@@ -148,8 +148,7 @@ func TestProcessFinalUpdates_CanProcess(t *testing.T) {
 	assert.DeepNotEqual(t, params.BeaconConfig().ZeroHash[:], mix, "latest RANDAO still zero hashes")
 
 	// Verify historical root accumulator was appended.
-	roots, err := newS.HistoricalRoots()
-	require.NoError(t, err)
+	roots := newS.HistoricalRoots()
 	assert.Equal(t, 1, len(roots), "Unexpected slashed balance")
 	currAtt, err := newS.CurrentEpochAttestations()
 	require.NoError(t, err)
@@ -379,8 +378,7 @@ func TestProcessHistoricalDataUpdate(t *testing.T) {
 				return st
 			},
 			verifier: func(st state.BeaconState) {
-				roots, err := st.HistoricalRoots()
-				require.NoError(t, err)
+				roots := st.HistoricalRoots()
 				require.Equal(t, 0, len(roots))
 			},
 		},
@@ -393,8 +391,7 @@ func TestProcessHistoricalDataUpdate(t *testing.T) {
 				return st
 			},
 			verifier: func(st state.BeaconState) {
-				roots, err := st.HistoricalRoots()
-				require.NoError(t, err)
+				roots := st.HistoricalRoots()
 				require.Equal(t, 1, len(roots))
 
 				b := &ethpb.HistoricalBatch{
@@ -431,8 +428,7 @@ func TestProcessHistoricalDataUpdate(t *testing.T) {
 					StateSummaryRoot: sr[:],
 				}
 				require.DeepEqual(t, b, summaries[0])
-				hrs, err := st.HistoricalRoots()
-				require.NoError(t, err)
+				hrs := st.HistoricalRoots()
 				require.DeepEqual(t, hrs, [][]byte{})
 			},
 		},

beacon-chain/core/execution/upgrade.go

@@ -35,10 +35,6 @@ func UpgradeToBellatrix(state state.BeaconState) (state.BeaconState, error) {
 		return nil, err
 	}
 
-	hrs, err := state.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	s := &ethpb.BeaconStateBellatrix{
 		GenesisTime:           state.GenesisTime(),
 		GenesisValidatorsRoot: state.GenesisValidatorsRoot(),
@@ -51,7 +47,7 @@ func UpgradeToBellatrix(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             hrs,
+		HistoricalRoots:             state.HistoricalRoots(),
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/execution/upgrade_test.go

@@ -24,10 +24,8 @@ func TestUpgradeToBellatrix(t *testing.T) {
 	require.DeepSSZEqual(t, preForkState.LatestBlockHeader(), mSt.LatestBlockHeader())
 	require.DeepSSZEqual(t, preForkState.BlockRoots(), mSt.BlockRoots())
 	require.DeepSSZEqual(t, preForkState.StateRoots(), mSt.StateRoots())
-	r1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	r2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	r1 := preForkState.HistoricalRoots()
+	r2 := mSt.HistoricalRoots()
 	require.DeepSSZEqual(t, r1, r2)
 	require.DeepSSZEqual(t, preForkState.Eth1Data(), mSt.Eth1Data())
 	require.DeepSSZEqual(t, preForkState.Eth1DataVotes(), mSt.Eth1DataVotes())

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

@@ -11,6 +11,8 @@ const (
 
 // ReceivedBlockData is the data sent with ReceivedBlock events.
 type ReceivedBlockData struct {
-	SignedBlock  interfaces.ReadOnlySignedBeaconBlock
-	IsOptimistic bool
+	SignedBlock       interfaces.ReadOnlySignedBeaconBlock
+	CurrDependentRoot [32]byte
+	PrevDependentRoot [32]byte
+	IsOptimistic      bool
 }

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

@@ -43,6 +43,10 @@ type BlockProcessedData struct {
 	BlockRoot [32]byte
 	// SignedBlock is the physical processed block.
 	SignedBlock interfaces.ReadOnlySignedBeaconBlock
+	// CurrDependentRoot is the current dependent root
+	CurrDependentRoot [32]byte
+	// PrevDependentRoot is the previous dependent root
+	PrevDependentRoot [32]byte
 	// Verified is true if the block's BLS contents have been verified.
 	Verified bool
 	// Optimistic is true if the block is optimistic.

beacon-chain/core/fulu/upgrade.go

@@ -11,7 +11,7 @@ import (
 )
 
 // UpgradeToFulu updates inputs a generic state to return the version Fulu state.
-// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/fork.md#upgrading-the-state
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/fork.md#upgrading-the-state
 func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 	currentSyncCommittee, err := beaconState.CurrentSyncCommittee()
 	if err != nil {
@@ -57,10 +57,6 @@ func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 	if err != nil {
 		return nil, err
 	}
-	historicalRoots, err := beaconState.HistoricalRoots()
-	if err != nil {
-		return nil, err
-	}
 	excessBlobGas, err := payloadHeader.ExcessBlobGas()
 	if err != nil {
 		return nil, err
@@ -69,6 +65,10 @@ func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 	if err != nil {
 		return nil, err
 	}
+	depositRequestsStartIndex, err := beaconState.DepositRequestsStartIndex()
+	if err != nil {
+		return nil, err
+	}
 	depositBalanceToConsume, err := beaconState.DepositBalanceToConsume()
 	if err != nil {
 		return nil, err
@@ -114,7 +114,7 @@ func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           beaconState.LatestBlockHeader(),
 		BlockRoots:                  beaconState.BlockRoots(),
 		StateRoots:                  beaconState.StateRoots(),
-		HistoricalRoots:             historicalRoots,
+		HistoricalRoots:             beaconState.HistoricalRoots(),
 		Eth1Data:                    beaconState.Eth1Data(),
 		Eth1DataVotes:               beaconState.Eth1DataVotes(),
 		Eth1DepositIndex:            beaconState.Eth1DepositIndex(),
@@ -154,7 +154,7 @@ func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
 		NextWithdrawalValidatorIndex: vi,
 		HistoricalSummaries:          summaries,
 
-		DepositRequestsStartIndex:     params.BeaconConfig().UnsetDepositRequestsStartIndex,
+		DepositRequestsStartIndex:     depositRequestsStartIndex,
 		DepositBalanceToConsume:       depositBalanceToConsume,
 		ExitBalanceToConsume:          exitBalanceToConsume,
 		EarliestExitEpoch:             earliestExitEpoch,

beacon-chain/core/fulu/upgrade_test.go

@@ -43,10 +43,8 @@ func TestUpgradeToFulu(t *testing.T) {
 	require.DeepSSZEqual(t, preForkState.BlockRoots(), mSt.BlockRoots())
 	require.DeepSSZEqual(t, preForkState.StateRoots(), mSt.StateRoots())
 
-	hr1, err := preForkState.HistoricalRoots()
-	require.NoError(t, err)
-	hr2, err := mSt.HistoricalRoots()
-	require.NoError(t, err)
+	hr1 := preForkState.HistoricalRoots()
+	hr2 := mSt.HistoricalRoots()
 	require.DeepEqual(t, hr1, hr2)
 
 	require.DeepSSZEqual(t, preForkState.Eth1Data(), mSt.Eth1Data())

beacon-chain/core/helpers/attestation.go

@@ -187,9 +187,7 @@ func ValidateAttestationTime(attSlot primitives.Slot, genesisTime time.Time, clo
 // VerifyCheckpointEpoch is within current epoch and previous epoch
 // with respect to current time. Returns true if it's within, false if it's not.
 func VerifyCheckpointEpoch(c *ethpb.Checkpoint, genesis time.Time) bool {
-	now := uint64(prysmTime.Now().Unix())
-	genesisTime := uint64(genesis.Unix())
-	currentSlot := primitives.Slot((now - genesisTime) / params.BeaconConfig().SecondsPerSlot)
+	currentSlot := slots.CurrentSlot(uint64(genesis.Unix()))
 	currentEpoch := slots.ToEpoch(currentSlot)
 
 	var prevEpoch primitives.Epoch

beacon-chain/core/helpers/beacon_committee.go

@@ -18,6 +18,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/math"
+	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -118,6 +119,9 @@ func attestationCommittees(
 
 // BeaconCommittees returns the list of all beacon committees for a given state at a given slot.
 func BeaconCommittees(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot) ([][]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.BeaconCommittees")
+	defer span.End()
+
 	epoch := slots.ToEpoch(slot)
 	activeCount, err := ActiveValidatorCount(ctx, state, epoch)
 	if err != nil {
@@ -244,6 +248,9 @@ func BeaconCommittee(
 	slot primitives.Slot,
 	committeeIndex primitives.CommitteeIndex,
 ) ([]primitives.ValidatorIndex, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.BeaconCommittee")
+	defer span.End()
+
 	committee, err := committeeCache.Committee(ctx, slot, seed, committeeIndex)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not interface with committee cache")
@@ -297,6 +304,9 @@ func verifyAssignmentEpoch(epoch primitives.Epoch, state state.BeaconState) erro
 // It verifies the validity of the epoch, then iterates through each slot in the epoch to determine the
 // proposer for that slot and assigns them accordingly.
 func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch primitives.Epoch) (map[primitives.ValidatorIndex][]primitives.Slot, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.ProposerAssignments")
+	defer span.End()
+
 	// Verify if the epoch is valid for assignment based on the provided state.
 	if err := verifyAssignmentEpoch(epoch, state); err != nil {
 		return nil, err
@@ -345,6 +355,9 @@ func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch pri
 // It retrieves active validator indices, determines the number of committees per slot, and computes
 // assignments for each validator based on their presence in the provided validators slice.
 func CommitteeAssignments(ctx context.Context, state state.BeaconState, epoch primitives.Epoch, validators []primitives.ValidatorIndex) (map[primitives.ValidatorIndex]*CommitteeAssignment, error) {
+	ctx, span := trace.StartSpan(ctx, "helpers.CommitteeAssignments")
+	defer span.End()
+
 	// Verify if the epoch is valid for assignment based on the provided state.
 	if err := verifyAssignmentEpoch(epoch, state); err != nil {
 		return nil, err
@@ -432,6 +445,9 @@ func CommitteeIndices(committeeBits bitfield.Bitfield) []primitives.CommitteeInd
 // UpdateCommitteeCache gets called at the beginning of every epoch to cache the committee shuffled indices
 // list with committee index and epoch number. It caches the shuffled indices for the input epoch.
 func UpdateCommitteeCache(ctx context.Context, state state.ReadOnlyBeaconState, e primitives.Epoch) error {
+	ctx, span := trace.StartSpan(ctx, "committeeCache.UpdateCommitteeCache")
+	defer span.End()
+
 	seed, err := Seed(state, e, params.BeaconConfig().DomainBeaconAttester)
 	if err != nil {
 		return err

beacon-chain/core/helpers/validators.go

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

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

@@ -45,6 +45,7 @@ go_test(
         "//encoding/ssz:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "@com_github_pkg_errors//:go_default_library",

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

@@ -1013,3 +1013,9 @@ func createDefaultLightClientBootstrap(currentSlot primitives.Slot) (interfaces.
 
 	return light_client.NewWrappedBootstrap(m)
 }
+
+func UpdateHasSupermajority(syncAggregate *pb.SyncAggregate) bool {
+	maxActiveParticipants := syncAggregate.SyncCommitteeBits.Len()
+	numActiveParticipants := syncAggregate.SyncCommitteeBits.Count()
+	return numActiveParticipants*3 >= maxActiveParticipants*2
+}

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

@@ -8,6 +8,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	light_client "github.com/OffchainLabs/prysm/v6/consensus-types/light-client"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -32,7 +33,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	params.OverrideBeaconConfig(cfg)
 
 	t.Run("Altair", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+		l := util.NewTestLightClient(t, version.Altair)
 
 		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
@@ -44,7 +45,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	})
 
 	t.Run("Capella", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+		l := util.NewTestLightClient(t, version.Capella)
 
 		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
@@ -57,7 +58,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	})
 
 	t.Run("Deneb", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+		l := util.NewTestLightClient(t, version.Deneb)
 
 		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
@@ -70,7 +71,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	})
 
 	t.Run("Electra", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestElectra(false, 0, true)
+		l := util.NewTestLightClient(t, version.Electra)
 
 		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
@@ -94,7 +95,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 
 	t.Run("Altair", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+		l := util.NewTestLightClient(t, version.Altair)
 
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
@@ -131,7 +132,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 	t.Run("Capella", func(t *testing.T) {
 
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+			l := util.NewTestLightClient(t, version.Capella)
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
@@ -205,7 +206,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		})
 
 		t.Run("FinalizedBlock In Previous Fork", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapellaFinalizedBlockAltair(false)
+			l := util.NewTestLightClient(t, version.Capella, util.WithFinalizedCheckpointInPrevFork())
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
@@ -238,7 +239,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 	t.Run("Deneb", func(t *testing.T) {
 
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+			l := util.NewTestLightClient(t, version.Deneb)
 
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
@@ -313,7 +314,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		})
 
 		t.Run("FinalizedBlock In Previous Fork", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDenebFinalizedBlockCapella(false)
+			l := util.NewTestLightClient(t, version.Deneb, util.WithFinalizedCheckpointInPrevFork())
 
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
@@ -390,7 +391,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 
 	t.Run("Electra", func(t *testing.T) {
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestElectra(false, 0, true)
+			l := util.NewTestLightClient(t, version.Electra)
 
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
@@ -465,7 +466,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		})
 
 		t.Run("FinalizedBlock In Previous Fork", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestElectraFinalizedBlockDeneb(false)
+			l := util.NewTestLightClient(t, version.Electra, util.WithFinalizedCheckpointInPrevFork())
 
 			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
@@ -542,7 +543,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 
 func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 	t.Run("Altair", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+		l := util.NewTestLightClient(t, version.Altair)
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
@@ -565,7 +566,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 	})
 
 	t.Run("Bellatrix", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestBellatrix(0, true)
+		l := util.NewTestLightClient(t, version.Bellatrix)
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
@@ -589,7 +590,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 	t.Run("Capella", func(t *testing.T) {
 		t.Run("Non-Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+			l := util.NewTestLightClient(t, version.Capella)
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
@@ -650,7 +651,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 		})
 
 		t.Run("Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(true, 0, true)
+			l := util.NewTestLightClient(t, version.Capella, util.WithBlinded())
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
@@ -713,7 +714,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 	t.Run("Deneb", func(t *testing.T) {
 		t.Run("Non-Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+			l := util.NewTestLightClient(t, version.Deneb)
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
@@ -782,7 +783,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 		})
 
 		t.Run("Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestDeneb(true, 0, true)
+			l := util.NewTestLightClient(t, version.Deneb, util.WithBlinded())
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
@@ -853,7 +854,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 	t.Run("Electra", func(t *testing.T) {
 		t.Run("Non-Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestElectra(false, 0, true)
+			l := util.NewTestLightClient(t, version.Electra)
 
 			header, err := lightClient.BlockToLightClientHeader(l.Ctx, l.State.Slot(), l.Block)
 			require.NoError(t, err)
@@ -918,7 +919,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 		})
 
 		t.Run("Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestElectra(true, 0, true)
+			l := util.NewTestLightClient(t, version.Electra, util.WithBlinded())
 
 			header, err := lightClient.BlockToLightClientHeader(l.Ctx, l.State.Slot(), l.Block)
 			require.NoError(t, err)
@@ -984,7 +985,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 	})
 
 	t.Run("Capella fork with Altair block", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+		l := util.NewTestLightClient(t, version.Altair)
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
@@ -1006,7 +1007,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 	})
 
 	t.Run("Deneb fork with Altair block", func(t *testing.T) {
-		l := util.NewTestLightClient(t).SetupTestAltair(0, true)
+		l := util.NewTestLightClient(t, version.Altair)
 
 		header, err := lightClient.BlockToLightClientHeader(
 			l.Ctx,
@@ -1029,7 +1030,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 
 	t.Run("Deneb fork with Capella block", func(t *testing.T) {
 		t.Run("Non-Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+			l := util.NewTestLightClient(t, version.Capella)
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,
@@ -1089,7 +1090,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 		})
 
 		t.Run("Blinded Beacon Block", func(t *testing.T) {
-			l := util.NewTestLightClient(t).SetupTestCapella(true, 0, true)
+			l := util.NewTestLightClient(t, version.Capella, util.WithBlinded())
 
 			header, err := lightClient.BlockToLightClientHeader(
 				l.Ctx,

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

@@ -5,6 +5,7 @@ import (
 
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 )
@@ -23,7 +24,7 @@ func TestLightClientStore(t *testing.T) {
 	lcStore := &lightClient.Store{}
 
 	// Create test light client updates for Capella and Deneb
-	lCapella := util.NewTestLightClient(t).SetupTestCapella(false, 0, true)
+	lCapella := util.NewTestLightClient(t, version.Capella)
 	opUpdateCapella, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lCapella.Ctx, lCapella.State.Slot(), lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock)
 	require.NoError(t, err)
 	require.NotNil(t, opUpdateCapella, "OptimisticUpdateCapella is nil")
@@ -31,7 +32,7 @@ func TestLightClientStore(t *testing.T) {
 	require.NoError(t, err)
 	require.NotNil(t, finUpdateCapella, "FinalityUpdateCapella is nil")
 
-	lDeneb := util.NewTestLightClient(t).SetupTestDeneb(false, 0, true)
+	lDeneb := util.NewTestLightClient(t, version.Deneb)
 	opUpdateDeneb, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State.Slot(), lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock)
 	require.NoError(t, err)
 	require.NotNil(t, opUpdateDeneb, "OptimisticUpdateDeneb is nil")

beacon-chain/core/peerdas/BUILD.bazel

@@ -0,0 +1,73 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "das_core.go",
+        "info.go",
+        "metrics.go",
+        "p2p_interface.go",
+        "reconstruction.go",
+        "validator.go",
+        "verification.go",
+    ],
+    importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
+        "//beacon-chain/state: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",
+        "//consensus-types/primitives:go_default_library",
+        "//container/trie:go_default_library",
+        "//crypto/hash:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime/version: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_hashicorp_golang_lru//:go_default_library",
+        "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+        "@org_golang_x_sync//errgroup:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "das_core_test.go",
+        "info_test.go",
+        "p2p_interface_test.go",
+        "reconstruction_test.go",
+        "utils_test.go",
+        "validator_test.go",
+        "verification_test.go",
+    ],
+    deps = [
+        ":go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
+        "//beacon-chain/state/state-native:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/primitives:go_default_library",
+        "//proto/engine/v1: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/enode:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@org_golang_x_sync//errgroup:go_default_library",
+    ],
+)

beacon-chain/core/peerdas/das_core.go

@@ -0,0 +1,276 @@
+package peerdas
+
+import (
+	"encoding/binary"
+	"math"
+	"slices"
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/crypto/hash"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/holiman/uint256"
+	"github.com/pkg/errors"
+)
+
+var (
+	// Custom errors
+	ErrCustodyGroupTooLarge               = errors.New("custody group too large")
+	ErrCustodyGroupCountTooLarge          = errors.New("custody group count too large")
+	ErrSizeMismatch                       = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
+	ErrNotEnoughDataColumnSidecars        = errors.New("not enough columns")
+	ErrDataColumnSidecarsNotSortedByIndex = errors.New("data column sidecars are not sorted by index")
+	errWrongComputedCustodyGroupCount     = errors.New("wrong computed custody group count, should never happen")
+
+	// maxUint256 is the maximum value of an uint256.
+	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
+)
+
+type CustodyType int
+
+const (
+	Target CustodyType = iota
+	Actual
+)
+
+// CustodyGroups computes the custody groups the node should participate in for custody.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#get_custody_groups
+func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error) {
+	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+
+	// Check if the custody group count is larger than the number of custody groups.
+	if custodyGroupCount > numberOfCustodyGroup {
+		return nil, ErrCustodyGroupCountTooLarge
+	}
+
+	// Shortcut if all custody groups are needed.
+	if custodyGroupCount == numberOfCustodyGroup {
+		custodyGroups := make([]uint64, 0, numberOfCustodyGroup)
+		for i := range numberOfCustodyGroup {
+			custodyGroups = append(custodyGroups, i)
+		}
+
+		return custodyGroups, nil
+	}
+
+	one := uint256.NewInt(1)
+
+	custodyGroupsMap := make(map[uint64]bool, custodyGroupCount)
+	custodyGroups := make([]uint64, 0, custodyGroupCount)
+	for currentId := new(uint256.Int).SetBytes(nodeId.Bytes()); uint64(len(custodyGroups)) < custodyGroupCount; {
+		// 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 custody group ID.
+		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroup
+
+		// Add the custody group to the map.
+		if !custodyGroupsMap[custodyGroup] {
+			custodyGroupsMap[custodyGroup] = true
+			custodyGroups = append(custodyGroups, custodyGroup)
+		}
+
+		if currentId.Cmp(maxUint256) == 0 {
+			// Overflow prevention.
+			currentId = uint256.NewInt(0)
+		} else {
+			// Increment the current ID.
+			currentId.Add(currentId, one)
+		}
+
+		// Sort the custody groups.
+		slices.Sort[[]uint64](custodyGroups)
+	}
+
+	// Final check.
+	if uint64(len(custodyGroups)) != custodyGroupCount {
+		return nil, errWrongComputedCustodyGroupCount
+	}
+
+	return custodyGroups, nil
+}
+
+// ComputeColumnsForCustodyGroup computes the columns for a given custody group.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#compute_columns_for_custody_group
+func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
+	beaconConfig := params.BeaconConfig()
+	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+
+	if custodyGroup >= numberOfCustodyGroup {
+		return nil, ErrCustodyGroupTooLarge
+	}
+
+	numberOfColumns := beaconConfig.NumberOfColumns
+
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroup
+
+	columns := make([]uint64, 0, columnsPerGroup)
+	for i := range columnsPerGroup {
+		column := numberOfCustodyGroup*i + custodyGroup
+		columns = append(columns, column)
+	}
+
+	return columns, nil
+}
+
+// DataColumnSidecars computes the data column sidecars from the signed block, cells and cell proofs.
+// The returned value contains pointers to function parameters.
+// (If the caller alterates `cellsAndProofs` afterwards, the returned value will be modified as well.)
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.3/specs/fulu/das-core.md#get_data_column_sidecars
+func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
+	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
+		return nil, nil
+	}
+
+	block := signedBlock.Block()
+	blockBody := block.Body()
+	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	if len(blobKzgCommitments) != len(cellsAndProofs) {
+		return nil, ErrSizeMismatch
+	}
+
+	signedBlockHeader, err := signedBlock.Header()
+	if err != nil {
+		return nil, errors.Wrap(err, "signed block header")
+	}
+
+	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
+	if err != nil {
+		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
+	}
+
+	dataColumnSidecars, err := dataColumnsSidecars(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidecars")
+	}
+
+	return dataColumnSidecars, nil
+}
+
+// ComputeCustodyGroupForColumn computes the custody group for a given column.
+// It is the reciprocal function of ComputeColumnsForCustodyGroup.
+func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
+	beaconConfig := params.BeaconConfig()
+	numberOfColumns := beaconConfig.NumberOfColumns
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
+
+	if columnIndex >= numberOfColumns {
+		return 0, ErrIndexTooLarge
+	}
+
+	return columnIndex % numberOfCustodyGroups, nil
+}
+
+// CustodyGroupSamplingSize returns the number of custody groups the node should sample from.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#custody-sampling
+func (custodyInfo *CustodyInfo) CustodyGroupSamplingSize(ct CustodyType) uint64 {
+	custodyGroupCount := custodyInfo.TargetGroupCount.Get()
+
+	if ct == Actual {
+		custodyGroupCount = custodyInfo.ActualGroupCount()
+	}
+
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+	return max(samplesPerSlot, custodyGroupCount)
+}
+
+// CustodyColumns computes the custody columns from the custody groups.
+func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+
+	custodyGroupCount := len(custodyGroups)
+
+	// Compute the columns for each custody group.
+	columns := make(map[uint64]bool, custodyGroupCount)
+	for _, group := range custodyGroups {
+		if group >= numberOfCustodyGroups {
+			return nil, ErrCustodyGroupTooLarge
+		}
+
+		groupColumns, err := ComputeColumnsForCustodyGroup(group)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute columns for custody group")
+		}
+
+		for _, column := range groupColumns {
+			columns[column] = true
+		}
+	}
+
+	return columns, nil
+}
+
+// dataColumnsSidecars computes the data column sidecars from the signed block header, the blob KZG commiments,
+// the KZG commitment includion proofs and cells and cell proofs.
+// The returned value contains pointers to function parameters.
+// (If the caller alterates input parameters afterwards, the returned value will be modified as well.)
+func dataColumnsSidecars(
+	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
+	blobKzgCommitments [][]byte,
+	kzgCommitmentsInclusionProof [][]byte,
+	cellsAndProofs []kzg.CellsAndProofs,
+) ([]*ethpb.DataColumnSidecar, error) {
+	start := time.Now()
+	if len(blobKzgCommitments) != len(cellsAndProofs) {
+		return nil, ErrSizeMismatch
+	}
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	blobsCount := len(cellsAndProofs)
+	sidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
+	for columnIndex := range numberOfColumns {
+		column := make([]kzg.Cell, 0, blobsCount)
+		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
+
+		for rowIndex := range blobsCount {
+			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 {
+			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, kzgProof[:])
+		}
+
+		sidecar := &ethpb.DataColumnSidecar{
+			Index:                        columnIndex,
+			Column:                       columnBytes,
+			KzgCommitments:               blobKzgCommitments,
+			KzgProofs:                    kzgProofOfColumnBytes,
+			SignedBlockHeader:            signedBlockHeader,
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+
+		sidecars = append(sidecars, sidecar)
+	}
+
+	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
+	return sidecars, nil
+}

beacon-chain/core/peerdas/das_core_test.go

@@ -0,0 +1,180 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+func TestCustodyGroups(t *testing.T) {
+	// --------------------------------------------
+	// The happy path is unit tested in spec tests.
+	// --------------------------------------------
+	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroup+1)
+	require.ErrorIs(t, err, peerdas.ErrCustodyGroupCountTooLarge)
+}
+
+func TestComputeColumnsForCustodyGroup(t *testing.T) {
+	// --------------------------------------------
+	// The happy path is unit tested in spec tests.
+	// --------------------------------------------
+	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroup)
+	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
+}
+
+func TestDataColumnSidecars(t *testing.T) {
+	t.Run("nil signed block", func(t *testing.T) {
+		var expected []*ethpb.DataColumnSidecar = nil
+		actual, err := peerdas.DataColumnSidecars(nil, []kzg.CellsAndProofs{})
+		require.NoError(t, err)
+
+		require.DeepSSZEqual(t, expected, actual)
+	})
+
+	t.Run("empty cells and proofs", func(t *testing.T) {
+		// Create a protobuf signed beacon block.
+		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		actual, err := peerdas.DataColumnSidecars(signedBeaconBlock, []kzg.CellsAndProofs{})
+		require.NoError(t, err)
+		require.IsNil(t, actual)
+	})
+
+	t.Run("sizes mismatch", func(t *testing.T) {
+		// Create a protobuf signed beacon block.
+		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs.
+		cellsAndProofs := make([]kzg.CellsAndProofs, 1)
+
+		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
+		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
+	})
+}
+
+func TestComputeCustodyGroupForColumn(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.NumberOfColumns = 128
+	config.NumberOfCustodyGroups = 64
+	params.OverrideBeaconConfig(config)
+
+	t.Run("index too large", func(t *testing.T) {
+		_, err := peerdas.ComputeCustodyGroupForColumn(1_000_000)
+		require.ErrorIs(t, err, peerdas.ErrIndexTooLarge)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		expected := uint64(2)
+		actual, err := peerdas.ComputeCustodyGroupForColumn(2)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+
+		expected = uint64(3)
+		actual, err = peerdas.ComputeCustodyGroupForColumn(3)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+
+		expected = uint64(2)
+		actual, err = peerdas.ComputeCustodyGroupForColumn(66)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+
+		expected = uint64(3)
+		actual, err = peerdas.ComputeCustodyGroupForColumn(67)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+	})
+}
+
+func TestCustodyGroupSamplingSize(t *testing.T) {
+	testCases := []struct {
+		name                         string
+		custodyType                  peerdas.CustodyType
+		validatorsCustodyRequirement uint64
+		toAdvertiseCustodyGroupCount uint64
+		expected                     uint64
+	}{
+		{
+			name:                         "target, lower than samples per slot",
+			custodyType:                  peerdas.Target,
+			validatorsCustodyRequirement: 2,
+			expected:                     8,
+		},
+		{
+			name:                         "target, higher than samples per slot",
+			custodyType:                  peerdas.Target,
+			validatorsCustodyRequirement: 100,
+			expected:                     100,
+		},
+		{
+			name:                         "actual, lower than samples per slot",
+			custodyType:                  peerdas.Actual,
+			validatorsCustodyRequirement: 3,
+			toAdvertiseCustodyGroupCount: 4,
+			expected:                     8,
+		},
+		{
+			name:                         "actual, higher than samples per slot",
+			custodyType:                  peerdas.Actual,
+			validatorsCustodyRequirement: 100,
+			toAdvertiseCustodyGroupCount: 101,
+			expected:                     100,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Create a custody info.
+			custodyInfo := peerdas.CustodyInfo{}
+
+			// Set the validators custody requirement for target custody group count.
+			custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(tc.validatorsCustodyRequirement)
+
+			// Set the to advertise custody group count.
+			custodyInfo.ToAdvertiseGroupCount.Set(tc.toAdvertiseCustodyGroupCount)
+
+			// Compute the custody group sampling size.
+			actual := custodyInfo.CustodyGroupSamplingSize(tc.custodyType)
+
+			// Check the result.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestCustodyColumns(t *testing.T) {
+	t.Run("group too large", func(t *testing.T) {
+		_, err := peerdas.CustodyColumns([]uint64{1_000_000})
+		require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		input := []uint64{1, 2}
+		expected := map[uint64]bool{1: true, 2: true}
+
+		actual, err := peerdas.CustodyColumns(input)
+		require.NoError(t, err)
+		require.Equal(t, len(expected), len(actual))
+		for i := range actual {
+			require.Equal(t, expected[i], actual[i])
+		}
+	})
+}

beacon-chain/core/peerdas/info.go

@@ -0,0 +1,192 @@
+package peerdas
+
+import (
+	"encoding/binary"
+	"sync"
+
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	lru "github.com/hashicorp/golang-lru"
+	"github.com/pkg/errors"
+)
+
+// info contains all useful peerDAS related information regarding a peer.
+type (
+	info struct {
+		CustodyGroups      map[uint64]bool
+		CustodyColumns     map[uint64]bool
+		DataColumnsSubnets map[uint64]bool
+	}
+
+	targetCustodyGroupCount struct {
+		mut                          sync.RWMutex
+		validatorsCustodyRequirement uint64
+	}
+
+	toAdverstiseCustodyGroupCount struct {
+		mut   sync.RWMutex
+		value uint64
+	}
+
+	CustodyInfo struct {
+		// Mut is a mutex to be used by caller to ensure neither
+		// TargetCustodyGroupCount nor ToAdvertiseCustodyGroupCount are being modified.
+		// (This is not necessary to use this mutex for any data protection.)
+		Mut sync.RWMutex
+
+		// TargetGroupCount represents the target number of custody groups we should custody
+		// regarding the validators we are tracking.
+		TargetGroupCount targetCustodyGroupCount
+
+		// ToAdvertiseGroupCount represents the number of custody groups to advertise to the network.
+		ToAdvertiseGroupCount toAdverstiseCustodyGroupCount
+	}
+)
+
+const (
+	nodeInfoCacheSize   = 200
+	nodeInfoCachKeySize = 32 + 8
+)
+
+var (
+	nodeInfoCacheMut sync.Mutex
+	nodeInfoCache    *lru.Cache
+)
+
+// Info returns the peerDAS information for a given nodeID and custodyGroupCount.
+// It returns a boolean indicating if the peer info was already in the cache and an error if any.
+func Info(nodeID enode.ID, custodyGroupCount uint64) (*info, bool, error) {
+	// Create a new cache if it doesn't exist.
+	if err := createInfoCacheIfNeeded(); err != nil {
+		return nil, false, errors.Wrap(err, "create cache if needed")
+	}
+
+	// Compute the key.
+	key := computeInfoCacheKey(nodeID, custodyGroupCount)
+
+	// If the value is already in the cache, return it.
+	if value, ok := nodeInfoCache.Get(key); ok {
+		peerInfo, ok := value.(*info)
+		if !ok {
+			return nil, false, errors.New("failed to cast peer info (should never happen)")
+		}
+
+		return peerInfo, true, nil
+	}
+
+	// The peer info is not in the cache, compute it.
+	// Compute custody groups.
+	custodyGroups, err := CustodyGroups(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, false, errors.Wrap(err, "custody groups")
+	}
+
+	// Compute custody columns.
+	custodyColumns, err := CustodyColumns(custodyGroups)
+	if err != nil {
+		return nil, false, errors.Wrap(err, "custody columns")
+	}
+
+	// Compute data columns subnets.
+	dataColumnsSubnets := DataColumnSubnets(custodyColumns)
+
+	// Convert the custody groups to a map.
+	custodyGroupsMap := make(map[uint64]bool, len(custodyGroups))
+	for _, group := range custodyGroups {
+		custodyGroupsMap[group] = true
+	}
+
+	result := &info{
+		CustodyGroups:      custodyGroupsMap,
+		CustodyColumns:     custodyColumns,
+		DataColumnsSubnets: dataColumnsSubnets,
+	}
+
+	// Add the result to the cache.
+	nodeInfoCache.Add(key, result)
+
+	return result, false, nil
+}
+
+// ActualGroupCount returns the actual custody group count.
+func (custodyInfo *CustodyInfo) ActualGroupCount() uint64 {
+	return min(custodyInfo.TargetGroupCount.Get(), custodyInfo.ToAdvertiseGroupCount.Get())
+}
+
+// CustodyGroupCount returns the number of groups we should participate in for custody.
+func (tcgc *targetCustodyGroupCount) Get() uint64 {
+	// If subscribed to all subnets, return the number of custody groups.
+	if flags.Get().SubscribeAllDataSubnets {
+		return params.BeaconConfig().NumberOfCustodyGroups
+	}
+
+	tcgc.mut.RLock()
+	defer tcgc.mut.RUnlock()
+
+	// If no validators are tracked, return the default custody requirement.
+	if tcgc.validatorsCustodyRequirement == 0 {
+		return params.BeaconConfig().CustodyRequirement
+	}
+
+	// Return the validators custody requirement.
+	return tcgc.validatorsCustodyRequirement
+}
+
+// setValidatorsCustodyRequirement sets the validators custody requirement.
+func (tcgc *targetCustodyGroupCount) SetValidatorsCustodyRequirement(value uint64) {
+	tcgc.mut.Lock()
+	defer tcgc.mut.Unlock()
+
+	tcgc.validatorsCustodyRequirement = value
+}
+
+// Get returns the to advertise custody group count.
+func (tacgc *toAdverstiseCustodyGroupCount) Get() uint64 {
+	// If subscribed to all subnets, return the number of custody groups.
+	if flags.Get().SubscribeAllDataSubnets {
+		return params.BeaconConfig().NumberOfCustodyGroups
+	}
+
+	custodyRequirement := params.BeaconConfig().CustodyRequirement
+
+	tacgc.mut.RLock()
+	defer tacgc.mut.RUnlock()
+
+	return max(tacgc.value, custodyRequirement)
+}
+
+// Set sets the to advertise custody group count.
+func (tacgc *toAdverstiseCustodyGroupCount) Set(value uint64) {
+	tacgc.mut.Lock()
+	defer tacgc.mut.Unlock()
+
+	tacgc.value = value
+}
+
+// createInfoCacheIfNeeded creates a new cache if it doesn't exist.
+func createInfoCacheIfNeeded() error {
+	nodeInfoCacheMut.Lock()
+	defer nodeInfoCacheMut.Unlock()
+
+	if nodeInfoCache == nil {
+		c, err := lru.New(nodeInfoCacheSize)
+		if err != nil {
+			return errors.Wrap(err, "lru new")
+		}
+
+		nodeInfoCache = c
+	}
+
+	return nil
+}
+
+// computeInfoCacheKey returns a unique key for a node and its custodyGroupCount.
+func computeInfoCacheKey(nodeID enode.ID, custodyGroupCount uint64) [nodeInfoCachKeySize]byte {
+	var key [nodeInfoCachKeySize]byte
+
+	copy(key[:32], nodeID[:])
+	binary.BigEndian.PutUint64(key[32:], custodyGroupCount)
+
+	return key
+}

beacon-chain/core/peerdas/info_test.go

@@ -0,0 +1,133 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+func TestInfo(t *testing.T) {
+	nodeID := enode.ID{}
+	custodyGroupCount := uint64(7)
+
+	expectedCustodyGroup := map[uint64]bool{1: true, 17: true, 19: true, 42: true, 75: true, 87: true, 102: true}
+	expectedCustodyColumns := map[uint64]bool{1: true, 17: true, 19: true, 42: true, 75: true, 87: true, 102: true}
+	expectedDataColumnsSubnets := map[uint64]bool{1: true, 17: true, 19: true, 42: true, 75: true, 87: true, 102: true}
+
+	for _, cached := range []bool{false, true} {
+		actual, ok, err := peerdas.Info(nodeID, custodyGroupCount)
+		require.NoError(t, err)
+		require.Equal(t, cached, ok)
+		require.DeepEqual(t, expectedCustodyGroup, actual.CustodyGroups)
+		require.DeepEqual(t, expectedCustodyColumns, actual.CustodyColumns)
+		require.DeepEqual(t, expectedDataColumnsSubnets, actual.DataColumnsSubnets)
+	}
+}
+
+func TestTargetCustodyGroupCount(t *testing.T) {
+	testCases := []struct {
+		name                         string
+		subscribeToAllColumns        bool
+		validatorsCustodyRequirement uint64
+		expected                     uint64
+	}{
+		{
+			name:                         "subscribed to all data subnets",
+			subscribeToAllColumns:        true,
+			validatorsCustodyRequirement: 100,
+			expected:                     128,
+		},
+		{
+			name:                         "no validators attached",
+			subscribeToAllColumns:        false,
+			validatorsCustodyRequirement: 0,
+			expected:                     4,
+		},
+		{
+			name:                         "some validators attached",
+			subscribeToAllColumns:        false,
+			validatorsCustodyRequirement: 100,
+			expected:                     100,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Subscribe to all subnets if needed.
+			if tc.subscribeToAllColumns {
+				resetFlags := flags.Get()
+				gFlags := new(flags.GlobalFlags)
+				gFlags.SubscribeAllDataSubnets = true
+				flags.Init(gFlags)
+				defer flags.Init(resetFlags)
+			}
+
+			var custodyInfo peerdas.CustodyInfo
+
+			// Set the validators custody requirement.
+			custodyInfo.TargetGroupCount.SetValidatorsCustodyRequirement(tc.validatorsCustodyRequirement)
+
+			// Get the target custody group count.
+			actual := custodyInfo.TargetGroupCount.Get()
+
+			// Compare the expected and actual values.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestToAdvertiseCustodyGroupCount(t *testing.T) {
+	testCases := []struct {
+		name                         string
+		subscribeToAllColumns        bool
+		toAdvertiseCustodyGroupCount uint64
+		expected                     uint64
+	}{
+		{
+			name:                         "subscribed to all subnets",
+			subscribeToAllColumns:        true,
+			toAdvertiseCustodyGroupCount: 100,
+			expected:                     128,
+		},
+		{
+			name:                         "higher than custody requirement",
+			subscribeToAllColumns:        false,
+			toAdvertiseCustodyGroupCount: 100,
+			expected:                     100,
+		},
+		{
+			name:                         "lower than custody requirement",
+			subscribeToAllColumns:        false,
+			toAdvertiseCustodyGroupCount: 1,
+			expected:                     4,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Subscribe to all subnets if needed.
+			if tc.subscribeToAllColumns {
+				resetFlags := flags.Get()
+				gFlags := new(flags.GlobalFlags)
+				gFlags.SubscribeAllDataSubnets = true
+				flags.Init(gFlags)
+				defer flags.Init(resetFlags)
+			}
+
+			// Create a custody info.
+			var custodyInfo peerdas.CustodyInfo
+
+			// Set the to advertise custody group count.
+			custodyInfo.ToAdvertiseGroupCount.Set(tc.toAdvertiseCustodyGroupCount)
+
+			// Get the to advertise custody group count.
+			actual := custodyInfo.ToAdvertiseGroupCount.Get()
+
+			// Compare the expected and actual values.
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}

beacon-chain/core/peerdas/metrics.go

@@ -0,0 +1,14 @@
+package peerdas
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var dataColumnComputationTime = promauto.NewHistogram(
+	prometheus.HistogramOpts{
+		Name:    "beacon_data_column_sidecar_computation_milliseconds",
+		Help:    "Captures the time taken to compute data column sidecars from blobs.",
+		Buckets: []float64{25, 50, 100, 250, 500, 750, 1000},
+	},
+)

beacon-chain/core/peerdas/p2p_interface.go

@@ -0,0 +1,162 @@
+package peerdas
+
+import (
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/container/trie"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/pkg/errors"
+)
+
+const (
+	CustodyGroupCountEnrKey = "cgc"
+	kzgPosition             = 11 // The index of the KZG commitment list in the Body
+)
+
+var (
+	ErrIndexTooLarge               = errors.New("column index is larger than the specified columns count")
+	ErrNoKzgCommitments            = errors.New("no KZG commitments found")
+	ErrMismatchLength              = errors.New("mismatch in the length of the column, commitments or proofs")
+	ErrInvalidKZGProof             = errors.New("invalid KZG proof")
+	ErrBadRootLength               = errors.New("bad root length")
+	ErrInvalidInclusionProof       = errors.New("invalid inclusion proof")
+	ErrRecordNil                   = errors.New("record is nil")
+	ErrNilBlockHeader              = errors.New("nil beacon block header")
+	ErrCannotLoadCustodyGroupCount = errors.New("cannot load the custody group count from peer")
+)
+
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#custody-group-count
+type Cgc uint64
+
+func (Cgc) ENRKey() string { return CustodyGroupCountEnrKey }
+
+// VerifyDataColumnSidecar verifies if the data column sidecar is valid.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar
+func VerifyDataColumnSidecar(sidecar blocks.RODataColumn) error {
+	// The sidecar index must be within the valid range.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	if sidecar.Index >= numberOfColumns {
+		return ErrIndexTooLarge
+	}
+
+	// A sidecar for zero blobs is invalid.
+	if len(sidecar.KzgCommitments) == 0 {
+		return ErrNoKzgCommitments
+	}
+
+	// The column length must be equal to the number of commitments/proofs.
+	if len(sidecar.Column) != len(sidecar.KzgCommitments) || len(sidecar.Column) != len(sidecar.KzgProofs) {
+		return ErrMismatchLength
+	}
+
+	return nil
+}
+
+// VerifyDataColumnsSidecarKZGProofs verifies if the KZG proofs are correct.
+// Note: We are slightly deviating from the specification here:
+// The specification verifies the KZG proofs for each sidecar separately,
+// while we are verifying all the KZG proofs from multiple sidecars in a batch.
+// This is done to improve performance since the internal KZG library is way more
+// efficient when verifying in batch.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar_kzg_proofs
+func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) error {
+	// Compute the total count.
+	count := 0
+	for _, sidecar := range sidecars {
+		count += len(sidecar.Column)
+	}
+
+	commitments := make([]kzg.Bytes48, 0, count)
+	indices := make([]uint64, 0, count)
+	cells := make([]kzg.Cell, 0, count)
+	proofs := make([]kzg.Bytes48, 0, count)
+
+	for _, sidecar := range sidecars {
+		for i := range sidecar.Column {
+			commitments = append(commitments, kzg.Bytes48(sidecar.KzgCommitments[i]))
+			indices = append(indices, sidecar.Index)
+			cells = append(cells, kzg.Cell(sidecar.Column[i]))
+			proofs = append(proofs, kzg.Bytes48(sidecar.KzgProofs[i]))
+		}
+	}
+
+	// Batch verify that the cells match the corresponding commitments and proofs.
+	verified, err := kzg.VerifyCellKZGProofBatch(commitments, indices, cells, proofs)
+	if err != nil {
+		return errors.Wrap(err, "verify cell KZG proof batch")
+	}
+
+	if !verified {
+		return ErrInvalidKZGProof
+	}
+
+	return nil
+}
+
+// VerifyDataColumnSidecarInclusionProof verifies if the given KZG commitments included in the given beacon block.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#verify_data_column_sidecar_inclusion_proof
+func VerifyDataColumnSidecarInclusionProof(sidecar blocks.RODataColumn) error {
+	if sidecar.SignedBlockHeader == nil || sidecar.SignedBlockHeader.Header == nil {
+		return ErrNilBlockHeader
+	}
+
+	root := sidecar.SignedBlockHeader.Header.BodyRoot
+	if len(root) != fieldparams.RootLength {
+		return ErrBadRootLength
+	}
+
+	leaves := blocks.LeavesFromCommitments(sidecar.KzgCommitments)
+
+	sparse, err := trie.GenerateTrieFromItems(leaves, fieldparams.LogMaxBlobCommitments)
+	if err != nil {
+		return errors.Wrap(err, "generate trie from items")
+	}
+
+	hashTreeRoot, err := sparse.HashTreeRoot()
+	if err != nil {
+		return errors.Wrap(err, "hash tree root")
+	}
+
+	verified := trie.VerifyMerkleProof(root, hashTreeRoot[:], kzgPosition, sidecar.KzgCommitmentsInclusionProof)
+	if !verified {
+		return ErrInvalidInclusionProof
+	}
+
+	return nil
+}
+
+// ComputeSubnetForDataColumnSidecar computes the subnet for a data column sidecar.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
+func ComputeSubnetForDataColumnSidecar(columnIndex uint64) uint64 {
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+	return columnIndex % dataColumnSidecarSubnetCount
+}
+
+// DataColumnSubnets computes the subnets for the data columns.
+func DataColumnSubnets(dataColumns map[uint64]bool) map[uint64]bool {
+	subnets := make(map[uint64]bool, len(dataColumns))
+
+	for column := range dataColumns {
+		subnet := ComputeSubnetForDataColumnSidecar(column)
+		subnets[subnet] = true
+	}
+
+	return subnets
+}
+
+// CustodyGroupCountFromRecord extracts the custody group count from an ENR record.
+func CustodyGroupCountFromRecord(record *enr.Record) (uint64, error) {
+	if record == nil {
+		return 0, ErrRecordNil
+	}
+
+	// Load the `cgc`
+	var cgc Cgc
+	if err := record.Load(&cgc); err != nil {
+		return 0, ErrCannotLoadCustodyGroupCount
+	}
+
+	return uint64(cgc), nil
+}

beacon-chain/core/peerdas/p2p_interface_test.go

@@ -0,0 +1,398 @@
+package peerdas_test
+
+import (
+	"crypto/rand"
+	"fmt"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+)
+
+func TestVerifyDataColumnSidecar(t *testing.T) {
+	t.Run("index too large", func(t *testing.T) {
+		roSidecar := createTestSidecar(t, 1_000_000, nil, nil, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrIndexTooLarge)
+	})
+
+	t.Run("no commitments", func(t *testing.T) {
+		roSidecar := createTestSidecar(t, 0, nil, nil, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrNoKzgCommitments)
+	})
+
+	t.Run("KZG commitments size mismatch", func(t *testing.T) {
+		kzgCommitments := make([][]byte, 1)
+		roSidecar := createTestSidecar(t, 0, nil, kzgCommitments, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrMismatchLength)
+	})
+
+	t.Run("KZG proofs size mismatch", func(t *testing.T) {
+		column, kzgCommitments := make([][]byte, 1), make([][]byte, 1)
+		roSidecar := createTestSidecar(t, 0, column, kzgCommitments, nil)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.ErrorIs(t, err, peerdas.ErrMismatchLength)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		column, kzgCommitments, kzgProofs := make([][]byte, 1), make([][]byte, 1), make([][]byte, 1)
+		roSidecar := createTestSidecar(t, 0, column, kzgCommitments, kzgProofs)
+		err := peerdas.VerifyDataColumnSidecar(roSidecar)
+		require.NoError(t, err)
+	})
+}
+
+func TestVerifyDataColumnSidecarKZGProofs(t *testing.T) {
+	const (
+		blobCount = 6
+		seed      = 0
+	)
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("invalid proof", func(t *testing.T) {
+		sidecars := generateRandomSidecars(t, seed, blobCount)
+		sidecars[0].Column[0][0]++ // It is OK to overflow
+		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
+
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		require.ErrorIs(t, err, peerdas.ErrInvalidKZGProof)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		sidecars := generateRandomSidecars(t, seed, blobCount)
+		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
+
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		require.NoError(t, err)
+	})
+}
+
+func Test_VerifyKZGInclusionProofColumn(t *testing.T) {
+	const (
+		blobCount   = 3
+		columnIndex = 0
+	)
+
+	// Generate random KZG commitments `blobCount` blobs.
+	kzgCommitments := make([][]byte, blobCount)
+
+	for i := 0; i < blobCount; i++ {
+		kzgCommitments[i] = make([]byte, 48)
+		_, err := rand.Read(kzgCommitments[i])
+		require.NoError(t, err)
+	}
+
+	pbBody := &ethpb.BeaconBlockBodyDeneb{
+		RandaoReveal: make([]byte, 96),
+		Eth1Data: &ethpb.Eth1Data{
+			DepositRoot: make([]byte, fieldparams.RootLength),
+			BlockHash:   make([]byte, fieldparams.RootLength),
+		},
+		Graffiti: make([]byte, 32),
+		SyncAggregate: &ethpb.SyncAggregate{
+			SyncCommitteeBits:      make([]byte, fieldparams.SyncAggregateSyncCommitteeBytesLength),
+			SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+		},
+		ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, 20),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, 256),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+		},
+		BlobKzgCommitments: kzgCommitments,
+	}
+
+	root, err := pbBody.HashTreeRoot()
+	require.NoError(t, err)
+
+	body, err := blocks.NewBeaconBlockBody(pbBody)
+	require.NoError(t, err)
+
+	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(body)
+	require.NoError(t, err)
+
+	testCases := []struct {
+		name              string
+		expectedError     error
+		dataColumnSidecar *ethpb.DataColumnSidecar
+	}{
+		{
+			name:              "nilSignedBlockHeader",
+			expectedError:     peerdas.ErrNilBlockHeader,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{},
+		},
+		{
+			name:          "nilHeader",
+			expectedError: peerdas.ErrNilBlockHeader,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{},
+			},
+		},
+		{
+			name:          "invalidBodyRoot",
+			expectedError: peerdas.ErrBadRootLength,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+					Header: &ethpb.BeaconBlockHeader{},
+				},
+			},
+		},
+		{
+			name:          "unverifiedMerkleProof",
+			expectedError: peerdas.ErrInvalidInclusionProof,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+					Header: &ethpb.BeaconBlockHeader{
+						BodyRoot: make([]byte, 32),
+					},
+				},
+				KzgCommitments: kzgCommitments,
+			},
+		},
+		{
+			name:          "nominal",
+			expectedError: nil,
+			dataColumnSidecar: &ethpb.DataColumnSidecar{
+				KzgCommitments: kzgCommitments,
+				SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+					Header: &ethpb.BeaconBlockHeader{
+						BodyRoot: root[:],
+					},
+				},
+				KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			roDataColumn := blocks.RODataColumn{DataColumnSidecar: tc.dataColumnSidecar}
+			err = peerdas.VerifyDataColumnSidecarInclusionProof(roDataColumn)
+			if tc.expectedError == nil {
+				require.NoError(t, err)
+				return
+			}
+
+			require.ErrorIs(t, tc.expectedError, err)
+		})
+	}
+}
+
+func TestComputeSubnetForDataColumnSidecar(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.DataColumnSidecarSubnetCount = 128
+	params.OverrideBeaconConfig(config)
+
+	require.Equal(t, uint64(0), peerdas.ComputeSubnetForDataColumnSidecar(0))
+	require.Equal(t, uint64(1), peerdas.ComputeSubnetForDataColumnSidecar(1))
+	require.Equal(t, uint64(0), peerdas.ComputeSubnetForDataColumnSidecar(128))
+	require.Equal(t, uint64(1), peerdas.ComputeSubnetForDataColumnSidecar(129))
+}
+
+func TestDataColumnSubnets(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.DataColumnSidecarSubnetCount = 128
+	params.OverrideBeaconConfig(config)
+
+	input := map[uint64]bool{0: true, 1: true, 128: true, 129: true, 131: true}
+	expected := map[uint64]bool{0: true, 1: true, 3: true}
+	actual := peerdas.DataColumnSubnets(input)
+
+	require.Equal(t, len(expected), len(actual))
+	for k, v := range expected {
+		require.Equal(t, v, actual[k])
+	}
+}
+
+func TestCustodyGroupCountFromRecord(t *testing.T) {
+	t.Run("nil record", func(t *testing.T) {
+		_, err := peerdas.CustodyGroupCountFromRecord(nil)
+		require.ErrorIs(t, err, peerdas.ErrRecordNil)
+	})
+
+	t.Run("no cgc", func(t *testing.T) {
+		_, err := peerdas.CustodyGroupCountFromRecord(&enr.Record{})
+		require.ErrorIs(t, err, peerdas.ErrCannotLoadCustodyGroupCount)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		const expected uint64 = 7
+
+		record := &enr.Record{}
+		record.Set(peerdas.Cgc(expected))
+
+		actual, err := peerdas.CustodyGroupCountFromRecord(record)
+		require.NoError(t, err)
+		require.Equal(t, expected, actual)
+	})
+}
+
+func BenchmarkVerifyDataColumnSidecarKZGProofs_SameCommitments_NoBatch(b *testing.B) {
+	const blobCount = 12
+	err := kzg.Start()
+	require.NoError(b, err)
+
+	b.StopTimer()
+	b.ResetTimer()
+	for i := range int64(b.N) {
+		// Generate new random sidecars to ensure the KZG backend does not cache anything.
+		sidecars := generateRandomSidecars(b, i, blobCount)
+		roDataColumnSidecars := generateRODataColumnSidecars(b, sidecars)
+
+		for _, sidecar := range roDataColumnSidecars {
+			sidecars := []blocks.RODataColumn{sidecar}
+			b.StartTimer()
+			err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
+			b.StopTimer()
+			require.NoError(b, err)
+		}
+	}
+}
+
+func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch(b *testing.B) {
+	const blobCount = 12
+	numberOfColumns := int64(params.BeaconConfig().NumberOfColumns)
+	err := kzg.Start()
+	require.NoError(b, err)
+
+	columnsCounts := []int64{1, 2, 4, 8, 16, 32, 64, 128}
+
+	for i, columnsCount := range columnsCounts {
+		b.Run(fmt.Sprintf("columnsCount_%d", columnsCount), func(b *testing.B) {
+			b.StopTimer()
+			b.ResetTimer()
+
+			for j := range int64(b.N) {
+				allSidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
+				for k := int64(0); k < numberOfColumns; k += columnsCount {
+					// Use different seeds to generate different blobs/commitments
+					seed := int64(b.N*i) + numberOfColumns*j + blobCount*k
+					sidecars := generateRandomSidecars(b, seed, blobCount)
+
+					// Pick sidecars.
+					allSidecars = append(allSidecars, sidecars[k:k+columnsCount]...)
+				}
+
+				roDataColumnSidecars := generateRODataColumnSidecars(b, allSidecars)
+
+				b.StartTimer()
+				err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+				b.StopTimer()
+				require.NoError(b, err)
+			}
+		})
+	}
+}
+
+func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch4(b *testing.B) {
+	const (
+		blobCount = 12
+
+		// columnsCount*batchCount = 128
+		columnsCount = 4
+		batchCount   = 32
+	)
+
+	err := kzg.Start()
+	require.NoError(b, err)
+
+	b.StopTimer()
+	b.ResetTimer()
+
+	for i := range int64(b.N) {
+		allSidecars := make([][]blocks.RODataColumn, 0, batchCount)
+		for j := range int64(batchCount) {
+			// Use different seeds to generate different blobs/commitments
+			sidecars := generateRandomSidecars(b, int64(batchCount)*i+j*blobCount, blobCount)
+			roDataColumnSidecars := generateRODataColumnSidecars(b, sidecars[:columnsCount])
+			allSidecars = append(allSidecars, roDataColumnSidecars)
+		}
+
+		for _, sidecars := range allSidecars {
+			b.StartTimer()
+			err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
+			b.StopTimer()
+			require.NoError(b, err)
+		}
+	}
+}
+
+func createTestSidecar(t *testing.T, index uint64, column, kzgCommitments, kzgProofs [][]byte) blocks.RODataColumn {
+	pbSignedBeaconBlock := util.NewBeaconBlockDeneb()
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(pbSignedBeaconBlock)
+	require.NoError(t, err)
+
+	signedBlockHeader, err := signedBeaconBlock.Header()
+	require.NoError(t, err)
+
+	sidecar := &ethpb.DataColumnSidecar{
+		Index:             index,
+		Column:            column,
+		KzgCommitments:    kzgCommitments,
+		KzgProofs:         kzgProofs,
+		SignedBlockHeader: signedBlockHeader,
+	}
+
+	roSidecar, err := blocks.NewRODataColumn(sidecar)
+	require.NoError(t, err)
+
+	return roSidecar
+}
+
+func generateRandomSidecars(t testing.TB, seed, blobCount int64) []*ethpb.DataColumnSidecar {
+	dbBlock := util.NewBeaconBlockDeneb()
+
+	commitments := make([][]byte, 0, blobCount)
+	blobs := make([]kzg.Blob, 0, blobCount)
+
+	for i := range blobCount {
+		subSeed := seed + i
+		blob := getRandBlob(subSeed)
+		commitment, err := generateCommitment(&blob)
+		require.NoError(t, err)
+
+		commitments = append(commitments, commitment[:])
+		blobs = append(blobs, blob)
+	}
+
+	dbBlock.Block.Body.BlobKzgCommitments = commitments
+	sBlock, err := blocks.NewSignedBeaconBlock(dbBlock)
+	require.NoError(t, err)
+
+	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
+	sidecars, err := peerdas.DataColumnSidecars(sBlock, cellsAndProofs)
+	require.NoError(t, err)
+
+	return sidecars
+}
+
+func generateRODataColumnSidecars(t testing.TB, sidecars []*ethpb.DataColumnSidecar) []blocks.RODataColumn {
+	roDataColumnSidecars := make([]blocks.RODataColumn, 0, len(sidecars))
+	for _, sidecar := range sidecars {
+		roCol, err := blocks.NewRODataColumn(sidecar)
+		require.NoError(t, err)
+
+		roDataColumnSidecars = append(roDataColumnSidecars, roCol)
+	}
+
+	return roDataColumnSidecars
+}

beacon-chain/core/peerdas/reconstruction.go

@@ -0,0 +1,322 @@
+package peerdas
+
+import (
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/pkg/errors"
+	"golang.org/x/sync/errgroup"
+)
+
+var (
+	ErrColumnLengthsDiffer      = errors.New("columns do not have the same length")
+	ErrBlobIndexTooHigh         = errors.New("blob index is too high")
+	ErrBlockRootMismatch        = errors.New("block root mismatch")
+	ErrBlobsCellsProofsMismatch = errors.New("blobs and cells proofs mismatch")
+)
+
+// MinimumColumnsCountToReconstruct return the minimum number of columns needed to proceed to a reconstruction.
+func MinimumColumnsCountToReconstruct() uint64 {
+	// If the number of columns is odd, then we need total / 2 + 1 columns to reconstruct.
+	// If the number of columns is even, then we need total / 2 columns to reconstruct.
+	return (params.BeaconConfig().NumberOfColumns + 1) / 2
+}
+
+// ReconstructDataColumnSidecars reconstructs all the data column sidecars from the given input data column sidecars.
+// All input sidecars must be committed to the same block.
+// `inVerifiedRoSidecars` should contain enough (unique) sidecars to reconstruct the missing columns.
+func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataColumn) ([]blocks.VerifiedRODataColumn, error) {
+	// Check if there is at least one input sidecar.
+	if len(inVerifiedRoSidecars) == 0 {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Safely retrieve the first sidecar as a reference.
+	referenceSidecar := inVerifiedRoSidecars[0]
+
+	// Check if all columns have the same length and are commmitted to the same block.
+	blobCount := len(referenceSidecar.Column)
+	blockRoot := referenceSidecar.BlockRoot()
+	for _, sidecar := range inVerifiedRoSidecars[1:] {
+		if len(sidecar.Column) != blobCount {
+			return nil, ErrColumnLengthsDiffer
+		}
+
+		if sidecar.BlockRoot() != blockRoot {
+			return nil, ErrBlockRootMismatch
+		}
+	}
+
+	// Deduplicate sidecars.
+	sidecarByIndex := make(map[uint64]blocks.VerifiedRODataColumn, len(inVerifiedRoSidecars))
+	for _, inVerifiedRoSidecar := range inVerifiedRoSidecars {
+		sidecarByIndex[inVerifiedRoSidecar.Index] = inVerifiedRoSidecar
+	}
+
+	// Check if there is enough sidecars to reconstruct the missing columns.
+	sidecarCount := len(sidecarByIndex)
+	if uint64(sidecarCount) < MinimumColumnsCountToReconstruct() {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Sidecars are verified and are committed to the same block.
+	// All signed block headers, KZG commitments, and inclusion proofs are the same.
+	signedBlockHeader := referenceSidecar.SignedBlockHeader
+	kzgCommitments := referenceSidecar.KzgCommitments
+	kzgCommitmentsInclusionProof := referenceSidecar.KzgCommitmentsInclusionProof
+
+	// Recover cells and compute proofs in parallel.
+	var wg errgroup.Group
+	cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+	for blobIndex := range uint64(blobCount) {
+		wg.Go(func() error {
+			cellsIndices := make([]uint64, 0, sidecarCount)
+			cells := make([]kzg.Cell, 0, sidecarCount)
+
+			for columnIndex, sidecar := range sidecarByIndex {
+				cell := sidecar.Column[blobIndex]
+				cells = append(cells, kzg.Cell(cell))
+				cellsIndices = append(cellsIndices, columnIndex)
+			}
+
+			// Recover the cells and proofs for the corresponding blob
+			cellsAndProofsForBlob, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
+
+			if err != nil {
+				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", blobIndex)
+			}
+
+			// It is safe for multiple goroutines to concurrently write to the same slice,
+			// as long as they are writing to different indices, which is the case here.
+			cellsAndProofs[blobIndex] = cellsAndProofsForBlob
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, errors.Wrap(err, "wait for RecoverCellsAndKZGProofs")
+	}
+
+	outSidecars, err := dataColumnsSidecars(signedBlockHeader, kzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidecars from items")
+	}
+
+	// Input sidecars are verified, and we reconstructed ourselves the missing sidecars.
+	// As a consequence, reconstructed sidecars are also verified.
+	outVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(outSidecars))
+	for _, sidecar := range outSidecars {
+		roSidecar, err := blocks.NewRODataColumnWithRoot(sidecar, blockRoot)
+		if err != nil {
+			return nil, errors.Wrap(err, "new RO data column with root")
+		}
+
+		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+		outVerifiedRoSidecars = append(outVerifiedRoSidecars, verifiedRoSidecar)
+	}
+
+	return outVerifiedRoSidecars, nil
+}
+
+// ConstructDataColumnSidecars constructs data column sidecars from a block, (un-extended) blobs and
+// cell proofs corresponding the extended blobs. The main purpose of this function is to
+// construct data columns sidecars from data obtained from the execution client via:
+// - `engine_getBlobsV2` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getblobsv2, or
+// - `engine_getPayloadV5` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getpayloadv5
+// Note: In this function, to stick with the `BlobsBundleV2` format returned by the execution client in `engine_getPayloadV5`,
+// cell proofs are "flattened".
+func ConstructDataColumnSidecars(block interfaces.ReadOnlySignedBeaconBlock, blobs [][]byte, cellProofs [][]byte) ([]*ethpb.DataColumnSidecar, error) {
+	// Check if the cells count is equal to the cell proofs count.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	blobCount := uint64(len(blobs))
+	cellProofsCount := uint64(len(cellProofs))
+
+	cellsCount := blobCount * numberOfColumns
+	if cellsCount != cellProofsCount {
+		return nil, ErrBlobsCellsProofsMismatch
+	}
+
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
+	for i, blob := range blobs {
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute cells")
+		}
+
+		var proofs []kzg.Proof
+		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
+				return nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			proofs = append(proofs, kzgProof)
+		}
+
+		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
+		cellsAndProofs = append(cellsAndProofs, cellsProofs)
+	}
+
+	dataColumnSidecars, err := DataColumnSidecars(block, cellsAndProofs)
+	if err != nil {
+		return nil, errors.Wrap(err, "data column sidcars")
+	}
+
+	return dataColumnSidecars, nil
+}
+
+// ReconstructBlobs constructs verified read only blobs sidecars from verified read only blob sidecars.
+// The following constraints must be satisfied:
+//   - All `dataColumnSidecars` has to be committed to the same block, and
+//   - `dataColumnSidecars` must be sorted by index and should not contain duplicates.
+//   - `dataColumnSidecars` must contain either all sidecars corresponding to (non-extended) blobs,
+//     or either enough sidecars to reconstruct the blobs.
+func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
+	// Return early if no blobs are requested.
+	if len(indices) == 0 {
+		return nil, nil
+	}
+
+	if len(verifiedDataColumnSidecars) == 0 {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Check if the sidecars are sorted by index and do not contain duplicates.
+	previousColumnIndex := verifiedDataColumnSidecars[0].Index
+	for _, dataColumnSidecar := range verifiedDataColumnSidecars[1:] {
+		columnIndex := dataColumnSidecar.Index
+		if columnIndex <= previousColumnIndex {
+			return nil, ErrDataColumnSidecarsNotSortedByIndex
+		}
+
+		previousColumnIndex = columnIndex
+	}
+
+	// Check if we have enough columns.
+	cellsPerBlob := fieldparams.CellsPerBlob
+	if len(verifiedDataColumnSidecars) < cellsPerBlob {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Check if the blob index is too high.
+	commitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	for _, blobIndex := range indices {
+		if blobIndex >= len(commitments) {
+			return nil, ErrBlobIndexTooHigh
+		}
+	}
+
+	// Check if the data column sidecars are aligned with the block.
+	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(verifiedDataColumnSidecars))
+	for _, verifiedDataColumnSidecar := range verifiedDataColumnSidecars {
+		dataColumnSicecar := verifiedDataColumnSidecar.RODataColumn
+		dataColumnSidecars = append(dataColumnSidecars, dataColumnSicecar)
+	}
+
+	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
+		return nil, errors.Wrap(err, "data columns align with block")
+	}
+
+	// If all column sidecars corresponding to (non-extended) blobs are present, no need to reconstruct.
+	if verifiedDataColumnSidecars[cellsPerBlob-1].Index == uint64(cellsPerBlob-1) {
+		// Convert verified data column sidecars to verified blob sidecars.
+		blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, verifiedDataColumnSidecars, indices)
+		if err != nil {
+			return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
+		}
+
+		return blobSidecars, nil
+	}
+
+	// We need to reconstruct the blobs.
+	reconstructedDataColumnSidecars, err := ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
+	if err != nil {
+		return nil, errors.Wrap(err, "reconstruct data column sidecars")
+	}
+
+	// Convert verified data column sidecars to verified blob sidecars.
+	blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, reconstructedDataColumnSidecars, indices)
+	if err != nil {
+		return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
+	}
+
+	return blobSidecars, nil
+}
+
+// blobSidecarsFromDataColumnSidecars converts verified data column sidecars to verified blob sidecars.
+func blobSidecarsFromDataColumnSidecars(roBlock blocks.ROBlock, dataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
+	referenceSidecar := dataColumnSidecars[0]
+
+	kzgCommitments := referenceSidecar.KzgCommitments
+	signedBlockHeader := referenceSidecar.SignedBlockHeader
+
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, len(indices))
+	for _, blobIndex := range indices {
+		var blob kzg.Blob
+
+		// Compute the content of the blob.
+		for columnIndex := range fieldparams.CellsPerBlob {
+			dataColumnSidecar := dataColumnSidecars[columnIndex]
+			cell := dataColumnSidecar.Column[blobIndex]
+			if copy(blob[kzg.BytesPerCell*columnIndex:], cell) != kzg.BytesPerCell {
+				return nil, errors.New("wrong cell size - should never happen")
+			}
+		}
+
+		// Extract the KZG commitment.
+		var kzgCommitment kzg.Commitment
+		if copy(kzgCommitment[:], kzgCommitments[blobIndex]) != len(kzgCommitment) {
+			return nil, errors.New("wrong KZG commitment size - should never happen")
+		}
+
+		// Compute the blob KZG proof.
+		blobKzgProof, err := kzg.ComputeBlobKZGProof(&blob, kzgCommitment)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute blob KZG proof")
+		}
+
+		// Build the inclusion proof for the blob.
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob[:]) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		commitmentInclusionProof, err := blocks.MerkleProofKZGCommitment(roBlock.Block().Body(), blobIndex)
+		if err != nil {
+			return nil, errors.Wrap(err, "merkle proof KZG commitment")
+		}
+
+		// Build the blob sidecar.
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    uint64(blobIndex),
+			Blob:                     blob[:],
+			KzgCommitment:            kzgCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        signedBlockHeader,
+			CommitmentInclusionProof: commitmentInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		if err != nil {
+			return nil, errors.Wrap(err, "new RO blob")
+		}
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	return verifiedROBlobs, nil
+}

beacon-chain/core/peerdas/reconstruction_test.go

@@ -0,0 +1,321 @@
+package peerdas_test
+
+import (
+	"encoding/binary"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/pkg/errors"
+	"golang.org/x/sync/errgroup"
+)
+
+func TestMinimumColumnsCountToReconstruct(t *testing.T) {
+	testCases := []struct {
+		name            string
+		numberOfColumns uint64
+		expected        uint64
+	}{
+		{
+			name:            "numberOfColumns=128",
+			numberOfColumns: 128,
+			expected:        64,
+		},
+		{
+			name:            "numberOfColumns=129",
+			numberOfColumns: 129,
+			expected:        65,
+		},
+		{
+			name:            "numberOfColumns=130",
+			numberOfColumns: 130,
+			expected:        65,
+		},
+	}
+
+	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.numberOfColumns
+			params.OverrideBeaconConfig(cfg)
+
+			// Compute the minimum number of columns needed to reconstruct.
+			actual := peerdas.MinimumColumnsCountToReconstruct()
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestReconstructDataColumnSidecars(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("empty input", func(t *testing.T) {
+		_, err := peerdas.ReconstructDataColumnSidecars(nil)
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("columns lengths differ", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// Arbitrarily alter the column with index 3
+		verifiedRoSidecars[3].Column = verifiedRoSidecars[3].Column[1:]
+
+		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars)
+		require.ErrorIs(t, err, peerdas.ErrColumnLengthsDiffer)
+	})
+
+	t.Run("roots differ", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{1}))
+		_, _, verifiedRoSidecarsAlter := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{2}))
+
+		// Arbitrarily alter the column with index 3
+		verifiedRoSidecars[3] = verifiedRoSidecarsAlter[3]
+		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockRootMismatch)
+	})
+
+	const blobCount = 6
+	signedBeaconBlockPb := util.NewBeaconBlockFulu()
+	block := signedBeaconBlockPb.Block
+
+	commitments := make([][]byte, 0, blobCount)
+	for i := range uint64(blobCount) {
+		var commitment [fieldparams.KzgCommitmentSize]byte
+		binary.BigEndian.PutUint64(commitment[:], i)
+		commitments = append(commitments, commitment[:])
+	}
+
+	block.Body.BlobKzgCommitments = commitments
+
+	t.Run("not enough columns to enable reconstruction", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		minimum := peerdas.MinimumColumnsCountToReconstruct()
+		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars[:minimum-1])
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		// Build a full set of verified data column sidecars.
+		_, _, inputVerifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// Arbitrarily keep only the even sicars.
+		filteredVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(inputVerifiedRoSidecars)/2)
+		for i := 0; i < len(inputVerifiedRoSidecars); i += 2 {
+			filteredVerifiedRoSidecars = append(filteredVerifiedRoSidecars, inputVerifiedRoSidecars[i])
+		}
+
+		// Reconstruct the data column sidecars.
+		reconstructedVerifiedRoSidecars, err := peerdas.ReconstructDataColumnSidecars(filteredVerifiedRoSidecars)
+		require.NoError(t, err)
+
+		// Verify that the reconstructed sidecars are equal to the original ones.
+		require.DeepSSZEqual(t, inputVerifiedRoSidecars, reconstructedVerifiedRoSidecars)
+	})
+}
+
+func TestConstructDataColumnSidecars(t *testing.T) {
+	const (
+		blobCount    = 3
+		cellsPerBlob = fieldparams.CellsPerBlob
+	)
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	roBlock, _, baseVerifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
+
+	// Extract blobs and proofs from the sidecars.
+	blobs := make([][]byte, 0, blobCount)
+	cellProofs := make([][]byte, 0, cellsPerBlob)
+	for blobIndex := range blobCount {
+		blob := make([]byte, 0, cellsPerBlob)
+		for columnIndex := range cellsPerBlob {
+			cell := baseVerifiedRoSidecars[columnIndex].Column[blobIndex]
+			blob = append(blob, cell...)
+		}
+
+		blobs = append(blobs, blob)
+
+		for columnIndex := range numberOfColumns {
+			cellProof := baseVerifiedRoSidecars[columnIndex].KzgProofs[blobIndex]
+			cellProofs = append(cellProofs, cellProof)
+		}
+	}
+
+	actual, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
+	require.NoError(t, err)
+
+	// Extract the base verified ro sidecars into sidecars.
+	expected := make([]*ethpb.DataColumnSidecar, 0, len(baseVerifiedRoSidecars))
+	for _, verifiedRoSidecar := range baseVerifiedRoSidecars {
+		expected = append(expected, verifiedRoSidecar.DataColumnSidecar)
+	}
+
+	require.DeepSSZEqual(t, expected, actual)
+}
+
+func TestReconstructBlobs(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	var emptyBlock blocks.ROBlock
+
+	t.Run("no index", func(t *testing.T) {
+		actual, err := peerdas.ReconstructBlobs(emptyBlock, nil, nil)
+		require.NoError(t, err)
+		require.IsNil(t, actual)
+	})
+
+	t.Run("empty input", func(t *testing.T) {
+		_, err := peerdas.ReconstructBlobs(emptyBlock, nil, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("not sorted", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// Arbitrarily change the order of the sidecars.
+		verifiedRoSidecars[3], verifiedRoSidecars[2] = verifiedRoSidecars[2], verifiedRoSidecars[3]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
+	t.Run("not enough columns", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		inputSidecars := verifiedRoSidecars[:fieldparams.CellsPerBlob-1]
+		_, err := peerdas.ReconstructBlobs(emptyBlock, inputSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("index too high", func(t *testing.T) {
+		const blobCount = 3
+
+		roBlock, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
+
+		_, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, []int{1, blobCount})
+		require.ErrorIs(t, err, peerdas.ErrBlobIndexTooHigh)
+	})
+
+	t.Run("not committed to the same block", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{1}))
+		roBlock, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{2}))
+
+		_, err = peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, []int{0})
+		require.ErrorContains(t, peerdas.ErrRootMismatch.Error(), err)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		const blobCount = 3
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+		roBlock, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)
+
+		// Compute cells and proofs from blob sidecars.
+		var wg errgroup.Group
+		blobs := make([][]byte, blobCount)
+		cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		for i := range blobCount {
+			blob := roBlobSidecars[i].Blob
+			blobs[i] = blob
+
+			wg.Go(func() error {
+				var kzgBlob kzg.Blob
+				count := copy(kzgBlob[:], blob)
+				require.Equal(t, len(kzgBlob), count)
+
+				cp, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				if err != nil {
+					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
+				}
+
+				// It is safe for multiple goroutines to concurrently write to the same slice,
+				// as long as they are writing to different indices, which is the case here.
+				cellsAndProofs[i] = cp
+
+				return nil
+			})
+		}
+
+		err := wg.Wait()
+		require.NoError(t, err)
+
+		// Flatten proofs.
+		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
+		for _, cp := range cellsAndProofs {
+			for _, proof := range cp.Proofs {
+				cellProofs = append(cellProofs, proof[:])
+			}
+		}
+
+		// Construct data column sidecars.
+		// It is OK to use the public function `ConstructDataColumnSidecars`, as long as
+		// `TestConstructDataColumnSidecars` tests pass.
+		dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
+		require.NoError(t, err)
+
+		// Convert to verified data column sidecars.
+		verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
+		for _, dataColumnSidecar := range dataColumnSidecars {
+			roSidecar, err := blocks.NewRODataColumn(dataColumnSidecar)
+			require.NoError(t, err)
+
+			verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+			verifiedRoSidecars = append(verifiedRoSidecars, verifiedRoSidecar)
+		}
+
+		indices := []int{2, 0}
+
+		t.Run("no reconstruction needed", func(t *testing.T) {
+			// Reconstruct blobs.
+			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, indices)
+			require.NoError(t, err)
+
+			// Compare blobs.
+			for i, blobIndex := range indices {
+				expected := roBlobSidecars[blobIndex]
+				actual := reconstructedVerifiedRoBlobSidecars[i].ROBlob
+
+				require.DeepSSZEqual(t, expected, actual)
+			}
+		})
+
+		t.Run("reconstruction needed", func(t *testing.T) {
+			// Arbitrarily keep only the even sidecars.
+			filteredSidecars := make([]blocks.VerifiedRODataColumn, 0, len(verifiedRoSidecars)/2)
+			for i := 0; i < len(verifiedRoSidecars); i += 2 {
+				filteredSidecars = append(filteredSidecars, verifiedRoSidecars[i])
+			}
+
+			// Reconstruct blobs.
+			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(roBlock, filteredSidecars, indices)
+			require.NoError(t, err)
+
+			// Compare blobs.
+			for i, blobIndex := range indices {
+				expected := roBlobSidecars[blobIndex]
+				actual := reconstructedVerifiedRoBlobSidecars[i].ROBlob
+
+				require.DeepSSZEqual(t, expected, actual)
+			}
+		})
+
+	})
+
+}

beacon-chain/core/peerdas/utils_test.go

@@ -0,0 +1,69 @@
+package peerdas_test
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+func generateCommitment(blob *kzg.Blob) (*kzg.Commitment, error) {
+	commitment, err := kzg.BlobToKZGCommitment(blob)
+	if err != nil {
+		return nil, errors.Wrap(err, "blob to kzg commitment")
+	}
+
+	return &commitment, nil
+}
+
+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
+}
+
+// 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
+}
+
+// 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)
+}
+
+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)
+}

beacon-chain/core/peerdas/validator.go

@@ -0,0 +1,30 @@
+package peerdas
+
+import (
+	beaconState "github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+// ValidatorsCustodyRequirement returns the number of custody groups regarding the validator indices attached to the beacon node.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/validator.md#validator-custody
+func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validatorsIndex map[primitives.ValidatorIndex]bool) (uint64, error) {
+	totalNodeBalance := uint64(0)
+	for index := range validatorsIndex {
+		validator, err := state.ValidatorAtIndexReadOnly(index)
+		if err != nil {
+			return 0, errors.Wrapf(err, "validator at index %v", index)
+		}
+
+		totalNodeBalance += validator.EffectiveBalance()
+	}
+
+	beaconConfig := params.BeaconConfig()
+	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	validatorCustodyRequirement := beaconConfig.ValidatorCustodyRequirement
+	balancePerAdditionalCustodyGroup := beaconConfig.BalancePerAdditionalCustodyGroup
+
+	count := totalNodeBalance / balancePerAdditionalCustodyGroup
+	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroup), nil
+}

beacon-chain/core/peerdas/validator_test.go

@@ -0,0 +1,55 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestValidatorsCustodyRequirement(t *testing.T) {
+	testCases := []struct {
+		name     string
+		count    uint64
+		expected uint64
+	}{
+		{name: "0 validators", count: 0, expected: 8},
+		{name: "1 validator", count: 1, expected: 8},
+		{name: "8 validators", count: 8, expected: 8},
+		{name: "9 validators", count: 9, expected: 9},
+		{name: "100 validators", count: 100, expected: 100},
+		{name: "128 validators", count: 128, expected: 128},
+		{name: "129 validators", count: 129, expected: 128},
+		{name: "1000 validators", count: 1000, expected: 128},
+	}
+
+	const balance = uint64(32_000_000_000)
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			validators := make([]*ethpb.Validator, 0, tc.count)
+			for range tc.count {
+				validator := &ethpb.Validator{
+					EffectiveBalance: balance,
+				}
+
+				validators = append(validators, validator)
+			}
+
+			validatorsIndex := make(map[primitives.ValidatorIndex]bool)
+			for i := range tc.count {
+				validatorsIndex[primitives.ValidatorIndex(i)] = true
+			}
+
+			beaconState, err := state_native.InitializeFromProtoFulu(&ethpb.BeaconStateElectra{Validators: validators})
+			require.NoError(t, err)
+
+			actual, err := peerdas.ValidatorsCustodyRequirement(beaconState, validatorsIndex)
+			require.NoError(t, err)
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}

beacon-chain/core/peerdas/verification.go

@@ -0,0 +1,65 @@
+package peerdas
+
+import (
+	"bytes"
+
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/pkg/errors"
+)
+
+var (
+	ErrBlockColumnSizeMismatch = errors.New("size mismatch between data column and block")
+	ErrTooManyCommitments      = errors.New("too many commitments")
+	ErrRootMismatch            = errors.New("root mismatch between data column and block")
+	ErrCommitmentMismatch      = errors.New("commitment mismatch between data column and block")
+)
+
+// DataColumnsAlignWithBlock checks if the data columns align with the block.
+func DataColumnsAlignWithBlock(block blocks.ROBlock, dataColumns []blocks.RODataColumn) error {
+	// No data columns before Fulu.
+	if block.Version() < version.Fulu {
+		return nil
+	}
+
+	// Compute the maximum number of blobs per block.
+	blockSlot := block.Block().Slot()
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(blockSlot)
+
+	// Check if the block has not too many commitments.
+	blockCommitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return errors.Wrap(err, "blob KZG commitments")
+	}
+
+	blockCommitmentCount := len(blockCommitments)
+	if blockCommitmentCount > maxBlobsPerBlock {
+		return ErrTooManyCommitments
+	}
+
+	blockRoot := block.Root()
+
+	for _, dataColumn := range dataColumns {
+		// Check if the root of the data column sidecar matches the block root.
+		if dataColumn.BlockRoot() != blockRoot {
+			return ErrRootMismatch
+		}
+
+		// Check if the content length of the data column sidecar matches the block.
+		if len(dataColumn.Column) != blockCommitmentCount ||
+			len(dataColumn.KzgCommitments) != blockCommitmentCount ||
+			len(dataColumn.KzgProofs) != blockCommitmentCount {
+			return ErrBlockColumnSizeMismatch
+		}
+
+		// Check if the commitments of the data column sidecar match the block.
+		for i := range blockCommitments {
+			if !bytes.Equal(blockCommitments[i], dataColumn.KzgCommitments[i]) {
+				return ErrCommitmentMismatch
+			}
+		}
+	}
+
+	return nil
+}

beacon-chain/core/peerdas/verification_test.go

@@ -0,0 +1,77 @@
+package peerdas_test
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+)
+
+func TestDataColumnsAlignWithBlock(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("pre fulu", func(t *testing.T) {
+		block, _ := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 0, 0)
+		err := peerdas.DataColumnsAlignWithBlock(block, nil)
+		require.NoError(t, err)
+	})
+
+	t.Run("too many commitmnets", func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		config := params.BeaconConfig()
+		config.BlobSchedule = []params.BlobScheduleEntry{{}}
+		params.OverrideBeaconConfig(config)
+
+		block, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 3)
+		err := peerdas.DataColumnsAlignWithBlock(block, nil)
+		require.ErrorIs(t, err, peerdas.ErrTooManyCommitments)
+	})
+
+	t.Run("root mismatch", func(t *testing.T) {
+		_, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		block, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 0)
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrRootMismatch)
+	})
+
+	t.Run("column size mismatch", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		sidecars[0].Column = [][]byte{}
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockColumnSizeMismatch)
+	})
+
+	t.Run("KZG commitments size mismatch", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		sidecars[0].KzgCommitments = [][]byte{}
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockColumnSizeMismatch)
+	})
+
+	t.Run("KZG proofs mismatch", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		sidecars[0].KzgProofs = [][]byte{}
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.ErrorIs(t, err, peerdas.ErrBlockColumnSizeMismatch)
+	})
+
+	t.Run("commitment mismatch", func(t *testing.T) {
+		block, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		_, alteredSidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		alteredSidecars[1].KzgCommitments[0][0]++ // Overflow is OK
+		err := peerdas.DataColumnsAlignWithBlock(block, alteredSidecars)
+		require.ErrorIs(t, err, peerdas.ErrCommitmentMismatch)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		block, sidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, 2)
+		err := peerdas.DataColumnsAlignWithBlock(block, sidecars)
+		require.NoError(t, err)
+	})
+}

beacon-chain/core/transition/BUILD.bazel

@@ -46,6 +46,7 @@ go_library(
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",

beacon-chain/core/transition/transition.go

@@ -27,7 +27,9 @@ import (
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing"
 	prysmTrace "github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -291,6 +293,8 @@ func ProcessSlotsCore(ctx context.Context, span trace.Span, state state.BeaconSt
 			tracing.AnnotateError(span, err)
 			return nil, errors.Wrap(err, "failed to upgrade state")
 		}
+
+		logBlobLimitIncrease(state.Slot())
 	}
 	return state, nil
 }
@@ -507,3 +511,19 @@ func ProcessEpochPrecompute(ctx context.Context, state state.BeaconState) (state
 	}
 	return state, nil
 }
+
+func logBlobLimitIncrease(slot primitives.Slot) {
+	if !slots.IsEpochStart(slot) {
+		return
+	}
+
+	epoch := slots.ToEpoch(slot)
+	for _, entry := range params.BeaconConfig().BlobSchedule {
+		if entry.Epoch == epoch {
+			log.WithFields(logrus.Fields{
+				"epoch":     epoch,
+				"blobLimit": entry.MaxBlobsPerBlock,
+			}).Info("Blob limit updated")
+		}
+	}
+}

beacon-chain/db/filesystem/BUILD.bazel

@@ -5,6 +5,9 @@ go_library(
     srcs = [
         "blob.go",
         "cache.go",
+        "data_column.go",
+        "data_column_cache.go",
+        "doc.go",
         "iteration.go",
         "layout.go",
         "layout_by_epoch.go",
@@ -17,6 +20,8 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem",
     visibility = ["//visibility:public"],
     deps = [
+        "//async:go_default_library",
+        "//async/event:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -41,6 +46,8 @@ go_test(
     srcs = [
         "blob_test.go",
         "cache_test.go",
+        "data_column_cache_test.go",
+        "data_column_test.go",
         "iteration_test.go",
         "layout_test.go",
         "migration_test.go",
@@ -50,6 +57,7 @@ go_test(
     deps = [
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/verification:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",

beacon-chain/db/filesystem/data_column_cache.go

@@ -0,0 +1,243 @@
+package filesystem
+
+import (
+	"sync"
+
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/pkg/errors"
+)
+
+var errDataColumnIndexOutOfBounds = errors.New("data column index too high")
+
+// DataColumnStorageSummary represents cached information about the DataColumnSidecars on disk for each root the cache knows about.
+type DataColumnStorageSummary struct {
+	epoch primitives.Epoch
+	mask  [fieldparams.NumberOfColumns]bool
+}
+
+// NewDataColumnStorageSummary creates a new DataColumnStorageSummary for a given epoch and mask.
+func NewDataColumnStorageSummary(epoch primitives.Epoch, mask [fieldparams.NumberOfColumns]bool) DataColumnStorageSummary {
+	return DataColumnStorageSummary{
+		epoch: epoch,
+		mask:  mask,
+	}
+}
+
+// HasIndex returns true if the DataColumnSidecar at the given index is available in the filesystem.
+func (s DataColumnStorageSummary) HasIndex(index uint64) bool {
+	if index >= uint64(fieldparams.NumberOfColumns) {
+		return false
+	}
+	return s.mask[index]
+}
+
+// HasAtLeastOneIndex returns true if at least one of the DataColumnSidecars at the given indices is available in the filesystem.
+func (s DataColumnStorageSummary) HasAtLeastOneIndex(indices []uint64) bool {
+	for _, index := range indices {
+		if s.mask[index] {
+			return true
+		}
+	}
+
+	return false
+}
+
+// Count returns the number of available data columns.
+func (s DataColumnStorageSummary) Count() uint64 {
+	count := uint64(0)
+
+	for _, available := range s.mask {
+		if available {
+			count++
+		}
+	}
+
+	return count
+}
+
+// AllAvailable returns true if we have all data columns for corresponding indices.
+func (s DataColumnStorageSummary) AllAvailable(indices map[uint64]bool) bool {
+	if len(indices) > len(s.mask) {
+		return false
+	}
+
+	for index := range indices {
+		if !s.mask[index] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Stored returns a map of all stored data columns.
+func (s DataColumnStorageSummary) Stored() map[uint64]bool {
+	stored := make(map[uint64]bool, fieldparams.NumberOfColumns)
+	for index, exists := range s.mask {
+		if exists {
+			stored[uint64(index)] = true
+		}
+	}
+
+	return stored
+}
+
+// DataColumnStorageSummarizer can be used to receive a summary of metadata about data columns on disk for a given root.
+// The DataColumnStorageSummary can be used to check which indices (if any) are available for a given block by root.
+type DataColumnStorageSummarizer interface {
+	Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary
+}
+
+type dataColumnStorageSummaryCache struct {
+	mu                 sync.RWMutex
+	dataColumnCount    float64
+	lowestCachedEpoch  primitives.Epoch
+	highestCachedEpoch primitives.Epoch
+	cache              map[[fieldparams.RootLength]byte]DataColumnStorageSummary
+}
+
+var _ DataColumnStorageSummarizer = &dataColumnStorageSummaryCache{}
+
+func newDataColumnStorageSummaryCache() *dataColumnStorageSummaryCache {
+	return &dataColumnStorageSummaryCache{
+		cache:             make(map[[fieldparams.RootLength]byte]DataColumnStorageSummary),
+		lowestCachedEpoch: params.BeaconConfig().FarFutureEpoch,
+	}
+}
+
+// Summary returns the DataColumnStorageSummary for `root`.
+// The DataColumnStorageSummary can be used to check for the presence of DataColumnSidecars based on Index.
+func (sc *dataColumnStorageSummaryCache) Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+
+	return sc.cache[root]
+}
+
+func (sc *dataColumnStorageSummaryCache) HighestEpoch() primitives.Epoch {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+	return sc.highestCachedEpoch
+}
+
+// set updates the cache.
+func (sc *dataColumnStorageSummaryCache) set(dataColumnsIdent DataColumnsIdent) error {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	summary := sc.cache[dataColumnsIdent.Root]
+	summary.epoch = dataColumnsIdent.Epoch
+
+	count := uint64(0)
+	for _, index := range dataColumnsIdent.Indices {
+		if index >= numberOfColumns {
+			return errDataColumnIndexOutOfBounds
+		}
+
+		if summary.mask[index] {
+			continue
+		}
+
+		count++
+
+		summary.mask[index] = true
+		sc.lowestCachedEpoch = min(sc.lowestCachedEpoch, dataColumnsIdent.Epoch)
+		sc.highestCachedEpoch = max(sc.highestCachedEpoch, dataColumnsIdent.Epoch)
+	}
+
+	sc.cache[dataColumnsIdent.Root] = summary
+
+	countFloat := float64(count)
+	sc.dataColumnCount += countFloat
+	dataColumnDiskCount.Set(sc.dataColumnCount)
+	dataColumnWrittenCounter.Add(countFloat)
+
+	return nil
+}
+
+// get returns the DataColumnStorageSummary for the given block root.
+// If the root is not in the cache, the second return value will be false.
+func (sc *dataColumnStorageSummaryCache) get(blockRoot [fieldparams.RootLength]byte) (DataColumnStorageSummary, bool) {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+
+	v, ok := sc.cache[blockRoot]
+	return v, ok
+}
+
+// evict removes the DataColumnStorageSummary for the given block root from the cache.
+func (s *dataColumnStorageSummaryCache) evict(blockRoot [fieldparams.RootLength]byte) int {
+	deleted := 0
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	summary, ok := s.cache[blockRoot]
+	if !ok {
+		return 0
+	}
+
+	for i := range summary.mask {
+		if summary.mask[i] {
+			deleted += 1
+		}
+	}
+
+	delete(s.cache, blockRoot)
+	if deleted > 0 {
+		s.dataColumnCount -= float64(deleted)
+		dataColumnDiskCount.Set(s.dataColumnCount)
+	}
+
+	// The lowest and highest cached epoch may no longer be valid here,
+	// but is not worth the effort to recalculate.
+
+	return deleted
+}
+
+// pruneUpTo removes all entries from the cache up to the given target epoch included.
+func (sc *dataColumnStorageSummaryCache) pruneUpTo(targetEpoch primitives.Epoch) uint64 {
+	sc.mu.Lock()
+	defer sc.mu.Unlock()
+
+	prunedCount := uint64(0)
+	newLowestCachedEpoch := params.BeaconConfig().FarFutureEpoch
+	newHighestCachedEpoch := primitives.Epoch(0)
+
+	for blockRoot, summary := range sc.cache {
+		epoch := summary.epoch
+
+		if epoch > targetEpoch {
+			newLowestCachedEpoch = min(newLowestCachedEpoch, epoch)
+			newHighestCachedEpoch = max(newHighestCachedEpoch, epoch)
+		}
+
+		if epoch <= targetEpoch {
+			for i := range summary.mask {
+				if summary.mask[i] {
+					prunedCount += 1
+				}
+			}
+
+			delete(sc.cache, blockRoot)
+		}
+	}
+
+	if prunedCount > 0 {
+		sc.lowestCachedEpoch = newLowestCachedEpoch
+		sc.highestCachedEpoch = newHighestCachedEpoch
+		sc.dataColumnCount -= float64(prunedCount)
+		dataColumnDiskCount.Set(sc.dataColumnCount)
+	}
+
+	return prunedCount
+}
+
+// clear removes all entries from the cache.
+func (sc *dataColumnStorageSummaryCache) clear() uint64 {
+	return sc.pruneUpTo(params.BeaconConfig().FarFutureEpoch)
+}

beacon-chain/db/filesystem/data_column_cache_test.go

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

beacon-chain/db/filesystem/data_column_test.go

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

beacon-chain/db/filesystem/doc.go

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

beacon-chain/db/filesystem/metrics.go

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

beacon-chain/db/filesystem/mock.go

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

beacon-chain/db/kv/BUILD.bazel

@@ -59,7 +59,7 @@ go_library(
         "//runtime/version:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_dgraph_io_ristretto//:go_default_library",
+        "@com_github_dgraph_io_ristretto_v2//:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_golang_snappy//:go_default_library",

beacon-chain/db/kv/blocks.go

@@ -40,7 +40,7 @@ func (s *Store) Block(ctx context.Context, blockRoot [32]byte) (interfaces.ReadO
 
 func (s *Store) getBlock(ctx context.Context, blockRoot [32]byte, tx *bolt.Tx) (interfaces.ReadOnlySignedBeaconBlock, error) {
 	if v, ok := s.blockCache.Get(string(blockRoot[:])); v != nil && ok {
-		return v.(interfaces.ReadOnlySignedBeaconBlock), nil
+		return v, nil
 	}
 	// This method allows the caller to pass in its tx if one is already open.
 	// Or if a nil value is used, a transaction will be managed intenally.

beacon-chain/db/kv/error.go

@@ -16,9 +16,6 @@ var ErrNotFoundOriginBlockRoot = errors.Wrap(ErrNotFound, "OriginBlockRoot")
 // ErrNotFoundGenesisBlockRoot means no genesis block root was found, indicating the db was not initialized with genesis
 var ErrNotFoundGenesisBlockRoot = errors.Wrap(ErrNotFound, "OriginGenesisRoot")
 
-// ErrNotFoundBackfillBlockRoot is an error specifically for the origin block root getter
-var ErrNotFoundBackfillBlockRoot = errors.Wrap(ErrNotFound, "BackfillBlockRoot")
-
 // ErrNotFoundFeeRecipient is a not found error specifically for the fee recipient getter
 var ErrNotFoundFeeRecipient = errors.Wrap(ErrNotFound, "fee recipient")
 

beacon-chain/db/kv/kv.go

@@ -13,8 +13,10 @@ import (
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/io/file"
-	"github.com/dgraph-io/ristretto"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/dgraph-io/ristretto/v2"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -86,8 +88,8 @@ var blockedBuckets = [][]byte{
 type Store struct {
 	db                  *bolt.DB
 	databasePath        string
-	blockCache          *ristretto.Cache
-	validatorEntryCache *ristretto.Cache
+	blockCache          *ristretto.Cache[string, interfaces.ReadOnlySignedBeaconBlock]
+	validatorEntryCache *ristretto.Cache[[]byte, *ethpb.Validator]
 	stateSummaryCache   *stateSummaryCache
 	ctx                 context.Context
 }
@@ -156,7 +158,7 @@ func NewKVStore(ctx context.Context, dirPath string, opts ...KVStoreOption) (*St
 		return nil, err
 	}
 	boltDB.AllocSize = boltAllocSize
-	blockCache, err := ristretto.NewCache(&ristretto.Config{
+	blockCache, err := ristretto.NewCache(&ristretto.Config[string, interfaces.ReadOnlySignedBeaconBlock]{
 		NumCounters: 1000,           // number of keys to track frequency of (1000).
 		MaxCost:     BlockCacheSize, // maximum cost of cache (1000 Blocks).
 		BufferItems: 64,             // number of keys per Get buffer.
@@ -165,7 +167,7 @@ func NewKVStore(ctx context.Context, dirPath string, opts ...KVStoreOption) (*St
 		return nil, err
 	}
 
-	validatorCache, err := ristretto.NewCache(&ristretto.Config{
+	validatorCache, err := ristretto.NewCache(&ristretto.Config[[]byte, *ethpb.Validator]{
 		NumCounters: NumOfValidatorEntries, // number of entries in cache (2 Million).
 		MaxCost:     ValidatorEntryMaxCost, // maximum size of the cache (64Mb)
 		BufferItems: 64,                    // number of keys per Get buffer.

beacon-chain/db/kv/state.go

@@ -744,14 +744,9 @@ func (s *Store) validatorEntries(ctx context.Context, blockRoot [32]byte) ([]*et
 			// get the entry bytes from the cache or from the DB.
 			v, ok := s.validatorEntryCache.Get(key)
 			if ok {
-				valEntry, vType := v.(*ethpb.Validator)
-				if vType {
-					validatorEntries = append(validatorEntries, valEntry)
-					validatorEntryCacheHit.Inc()
-				} else {
-					// this should never happen, but anyway it's good to bail out if one happens.
-					return errors.New("validator cache does not have proper object type")
-				}
+				valEntry := v
+				validatorEntries = append(validatorEntries, valEntry)
+				validatorEntryCacheHit.Inc()
 			} else {
 				// not in cache, so get it from the DB, decode it and add to the entry list.
 				valEntryBytes := valBkt.Get(key)

beacon-chain/db/kv/state_test.go

@@ -321,15 +321,11 @@ func TestState_CanSaveRetrieveValidatorEntriesFromCache(t *testing.T) {
 		hash, hashErr := stateValidators[i].HashTreeRoot()
 		assert.NoError(t, hashErr)
 
-		data, ok := db.validatorEntryCache.Get(string(hash[:]))
+		data, ok := db.validatorEntryCache.Get(hash[:])
 		assert.Equal(t, true, ok)
 		require.NotNil(t, data)
 
-		valEntry, vType := data.(*ethpb.Validator)
-		assert.Equal(t, true, vType)
-		require.NotNil(t, valEntry)
-
-		require.DeepSSZEqual(t, stateValidators[i], valEntry, "validator entry is not matching")
+		require.DeepSSZEqual(t, stateValidators[i], data, "validator entry is not matching")
 	}
 
 	// check if all the validator entries are still intact in the validator entry bucket.
@@ -447,7 +443,7 @@ func TestState_DeleteState(t *testing.T) {
 		assert.NoError(t, hashErr)
 		v, found := db.validatorEntryCache.Get(hash[:])
 		require.Equal(t, false, found)
-		require.Equal(t, nil, v)
+		require.IsNil(t, v)
 	}
 
 	// check if the index of the first state is deleted.

beacon-chain/execution/log_processing_test.go

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

beacon-chain/execution/service.go

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

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

@@ -267,7 +267,7 @@ func (f *ForkChoice) HighestReceivedBlockSlot() primitives.Slot {
 	return f.store.highestReceivedNode.slot
 }
 
-// HighestReceivedBlockSlotDelay returns the number of slots that the highest
+// HighestReceivedBlockDelay returns the number of slots that the highest
 // received block was late when receiving it
 func (f *ForkChoice) HighestReceivedBlockDelay() primitives.Slot {
 	n := f.store.highestReceivedNode

beacon-chain/node/node.go

@@ -779,6 +779,7 @@ func (b *BeaconNode) registerBlockchainService(fc forkchoice.ForkChoicer, gs *st
 		blockchain.WithPayloadIDCache(b.payloadIDCache),
 		blockchain.WithSyncChecker(b.syncChecker),
 		blockchain.WithSlasherEnabled(b.slasherEnabled),
+		blockchain.WithLightClientStore(b.lcStore),
 	)
 
 	blockchainService, err := blockchain.NewService(b.ctx, opts...)
@@ -864,6 +865,7 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithVerifierWaiter(b.verifyInitWaiter),
 		regularsync.WithAvailableBlocker(bFillStore),
 		regularsync.WithSlasherEnabled(b.slasherEnabled),
+		regularsync.WithLightClientStore(b.lcStore),
 	)
 	return b.services.RegisterService(rs)
 }
@@ -1010,6 +1012,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		BlobStorage:               b.BlobStorage,
 		TrackedValidatorsCache:    b.trackedValidatorsCache,
 		PayloadIDCache:            b.payloadIDCache,
+		LCStore:                   b.lcStore,
 	})
 
 	return b.services.RegisterService(rpcService)
@@ -1029,6 +1032,7 @@ func (b *BeaconNode) registerPrometheusService(_ *cli.Context) error {
 	}
 
 	service := prometheus.NewService(
+		b.cliCtx.Context,
 		fmt.Sprintf("%s:%d", b.cliCtx.String(cmd.MonitoringHostFlag.Name), b.cliCtx.Int(flags.MonitoringPortFlag.Name)),
 		b.services,
 		additionalHandlers...,

beacon-chain/p2p/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "broadcaster.go",
         "config.go",
         "connection_gater.go",
+        "custody.go",
         "dial_relay_node.go",
         "discovery.go",
         "doc.go",
@@ -45,6 +46,7 @@ go_library(
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",
@@ -55,7 +57,9 @@ go_library(
         "//beacon-chain/startup:go_default_library",
         "//cmd/beacon-chain/flags:go_default_library",
         "//config/features:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
         "//container/leaky-bucket:go_default_library",
@@ -116,6 +120,7 @@ go_test(
         "addr_factory_test.go",
         "broadcaster_test.go",
         "connection_gater_test.go",
+        "custody_test.go",
         "dial_relay_node_test.go",
         "discovery_test.go",
         "fork_test.go",
@@ -137,9 +142,12 @@ go_test(
     flaky = True,
     tags = ["requires-network"],
     deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/p2p/encoder:go_default_library",
@@ -152,6 +160,7 @@ go_test(
         "//cmd/beacon-chain/flags:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
         "//container/leaky-bucket:go_default_library",
@@ -162,11 +171,14 @@ 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

@@ -9,10 +9,13 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/altair"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
+	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
@@ -96,7 +99,7 @@ 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 +155,7 @@ 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 +231,7 @@ 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 +246,7 @@ 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 +255,7 @@ 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 +271,184 @@ func (s *Service) internalBroadcastBlob(ctx context.Context, subnet uint64, blob
 	}
 }
 
+func (s *Service) BroadcastLightClientOptimisticUpdate(ctx context.Context, update interfaces.LightClientOptimisticUpdate) error {
+	ctx, span := trace.StartSpan(ctx, "p2p.BroadcastLightClientOptimisticUpdate")
+	defer span.End()
+
+	if update == nil || update.IsNil() {
+		return errors.New("attempted to broadcast nil light client optimistic update")
+	}
+
+	forkDigest, err := forks.ForkDigestFromEpoch(slots.ToEpoch(update.AttestedHeader().Beacon().Slot), s.genesisValidatorsRoot)
+	if err != nil {
+		err := errors.Wrap(err, "could not retrieve fork digest")
+		tracing.AnnotateError(span, err)
+		return err
+	}
+
+	if err := s.broadcastObject(ctx, update, lcOptimisticToTopic(forkDigest)); err != nil {
+		log.WithError(err).Debug("Failed to broadcast light client optimistic update")
+		err := errors.Wrap(err, "could not publish message")
+		tracing.AnnotateError(span, err)
+		return err
+	}
+	log.Debug("Successfully broadcast light client optimistic update")
+
+	return nil
+}
+
+func (s *Service) BroadcastLightClientFinalityUpdate(ctx context.Context, update interfaces.LightClientFinalityUpdate) error {
+	ctx, span := trace.StartSpan(ctx, "p2p.BroadcastLightClientFinalityUpdate")
+	defer span.End()
+
+	if update == nil || update.IsNil() {
+		return errors.New("attempted to broadcast nil light client finality update")
+	}
+
+	forkDigest, err := forks.ForkDigestFromEpoch(slots.ToEpoch(update.AttestedHeader().Beacon().Slot), s.genesisValidatorsRoot)
+	if err != nil {
+		err := errors.Wrap(err, "could not retrieve fork digest")
+		tracing.AnnotateError(span, err)
+		return err
+	}
+
+	if err := s.broadcastObject(ctx, update, lcFinalityToTopic(forkDigest)); err != nil {
+		log.WithError(err).Debug("Failed to broadcast light client finality update")
+		err := errors.Wrap(err, "could not publish message")
+		tracing.AnnotateError(span, err)
+		return err
+	}
+	log.Debug("Successfully broadcast light client finality update")
+
+	return nil
+}
+
+// BroadcastDataColumn broadcasts a data column to the p2p network, the message is assumed to be
+// broadcasted to the current fork and to the input column subnet.
+func (s *Service) BroadcastDataColumn(
+	root [fieldparams.RootLength]byte,
+	dataColumnSubnet uint64,
+	dataColumnSidecar *ethpb.DataColumnSidecar,
+	peersCheckedChans ...chan<- bool, // Used for testing purposes to signal when peers are checked.
+) error {
+	// Add tracing to the function.
+	ctx, span := trace.StartSpan(s.ctx, "p2p.BroadcastDataColumn")
+	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", dataColumnSubnet)
+	}
+
+	// Retrieve the current fork digest.
+	forkDigest, err := s.currentForkDigest()
+	if err != nil {
+		err := errors.Wrap(err, "current fork digest")
+		tracing.AnnotateError(span, err)
+		return err
+	}
+
+	// Non-blocking broadcast, with attempts to discover a column subnet peer if none available.
+	go s.internalBroadcastDataColumn(ctx, root, dataColumnSubnet, dataColumnSidecar, forkDigest, peersCheckedChans)
+
+	return nil
+}
+
+func (s *Service) internalBroadcastDataColumn(
+	ctx context.Context,
+	root [fieldparams.RootLength]byte,
+	columnSubnet uint64,
+	dataColumnSidecar *ethpb.DataColumnSidecar,
+	forkDigest [fieldparams.VersionLength]byte,
+	peersCheckedChans []chan<- bool, // Used for testing purposes to signal when peers are checked.
+) {
+	// Add tracing to the function.
+	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastDataColumn")
+	defer span.End()
+
+	// Increase the number of broadcast attempts.
+	dataColumnSidecarBroadcastAttempts.Inc()
+
+	// Define a one-slot length context timeout.
+	secondsPerSlot := params.BeaconConfig().SecondsPerSlot
+	oneSlot := time.Duration(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
+
+	// Find peers if needed.
+	if err := s.findPeersIfNeeded(ctx, wrappedSubIdx, topic, columnSubnet, peersCheckedChans); err != nil {
+		log.WithError(err).Error("Failed to find peers for data column subnet")
+		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)
+		return
+	}
+
+	header := dataColumnSidecar.SignedBlockHeader.GetHeader()
+	slot := header.GetSlot()
+
+	slotStartTime, err := slots.ToTime(uint64(s.genesisTime.Unix()), slot)
+	if err != nil {
+		log.WithError(err).Error("Failed to convert slot to time")
+	}
+
+	log.WithFields(logrus.Fields{
+		"slot":               slot,
+		"timeSinceSlotStart": time.Since(slotStartTime),
+		"root":               fmt.Sprintf("%#x", root),
+		"columnSubnet":       columnSubnet,
+	}).Debug("Broadcasted data column sidecar")
+
+	// Increase the number of successful broadcasts.
+	dataColumnSidecarBroadcasts.Inc()
+}
+
+func (s *Service) findPeersIfNeeded(
+	ctx context.Context,
+	wrappedSubIdx uint64,
+	topic string,
+	subnet uint64,
+	peersCheckedChans []chan<- bool, // Used for testing purposes to signal when peers are checked.
+) error {
+	s.subnetLocker(wrappedSubIdx).Lock()
+	defer s.subnetLocker(wrappedSubIdx).Unlock()
+
+	// Sending a data column sidecar to only one peer is not ideal,
+	// but it ensures at least one peer receives it.
+	const peerCount = 1
+
+	if s.hasPeerWithSubnet(topic) {
+		// Exit early if we already have peers with this subnet.
+		return nil
+	}
+
+	// Used for testing purposes.
+	if len(peersCheckedChans) > 0 {
+		peersCheckedChans[0] <- true
+	}
+
+	// No peers found, attempt to find peers with this subnet.
+	ok, err := s.FindPeersWithSubnet(ctx, topic, subnet, peerCount)
+	if err != nil {
+		return errors.Wrap(err, "find peers with subnet")
+	}
+	if !ok {
+		return errors.Errorf("failed to find peers for topic %s with subnet %d", topic, subnet)
+	}
+
+	return nil
+}
+
 // 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 +478,26 @@ 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 lcOptimisticToTopic(forkDigest [4]byte) string {
+	return fmt.Sprintf(LightClientOptimisticUpdateTopicFormat, forkDigest)
+}
+
+func lcFinalityToTopic(forkDigest [4]byte) string {
+	return fmt.Sprintf(LightClientFinalityUpdateTopicFormat, forkDigest)
+}
+
+func dataColumnSubnetToTopic(subnet uint64, forkDigest [fieldparams.VersionLength]byte) string {
+	return fmt.Sprintf(DataColumnSubnetTopicFormat, forkDigest, subnet)
+}

beacon-chain/p2p/broadcaster_test.go

@@ -9,18 +9,26 @@ import (
 	"testing"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
+	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	testpb "github.com/OffchainLabs/prysm/v6/proto/testing"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/prysmaticlabs/go-bitfield"
@@ -516,3 +524,233 @@ 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_BroadcastLightClientOptimisticUpdate(t *testing.T) {
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
+	p1.Connect(p2)
+	require.NotEqual(t, 0, len(p1.BHost.Network().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{},
+		}),
+	}
+
+	l := util.NewTestLightClient(t, version.Altair)
+	msg, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+	require.NoError(t, err)
+
+	GossipTypeMapping[reflect.TypeOf(msg)] = LightClientOptimisticUpdateTopicFormat
+	digest, err := forks.ForkDigestFromEpoch(slots.ToEpoch(msg.AttestedHeader().Beacon().Slot), p.genesisValidatorsRoot)
+	require.NoError(t, err)
+	topic := fmt.Sprintf(LightClientOptimisticUpdateTopicFormat, digest)
+
+	// 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()
+
+		incomingMessage, err := sub.Next(ctx)
+		require.NoError(t, err)
+
+		result := &ethpb.LightClientOptimisticUpdateAltair{}
+		require.NoError(t, p.Encoding().DecodeGossip(incomingMessage.Data, result))
+		if !proto.Equal(result, msg.Proto()) {
+			tt.Errorf("Did not receive expected message, got %+v, wanted %+v", result, msg)
+		}
+	}(t)
+
+	// Broadcasting nil should fail.
+	ctx := context.Background()
+	require.ErrorContains(t, "attempted to broadcast nil", p.BroadcastLightClientOptimisticUpdate(ctx, nil))
+	var nilUpdate interfaces.LightClientOptimisticUpdate
+	require.ErrorContains(t, "attempted to broadcast nil", p.BroadcastLightClientOptimisticUpdate(ctx, nilUpdate))
+
+	// Broadcast to peers and wait.
+	require.NoError(t, p.BroadcastLightClientOptimisticUpdate(ctx, msg))
+	if util.WaitTimeout(&wg, 1*time.Second) {
+		t.Error("Failed to receive pubsub within 1s")
+	}
+}
+
+func TestService_BroadcastLightClientFinalityUpdate(t *testing.T) {
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
+	p1.Connect(p2)
+	require.NotEqual(t, 0, len(p1.BHost.Network().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{},
+		}),
+	}
+
+	l := util.NewTestLightClient(t, version.Altair)
+	msg, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+	require.NoError(t, err)
+
+	GossipTypeMapping[reflect.TypeOf(msg)] = LightClientFinalityUpdateTopicFormat
+	digest, err := forks.ForkDigestFromEpoch(slots.ToEpoch(msg.AttestedHeader().Beacon().Slot), p.genesisValidatorsRoot)
+	require.NoError(t, err)
+	topic := fmt.Sprintf(LightClientFinalityUpdateTopicFormat, digest)
+
+	// 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()
+
+		incomingMessage, err := sub.Next(ctx)
+		require.NoError(t, err)
+
+		result := &ethpb.LightClientFinalityUpdateAltair{}
+		require.NoError(t, p.Encoding().DecodeGossip(incomingMessage.Data, result))
+		if !proto.Equal(result, msg.Proto()) {
+			tt.Errorf("Did not receive expected message, got %+v, wanted %+v", result, msg)
+		}
+	}(t)
+
+	// Broadcasting nil should fail.
+	ctx := context.Background()
+	require.ErrorContains(t, "attempted to broadcast nil", p.BroadcastLightClientFinalityUpdate(ctx, nil))
+	var nilUpdate interfaces.LightClientFinalityUpdate
+	require.ErrorContains(t, "attempted to broadcast nil", p.BroadcastLightClientFinalityUpdate(ctx, nilUpdate))
+
+	// Broadcast to peers and wait.
+	require.NoError(t, p.BroadcastLightClientFinalityUpdate(ctx, msg))
+	if util.WaitTimeout(&wg, 1*time.Second) {
+		t.Error("Failed to receive pubsub within 1s")
+	}
+}
+
+func TestService_BroadcastDataColumn(t *testing.T) {
+	const (
+		port        = 2000
+		columnIndex = 12
+		topicFormat = DataColumnSubnetTopicFormat
+	)
+
+	// Load the KZG trust setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	gFlags := new(flags.GlobalFlags)
+	gFlags.MinimumPeersPerSubnet = 1
+	flags.Init(gFlags)
+
+	// Reset config.
+	defer flags.Init(new(flags.GlobalFlags))
+
+	// Create two peers and connect them.
+	p1, p2 := p2ptest.NewTestP2P(t), p2ptest.NewTestP2P(t)
+	p1.Connect(p2)
+
+	// Test the peers are connected.
+	require.NotEqual(t, 0, len(p1.BHost.Network().Peers()), "No peers")
+
+	// Create a host.
+	_, pkey, ipAddr := createHost(t, port)
+
+	p := &Service{
+		ctx:                   context.Background(),
+		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{}}),
+	}
+
+	// Create a listener.
+	listener, err := p.startDiscoveryV5(ipAddr, pkey)
+	require.NoError(t, err)
+
+	p.dv5Listener = listener
+
+	digest, err := p.currentForkDigest()
+	require.NoError(t, err)
+
+	subnet := peerdas.ComputeSubnetForDataColumnSidecar(columnIndex)
+	topic := fmt.Sprintf(topicFormat, digest, subnet)
+
+	roSidecars, _ := util.CreateTestVerifiedRoDataColumnSidecars(t, util.DataColumnsParamsByRoot{{}: {{ColumnIndex: columnIndex}}})
+	sidecar := roSidecars[0].DataColumnSidecar
+
+	// Async listen for the pubsub, must be before the broadcast.
+	var wg sync.WaitGroup
+	wg.Add(1)
+
+	peersChecked := make(chan bool, 0)
+
+	go func(tt *testing.T) {
+		defer wg.Done()
+
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		// Wait for the peers to be checked.
+		<-peersChecked
+
+		// External peer subscribes to the topic.
+		topic += p.Encoding().ProtocolSuffix()
+		sub, err := p2.SubscribeToTopic(topic)
+		require.NoError(tt, err)
+
+		msg, err := sub.Next(ctx)
+		require.NoError(tt, err)
+
+		var result ethpb.DataColumnSidecar
+		require.NoError(tt, p.Encoding().DecodeGossip(msg.Data, &result))
+		require.DeepEqual(tt, &result, sidecar)
+	}(t)
+
+	var emptyRoot [fieldparams.RootLength]byte
+
+	// Attempt to broadcast nil object should fail.
+	err = p.BroadcastDataColumn(emptyRoot, subnet, nil)
+	require.ErrorContains(t, "attempted to broadcast nil", err)
+
+	// Broadcast to peers and wait.
+	err = p.BroadcastDataColumn(emptyRoot, subnet, sidecar, peersChecked)
+	require.NoError(t, err)
+	require.Equal(t, false, util.WaitTimeout(&wg, 1*time.Minute), "Failed to receive pubsub within 1s")
+}