Peer das sync empty requests (#14854 )

* `TestBuildBwbSlices`: Add test case failing with the current implementation. * Fix `buildBwbSlices` to comply with the new test case. * `block_fetchers.go`: Improve logging and godoc. * `DataColumnsRPCMinValidSlot`: Update to Fulu.
Sync: Integrate batch directly in buildBwbSlices. (#14843 )
2026-01-10 05:47:59 -05:00 · 2025-02-03 15:23:04 +01:00 · 2025-01-30 12:11:06 +01:00 · 2025-01-27 15:15:34 +01:00 · 2025-01-22 21:30:32 +01:00 · 2025-01-22 19:56:55 +00:00
605 changed files with 50076 additions and 33637 deletions
--- a/.bazelrc
+++ b/.bazelrc
@@ -22,6 +22,7 @@ coverage --define=coverage_enabled=1
 build --workspace_status_command=./hack/workspace_status.sh

 build --define blst_disabled=false
+build --compilation_mode=opt
 run --define blst_disabled=false

 build:blst_disabled --define blst_disabled=true
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -33,5 +33,5 @@ Fixes #
 **Acknowledgements**

 - [ ] I have read [CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
- [ ] I have made an appropriate entry to [CHANGELOG.md](https://github.com/prysmaticlabs/prysm/blob/develop/CHANGELOG.md).
+- [ ] I have included a uniquely named [changelog fragment file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
 - [ ] I have added a description to this PR with sufficient context for reviewers to understand this PR.
--- a/.github/workflows/changelog.yml
+++ b/.github/workflows/changelog.yml
@@ -1,33 +1,34 @@
-name: CI
+# This workflow will build a golang project
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
+
+name: changelog

 on:
  pull_request:
-    branches:
-      - develop
+    branches: [ "develop" ]

 jobs:
-  changed_files:
-    runs-on: ubuntu-latest 
-    name: Check CHANGELOG.md
+  run-changelog-check:
+    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v4
-      - name: changelog modified
-        id: changelog-modified
+      - name: Checkout source code
+        uses: actions/checkout@v3
+
+      - name: Download unclog binary
+        uses: dsaltares/fetch-gh-release-asset@aa2ab1243d6e0d5b405b973c89fa4d06a2d0fff7 # 1.1.2
+        with:
+          repo: OffchainLabs/unclog
+          version: "tags/v0.1.3"
+          file: "unclog"
+
+      - name: Get new changelog files
+        id: new-changelog-files
        uses: tj-actions/changed-files@v45
        with:
-          files: CHANGELOG.md
+          files: |
+            changelog/**.md

-      - name: List all changed files
+      - name: Run lint command
        env:
-          ALL_CHANGED_FILES: ${{ steps.changelog-modified.outputs.all_changed_files }}
-        run: |
-          if [[ ${ALL_CHANGED_FILES[*]} =~ (^|[[:space:]])"CHANGELOG.md"($|[[:space:]]) ]];
-          then
-            echo "CHANGELOG.md was modified.";
-            exit 0;
-          else
-            echo "CHANGELOG.md was not modified.";
-            echo "Please see CHANGELOG.md and follow the instructions to add your changes to that file."
-            echo "In some rare scenarios, a changelog entry is not required and this CI check can be ignored."
-            exit 1;
-          fi
+          ALL_ADDED_MARKDOWN: ${{ steps.new-changelog-files.outputs.added_files }}
+        run: chmod +x unclog && ./unclog check -fragment-env=ALL_ADDED_MARKDOWN
--- a/.github/workflows/fuzz.yml
+++ b/.github/workflows/fuzz.yml
@@ -16,7 +16,7 @@ jobs:
      - uses: actions/checkout@v3
      - uses: actions/setup-go@v4
        with:
-          go-version: '1.22.3'
+          go-version: '1.22.10'
      - id: list
        uses: shogo82148/actions-go-fuzz/list@v0
        with:
@@ -36,7 +36,7 @@ jobs:
      - uses: actions/checkout@v3
      - uses: actions/setup-go@v4
        with:
-          go-version: '1.22.3'
+          go-version: '1.22.10'
      - uses: shogo82148/actions-go-fuzz/run@v0
        with:
          packages: ${{ matrix.package }}
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -31,7 +31,7 @@ jobs:
      - name: Set up Go 1.22
        uses: actions/setup-go@v4
        with:
-          go-version: '1.22.6'
+          go-version: '1.22.10'
      - name: Run Gosec Security Scanner
        run: | # https://github.com/securego/gosec/issues/469
          export PATH=$PATH:$(go env GOPATH)/bin
@@ -48,7 +48,7 @@ jobs:
      - name: Set up Go 1.22
        uses: actions/setup-go@v4
        with:
-          go-version: '1.22.6'
+          go-version: '1.22.10'
          id: go

      - name: Golangci-lint
@@ -64,7 +64,7 @@ jobs:
      - name: Set up Go 1.x
        uses: actions/setup-go@v4
        with:
-          go-version: '1.22.6'
+          go-version: '1.22.10'
        id: go

      - name: Check out code into the Go module directory
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -6,7 +6,7 @@ run:
    - proto
    - tools/analyzers
  timeout: 10m
-  go: '1.22.6'
+  go: '1.22.10'

 linters:
  enable-all: true
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,23 @@ 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.

-## [Unreleased](https://github.com/prysmaticlabs/prysm/compare/v5.1.2...HEAD)
+## [v5.2.0](https://github.com/prysmaticlabs/prysm/compare/v5.1.2...v5.2.0)
+
+Updating to this release is highly recommended, especially for users running v5.1.1 or v5.1.2.
+This release is **mandatory** for all validator clients using mev-boost with a gas limit increase.
+Without upgrading to this release, validator clients will default to using local execution blocks
+when the gas limit starts to increase.
+
+This release has several fixes and new features. In this release, we have enabled QUIC protocol by
+default, which uses port 13000 for `--p2p-quic-port`. This may be a [breaking change](https://github.com/prysmaticlabs/prysm/pull/14688#issuecomment-2516713826)
+if you're using port 13000 already. This release has some improvements for raising the gas limit,
+but there are [known issues](https://hackmd.io/@ttsao/prysm-gas-limit) with the proposer settings
+file provided gas limit not being respected for mev-boost outsourced blocks. Signalling an increase
+for the gas limit works perfectly for local block production as of this release. See [pumpthegas.org](https://pumpthegas.org) for more info on raising the gas limit on L1.
+
+Notable features:
+- Prysm can reuse blobs from the EL via engine_getBlobsV1, [potentially saving bandwidth](https://hackmd.io/@ttsao/get-blobs-early-results).
+- QUIC is enabled by default. This is a UDP based networking protocol with default port 13000.

 ### Added

@@ -33,8 +49,8 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Added a Prometheus error counter metric for SSE requests.
 - Save light client updates and bootstraps in DB.
 - Added more comprehensive tests for `BlockToLightClientHeader`. [PR](https://github.com/prysmaticlabs/prysm/pull/14699)
- Added an error field to log `Finished building block`.
- Implemented a new `EmptyExecutionPayloadHeader` function.
+- Added light client feature flag check to RPC handlers. [PR](https://github.com/prysmaticlabs/prysm/pull/14736)
+- Light client: Add better error handling. [PR](https://github.com/prysmaticlabs/prysm/pull/14749)

 ### Changed

@@ -79,7 +95,6 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Check kzg commitments align with blobs and proofs for beacon api end point.
 - Revert "Proposer checks gas limit before accepting builder's bid".
 - Updated quic-go to v0.48.2 .
- Process light client finality updates only for new finalized epochs instead of doing it for every block.

 ### Deprecated

@@ -91,7 +106,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Removed finalized validator index cache, no longer needed.
 - Removed validator queue position log on key reload and wait for activation.
 - Removed outdated spectest exclusions for EIP-6110.
- Removed support for starting a beacon node with a deterministic interop genesis state via interop flags. Alteratively, create a genesis state with prysmctl and use `--genesis-state`. This removes about 9Mb (~11%) of unnecessary code and dependencies from the final production binary.
+- Removed support for starting a beacon node with a deterministic interop genesis state via interop flags. Alternatively, create a genesis state with prysmctl and use `--genesis-state`. This removes about 9Mb (~11%) of unnecessary code and dependencies from the final production binary.
 - Removed kzg proof check from blob reconstructor.

 ### Fixed
@@ -105,7 +120,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Fix `--backfill-oldest-slot` handling - this flag was totally broken, the code would always backfill to the default slot [pr](https://github.com/prysmaticlabs/prysm/pull/14584)
 - Fix keymanager API should return corrected error format for malformed tokens
 - Fix keymanager API so that get keys returns an empty response instead of a 500 error when using an unsupported keystore.
- Small log imporvement, removing some redundant or duplicate logs
+- Small log improvement, removing some redundant or duplicate logs
 - EIP7521 - Fixes withdrawal bug by accounting for pending partial withdrawals and deducting already withdrawn amounts from the sweep balance. [PR](https://github.com/prysmaticlabs/prysm/pull/14578)
 - unskip electra merkle spec test
 - Fix panic in validator REST mode when checking status after removing all keys
@@ -135,7 +150,7 @@ meantime we are issuing a patch that recovers from the panic to prevent the node

 This only impacts the v5.1.1 release beacon api event stream endpoints. This endpoint is used by the
 prysm REST mode validator (a feature which requires the validator to be configured to use the beacon
-api intead of prysm's stock grpc endpoints) or accessory software that connects to the events api,
+api instead of prysm's stock grpc endpoints) or accessory software that connects to the events api,
 like https://github.com/ethpandaops/ethereum-metrics-exporter

 ### Fixed 
@@ -378,7 +393,7 @@ Updating to this release is recommended at your earliest convenience, especially
 - use time.NewTimer() to avoid possible memory leaks
 - paranoid underflow protection without error handling
 - Fix CommitteeAssignments to not return every validator
- Fix dependent root retrival genesis case
+- Fix dependent root retrieval genesis case
 - Restrict Dials From Discovery
 - Always close cache warm chan to prevent blocking
 - Keep only the latest value in the health channel
@@ -530,7 +545,7 @@ block profit. If you want to preserve the existing behavior, set --local-block-v
 - handle special case of batch size=1
 - Always Set Inprogress Boolean In Cache
 - Builder APIs: adding headers to post endpoint
- Rename mispelled variable
+- Rename misspelled variable
 - allow blob by root within da period
 - Rewrite Pruning Implementation To Handle EIP 7045
 - Set default fee recipient if tracked val fails
@@ -600,7 +615,7 @@ Known Issues
 - Support beacon_committee_selections
 - /eth/v1/beacon/deposit_snapshot
 - Docker images now have coreutils pre-installed
- da_waited_time_milliseconds tracks total time waiting for data availablity check in ReceiveBlock
+- da_waited_time_milliseconds tracks total time waiting for data availability check in ReceiveBlock
 - blob_written, blob_disk_count, blob_disk_bytes new metrics for tracking blobs on disk
 - Backfill supports blob backfilling
 - Add mainnet deneb fork epoch config
@@ -775,7 +790,7 @@ and Raspberry Pi users.
 - Add Goerli Deneb Fork Epoch
 - Use deneb key for deneb state in saveStatesEfficientInternal
 - Initialize Inactivity Scores Correctly
- Excluse DA wait time for chain processing time
+- Excludes DA wait time for chain processing time
 - Initialize sig cache for verification.Initializer
 - Verify roblobs
 - KZG Commitment inclusion proof verifier
@@ -808,7 +823,7 @@ and Raspberry Pi users.
 - Exit early if blob by root request is empty
 - Request missing blobs while processing pending queue
 - Check blob exists before requesting from peer
- Passing block as arugment for sidecar validation
+- Passing block as argument for sidecar validation

 #### Blob Management

@@ -1105,13 +1120,13 @@ _Most of the PRs here involve shifting our http endpoints to using vanilla http
 - Remove no-op cancel func
 - Update Terms of Service
 - fix head slot in log
- DEPRECTATION: Remove exchange transition configuration call
+- DEPRECATION: Remove exchange transition configuration call
 - fix segmentation fork when Capella for epoch is MaxUint64
 - Return Error Gracefully When Removing 4881 Flag
 - Add zero length check on indices during NextSyncCommitteeIndices
 - Replace Empty Slice Literals with Nil Slices
 - Refactor Error String Formatting According to Go Best Practices
- Fix redundant type converstion
+- Fix redundant type conversion
 - docs: fix typo
 - Add Clarification To Sync Committee Cache
 - Fix typos
@@ -1133,7 +1148,7 @@ small set of users.

 ### Security

-No security issues in thsi release.
+No security issues in this release.

 ## [v4.1.0](https://github.com/prysmaticlabs/prysm/compare/v4.0.8...v4.1.0) - 2023-08-22

@@ -1649,7 +1664,7 @@ notes [here](https://hackmd.io/TtyFurRJRKuklG3n8lMO9Q). This release is **strong
 Note: The released docker images are using the portable version of the blst cryptography library. The Prysm team will
 release docker images with the non-portable blst library as the default image. In the meantime, you can compile docker
 images with blst non-portable locally with the `--define=blst_modern=true` bazel flag, use the "-modern-" assets
-attached to releases, or set environment varaible USE_PRYSM_MODERN=true when using prysm.sh.
+attached to releases, or set environment variable USE_PRYSM_MODERN=true when using prysm.sh.

 ### Added

@@ -1998,7 +2013,7 @@ There are some known issues with this release.
 - Beacon node can bootstrap from non-genesis state (i.e bellatrix state)
 - Refactor bytesutil, add support for go1.20 slice to array conversions
 - Add Span information for attestation record save request
- Matric addition
+- Metric addition
 - Identify invalid signature within batch verification
 - Support for getting consensus values from beacon config
 - EIP-4881: Spec implementation
@@ -2064,7 +2079,7 @@ See [flashbots/mev-boost#404](https://github.com/flashbots/mev-boost/issues/404)
 - Added more histogram metrics for block arrival latency times block_arrival_latency_milliseconds
 - Priority queue RetrieveByKey now uses read lock instead of write lock
 - Use custom types for certain ethclient requests. Fixes an issue when using prysm on gnosis chain.
- Updted forkchoice endpoint /eth/v1/debug/forkchoice (was /eth/v1/debug/beacon/forkchoice)
+- Updated forkchoice endpoint /eth/v1/debug/forkchoice (was /eth/v1/debug/beacon/forkchoice)
 - Include empty fields in builder json client.
 - Computing committee assignments for slots older than the oldest historical root in the beacon state is now forbidden

@@ -2296,7 +2311,7 @@ There are no security updates in this release.
  removed: `GetBeaconState`, `ProduceBlock`, `ListForkChoiceHeads`, `ListBlocks`, `SubmitValidatorRegistration`, `GetBlock`, `ProposeBlock`
 - API: Forkchoice method `GetForkChoice` has been removed.
 - All previously deprecated feature flags have been
-  removed. `--enable-active-balance-cache`, `--correctly-prune-canonical-atts`, `--correctly-insert-orphaned-atts`, `--enable-next-slot-state-cache`, `--enable-batch-gossip-verification`, `--enable-get-block-optimizations`, `--enable-balance-trie-computation`, `--disable-next-slot-state-cache`, `--attestation-aggregation-strategy`, `--attestation-aggregation-force-opt-maxcover`, `--pyrmont`, `--disable-get-block-optimizations`, `--disable-proposer-atts-selection-using-max-cover`, `--disable-optimized-balance-update`, `--disable-active-balance-cache`, `--disable-balance-trie-computation`, `--disable-batch-gossip-verification`, `--disable-correctly-prune-canonical-atts`, `--disable-correctly-insert-orphaned-atts`, `--enable-native-state`, `--enable-peer-scorer`, `--enable-gossip-batch-aggregation`, `--experimental-disable-boundry-checks`
+  removed. `--enable-active-balance-cache`, `--correctly-prune-canonical-atts`, `--correctly-insert-orphaned-atts`, `--enable-next-slot-state-cache`, `--enable-batch-gossip-verification`, `--enable-get-block-optimizations`, `--enable-balance-trie-computation`, `--disable-next-slot-state-cache`, `--attestation-aggregation-strategy`, `--attestation-aggregation-force-opt-maxcover`, `--pyrmont`, `--disable-get-block-optimizations`, `--disable-proposer-atts-selection-using-max-cover`, `--disable-optimized-balance-update`, `--disable-active-balance-cache`, `--disable-balance-trie-computation`, `--disable-batch-gossip-verification`, `--disable-correctly-prune-canonical-atts`, `--disable-correctly-insert-orphaned-atts`, `--enable-native-state`, `--enable-peer-scorer`, `--enable-gossip-batch-aggregation`, `--experimental-disable-boundary-checks`
 - Validator Web API: Removed unused ImportAccounts and DeleteAccounts rpc options

 ### Fixed
@@ -2512,7 +2527,7 @@ There are two known issues with this release:
 - Bellatrix support. See [kiln testnet instructions](https://hackmd.io/OqIoTiQvS9KOIataIFksBQ?view)
 - Weak subjectivity sync / checkpoint sync. This is an experimental feature and may have unintended side effects for
  certain operators serving historical data. See
-  the [documentation](https://docs.prylabs.network/docs/next/prysm-usage/checkpoint-sync) for more details.
+  the [documentation](https://docs.prylabs.network/docs/prysm-usage/checkpoint-sync) for more details.
 - A faster build of blst for beacon chain on linux amd64. Use the environment variable `USE_PRYSM_MODERN=true` with
  prysm.sh, use the "modern" binary, or bazel build with `--define=blst_modern=true`.
 - Vectorized sha256. This may have performance improvements with use of the new flag `--enable-vectorized-htr`.
@@ -2693,7 +2708,7 @@ notes [here](https://github.com/prysmaticlabs/prysm-web-ui/releases/tag/v1.0.0)
 - Added uint64 overflow protection
 - Sync committee pool returns empty slice instead of nil on cache miss
 - Improved description of datadir flag
- Simplied web password requirements
+- Simplified web password requirements
 - Web JWT tokens no longer expire.
 - Updated keymanager protos
 - Watch and update jwt secret when auth token file updated on disk.
@@ -2704,7 +2719,7 @@ notes [here](https://github.com/prysmaticlabs/prysm-web-ui/releases/tag/v1.0.0)
 - Refactor for weak subjectivity sync implementation
 - Update naming for Atlair previous epoch attester
 - Remove duplicate MerkleizeTrieLeaves method.
- Add explict error for validator flag checks on out of bound positions
+- Add explicit error for validator flag checks on out of bound positions
 - Simplify method to check if the beacon chain client should update the justified epoch value.
 - Rename web UI performance endpoint to "summary"
 - Refactor powchain service to be more functional
@@ -2730,7 +2745,7 @@ notes [here](https://github.com/prysmaticlabs/prysm-web-ui/releases/tag/v1.0.0)
  Upstream go-ethereum is now used with familiar go.mod tooling.
 - Removed duplicate aggergation validation p2p pipelines.
 - Metrics calculation removed extra condition
- Removed superflous errors from peer scoring parameters registration
+- Removed superfluous errors from peer scoring parameters registration

 ### Fixed

--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -125,11 +125,11 @@ Navigate to your fork of the repo on GitHub. On the upper left where the current

 **16. Add an entry to CHANGELOG.md.**

-If your change is user facing, you must include a CHANGELOG.md entry. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
+All PRs must must include a changelog fragment file in the `changelog` directory. If your change is not user-facing or should not be mentioned in the changelog for some other reason, you may use the `Ignored` changelog section in your fragment's header to satisfy this requirement without altering the final release changelog. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.

 **17. Create a pull request.**

-Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base master”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.
+Navigate your browser to https://github.com/prysmaticlabs/prysm and click on the new pull request button. In the “base” box on the left, leave the default selection “base develop”, the branch that you want your changes to be applied to. In the “compare” box on the right, select feature-in-progress-branch, the branch containing the changes you want to apply. You will then be asked to answer a few questions about your pull request. After you complete the questionnaire, the pull request will appear in the list of pull requests at https://github.com/prysmaticlabs/prysm/pulls. Ensure that you have added an entry to CHANGELOG.md if your PR is a user-facing change. See the [Maintaining CHANGELOG.md](#maintaining-changelogmd) section for more information.

 **18. Respond to comments by Core Contributors.**

@@ -177,16 +177,10 @@ $ git push myrepo feature-in-progress-branch -f

 ## Maintaining CHANGELOG.md

-This project follows the changelog guidelines from [keepachangelog.com](https://keepachangelog.com/en/1.1.0/).
-
-All PRs with user facing changes should have an entry in the CHANGELOG.md file and the change should be categorized in the appropriate category within the "Unreleased" section. The categories are:
-
-  `Added` for new features.
-  `Changed` for changes in existing functionality.
-  `Deprecated` for soon-to-be removed features.
-  `Removed` for now removed features.
-  `Fixed` for any bug fixes.
-  `Security` in case of vulnerabilities. Please see the [Security Policy](SECURITY.md) for responsible disclosure before adding a change with this category.
+This project follows the changelog guidelines from [keepachangelog.com](https://keepachangelog.com/en/1.1.0/). In order to minimize conflicts and workflow headaches, we chose to implement a changelog management
+strategy that uses changelog "fragment" files, managed by our changelog management tool called `unclog`. Each PR must include a new changelog fragment file in the `changelog` directory, as specified by unclog's
+[README.md](https://github.com/OffchainLabs/unclog?tab=readme-ov-file#what-is-a-changelog-fragment). As the `unclog` README suggests in the [Best Practices](https://github.com/OffchainLabs/unclog?tab=readme-ov-file#best-practices) section, 
+the standard naming convention for your PR's fragment file, to avoid conflicting with another fragment file, is `changelog/<github user name>_<PR branch name>.md`.

 ### Releasing

--- a/INTEROP.md
+++ b/INTEROP.md
@@ -4,7 +4,7 @@ This README details how to setup Prysm for interop testing for usage with other

 > [!IMPORTANT]  
 > This guide is likely to be outdated. The Prysm team does not have capacity to troubleshoot
-> outdated interop guides or instructions. If you experience issues with this guide, please file and
+> outdated interop guides or instructions. If you experience issues with this guide, please file an
 > issue for visibility and propose fixes, if possible.

 ## Installation & Setup
@@ -74,19 +74,19 @@ bazel run //cmd/beacon-chain --config=minimal -- \
 This will start the system with 256 validators. The flags used can be explained as such:

 - `bazel run //cmd/beacon-chain --config=minimal` builds and runs the beacon node in minimal build configuration.
- `--` is a flag divider to distingish between bazel flags and flags that should be passed to the application. All flags and arguments after this divider are passed to the beacon chain.
+- `--` is a flag divider to distinguish between bazel flags and flags that should be passed to the application. All flags and arguments after this divider are passed to the beacon chain.
 - `--minimal-config` tells the beacon node to use minimal network configuration. This is different from the compile time state configuration flag `--config=minimal` and both are required.
 - `--bootstrap-node=` disables the default bootstrap nodes. This prevents the client from attempting to peer with mainnet nodes.
 - `--datadir=/tmp/beacon-chain-minimal-devnet` sets the data directory in a temporary location. Change this to your preferred destination.
 - `--force-clear-db` will delete the beaconchain.db file without confirming with the user. This is helpful for iteratively running local devnets without changing the datadir, but less helpful for one off runs where there was no database in the data directory.
- `--min-sync-peers=0` allows the beacon node to skip initial sync without peers. This is essential because Prysm expects at least a few peers to start start the blockchain.
+- `--min-sync-peers=0` allows the beacon node to skip initial sync without peers. This is essential because Prysm expects at least a few peers to start the blockchain.
 - `--genesis-state=/tmp/genesis.ssz` defines the path to the generated genesis ssz file. The beacon node will use this as the initial genesis state.
 - `--chain-config-file=/tmp/minimal.yaml` defines the path to the yaml file with the chain configuration.

 As soon as the beacon node has started, start the validator in the other terminal window. 

 ```
-bazel run //cmd/validator --config=minimal -- --datadir=/tmp/validator --interopt-num-validators=256 --minimal-config --suggested-fee-recipient=0x8A04d14125D0FDCDc742F4A05C051De07232EDa4
+bazel run //cmd/validator --config=minimal -- --datadir=/tmp/validator --interop-num-validators=256 --minimal-config --suggested-fee-recipient=0x8A04d14125D0FDCDc742F4A05C051De07232EDa4
 ```

 This will launch and kickstart the system with your 256 validators performing their duties accordingly.
--- a/12
+++ b/12
@@ -182,7 +182,7 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_depe
 go_rules_dependencies()

 go_register_toolchains(
-    go_version = "1.22.4",
+    go_version = "1.22.10",
    nogo = "@//:nogo",
 )

@@ -227,7 +227,7 @@ filegroup(
    url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )

-consensus_spec_version = "v1.5.0-alpha.9"
+consensus_spec_version = "v1.5.0-alpha.10"

 bls_test_version = "v0.1.1"

@@ -243,7 +243,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-gHbvlnErUeJGWzW8/8JiVlk28JwmXSMhOzkynEIz+8g=",
+    integrity = "sha256-NtWIhbO/mVMb1edq5jqABL0o8R1tNFiuG8PCMAsUHcs=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/general.tar.gz" % consensus_spec_version,
 )

@@ -259,7 +259,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-hQkQdpm5ng4miGYa5WsOKWa0q8WtZu99Oqbv9QtBeJM=",
+    integrity = "sha256-DFlFlnzls1bBrDm+/xD8NK2ivvkhxR+rSNVLLqScVKc=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/minimal.tar.gz" % consensus_spec_version,
 )

@@ -275,7 +275,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-33sBsmApnJpcyYfR3olKaPB+WC1q00ZKNzHa2TczIxk=",
+    integrity = "sha256-G9ENPF8udZL/BqRHbi60GhFPnZDPZAH6UjcjRiOlvbk=",
    url = "https://github.com/ethereum/consensus-spec-tests/releases/download/%s/mainnet.tar.gz" % consensus_spec_version,
 )

@@ -290,7 +290,7 @@ filegroup(
    visibility = ["//visibility:public"],
 )
    """,
-    integrity = "sha256-GQulBKLc2khpql2K/MxV+NG/d2kAhLXl+gLnKIg7rt4=",
+    integrity = "sha256-ClOLKkmAcEi8/uKi6LDeqthask5+E3sgxVoA0bqmQ0c=",
    strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
    url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )
--- a/api/client/builder/BUILD.bazel
+++ b/api/client/builder/BUILD.bazel
@@ -15,6 +15,7 @@ go_library(
        "//api/client:go_default_library",
        "//api/server/structs:go_default_library",
        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
        "//consensus-types:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/interfaces:go_default_library",
--- a/api/client/builder/client.go
+++ b/api/client/builder/client.go
@@ -282,7 +282,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 	if err != nil {
 		return err
 	}
-	log.WithField("num_registrations", len(svr)).Info("successfully registered validator(s) on builder")
+	log.WithField("registrationCount", len(svr)).Debug("Successfully registered validator(s) on builder")
 	return nil
 }

--- a/api/client/builder/client_test.go
+++ b/api/client/builder/client_test.go
@@ -16,7 +16,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	v1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -124,7 +123,7 @@ func TestClient_RegisterValidator(t *testing.T) {
 func TestClient_GetHeader(t *testing.T) {
 	ctx := context.Background()
 	expectedPath := "/eth/v1/builder/header/23/0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2/0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a"
-	var slot types.Slot = 23
+	var slot primitives.Slot = 23
 	parentHash := ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2")
 	pubkey := ezDecode(t, "0x93247f2209abcacf57b75a51dafae777f9dd38bc7053d1af526f220a7489a6d3a2753e5f3e8b1cfe39b56f43611df74a")
 	t.Run("server error", func(t *testing.T) {
@@ -370,7 +369,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 1, len(withdrawals))
 		assert.Equal(t, uint64(1), withdrawals[0].Index)
-		assert.Equal(t, types.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 	})
@@ -409,7 +408,7 @@ func TestSubmitBlindedBlock(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 1, len(withdrawals))
 		assert.Equal(t, uint64(1), withdrawals[0].Index)
-		assert.Equal(t, types.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
+		assert.Equal(t, primitives.ValidatorIndex(1), withdrawals[0].ValidatorIndex)
 		assert.DeepEqual(t, ezDecode(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943"), withdrawals[0].Address)
 		assert.Equal(t, uint64(1), withdrawals[0].Amount)
 		require.NotNil(t, blobBundle)
--- a/api/client/builder/types.go
+++ b/api/client/builder/types.go
@@ -9,6 +9,7 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	types "github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
@@ -1013,7 +1014,7 @@ func (bb *BuilderBidDeneb) ToProto() (*eth.BuilderBidDeneb, error) {
 	if err != nil {
 		return nil, err
 	}
-	if len(bb.BlobKzgCommitments) > fieldparams.MaxBlobsPerBlock {
+	if len(bb.BlobKzgCommitments) > params.BeaconConfig().DeprecatedMaxBlobsPerBlock {
 		return nil, fmt.Errorf("too many blob commitments: %d", len(bb.BlobKzgCommitments))
 	}
 	kzgCommitments := make([][]byte, len(bb.BlobKzgCommitments))
--- a/api/server/structs/block.go
+++ b/api/server/structs/block.go
@@ -14,6 +14,10 @@ type SignedMessageJsoner interface {
 	SigString() string
 }

+// ----------------------------------------------------------------------------
+// Phase 0
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlock struct {
 	Message   *BeaconBlock `json:"message"`
 	Signature string       `json:"signature"`
@@ -48,6 +52,29 @@ type BeaconBlockBody struct {
 	VoluntaryExits    []*SignedVoluntaryExit `json:"voluntary_exits"`
 }

+type SignedBeaconBlockHeaderContainer struct {
+	Header    *SignedBeaconBlockHeader `json:"header"`
+	Root      string                   `json:"root"`
+	Canonical bool                     `json:"canonical"`
+}
+
+type SignedBeaconBlockHeader struct {
+	Message   *BeaconBlockHeader `json:"message"`
+	Signature string             `json:"signature"`
+}
+
+type BeaconBlockHeader struct {
+	Slot          string `json:"slot"`
+	ProposerIndex string `json:"proposer_index"`
+	ParentRoot    string `json:"parent_root"`
+	StateRoot     string `json:"state_root"`
+	BodyRoot      string `json:"body_root"`
+}
+
+// ----------------------------------------------------------------------------
+// Altair
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockAltair struct {
 	Message   *BeaconBlockAltair `json:"message"`
 	Signature string             `json:"signature"`
@@ -83,6 +110,10 @@ type BeaconBlockBodyAltair struct {
 	SyncAggregate     *SyncAggregate         `json:"sync_aggregate"`
 }

+// ----------------------------------------------------------------------------
+// Bellatrix
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockBellatrix struct {
 	Message   *BeaconBlockBellatrix `json:"message"`
 	Signature string                `json:"signature"`
@@ -155,6 +186,44 @@ type BlindedBeaconBlockBodyBellatrix struct {
 	ExecutionPayloadHeader *ExecutionPayloadHeader `json:"execution_payload_header"`
 }

+type ExecutionPayload struct {
+	ParentHash    string   `json:"parent_hash"`
+	FeeRecipient  string   `json:"fee_recipient"`
+	StateRoot     string   `json:"state_root"`
+	ReceiptsRoot  string   `json:"receipts_root"`
+	LogsBloom     string   `json:"logs_bloom"`
+	PrevRandao    string   `json:"prev_randao"`
+	BlockNumber   string   `json:"block_number"`
+	GasLimit      string   `json:"gas_limit"`
+	GasUsed       string   `json:"gas_used"`
+	Timestamp     string   `json:"timestamp"`
+	ExtraData     string   `json:"extra_data"`
+	BaseFeePerGas string   `json:"base_fee_per_gas"`
+	BlockHash     string   `json:"block_hash"`
+	Transactions  []string `json:"transactions"`
+}
+
+type ExecutionPayloadHeader struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+}
+
+// ----------------------------------------------------------------------------
+// Capella
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockCapella struct {
 	Message   *BeaconBlockCapella `json:"message"`
 	Signature string              `json:"signature"`
@@ -229,6 +298,46 @@ type BlindedBeaconBlockBodyCapella struct {
 	BLSToExecutionChanges  []*SignedBLSToExecutionChange  `json:"bls_to_execution_changes"`
 }

+type ExecutionPayloadCapella struct {
+	ParentHash    string        `json:"parent_hash"`
+	FeeRecipient  string        `json:"fee_recipient"`
+	StateRoot     string        `json:"state_root"`
+	ReceiptsRoot  string        `json:"receipts_root"`
+	LogsBloom     string        `json:"logs_bloom"`
+	PrevRandao    string        `json:"prev_randao"`
+	BlockNumber   string        `json:"block_number"`
+	GasLimit      string        `json:"gas_limit"`
+	GasUsed       string        `json:"gas_used"`
+	Timestamp     string        `json:"timestamp"`
+	ExtraData     string        `json:"extra_data"`
+	BaseFeePerGas string        `json:"base_fee_per_gas"`
+	BlockHash     string        `json:"block_hash"`
+	Transactions  []string      `json:"transactions"`
+	Withdrawals   []*Withdrawal `json:"withdrawals"`
+}
+
+type ExecutionPayloadHeaderCapella struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+	WithdrawalsRoot  string `json:"withdrawals_root"`
+}
+
+// ----------------------------------------------------------------------------
+// Deneb
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockContentsDeneb struct {
 	SignedBlock *SignedBeaconBlockDeneb `json:"signed_block"`
 	KzgProofs   []string                `json:"kzg_proofs"`
@@ -317,6 +426,50 @@ type BlindedBeaconBlockBodyDeneb struct {
 	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
 }

+type ExecutionPayloadDeneb struct {
+	ParentHash    string        `json:"parent_hash"`
+	FeeRecipient  string        `json:"fee_recipient"`
+	StateRoot     string        `json:"state_root"`
+	ReceiptsRoot  string        `json:"receipts_root"`
+	LogsBloom     string        `json:"logs_bloom"`
+	PrevRandao    string        `json:"prev_randao"`
+	BlockNumber   string        `json:"block_number"`
+	GasLimit      string        `json:"gas_limit"`
+	GasUsed       string        `json:"gas_used"`
+	Timestamp     string        `json:"timestamp"`
+	ExtraData     string        `json:"extra_data"`
+	BaseFeePerGas string        `json:"base_fee_per_gas"`
+	BlockHash     string        `json:"block_hash"`
+	Transactions  []string      `json:"transactions"`
+	Withdrawals   []*Withdrawal `json:"withdrawals"`
+	BlobGasUsed   string        `json:"blob_gas_used"`
+	ExcessBlobGas string        `json:"excess_blob_gas"`
+}
+
+type ExecutionPayloadHeaderDeneb struct {
+	ParentHash       string `json:"parent_hash"`
+	FeeRecipient     string `json:"fee_recipient"`
+	StateRoot        string `json:"state_root"`
+	ReceiptsRoot     string `json:"receipts_root"`
+	LogsBloom        string `json:"logs_bloom"`
+	PrevRandao       string `json:"prev_randao"`
+	BlockNumber      string `json:"block_number"`
+	GasLimit         string `json:"gas_limit"`
+	GasUsed          string `json:"gas_used"`
+	Timestamp        string `json:"timestamp"`
+	ExtraData        string `json:"extra_data"`
+	BaseFeePerGas    string `json:"base_fee_per_gas"`
+	BlockHash        string `json:"block_hash"`
+	TransactionsRoot string `json:"transactions_root"`
+	WithdrawalsRoot  string `json:"withdrawals_root"`
+	BlobGasUsed      string `json:"blob_gas_used"`
+	ExcessBlobGas    string `json:"excess_blob_gas"`
+}
+
+// ----------------------------------------------------------------------------
+// Electra
+// ----------------------------------------------------------------------------
+
 type SignedBeaconBlockContentsElectra struct {
 	SignedBlock *SignedBeaconBlockElectra `json:"signed_block"`
 	KzgProofs   []string                  `json:"kzg_proofs"`
@@ -362,7 +515,7 @@ type BeaconBlockBodyElectra struct {
 	Deposits              []*Deposit                    `json:"deposits"`
 	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
 	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
-	ExecutionPayload      *ExecutionPayloadElectra      `json:"execution_payload"`
+	ExecutionPayload      *ExecutionPayloadDeneb        `json:"execution_payload"`
 	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
 	BlobKzgCommitments    []string                      `json:"blob_kzg_commitments"`
 	ExecutionRequests     *ExecutionRequests            `json:"execution_requests"`
@@ -392,156 +545,119 @@ func (s *SignedBlindedBeaconBlockElectra) SigString() string {
 }

 type BlindedBeaconBlockBodyElectra struct {
-	RandaoReveal           string                         `json:"randao_reveal"`
-	Eth1Data               *Eth1Data                      `json:"eth1_data"`
-	Graffiti               string                         `json:"graffiti"`
-	ProposerSlashings      []*ProposerSlashing            `json:"proposer_slashings"`
-	AttesterSlashings      []*AttesterSlashingElectra     `json:"attester_slashings"`
-	Attestations           []*AttestationElectra          `json:"attestations"`
-	Deposits               []*Deposit                     `json:"deposits"`
-	VoluntaryExits         []*SignedVoluntaryExit         `json:"voluntary_exits"`
-	SyncAggregate          *SyncAggregate                 `json:"sync_aggregate"`
-	ExecutionPayloadHeader *ExecutionPayloadHeaderElectra `json:"execution_payload_header"`
-	BLSToExecutionChanges  []*SignedBLSToExecutionChange  `json:"bls_to_execution_changes"`
-	BlobKzgCommitments     []string                       `json:"blob_kzg_commitments"`
-	ExecutionRequests      *ExecutionRequests             `json:"execution_requests"`
+	RandaoReveal           string                        `json:"randao_reveal"`
+	Eth1Data               *Eth1Data                     `json:"eth1_data"`
+	Graffiti               string                        `json:"graffiti"`
+	ProposerSlashings      []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings      []*AttesterSlashingElectra    `json:"attester_slashings"`
+	Attestations           []*AttestationElectra         `json:"attestations"`
+	Deposits               []*Deposit                    `json:"deposits"`
+	VoluntaryExits         []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate          *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayloadHeader *ExecutionPayloadHeaderDeneb  `json:"execution_payload_header"`
+	BLSToExecutionChanges  []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
+	ExecutionRequests      *ExecutionRequests            `json:"execution_requests"`
 }

-type SignedBeaconBlockHeaderContainer struct {
-	Header    *SignedBeaconBlockHeader `json:"header"`
-	Root      string                   `json:"root"`
-	Canonical bool                     `json:"canonical"`
+type (
+	ExecutionRequests struct {
+		Deposits       []*DepositRequest       `json:"deposits"`
+		Withdrawals    []*WithdrawalRequest    `json:"withdrawals"`
+		Consolidations []*ConsolidationRequest `json:"consolidations"`
+	}
+)
+
+// ----------------------------------------------------------------------------
+// Fulu
+// ----------------------------------------------------------------------------
+
+type SignedBeaconBlockContentsFulu struct {
+	SignedBlock *SignedBeaconBlockFulu `json:"signed_block"`
+	KzgProofs   []string               `json:"kzg_proofs"`
+	Blobs       []string               `json:"blobs"`
 }

-type SignedBeaconBlockHeader struct {
-	Message   *BeaconBlockHeader `json:"message"`
-	Signature string             `json:"signature"`
+type BeaconBlockContentsFulu struct {
+	Block     *BeaconBlockFulu `json:"block"`
+	KzgProofs []string         `json:"kzg_proofs"`
+	Blobs     []string         `json:"blobs"`
 }

-type BeaconBlockHeader struct {
-	Slot          string `json:"slot"`
-	ProposerIndex string `json:"proposer_index"`
-	ParentRoot    string `json:"parent_root"`
-	StateRoot     string `json:"state_root"`
-	BodyRoot      string `json:"body_root"`
+type SignedBeaconBlockFulu struct {
+	Message   *BeaconBlockFulu `json:"message"`
+	Signature string           `json:"signature"`
 }

-type ExecutionPayload struct {
-	ParentHash    string   `json:"parent_hash"`
-	FeeRecipient  string   `json:"fee_recipient"`
-	StateRoot     string   `json:"state_root"`
-	ReceiptsRoot  string   `json:"receipts_root"`
-	LogsBloom     string   `json:"logs_bloom"`
-	PrevRandao    string   `json:"prev_randao"`
-	BlockNumber   string   `json:"block_number"`
-	GasLimit      string   `json:"gas_limit"`
-	GasUsed       string   `json:"gas_used"`
-	Timestamp     string   `json:"timestamp"`
-	ExtraData     string   `json:"extra_data"`
-	BaseFeePerGas string   `json:"base_fee_per_gas"`
-	BlockHash     string   `json:"block_hash"`
-	Transactions  []string `json:"transactions"`
+var _ SignedMessageJsoner = &SignedBeaconBlockFulu{}
+
+func (s *SignedBeaconBlockFulu) MessageRawJson() ([]byte, error) {
+	return json.Marshal(s.Message)
 }

-type ExecutionPayloadHeader struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
+func (s *SignedBeaconBlockFulu) SigString() string {
+	return s.Signature
 }

-type ExecutionPayloadCapella struct {
-	ParentHash    string        `json:"parent_hash"`
-	FeeRecipient  string        `json:"fee_recipient"`
-	StateRoot     string        `json:"state_root"`
-	ReceiptsRoot  string        `json:"receipts_root"`
-	LogsBloom     string        `json:"logs_bloom"`
-	PrevRandao    string        `json:"prev_randao"`
-	BlockNumber   string        `json:"block_number"`
-	GasLimit      string        `json:"gas_limit"`
-	GasUsed       string        `json:"gas_used"`
-	Timestamp     string        `json:"timestamp"`
-	ExtraData     string        `json:"extra_data"`
-	BaseFeePerGas string        `json:"base_fee_per_gas"`
-	BlockHash     string        `json:"block_hash"`
-	Transactions  []string      `json:"transactions"`
-	Withdrawals   []*Withdrawal `json:"withdrawals"`
+type BeaconBlockFulu struct {
+	Slot          string               `json:"slot"`
+	ProposerIndex string               `json:"proposer_index"`
+	ParentRoot    string               `json:"parent_root"`
+	StateRoot     string               `json:"state_root"`
+	Body          *BeaconBlockBodyFulu `json:"body"`
 }

-type ExecutionPayloadHeaderCapella struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-	WithdrawalsRoot  string `json:"withdrawals_root"`
+type BeaconBlockBodyFulu struct {
+	RandaoReveal          string                        `json:"randao_reveal"`
+	Eth1Data              *Eth1Data                     `json:"eth1_data"`
+	Graffiti              string                        `json:"graffiti"`
+	ProposerSlashings     []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings     []*AttesterSlashingElectra    `json:"attester_slashings"`
+	Attestations          []*AttestationElectra         `json:"attestations"`
+	Deposits              []*Deposit                    `json:"deposits"`
+	VoluntaryExits        []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate         *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayload      *ExecutionPayloadDeneb        `json:"execution_payload"`
+	BLSToExecutionChanges []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+	BlobKzgCommitments    []string                      `json:"blob_kzg_commitments"`
+	ExecutionRequests     *ExecutionRequests            `json:"execution_requests"`
 }

-type ExecutionPayloadDeneb struct {
-	ParentHash    string        `json:"parent_hash"`
-	FeeRecipient  string        `json:"fee_recipient"`
-	StateRoot     string        `json:"state_root"`
-	ReceiptsRoot  string        `json:"receipts_root"`
-	LogsBloom     string        `json:"logs_bloom"`
-	PrevRandao    string        `json:"prev_randao"`
-	BlockNumber   string        `json:"block_number"`
-	GasLimit      string        `json:"gas_limit"`
-	GasUsed       string        `json:"gas_used"`
-	Timestamp     string        `json:"timestamp"`
-	ExtraData     string        `json:"extra_data"`
-	BaseFeePerGas string        `json:"base_fee_per_gas"`
-	BlockHash     string        `json:"block_hash"`
-	Transactions  []string      `json:"transactions"`
-	Withdrawals   []*Withdrawal `json:"withdrawals"`
-	BlobGasUsed   string        `json:"blob_gas_used"`
-	ExcessBlobGas string        `json:"excess_blob_gas"`
+type BlindedBeaconBlockFulu struct {
+	Slot          string                      `json:"slot"`
+	ProposerIndex string                      `json:"proposer_index"`
+	ParentRoot    string                      `json:"parent_root"`
+	StateRoot     string                      `json:"state_root"`
+	Body          *BlindedBeaconBlockBodyFulu `json:"body"`
 }

-type ExecutionPayloadElectra = ExecutionPayloadDeneb
-
-type ExecutionPayloadHeaderDeneb struct {
-	ParentHash       string `json:"parent_hash"`
-	FeeRecipient     string `json:"fee_recipient"`
-	StateRoot        string `json:"state_root"`
-	ReceiptsRoot     string `json:"receipts_root"`
-	LogsBloom        string `json:"logs_bloom"`
-	PrevRandao       string `json:"prev_randao"`
-	BlockNumber      string `json:"block_number"`
-	GasLimit         string `json:"gas_limit"`
-	GasUsed          string `json:"gas_used"`
-	Timestamp        string `json:"timestamp"`
-	ExtraData        string `json:"extra_data"`
-	BaseFeePerGas    string `json:"base_fee_per_gas"`
-	BlockHash        string `json:"block_hash"`
-	TransactionsRoot string `json:"transactions_root"`
-	WithdrawalsRoot  string `json:"withdrawals_root"`
-	BlobGasUsed      string `json:"blob_gas_used"`
-	ExcessBlobGas    string `json:"excess_blob_gas"`
+type SignedBlindedBeaconBlockFulu struct {
+	Message   *BlindedBeaconBlockFulu `json:"message"`
+	Signature string                  `json:"signature"`
 }

-type ExecutionPayloadHeaderElectra = ExecutionPayloadHeaderDeneb
+var _ SignedMessageJsoner = &SignedBlindedBeaconBlockFulu{}

-type ExecutionRequests struct {
-	Deposits       []*DepositRequest       `json:"deposits"`
-	Withdrawals    []*WithdrawalRequest    `json:"withdrawals"`
-	Consolidations []*ConsolidationRequest `json:"consolidations"`
+func (s *SignedBlindedBeaconBlockFulu) MessageRawJson() ([]byte, error) {
+	return json.Marshal(s.Message)
+}
+
+func (s *SignedBlindedBeaconBlockFulu) SigString() string {
+	return s.Signature
+}
+
+type BlindedBeaconBlockBodyFulu struct {
+	RandaoReveal           string                        `json:"randao_reveal"`
+	Eth1Data               *Eth1Data                     `json:"eth1_data"`
+	Graffiti               string                        `json:"graffiti"`
+	ProposerSlashings      []*ProposerSlashing           `json:"proposer_slashings"`
+	AttesterSlashings      []*AttesterSlashingElectra    `json:"attester_slashings"`
+	Attestations           []*AttestationElectra         `json:"attestations"`
+	Deposits               []*Deposit                    `json:"deposits"`
+	VoluntaryExits         []*SignedVoluntaryExit        `json:"voluntary_exits"`
+	SyncAggregate          *SyncAggregate                `json:"sync_aggregate"`
+	ExecutionPayloadHeader *ExecutionPayloadHeaderDeneb  `json:"execution_payload_header"`
+	BLSToExecutionChanges  []*SignedBLSToExecutionChange `json:"bls_to_execution_changes"`
+	BlobKzgCommitments     []string                      `json:"blob_kzg_commitments"`
+	ExecutionRequests      *ExecutionRequests            `json:"execution_requests"`
 }
--- a/api/server/structs/conversions.go
+++ b/api/server/structs/conversions.go
@@ -432,6 +432,32 @@ func (a *AttestationElectra) ToConsensus() (*eth.AttestationElectra, error) {
 	}, nil
 }

+func (a *SingleAttestation) ToConsensus() (*eth.SingleAttestation, error) {
+	ci, err := strconv.ParseUint(a.CommitteeIndex, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "CommitteeIndex")
+	}
+	ai, err := strconv.ParseUint(a.AttesterIndex, 10, 64)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "AttesterIndex")
+	}
+	data, err := a.Data.ToConsensus()
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Data")
+	}
+	sig, err := bytesutil.DecodeHexWithLength(a.Signature, fieldparams.BLSSignatureLength)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
+
+	return &eth.SingleAttestation{
+		CommitteeId:   primitives.CommitteeIndex(ci),
+		AttesterIndex: primitives.ValidatorIndex(ai),
+		Data:          data,
+		Signature:     sig,
+	}, nil
+}
+
 func AttElectraFromConsensus(a *eth.AttestationElectra) *AttestationElectra {
 	return &AttestationElectra{
 		AggregationBits: hexutil.Encode(a.AggregationBits),
--- a/api/server/structs/conversions_block.go
+++ b/api/server/structs/conversions_block.go
--- a/api/server/structs/conversions_lightclient.go
+++ b/api/server/structs/conversions_lightclient.go
@@ -176,9 +176,9 @@ func lightClientHeaderToJSON(header interfaces.LightClientHeader) (json.RawMessa
 		if err != nil {
 			return nil, err
 		}
-		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderElectra)
+		ex, ok := exInterface.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
 		if !ok {
-			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderElectra{})
+			return nil, fmt.Errorf("execution data is not %T", &enginev1.ExecutionPayloadHeaderDeneb{})
 		}
 		execution, err := ExecutionPayloadHeaderElectraFromConsensus(ex)
 		if err != nil {
--- a/api/server/structs/conversions_state.go
+++ b/api/server/structs/conversions_state.go
@@ -11,6 +11,10 @@ import (

 var errPayloadHeaderNotFound = errors.New("expected payload header not found")

+// ----------------------------------------------------------------------------
+// Phase 0
+// ----------------------------------------------------------------------------
+
 func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -97,6 +101,10 @@ func BeaconStateFromConsensus(st beaconState.BeaconState) (*BeaconState, error)
 	}, nil
 }

+// ----------------------------------------------------------------------------
+// Altair
+// ----------------------------------------------------------------------------
+
 func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAltair, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -202,6 +210,10 @@ func BeaconStateAltairFromConsensus(st beaconState.BeaconState) (*BeaconStateAlt
 	}, nil
 }

+// ----------------------------------------------------------------------------
+// Bellatrix
+// ----------------------------------------------------------------------------
+
 func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconStateBellatrix, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -320,6 +332,10 @@ func BeaconStateBellatrixFromConsensus(st beaconState.BeaconState) (*BeaconState
 	}, nil
 }

+// ----------------------------------------------------------------------------
+// Capella
+// ----------------------------------------------------------------------------
+
 func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCapella, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -457,6 +473,10 @@ func BeaconStateCapellaFromConsensus(st beaconState.BeaconState) (*BeaconStateCa
 	}, nil
 }

+// ----------------------------------------------------------------------------
+// Deneb
+// ----------------------------------------------------------------------------
+
 func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDeneb, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -594,6 +614,10 @@ func BeaconStateDenebFromConsensus(st beaconState.BeaconState) (*BeaconStateDene
 	}, nil
 }

+// ----------------------------------------------------------------------------
+// Electra
+// ----------------------------------------------------------------------------
+
 func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateElectra, error) {
 	srcBr := st.BlockRoots()
 	br := make([]string, len(srcBr))
@@ -775,3 +799,189 @@ func BeaconStateElectraFromConsensus(st beaconState.BeaconState) (*BeaconStateEl
 		PendingConsolidations:         PendingConsolidationsFromConsensus(pc),
 	}, nil
 }
+
+// ----------------------------------------------------------------------------
+// Fulu
+// ----------------------------------------------------------------------------
+
+func BeaconStateFuluFromConsensus(st beaconState.BeaconState) (*BeaconStateFulu, error) {
+	srcBr := st.BlockRoots()
+	br := make([]string, len(srcBr))
+	for i, r := range srcBr {
+		br[i] = hexutil.Encode(r)
+	}
+	srcSr := st.StateRoots()
+	sr := make([]string, len(srcSr))
+	for i, r := range srcSr {
+		sr[i] = hexutil.Encode(r)
+	}
+	srcHr, err := st.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
+	hr := make([]string, len(srcHr))
+	for i, r := range srcHr {
+		hr[i] = hexutil.Encode(r)
+	}
+	srcVotes := st.Eth1DataVotes()
+	votes := make([]*Eth1Data, len(srcVotes))
+	for i, e := range srcVotes {
+		votes[i] = Eth1DataFromConsensus(e)
+	}
+	srcVals := st.Validators()
+	vals := make([]*Validator, len(srcVals))
+	for i, v := range srcVals {
+		vals[i] = ValidatorFromConsensus(v)
+	}
+	srcBals := st.Balances()
+	bals := make([]string, len(srcBals))
+	for i, b := range srcBals {
+		bals[i] = fmt.Sprintf("%d", b)
+	}
+	srcRm := st.RandaoMixes()
+	rm := make([]string, len(srcRm))
+	for i, m := range srcRm {
+		rm[i] = hexutil.Encode(m)
+	}
+	srcSlashings := st.Slashings()
+	slashings := make([]string, len(srcSlashings))
+	for i, s := range srcSlashings {
+		slashings[i] = fmt.Sprintf("%d", s)
+	}
+	srcPrevPart, err := st.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	prevPart := make([]string, len(srcPrevPart))
+	for i, p := range srcPrevPart {
+		prevPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcCurrPart, err := st.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currPart := make([]string, len(srcCurrPart))
+	for i, p := range srcCurrPart {
+		currPart[i] = fmt.Sprintf("%d", p)
+	}
+	srcIs, err := st.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	is := make([]string, len(srcIs))
+	for i, s := range srcIs {
+		is[i] = fmt.Sprintf("%d", s)
+	}
+	currSc, err := st.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSc, err := st.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	execData, err := st.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	srcPayload, ok := execData.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+	if !ok {
+		return nil, errPayloadHeaderNotFound
+	}
+	payload, err := ExecutionPayloadHeaderElectraFromConsensus(srcPayload)
+	if err != nil {
+		return nil, err
+	}
+	srcHs, err := st.HistoricalSummaries()
+	if err != nil {
+		return nil, err
+	}
+	hs := make([]*HistoricalSummary, len(srcHs))
+	for i, s := range srcHs {
+		hs[i] = HistoricalSummaryFromConsensus(s)
+	}
+	nwi, err := st.NextWithdrawalIndex()
+	if err != nil {
+		return nil, err
+	}
+	nwvi, err := st.NextWithdrawalValidatorIndex()
+	if err != nil {
+		return nil, err
+	}
+	drsi, err := st.DepositRequestsStartIndex()
+	if err != nil {
+		return nil, err
+	}
+	dbtc, err := st.DepositBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	ebtc, err := st.ExitBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	eee, err := st.EarliestExitEpoch()
+	if err != nil {
+		return nil, err
+	}
+	cbtc, err := st.ConsolidationBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	ece, err := st.EarliestConsolidationEpoch()
+	if err != nil {
+		return nil, err
+	}
+	pbd, err := st.PendingDeposits()
+	if err != nil {
+		return nil, err
+	}
+	ppw, err := st.PendingPartialWithdrawals()
+	if err != nil {
+		return nil, err
+	}
+	pc, err := st.PendingConsolidations()
+	if err != nil {
+		return nil, err
+	}
+
+	return &BeaconStateFulu{
+		GenesisTime:                   fmt.Sprintf("%d", st.GenesisTime()),
+		GenesisValidatorsRoot:         hexutil.Encode(st.GenesisValidatorsRoot()),
+		Slot:                          fmt.Sprintf("%d", st.Slot()),
+		Fork:                          ForkFromConsensus(st.Fork()),
+		LatestBlockHeader:             BeaconBlockHeaderFromConsensus(st.LatestBlockHeader()),
+		BlockRoots:                    br,
+		StateRoots:                    sr,
+		HistoricalRoots:               hr,
+		Eth1Data:                      Eth1DataFromConsensus(st.Eth1Data()),
+		Eth1DataVotes:                 votes,
+		Eth1DepositIndex:              fmt.Sprintf("%d", st.Eth1DepositIndex()),
+		Validators:                    vals,
+		Balances:                      bals,
+		RandaoMixes:                   rm,
+		Slashings:                     slashings,
+		PreviousEpochParticipation:    prevPart,
+		CurrentEpochParticipation:     currPart,
+		JustificationBits:             hexutil.Encode(st.JustificationBits()),
+		PreviousJustifiedCheckpoint:   CheckpointFromConsensus(st.PreviousJustifiedCheckpoint()),
+		CurrentJustifiedCheckpoint:    CheckpointFromConsensus(st.CurrentJustifiedCheckpoint()),
+		FinalizedCheckpoint:           CheckpointFromConsensus(st.FinalizedCheckpoint()),
+		InactivityScores:              is,
+		CurrentSyncCommittee:          SyncCommitteeFromConsensus(currSc),
+		NextSyncCommittee:             SyncCommitteeFromConsensus(nextSc),
+		LatestExecutionPayloadHeader:  payload,
+		NextWithdrawalIndex:           fmt.Sprintf("%d", nwi),
+		NextWithdrawalValidatorIndex:  fmt.Sprintf("%d", nwvi),
+		HistoricalSummaries:           hs,
+		DepositRequestsStartIndex:     fmt.Sprintf("%d", drsi),
+		DepositBalanceToConsume:       fmt.Sprintf("%d", dbtc),
+		ExitBalanceToConsume:          fmt.Sprintf("%d", ebtc),
+		EarliestExitEpoch:             fmt.Sprintf("%d", eee),
+		ConsolidationBalanceToConsume: fmt.Sprintf("%d", cbtc),
+		EarliestConsolidationEpoch:    fmt.Sprintf("%d", ece),
+		PendingDeposits:               PendingDepositsFromConsensus(pbd),
+		PendingPartialWithdrawals:     PendingPartialWithdrawalsFromConsensus(ppw),
+		PendingConsolidations:         PendingConsolidationsFromConsensus(pc),
+	}, nil
+}
--- a/api/server/structs/other.go
+++ b/api/server/structs/other.go
@@ -36,6 +36,13 @@ type AttestationElectra struct {
 	CommitteeBits   string           `json:"committee_bits"`
 }

+type SingleAttestation struct {
+	CommitteeIndex string           `json:"committee_index"`
+	AttesterIndex  string           `json:"attester_index"`
+	Data           *AttestationData `json:"data"`
+	Signature      string           `json:"signature"`
+}
+
 type AttestationData struct {
 	Slot            string      `json:"slot"`
 	CommitteeIndex  string      `json:"index"`
--- a/api/server/structs/state.go
+++ b/api/server/structs/state.go
@@ -142,41 +142,81 @@ type BeaconStateDeneb struct {
 }

 type BeaconStateElectra struct {
-	GenesisTime                   string                         `json:"genesis_time"`
-	GenesisValidatorsRoot         string                         `json:"genesis_validators_root"`
-	Slot                          string                         `json:"slot"`
-	Fork                          *Fork                          `json:"fork"`
-	LatestBlockHeader             *BeaconBlockHeader             `json:"latest_block_header"`
-	BlockRoots                    []string                       `json:"block_roots"`
-	StateRoots                    []string                       `json:"state_roots"`
-	HistoricalRoots               []string                       `json:"historical_roots"`
-	Eth1Data                      *Eth1Data                      `json:"eth1_data"`
-	Eth1DataVotes                 []*Eth1Data                    `json:"eth1_data_votes"`
-	Eth1DepositIndex              string                         `json:"eth1_deposit_index"`
-	Validators                    []*Validator                   `json:"validators"`
-	Balances                      []string                       `json:"balances"`
-	RandaoMixes                   []string                       `json:"randao_mixes"`
-	Slashings                     []string                       `json:"slashings"`
-	PreviousEpochParticipation    []string                       `json:"previous_epoch_participation"`
-	CurrentEpochParticipation     []string                       `json:"current_epoch_participation"`
-	JustificationBits             string                         `json:"justification_bits"`
-	PreviousJustifiedCheckpoint   *Checkpoint                    `json:"previous_justified_checkpoint"`
-	CurrentJustifiedCheckpoint    *Checkpoint                    `json:"current_justified_checkpoint"`
-	FinalizedCheckpoint           *Checkpoint                    `json:"finalized_checkpoint"`
-	InactivityScores              []string                       `json:"inactivity_scores"`
-	CurrentSyncCommittee          *SyncCommittee                 `json:"current_sync_committee"`
-	NextSyncCommittee             *SyncCommittee                 `json:"next_sync_committee"`
-	LatestExecutionPayloadHeader  *ExecutionPayloadHeaderElectra `json:"latest_execution_payload_header"`
-	NextWithdrawalIndex           string                         `json:"next_withdrawal_index"`
-	NextWithdrawalValidatorIndex  string                         `json:"next_withdrawal_validator_index"`
-	HistoricalSummaries           []*HistoricalSummary           `json:"historical_summaries"`
-	DepositRequestsStartIndex     string                         `json:"deposit_requests_start_index"`
-	DepositBalanceToConsume       string                         `json:"deposit_balance_to_consume"`
-	ExitBalanceToConsume          string                         `json:"exit_balance_to_consume"`
-	EarliestExitEpoch             string                         `json:"earliest_exit_epoch"`
-	ConsolidationBalanceToConsume string                         `json:"consolidation_balance_to_consume"`
-	EarliestConsolidationEpoch    string                         `json:"earliest_consolidation_epoch"`
-	PendingDeposits               []*PendingDeposit              `json:"pending_deposits"`
-	PendingPartialWithdrawals     []*PendingPartialWithdrawal    `json:"pending_partial_withdrawals"`
-	PendingConsolidations         []*PendingConsolidation        `json:"pending_consolidations"`
+	GenesisTime                   string                       `json:"genesis_time"`
+	GenesisValidatorsRoot         string                       `json:"genesis_validators_root"`
+	Slot                          string                       `json:"slot"`
+	Fork                          *Fork                        `json:"fork"`
+	LatestBlockHeader             *BeaconBlockHeader           `json:"latest_block_header"`
+	BlockRoots                    []string                     `json:"block_roots"`
+	StateRoots                    []string                     `json:"state_roots"`
+	HistoricalRoots               []string                     `json:"historical_roots"`
+	Eth1Data                      *Eth1Data                    `json:"eth1_data"`
+	Eth1DataVotes                 []*Eth1Data                  `json:"eth1_data_votes"`
+	Eth1DepositIndex              string                       `json:"eth1_deposit_index"`
+	Validators                    []*Validator                 `json:"validators"`
+	Balances                      []string                     `json:"balances"`
+	RandaoMixes                   []string                     `json:"randao_mixes"`
+	Slashings                     []string                     `json:"slashings"`
+	PreviousEpochParticipation    []string                     `json:"previous_epoch_participation"`
+	CurrentEpochParticipation     []string                     `json:"current_epoch_participation"`
+	JustificationBits             string                       `json:"justification_bits"`
+	PreviousJustifiedCheckpoint   *Checkpoint                  `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint    *Checkpoint                  `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint           *Checkpoint                  `json:"finalized_checkpoint"`
+	InactivityScores              []string                     `json:"inactivity_scores"`
+	CurrentSyncCommittee          *SyncCommittee               `json:"current_sync_committee"`
+	NextSyncCommittee             *SyncCommittee               `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader  *ExecutionPayloadHeaderDeneb `json:"latest_execution_payload_header"`
+	NextWithdrawalIndex           string                       `json:"next_withdrawal_index"`
+	NextWithdrawalValidatorIndex  string                       `json:"next_withdrawal_validator_index"`
+	HistoricalSummaries           []*HistoricalSummary         `json:"historical_summaries"`
+	DepositRequestsStartIndex     string                       `json:"deposit_requests_start_index"`
+	DepositBalanceToConsume       string                       `json:"deposit_balance_to_consume"`
+	ExitBalanceToConsume          string                       `json:"exit_balance_to_consume"`
+	EarliestExitEpoch             string                       `json:"earliest_exit_epoch"`
+	ConsolidationBalanceToConsume string                       `json:"consolidation_balance_to_consume"`
+	EarliestConsolidationEpoch    string                       `json:"earliest_consolidation_epoch"`
+	PendingDeposits               []*PendingDeposit            `json:"pending_deposits"`
+	PendingPartialWithdrawals     []*PendingPartialWithdrawal  `json:"pending_partial_withdrawals"`
+	PendingConsolidations         []*PendingConsolidation      `json:"pending_consolidations"`
+}
+
+type BeaconStateFulu struct {
+	GenesisTime                   string                       `json:"genesis_time"`
+	GenesisValidatorsRoot         string                       `json:"genesis_validators_root"`
+	Slot                          string                       `json:"slot"`
+	Fork                          *Fork                        `json:"fork"`
+	LatestBlockHeader             *BeaconBlockHeader           `json:"latest_block_header"`
+	BlockRoots                    []string                     `json:"block_roots"`
+	StateRoots                    []string                     `json:"state_roots"`
+	HistoricalRoots               []string                     `json:"historical_roots"`
+	Eth1Data                      *Eth1Data                    `json:"eth1_data"`
+	Eth1DataVotes                 []*Eth1Data                  `json:"eth1_data_votes"`
+	Eth1DepositIndex              string                       `json:"eth1_deposit_index"`
+	Validators                    []*Validator                 `json:"validators"`
+	Balances                      []string                     `json:"balances"`
+	RandaoMixes                   []string                     `json:"randao_mixes"`
+	Slashings                     []string                     `json:"slashings"`
+	PreviousEpochParticipation    []string                     `json:"previous_epoch_participation"`
+	CurrentEpochParticipation     []string                     `json:"current_epoch_participation"`
+	JustificationBits             string                       `json:"justification_bits"`
+	PreviousJustifiedCheckpoint   *Checkpoint                  `json:"previous_justified_checkpoint"`
+	CurrentJustifiedCheckpoint    *Checkpoint                  `json:"current_justified_checkpoint"`
+	FinalizedCheckpoint           *Checkpoint                  `json:"finalized_checkpoint"`
+	InactivityScores              []string                     `json:"inactivity_scores"`
+	CurrentSyncCommittee          *SyncCommittee               `json:"current_sync_committee"`
+	NextSyncCommittee             *SyncCommittee               `json:"next_sync_committee"`
+	LatestExecutionPayloadHeader  *ExecutionPayloadHeaderDeneb `json:"latest_execution_payload_header"`
+	NextWithdrawalIndex           string                       `json:"next_withdrawal_index"`
+	NextWithdrawalValidatorIndex  string                       `json:"next_withdrawal_validator_index"`
+	HistoricalSummaries           []*HistoricalSummary         `json:"historical_summaries"`
+	DepositRequestsStartIndex     string                       `json:"deposit_requests_start_index"`
+	DepositBalanceToConsume       string                       `json:"deposit_balance_to_consume"`
+	ExitBalanceToConsume          string                       `json:"exit_balance_to_consume"`
+	EarliestExitEpoch             string                       `json:"earliest_exit_epoch"`
+	ConsolidationBalanceToConsume string                       `json:"consolidation_balance_to_consume"`
+	EarliestConsolidationEpoch    string                       `json:"earliest_consolidation_epoch"`
+	PendingDeposits               []*PendingDeposit            `json:"pending_deposits"`
+	PendingPartialWithdrawals     []*PendingPartialWithdrawal  `json:"pending_partial_withdrawals"`
+	PendingConsolidations         []*PendingConsolidation      `json:"pending_consolidations"`
 }
--- a/beacon-chain/blockchain/BUILD.bazel
+++ b/beacon-chain/blockchain/BUILD.bazel
@@ -25,6 +25,7 @@ go_library(
        "receive_attestation.go",
        "receive_blob.go",
        "receive_block.go",
+        "receive_data_column.go",
        "service.go",
        "tracked_proposer.go",
        "weak_subjectivity_checks.go",
@@ -48,6 +49,7 @@ go_library(
        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
        "//beacon-chain/core/light-client:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/time:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
@@ -140,6 +142,7 @@ go_test(
        "//beacon-chain/core/blocks:go_default_library",
        "//beacon-chain/core/feed/state:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/light-client:go_default_library",
        "//beacon-chain/core/signing:go_default_library",
        "//beacon-chain/core/transition:go_default_library",
        "//beacon-chain/das:go_default_library",
@@ -156,6 +159,7 @@ 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",
--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -33,6 +33,7 @@ var (
 )

 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")
+var errMaxDataColumnsExceeded = errors.New("Expected data columns for node exceeds NUMBER_OF_COLUMNS")

 // An invalid block is the block that fails state transition based on the core protocol rules.
 // The beacon node shall not be accepting nor building blocks that branch off from an invalid block.
--- a/beacon-chain/blockchain/execution_engine.go
+++ b/beacon-chain/blockchain/execution_engine.go
@@ -362,15 +362,16 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 		return emptyAttri
 	}

-	var attr payloadattribute.Attributer
-	switch st.Version() {
-	case version.Deneb, version.Electra:
+	v := st.Version()
+
+	if v >= version.Deneb {
 		withdrawals, _, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
 			return emptyAttri
 		}
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV3{
+
+		attr, err := payloadattribute.New(&enginev1.PayloadAttributesV3{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
 			SuggestedFeeRecipient: val.FeeRecipient[:],
@@ -381,13 +382,18 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			log.WithError(err).Error("Could not get payload attribute")
 			return emptyAttri
 		}
-	case version.Capella:
+
+		return attr
+	}
+
+	if v >= version.Capella {
 		withdrawals, _, err := st.ExpectedWithdrawals()
 		if err != nil {
 			log.WithError(err).Error("Could not get expected withdrawals to get payload attribute")
 			return emptyAttri
 		}
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributesV2{
+
+		attr, err := payloadattribute.New(&enginev1.PayloadAttributesV2{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
 			SuggestedFeeRecipient: val.FeeRecipient[:],
@@ -397,8 +403,12 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			log.WithError(err).Error("Could not get payload attribute")
 			return emptyAttri
 		}
-	case version.Bellatrix:
-		attr, err = payloadattribute.New(&enginev1.PayloadAttributes{
+
+		return attr
+	}
+
+	if v >= version.Bellatrix {
+		attr, err := payloadattribute.New(&enginev1.PayloadAttributes{
 			Timestamp:             uint64(t.Unix()),
 			PrevRandao:            prevRando,
 			SuggestedFeeRecipient: val.FeeRecipient[:],
@@ -407,12 +417,12 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			log.WithError(err).Error("Could not get payload attribute")
 			return emptyAttri
 		}
-	default:
-		log.WithField("version", st.Version()).Error("Could not get payload attribute due to unknown state version")
-		return emptyAttri
+
+		return attr
 	}

-	return attr
+	log.WithField("version", version.String(st.Version())).Error("Could not get payload attribute due to unknown state version")
+	return emptyAttri
 }

 // removeInvalidBlockAndState removes the invalid block, blob and its corresponding state from the cache and DB.
--- a/beacon-chain/blockchain/head.go
+++ b/beacon-chain/blockchain/head.go
@@ -11,6 +11,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -404,13 +405,19 @@ func (s *Service) saveOrphanedOperations(ctx context.Context, orphanedRoot [32]b
 			if a.GetData().Slot+params.BeaconConfig().SlotsPerEpoch < s.CurrentSlot() {
 				continue
 			}
-			if helpers.IsAggregated(a) {
-				if err := s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+			if features.Get().EnableExperimentalAttestationPool {
+				if err = s.cfg.AttestationCache.Add(a); err != nil {
 					return err
 				}
 			} else {
-				if err := s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
-					return err
+				if a.IsAggregated() {
+					if err = s.cfg.AttPool.SaveAggregatedAttestation(a); err != nil {
+						return err
+					}
+				} else {
+					if err = s.cfg.AttPool.SaveUnaggregatedAttestation(a); err != nil {
+						return err
+					}
 				}
 			}
 			saveOrphanedAttCount.Inc()
--- a/beacon-chain/blockchain/kzg/BUILD.bazel
+++ b/beacon-chain/blockchain/kzg/BUILD.bazel
@@ -3,6 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
    name = "go_default_library",
    srcs = [
+        "kzg.go",
        "trusted_setup.go",
        "validation.go",
    ],
@@ -12,6 +13,9 @@ go_library(
    deps = [
        "//consensus-types/blocks:go_default_library",
        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_ethereum_c_kzg_4844//bindings/go:go_default_library",
+        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//crypto/kzg4844:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
 )
--- a/beacon-chain/blockchain/kzg/kzg.go
+++ b/beacon-chain/blockchain/kzg/kzg.go
@@ -0,0 +1,111 @@
+package kzg
+
+import (
+	"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
+}
+
+func BlobToKZGCommitment(blob *Blob) (Commitment, error) {
+	kzgBlob := kzg4844.Blob(*blob)
+	comm, err := kzg4844.BlobToCommitment(&kzgBlob)
+	if err != nil {
+		return Commitment{}, err
+	}
+	return Commitment(comm), nil
+}
+
+func ComputeBlobKZGProof(blob *Blob, commitment Commitment) (Proof, error) {
+	kzgBlob := kzg4844.Blob(*blob)
+	proof, err := kzg4844.ComputeBlobProof(&kzgBlob, kzg4844.Commitment(commitment))
+	if err != nil {
+		return [48]byte{}, err
+	}
+	return Proof(proof), nil
+}
+
+func ComputeCellsAndKZGProofs(blob *Blob) (CellsAndProofs, error) {
+	ckzgBlob := (*ckzg4844.Blob)(blob)
+	ckzgCells, ckzgProofs, err := ckzg4844.ComputeCellsAndKZGProofs(ckzgBlob)
+	if err != nil {
+		return CellsAndProofs{}, err
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+func VerifyCellKZGProofBatch(commitmentsBytes []Bytes48, cellIndices []uint64, cells []Cell, proofsBytes []Bytes48) (bool, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgCells := make([]ckzg4844.Cell, len(cells))
+	for i := range cells {
+		ckzgCells[i] = ckzg4844.Cell(cells[i])
+	}
+
+	return ckzg4844.VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, ckzgCells, proofsBytes)
+}
+
+func RecoverCellsAndKZGProofs(cellIndices []uint64, partialCells []Cell) (CellsAndProofs, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgPartialCells := make([]ckzg4844.Cell, len(partialCells))
+	for i := range partialCells {
+		ckzgPartialCells[i] = ckzg4844.Cell(partialCells[i])
+	}
+
+	ckzgCells, ckzgProofs, err := ckzg4844.RecoverCellsAndKZGProofs(cellIndices, ckzgPartialCells)
+	if err != nil {
+		return CellsAndProofs{}, err
+	}
+
+	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+}
+
+// Convert cells/proofs to the CellsAndProofs type defined in this package.
+func makeCellsAndProofs(ckzgCells []ckzg4844.Cell, ckzgProofs []ckzg4844.KZGProof) (CellsAndProofs, error) {
+	if len(ckzgCells) != len(ckzgProofs) {
+		return CellsAndProofs{}, errors.New("different number of cells/proofs")
+	}
+
+	var cells []Cell
+	var proofs []Proof
+	for i := range ckzgCells {
+		cells = append(cells, Cell(ckzgCells[i]))
+		proofs = append(proofs, Proof(ckzgProofs[i]))
+	}
+
+	return CellsAndProofs{
+		Cells:  cells,
+		Proofs: proofs,
+	}, nil
+}
--- a/beacon-chain/blockchain/kzg/trusted_setup.go
+++ b/beacon-chain/blockchain/kzg/trusted_setup.go
@@ -5,6 +5,8 @@ import (
 	"encoding/json"

 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	CKZG "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 )

@@ -12,17 +14,53 @@ var (
 	//go:embed trusted_setup.json
 	embeddedTrustedSetup []byte // 1.2Mb
 	kzgContext           *GoKZG.Context
+	kzgLoaded            bool
 )

+type TrustedSetup struct {
+	G1Monomial [GoKZG.ScalarsPerBlob]GoKZG.G1CompressedHexStr `json:"g1_monomial"`
+	G1Lagrange [GoKZG.ScalarsPerBlob]GoKZG.G1CompressedHexStr `json:"g1_lagrange"`
+	G2Monomial [65]GoKZG.G2CompressedHexStr                   `json:"g2_monomial"`
+}
+
 func Start() error {
-	parsedSetup := GoKZG.JSONTrustedSetup{}
-	err := json.Unmarshal(embeddedTrustedSetup, &parsedSetup)
+	trustedSetup := &TrustedSetup{}
+	err := json.Unmarshal(embeddedTrustedSetup, trustedSetup)
 	if err != nil {
 		return errors.Wrap(err, "could not parse trusted setup JSON")
 	}
-	kzgContext, err = GoKZG.NewContext4096(&parsedSetup)
+	kzgContext, err = GoKZG.NewContext4096(&GoKZG.JSONTrustedSetup{
+		SetupG2:         trustedSetup.G2Monomial[:],
+		SetupG1Lagrange: trustedSetup.G1Lagrange})
 	if err != nil {
 		return errors.Wrap(err, "could not initialize go-kzg context")
 	}
+
+	// Length of a G1 point, converted from hex to binary.
+	g1MonomialBytes := make([]byte, len(trustedSetup.G1Monomial)*(len(trustedSetup.G1Monomial[0])-2)/2)
+	for i, g1 := range &trustedSetup.G1Monomial {
+		copy(g1MonomialBytes[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
+	}
+	// Length of a G1 point, converted from hex to binary.
+	g1LagrangeBytes := make([]byte, len(trustedSetup.G1Lagrange)*(len(trustedSetup.G1Lagrange[0])-2)/2)
+	for i, g1 := range &trustedSetup.G1Lagrange {
+		copy(g1LagrangeBytes[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
+	}
+	// Length of a G2 point, converted from hex to binary.
+	g2MonomialBytes := make([]byte, len(trustedSetup.G2Monomial)*(len(trustedSetup.G2Monomial[0])-2)/2)
+	for i, g2 := range &trustedSetup.G2Monomial {
+		copy(g2MonomialBytes[i*(len(g2)-2)/2:], hexutil.MustDecode(g2))
+	}
+	if !kzgLoaded {
+		// TODO: Provide a configuration option for this.
+		var precompute uint = 8
+
+		// Free the current trusted setup before running this method. CKZG
+		// panics if the same setup is run multiple times.
+		if err = CKZG.LoadTrustedSetup(g1MonomialBytes, g1LagrangeBytes, g2MonomialBytes, precompute); err != nil {
+			panic(err)
+		}
+	}
+	kzgLoaded = true
 	return nil
 }
--- a/beacon-chain/blockchain/kzg/trusted_setup.json
+++ b/beacon-chain/blockchain/kzg/trusted_setup.json
--- a/beacon-chain/blockchain/kzg/validation.go
+++ b/beacon-chain/blockchain/kzg/validation.go
@@ -20,16 +20,17 @@ func Verify(sidecars ...blocks.ROBlob) error {
 	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
 	proofs := make([]GoKZG.KZGProof, len(sidecars))
 	for i, sidecar := range sidecars {
-		blobs[i] = bytesToBlob(sidecar.Blob)
+		blobs[i] = *bytesToBlob(sidecar.Blob)
 		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
 		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
 	}
 	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
 }

-func bytesToBlob(blob []byte) (ret GoKZG.Blob) {
+func bytesToBlob(blob []byte) *GoKZG.Blob {
+	var ret GoKZG.Blob
 	copy(ret[:], blob)
-	return
+	return &ret
 }

 func bytesToCommitment(commitment []byte) (ret GoKZG.KZGCommitment) {
--- a/beacon-chain/blockchain/kzg/validation_test.go
+++ b/beacon-chain/blockchain/kzg/validation_test.go
@@ -10,11 +10,11 @@ import (
 )

 func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZGProof, error) {
-	commitment, err := kzgContext.BlobToKZGCommitment(blob, 0)
+	commitment, err := kzgContext.BlobToKZGCommitment(&blob, 0)
 	if err != nil {
 		return GoKZG.KZGCommitment{}, GoKZG.KZGProof{}, err
 	}
-	proof, err := kzgContext.ComputeBlobKZGProof(blob, commitment, 0)
+	proof, err := kzgContext.ComputeBlobKZGProof(&blob, commitment, 0)
 	if err != nil {
 		return GoKZG.KZGCommitment{}, GoKZG.KZGProof{}, err
 	}
@@ -31,7 +31,7 @@ func TestBytesToAny(t *testing.T) {
 	blob := GoKZG.Blob{0x01, 0x02}
 	commitment := GoKZG.KZGCommitment{0x01, 0x02}
 	proof := GoKZG.KZGProof{0x01, 0x02}
-	require.DeepEqual(t, blob, bytesToBlob(bytes))
+	require.DeepEqual(t, blob, *bytesToBlob(bytes))
 	require.DeepEqual(t, commitment, bytesToCommitment(bytes))
 	require.DeepEqual(t, proof, bytesToKZGProof(bytes))
 }
--- a/beacon-chain/blockchain/options.go
+++ b/beacon-chain/blockchain/options.go
@@ -85,6 +85,14 @@ func WithTrackedValidatorsCache(c *cache.TrackedValidatorsCache) Option {
 	}
 }

+// WithAttestationCache for attestation lifecycle after chain inclusion.
+func WithAttestationCache(c *cache.AttestationCache) Option {
+	return func(s *Service) error {
+		s.cfg.AttestationCache = c
+		return nil
+	}
+}
+
 // WithAttestationPool for attestation lifecycle after chain inclusion.
 func WithAttestationPool(p attestations.Pool) Option {
 	return func(s *Service) error {
@@ -118,9 +126,9 @@ func WithBLSToExecPool(p blstoexec.PoolManager) Option {
 }

 // WithP2PBroadcaster to broadcast messages after appropriate processing.
-func WithP2PBroadcaster(p p2p.Broadcaster) Option {
+func WithP2PBroadcaster(p p2p.Acceser) Option {
 	return func(s *Service) error {
-		s.cfg.P2p = p
+		s.cfg.P2P = p
 		return nil
 	}
 }
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -3,11 +3,13 @@ package blockchain
 import (
 	"context"
 	"fmt"
+	"slices"
 	"time"

 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
 	coreTime "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
@@ -15,7 +17,6 @@ import (
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
-	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
@@ -70,6 +71,7 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 	if features.Get().EnableLightClient && slots.ToEpoch(s.CurrentSlot()) >= params.BeaconConfig().AltairForkEpoch {
 		defer s.processLightClientUpdates(cfg)
 		defer s.saveLightClientUpdate(cfg)
+		defer s.saveLightClientBootstrap(cfg)
 	}
 	defer s.sendStateFeedOnBlock(cfg)
 	defer reportProcessingTime(startTime)
@@ -234,7 +236,9 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 				return err
 			}
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
+
+		nodeID := s.cfg.P2P.NodeID()
+		if err := avs.IsDataAvailable(ctx, nodeID, s.CurrentSlot(), b); err != nil {
 			return errors.Wrapf(err, "could not validate blob data availability at slot %d", b.Block().Slot())
 		}
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b,
@@ -379,7 +383,11 @@ func (s *Service) handleBlockAttestations(ctx context.Context, blk interfaces.Re
 		r := bytesutil.ToBytes32(a.GetData().BeaconBlockRoot)
 		if s.cfg.ForkChoiceStore.HasNode(r) {
 			s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indices, r, a.GetData().Target.Epoch)
-		} else if err := s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
+		} else if features.Get().EnableExperimentalAttestationPool {
+			if err = s.cfg.AttestationCache.Add(a); err != nil {
+				return err
+			}
+		} else if err = s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
 			return err
 		}
 	}
@@ -419,7 +427,11 @@ func (s *Service) savePostStateInfo(ctx context.Context, r [32]byte, b interface
 func (s *Service) pruneAttsFromPool(headBlock interfaces.ReadOnlySignedBeaconBlock) error {
 	atts := headBlock.Block().Body().Attestations()
 	for _, att := range atts {
-		if helpers.IsAggregated(att) {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := s.cfg.AttestationCache.DeleteCovered(att); err != nil {
+				return errors.Wrap(err, "could not delete attestation")
+			}
+		} else if att.IsAggregated() {
 			if err := s.cfg.AttPool.DeleteAggregatedAttestation(att); err != nil {
 				return err
 			}
@@ -496,16 +508,17 @@ func (s *Service) runLateBlockTasks() {
 // It returns a map where each key represents a missing BlobSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // BlobSidecars against the set of known missing sidecars.
-func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte) (map[uint64]struct{}, error) {
+func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte, slot primitives.Slot) (map[uint64]struct{}, error) {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	if len(expected) == 0 {
 		return nil, nil
 	}
-	if len(expected) > fieldparams.MaxBlobsPerBlock {
+	if len(expected) > maxBlobsPerBlock {
 		return nil, errMaxBlobsExceeded
 	}
-	indices, err := bs.Indices(root)
+	indices, err := bs.Indices(root, slot)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "indices")
 	}
 	missing := make(map[uint64]struct{}, len(expected))
 	for i := range expected {
@@ -519,12 +532,40 @@ func missingIndices(bs *filesystem.BlobStorage, root [32]byte, expected [][]byte
 	return missing, nil
 }

+func missingDataColumns(bs *filesystem.BlobStorage, root [32]byte, expected map[uint64]bool) (map[uint64]bool, error) {
+	if len(expected) == 0 {
+		return nil, nil
+	}
+
+	if len(expected) > int(params.BeaconConfig().NumberOfColumns) {
+		return nil, errMaxDataColumnsExceeded
+	}
+
+	indices, err := bs.ColumnIndices(root)
+	if err != nil {
+		return nil, err
+	}
+
+	missing := make(map[uint64]bool, len(expected))
+	for col := range expected {
+		if !indices[col] {
+			missing[col] = true
+		}
+	}
+
+	return missing, nil
+}
+
 // isDataAvailable blocks until all BlobSidecars committed to in the block are available,
 // or an error or context cancellation occurs. A nil result means that the data availability check is successful.
 // The function will first check the database to see if all sidecars have been persisted. If any
 // sidecars are missing, it will then read from the blobNotifier channel for the given root until the channel is
 // closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
 func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed interfaces.ReadOnlySignedBeaconBlock) error {
+	if coreTime.PeerDASIsActive(signed.Block().Slot()) {
+		return s.areDataColumnsAvailable(ctx, root, signed)
+	}
+
 	if signed.Version() < version.Deneb {
 		return nil
 	}
@@ -552,9 +593,9 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 		return nil
 	}
 	// get a map of BlobSidecar indices that are not currently available.
-	missing, err := missingIndices(s.blobStorage, root, kzgCommitments)
+	missing, err := missingIndices(s.blobStorage, root, kzgCommitments, block.Slot())
 	if err != nil {
-		return err
+		return errors.Wrap(err, "missing indices")
 	}
 	// If there are no missing indices, all BlobSidecars are available.
 	if len(missing) == 0 {
@@ -563,7 +604,7 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int

 	// The gossip handler for blobs writes the index of each verified blob referencing the given
 	// root to the channel returned by blobNotifiers.forRoot.
-	nc := s.blobNotifiers.forRoot(root)
+	nc := s.blobNotifiers.forRoot(root, block.Slot())

 	// Log for DA checks that cross over into the next slot; helpful for debugging.
 	nextSlot := slots.BeginsAt(signed.Block().Slot()+1, s.genesisTime)
@@ -573,8 +614,13 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 			if len(missing) == 0 {
 				return
 			}
-			log.WithFields(daCheckLogFields(root, signed.Block().Slot(), expected, len(missing))).
-				Error("Still waiting for DA check at slot end.")
+
+			log.WithFields(logrus.Fields{
+				"slot":          signed.Block().Slot(),
+				"root":          fmt.Sprintf("%#x", root),
+				"blobsExpected": expected,
+				"blobsWaiting":  len(missing),
+			}).Error("Still waiting for blobs DA check at slot end.")
 		})
 		defer nst.Stop()
 	}
@@ -596,12 +642,176 @@ func (s *Service) isDataAvailable(ctx context.Context, root [32]byte, signed int
 	}
 }

-func daCheckLogFields(root [32]byte, slot primitives.Slot, expected, missing int) logrus.Fields {
-	return logrus.Fields{
-		"slot":          slot,
-		"root":          fmt.Sprintf("%#x", root),
-		"blobsExpected": expected,
-		"blobsWaiting":  missing,
+// uint64MapToSortedSlice produces a sorted uint64 slice from a map.
+func uint64MapToSortedSlice(input map[uint64]bool) []uint64 {
+	output := make([]uint64, 0, len(input))
+	for idx := range input {
+		output = append(output, idx)
+	}
+	slices.Sort[[]uint64](output)
+	return output
+}
+
+func (s *Service) areDataColumnsAvailable(ctx context.Context, root [32]byte, signed interfaces.ReadOnlySignedBeaconBlock) error {
+	if signed.Version() < version.Fulu {
+		return nil
+	}
+
+	block := signed.Block()
+	if block == nil {
+		return errors.New("invalid nil beacon block")
+	}
+
+	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
+	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
+
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return nil
+	}
+
+	body := block.Body()
+	if body == nil {
+		return errors.New("invalid nil beacon block body")
+	}
+
+	kzgCommitments, err := body.BlobKzgCommitments()
+	if err != nil {
+		return errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// If block has not commitments there is nothing to wait for.
+	if len(kzgCommitments) == 0 {
+		return nil
+	}
+
+	// All columns to sample need to be available for the block to be considered available.
+	// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/das-core.md#custody-sampling
+	nodeID := s.cfg.P2P.NodeID()
+	custodyGroupSamplingSize := peerdas.CustodyGroupSamplingSize()
+
+	custodyGroups, err := peerdas.CustodyGroups(nodeID, custodyGroupSamplingSize)
+	if err != nil {
+		return errors.Wrap(err, "custody groups")
+	}
+
+	// Exit early if the node is not expected to custody any data columns.
+	if len(custodyGroups) == 0 {
+		return nil
+	}
+
+	// Get the custody columns from the groups.
+	columnsMap, err := peerdas.CustodyColumns(custodyGroups)
+	if err != nil {
+		return errors.Wrap(err, "custody columns")
+	}
+
+	// Subscribe to newsly data columns stored in the database.
+	rootIndexChan := make(chan filesystem.RootIndexPair)
+	subscription := s.blobStorage.DataColumnFeed.Subscribe(rootIndexChan)
+	defer subscription.Unsubscribe()
+
+	// Get the count of data columns we already have in the store.
+	retrievedDataColumns, err := s.blobStorage.ColumnIndices(root)
+	if err != nil {
+		return errors.Wrap(err, "column indices")
+	}
+
+	retrievedDataColumnsCount := uint64(len(retrievedDataColumns))
+
+	// As soon as we have more than half of the data columns, we can reconstruct the missing ones.
+	// We don't need to wait for the rest of the data columns to declare the block as available.
+	if peerdas.CanSelfReconstruct(retrievedDataColumnsCount) {
+		return nil
+	}
+
+	// Get a map of data column indices that are not currently available.
+	missingMap, err := missingDataColumns(s.blobStorage, root, columnsMap)
+	if err != nil {
+		return err
+	}
+
+	// If there are no missing indices, all data column sidecars are available.
+	// This is the happy path.
+	if len(missingMap) == 0 {
+		return nil
+	}
+
+	// Log for DA checks that cross over into the next slot; helpful for debugging.
+	nextSlot := slots.BeginsAt(signed.Block().Slot()+1, s.genesisTime)
+	// Avoid logging if DA check is called after next slot start.
+	if nextSlot.After(time.Now()) {
+		nst := time.AfterFunc(time.Until(nextSlot), func() {
+			missingMapCount := uint64(len(missingMap))
+
+			if missingMapCount == 0 {
+				return
+			}
+
+			var (
+				expected interface{} = "all"
+				missing  interface{} = "all"
+			)
+
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
+			colMapCount := uint64(len(columnsMap))
+
+			if colMapCount < numberOfColumns {
+				expected = uint64MapToSortedSlice(columnsMap)
+			}
+
+			if missingMapCount < numberOfColumns {
+				missing = uint64MapToSortedSlice(missingMap)
+			}
+
+			log.WithFields(logrus.Fields{
+				"slot":            signed.Block().Slot(),
+				"root":            fmt.Sprintf("%#x", root),
+				"columnsExpected": expected,
+				"columnsWaiting":  missing,
+			}).Error("Some data columns are still unavailable at slot end")
+		})
+
+		defer nst.Stop()
+	}
+
+	for {
+		select {
+		case rootIndex := <-rootIndexChan:
+			if rootIndex.Root != root {
+				// This is not the root we are looking for.
+				continue
+			}
+
+			// This is a data column we are expecting.
+			if _, ok := missingMap[rootIndex.Index]; ok {
+				retrievedDataColumnsCount++
+			}
+
+			// As soon as we have more than half of the data columns, we can reconstruct the missing ones.
+			// We don't need to wait for the rest of the data columns to declare the block as available.
+			if peerdas.CanSelfReconstruct(retrievedDataColumnsCount) {
+				return nil
+			}
+
+			// Remove the index from the missing map.
+			delete(missingMap, rootIndex.Index)
+
+			// Exit if there is no more missing data columns.
+			if len(missingMap) == 0 {
+				return nil
+			}
+		case <-ctx.Done():
+			var missingIndices interface{} = "all"
+			numberOfColumns := params.BeaconConfig().NumberOfColumns
+			missingIndicesCount := uint64(len(missingMap))
+
+			if missingIndicesCount < numberOfColumns {
+				missingIndices = uint64MapToSortedSlice(missingMap)
+			}
+
+			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing %v", block.Slot(), root, missingIndices)
+		}
 	}
 }

@@ -688,7 +898,7 @@ func (s *Service) waitForSync() error {
 	}
 }

-func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, blockRoot [32]byte, parentRoot [32]byte) error {
+func (s *Service) handleInvalidExecutionError(ctx context.Context, err error, blockRoot, parentRoot [32]byte) error {
 	if IsInvalidBlock(err) && InvalidBlockLVH(err) != [32]byte{} {
 		return s.pruneInvalidBlock(ctx, blockRoot, parentRoot, InvalidBlockLVH(err))
 	}
--- a/beacon-chain/blockchain/process_block_helpers.go
+++ b/beacon-chain/blockchain/process_block_helpers.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"strings"
 	"time"

 	lightclient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
@@ -129,7 +130,7 @@ func (s *Service) saveLightClientUpdate(cfg *postBlockProcessConfig) {
 	attestedRoot := cfg.roblock.Block().ParentRoot()
 	attestedBlock, err := s.getBlock(cfg.ctx, attestedRoot)
 	if err != nil {
-		log.WithError(err).Error("Saving light client update failed: Could not get attested block")
+		log.WithError(err).Errorf("Saving light client update failed: Could not get attested block for root %#x", attestedRoot)
 		return
 	}
 	if attestedBlock == nil || attestedBlock.IsNil() {
@@ -138,7 +139,7 @@ func (s *Service) saveLightClientUpdate(cfg *postBlockProcessConfig) {
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(cfg.ctx, attestedRoot)
 	if err != nil {
-		log.WithError(err).Error("Saving light client update failed: Could not get attested state")
+		log.WithError(err).Errorf("Saving light client update failed: Could not get attested state for root %#x", attestedRoot)
 		return
 	}
 	if attestedState == nil || attestedState.IsNil() {
@@ -149,7 +150,11 @@ func (s *Service) saveLightClientUpdate(cfg *postBlockProcessConfig) {
 	finalizedRoot := attestedState.FinalizedCheckpoint().Root
 	finalizedBlock, err := s.getBlock(cfg.ctx, [32]byte(finalizedRoot))
 	if err != nil {
-		log.WithError(err).Error("Saving light client update failed: Could not get finalized block")
+		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
+			log.Debugf("Skipping saving light client update: Finalized block is nil for root %#x", finalizedRoot)
+		} else {
+			log.WithError(err).Errorf("Saving light client update failed: Could not get finalized block for root %#x", finalizedRoot)
+		}
 		return
 	}

@@ -224,28 +229,30 @@ func (s *Service) processLightClientFinalityUpdate(
 	attestedRoot := signed.Block().ParentRoot()
 	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
 	if err != nil {
-		return errors.Wrap(err, "could not get attested block")
+		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
-		return errors.Wrap(err, "could not get attested state")
+		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}

-	var finalizedBlock interfaces.ReadOnlySignedBeaconBlock
-	finalizedCheckPoint := attestedState.FinalizedCheckpoint()
-	if finalizedCheckPoint != nil {
-		finalizedRoot := bytesutil.ToBytes32(finalizedCheckPoint.Root)
-		finalizedBlock, err = s.cfg.BeaconDB.Block(ctx, finalizedRoot)
-		if err != nil {
-			finalizedBlock = nil
-		}
-	}
+	finalizedCheckpoint := attestedState.FinalizedCheckpoint()

 	// Check if the finalized checkpoint has changed
-	if finalizedCheckPoint == nil || bytes.Equal(finalizedCheckPoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
 		return nil
 	}

+	finalizedRoot := bytesutil.ToBytes32(finalizedCheckpoint.Root)
+	finalizedBlock, err := s.cfg.BeaconDB.Block(ctx, finalizedRoot)
+	if err != nil {
+		if errors.Is(err, errBlockNotFoundInCacheOrDB) {
+			log.Debugf("Skipping processing light client finality update: Finalized block is nil for root %#x", finalizedRoot)
+			return nil
+		}
+		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
+	}
+
 	update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
 		ctx,
 		postState.Slot(),
@@ -272,11 +279,11 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 	attestedRoot := signed.Block().ParentRoot()
 	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
 	if err != nil {
-		return errors.Wrap(err, "could not get attested block")
+		return errors.Wrapf(err, "could not get attested block for root %#x", attestedRoot)
 	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
-		return errors.Wrap(err, "could not get attested state")
+		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}

 	update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
@@ -289,6 +296,10 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 	)

 	if err != nil {
+		if strings.Contains(err.Error(), lightclient.ErrNotEnoughSyncCommitteeBits) {
+			log.WithError(err).Debug("Skipping processing light client optimistic update")
+			return nil
+		}
 		return errors.Wrap(err, "could not create light client optimistic update")
 	}

--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
@@ -14,6 +14,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/blocks"
+	lightClient "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/light-client"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
@@ -2205,23 +2206,23 @@ func TestMissingIndices(t *testing.T) {
 		},
 		{
 			name:     "expected exceeds max",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock + 1),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0) + 1),
 			err:      errMaxBlobsExceeded,
 		},
 		{
 			name:     "first missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0)),
 			present:  []uint64{1, 2, 3, 4, 5},
 			result:   fakeResult([]uint64{0}),
 		},
 		{
 			name:     "all missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0)),
 			result:   fakeResult([]uint64{0, 1, 2, 3, 4, 5}),
 		},
 		{
 			name:     "none missing",
-			expected: fakeCommitments(fieldparams.MaxBlobsPerBlock),
+			expected: fakeCommitments(params.BeaconConfig().MaxBlobsPerBlock(0)),
 			present:  []uint64{0, 1, 2, 3, 4, 5},
 			result:   fakeResult([]uint64{}),
 		},
@@ -2255,7 +2256,7 @@ func TestMissingIndices(t *testing.T) {
 		bm, bs := filesystem.NewEphemeralBlobStorageWithMocker(t)
 		t.Run(c.name, func(t *testing.T) {
 			require.NoError(t, bm.CreateFakeIndices(c.root, c.present...))
-			missing, err := missingIndices(bs, c.root, c.expected)
+			missing, err := missingIndices(bs, c.root, c.expected, 0)
 			if c.err != nil {
 				require.ErrorIs(t, err, c.err)
 				return
@@ -2505,173 +2506,500 @@ func fakeResult(missing []uint64) map[uint64]struct{} {
 }

 func TestSaveLightClientUpdate(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+
 	s, tr := minimalTestService(t)
 	ctx := tr.ctx

 	t.Run("Altair", func(t *testing.T) {
-		featCfg := &features.Flags{}
-		featCfg.EnableLightClient = true
-		reset := features.InitWithReset(featCfg)
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()

-		l := util.NewTestLightClient(t).SetupTestAltair()
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)

-		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+			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)

-		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)

-		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, 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)

-		err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
-		require.NoError(t, err)
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}

-		cfg := &postBlockProcessConfig{
-			ctx:            ctx,
-			roblock:        roblock,
-			postState:      l.State,
-			isValidPayload: true,
-		}
+			s.saveLightClientUpdate(cfg)

-		s.saveLightClientUpdate(cfg)
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))

-		// Check that the light client update is saved
-		period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Altair)
+		})

-		u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
-		require.NoError(t, err)
-		require.NotNil(t, u)
-		attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
-		require.NoError(t, err)
-		require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
-		require.Equal(t, u.Version(), version.Altair)
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()

-		reset()
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			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,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Altair)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestAltair()
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			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,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Altair)
+		})
 	})

 	t.Run("Capella", func(t *testing.T) {
-		featCfg := &features.Flags{}
-		featCfg.EnableLightClient = true
-		reset := features.InitWithReset(featCfg)
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)

-		l := util.NewTestLightClient(t).SetupTestCapella(false)
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)

-		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+			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)

-		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)

-		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, 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)

-		err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
-		require.NoError(t, err)
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}

-		cfg := &postBlockProcessConfig{
-			ctx:            ctx,
-			roblock:        roblock,
-			postState:      l.State,
-			isValidPayload: true,
-		}
+			s.saveLightClientUpdate(cfg)

-		s.saveLightClientUpdate(cfg)
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Capella)
+		})

-		// Check that the light client update is saved
-		period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
-		u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
-		require.NoError(t, err)
-		require.NotNil(t, u)
-		attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
-		require.NoError(t, err)
-		require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
-		require.Equal(t, u.Version(), version.Capella)
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)

-		reset()
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			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,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Capella)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestCapella(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			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,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Capella)
+		})
 	})

 	t.Run("Deneb", func(t *testing.T) {
-		featCfg := &features.Flags{}
-		featCfg.EnableLightClient = true
-		reset := features.InitWithReset(featCfg)
+		t.Run("No old update", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)

-		l := util.NewTestLightClient(t).SetupTestDeneb(false)
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)

-		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+			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)

-		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)

-		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, 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)

-		err = s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock)
-		require.NoError(t, err)
+			cfg := &postBlockProcessConfig{
+				ctx:            ctx,
+				roblock:        roblock,
+				postState:      l.State,
+				isValidPayload: true,
+			}

-		cfg := &postBlockProcessConfig{
-			ctx:            ctx,
-			roblock:        roblock,
-			postState:      l.State,
-			isValidPayload: true,
-		}
+			s.saveLightClientUpdate(cfg)

-		s.saveLightClientUpdate(cfg)
+			// Check that the light client update is saved
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Deneb)
+		})

-		// Check that the light client update is saved
-		period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
-		u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
-		require.NoError(t, err)
-		require.NotNil(t, u)
-		attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
-		require.NoError(t, err)
-		require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
-		require.Equal(t, u.Version(), version.Deneb)
+		t.Run("New update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)

-		reset()
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			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,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			attestedStateRoot, err := l.AttestedState.HashTreeRoot(ctx)
+			require.NoError(t, err)
+			require.Equal(t, attestedStateRoot, [32]byte(u.AttestedHeader().Beacon().StateRoot))
+			require.Equal(t, u.Version(), version.Deneb)
+		})
+
+		t.Run("Old update is better", func(t *testing.T) {
+			l := util.NewTestLightClient(t).SetupTestDeneb(false)
+
+			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
+
+			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,
+			}
+
+			period := slots.SyncCommitteePeriod(slots.ToEpoch(l.AttestedState.Slot()))
+
+			// create and save old update
+			oldUpdate, err := lightClient.CreateDefaultLightClientUpdate(s.CurrentSlot(), l.AttestedState)
+			require.NoError(t, err)
+
+			scb := make([]byte, 64)
+			for i := 0; i < 5; i++ {
+				scb[i] = 0x01
+			}
+			oldUpdate.SetSyncAggregate(&ethpb.SyncAggregate{
+				SyncCommitteeBits:      scb,
+				SyncCommitteeSignature: make([]byte, 96),
+			})
+
+			err = s.cfg.BeaconDB.SaveLightClientUpdate(ctx, period, oldUpdate)
+			require.NoError(t, err)
+
+			s.saveLightClientUpdate(cfg)
+
+			u, err := s.cfg.BeaconDB.LightClientUpdate(ctx, period)
+			require.NoError(t, err)
+			require.NotNil(t, u)
+			require.DeepEqual(t, oldUpdate, u)
+			require.Equal(t, u.Version(), version.Deneb)
+		})
 	})
+
+	reset()
 }

 func TestSaveLightClientBootstrap(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+
 	s, tr := minimalTestService(t)
 	ctx := tr.ctx

 	t.Run("Altair", func(t *testing.T) {
-		featCfg := &features.Flags{}
-		featCfg.EnableLightClient = true
-		reset := features.InitWithReset(featCfg)
-
 		l := util.NewTestLightClient(t).SetupTestAltair()

 		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().AltairForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
@@ -2704,15 +3032,9 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
 		require.Equal(t, b.Version(), version.Altair)
-
-		reset()
 	})

 	t.Run("Capella", func(t *testing.T) {
-		featCfg := &features.Flags{}
-		featCfg.EnableLightClient = true
-		reset := features.InitWithReset(featCfg)
-
 		l := util.NewTestLightClient(t).SetupTestCapella(false)

 		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().CapellaForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
@@ -2745,15 +3067,9 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
 		require.Equal(t, b.Version(), version.Capella)
-
-		reset()
 	})

 	t.Run("Deneb", func(t *testing.T) {
-		featCfg := &features.Flags{}
-		featCfg.EnableLightClient = true
-		reset := features.InitWithReset(featCfg)
-
 		l := util.NewTestLightClient(t).SetupTestDeneb(false)

 		s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().DenebForkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
@@ -2786,7 +3102,7 @@ func TestSaveLightClientBootstrap(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
 		require.Equal(t, b.Version(), version.Deneb)
-
-		reset()
 	})
+
+	reset()
 }
--- a/beacon-chain/blockchain/receive_attestation.go
+++ b/beacon-chain/blockchain/receive_attestation.go
@@ -9,6 +9,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -166,7 +167,13 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)

 // This processes fork choice attestations from the pool to account for validator votes and fork choice.
 func (s *Service) processAttestations(ctx context.Context, disparity time.Duration) {
-	atts := s.cfg.AttPool.ForkchoiceAttestations()
+	var atts []ethpb.Att
+	if features.Get().EnableExperimentalAttestationPool {
+		atts = s.cfg.AttestationCache.ForkchoiceAttestations()
+	} else {
+		atts = s.cfg.AttPool.ForkchoiceAttestations()
+	}
+
 	for _, a := range atts {
 		// Based on the spec, don't process the attestation until the subsequent slot.
 		// This delays consideration in the fork choice until their slot is in the past.
@@ -182,7 +189,11 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 			continue
 		}

-		if err := s.cfg.AttPool.DeleteForkchoiceAttestation(a); err != nil {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := s.cfg.AttestationCache.DeleteForkchoiceAttestation(a); err != nil {
+				log.WithError(err).Error("Could not delete fork choice attestation in pool")
+			}
+		} else if err := s.cfg.AttPool.DeleteForkchoiceAttestation(a); err != nil {
 			log.WithError(err).Error("Could not delete fork choice attestation in pool")
 		}

--- a/beacon-chain/blockchain/receive_blob.go
+++ b/beacon-chain/blockchain/receive_blob.go
@@ -4,12 +4,13 @@ import (
 	"context"

 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )

 // SendNewBlobEvent sends a message to the BlobNotifier channel that the blob
 // for the block root `root` is ready in the database
-func (s *Service) sendNewBlobEvent(root [32]byte, index uint64) {
-	s.blobNotifiers.notifyIndex(root, index)
+func (s *Service) sendNewBlobEvent(root [32]byte, index uint64, slot primitives.Slot) {
+	s.blobNotifiers.notifyIndex(root, index, slot)
 }

 // ReceiveBlob saves the blob to database and sends the new event
@@ -18,6 +19,6 @@ func (s *Service) ReceiveBlob(ctx context.Context, b blocks.VerifiedROBlob) erro
 		return err
 	}

-	s.sendNewBlobEvent(b.BlockRoot(), b.Index)
+	s.sendNewBlobEvent(b.BlockRoot(), b.Index, b.Slot())
 	return nil
 }
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -51,6 +51,12 @@ type BlobReceiver interface {
 	ReceiveBlob(context.Context, blocks.VerifiedROBlob) error
 }

+// DataColumnReceiver interface defines the methods of chain service for receiving new
+// data columns
+type DataColumnReceiver interface {
+	ReceiveDataColumn(blocks.VerifiedRODataColumn) error
+}
+
 // SlashingReceiver interface defines the methods of chain service for receiving validated slashing over the wire.
 type SlashingReceiver interface {
 	ReceiveAttesterSlashing(ctx context.Context, slashing ethpb.AttSlashing)
@@ -69,6 +75,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		log.WithField("blockRoot", fmt.Sprintf("%#x", blockRoot)).Debug("Ignoring already synced block")
 		return nil
 	}
+
 	receivedTime := time.Now()
 	s.blockBeingSynced.set(blockRoot)
 	defer s.blockBeingSynced.unset(blockRoot)
@@ -77,6 +84,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err != nil {
 		return err
 	}
+
 	preState, err := s.getBlockPreState(ctx, blockCopy.Block())
 	if err != nil {
 		return errors.Wrap(err, "could not get block's prestate")
@@ -92,10 +100,12 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	if err != nil {
 		return err
 	}
+
 	daWaitedTime, err := s.handleDA(ctx, blockCopy, blockRoot, avs)
 	if err != nil {
 		return err
 	}
+
 	// Defragment the state before continuing block processing.
 	s.defragmentState(postState)

@@ -231,12 +241,14 @@ func (s *Service) handleDA(
 		if err != nil {
 			return 0, err
 		}
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), rob); err != nil {
+
+		nodeID := s.cfg.P2P.NodeID()
+		if err := avs.IsDataAvailable(ctx, nodeID, s.CurrentSlot(), rob); err != nil {
 			return 0, errors.Wrap(err, "could not validate blob data availability (AvailabilityStore.IsDataAvailable)")
 		}
 	} else {
 		if err := s.isDataAvailable(ctx, blockRoot, block); err != nil {
-			return 0, errors.Wrap(err, "could not validate blob data availability")
+			return 0, errors.Wrap(err, "is data available")
 		}
 	}
 	daWaitedTime := time.Since(daStartTime)
--- a/beacon-chain/blockchain/receive_data_column.go
+++ b/beacon-chain/blockchain/receive_data_column.go
@@ -0,0 +1,14 @@
+package blockchain
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+)
+
+func (s *Service) ReceiveDataColumn(ds blocks.VerifiedRODataColumn) error {
+	if err := s.blobStorage.SaveDataColumn(ds); err != nil {
+		return errors.Wrap(err, "save data column")
+	}
+
+	return nil
+}
--- a/beacon-chain/blockchain/service.go
+++ b/beacon-chain/blockchain/service.go
@@ -37,6 +37,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -75,11 +76,12 @@ type config struct {
 	DepositCache            cache.DepositCache
 	PayloadIDCache          *cache.PayloadIDCache
 	TrackedValidatorsCache  *cache.TrackedValidatorsCache
+	AttestationCache        *cache.AttestationCache
 	AttPool                 attestations.Pool
 	ExitPool                voluntaryexits.PoolManager
 	SlashingPool            slashings.PoolManager
 	BLSToExecPool           blstoexec.PoolManager
-	P2p                     p2p.Broadcaster
+	P2P                     p2p.Acceser
 	MaxRoutines             int
 	StateNotifier           statefeed.Notifier
 	ForkChoiceStore         f.ForkChoicer
@@ -104,18 +106,26 @@ var ErrMissingClockSetter = errors.New("blockchain Service initialized without a
 type blobNotifierMap struct {
 	sync.RWMutex
 	notifiers map[[32]byte]chan uint64
-	seenIndex map[[32]byte][fieldparams.MaxBlobsPerBlock]bool
+	// TODO: Separate blobs from data columns
+	// seenIndex map[[32]byte][]bool
+	seenIndex map[[32]byte][fieldparams.NumberOfColumns]bool
 }

 // notifyIndex notifies a blob by its index for a given root.
 // It uses internal maps to keep track of seen indices and notifier channels.
-func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
-	if idx >= fieldparams.MaxBlobsPerBlock {
-		return
-	}
+func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64, slot primitives.Slot) {
+	// TODO: Separate blobs from data columns
+	// maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	// if idx >= uint64(maxBlobsPerBlock) {
+	// 	return
+	// }

 	bn.Lock()
 	seen := bn.seenIndex[root]
+	// TODO: Separate blobs from data columns
+	// if seen == nil {
+	// seen = make([]bool, maxBlobsPerBlock)
+	// }
 	if seen[idx] {
 		bn.Unlock()
 		return
@@ -126,7 +136,9 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	// Retrieve or create the notifier channel for the given root.
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		// TODO: Separate blobs from data columns
+		// c = make(chan uint64, maxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}

@@ -135,12 +147,16 @@ func (bn *blobNotifierMap) notifyIndex(root [32]byte, idx uint64) {
 	c <- idx
 }

-func (bn *blobNotifierMap) forRoot(root [32]byte) chan uint64 {
+func (bn *blobNotifierMap) forRoot(root [32]byte, slot primitives.Slot) chan uint64 {
+	// TODO: Separate blobs from data columns
+	// maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	bn.Lock()
 	defer bn.Unlock()
 	c, ok := bn.notifiers[root]
 	if !ok {
-		c = make(chan uint64, fieldparams.MaxBlobsPerBlock)
+		// TODO: Separate blobs from data columns
+		// c = make(chan uint64, maxBlobsPerBlock)
+		c = make(chan uint64, fieldparams.NumberOfColumns)
 		bn.notifiers[root] = c
 	}
 	return c
@@ -166,7 +182,9 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 	ctx, cancel := context.WithCancel(ctx)
 	bn := &blobNotifierMap{
 		notifiers: make(map[[32]byte]chan uint64),
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		// TODO: Separate blobs from data columns
+		// seenIndex: make(map[[32]byte][]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 	}
 	srv := &Service{
 		ctx:                  ctx,
--- a/beacon-chain/blockchain/service_test.go
+++ b/beacon-chain/blockchain/service_test.go
@@ -97,13 +97,14 @@ func setupBeaconChain(t *testing.T, beaconDB db.Database) *Service {
 		WithAttestationPool(attestations.NewPool()),
 		WithSlashingPool(slashings.NewPool()),
 		WithExitPool(voluntaryexits.NewPool()),
-		WithP2PBroadcaster(&mockBroadcaster{}),
+		WithP2PBroadcaster(&mockAccesser{}),
 		WithStateNotifier(&mockBeaconNode{}),
 		WithForkChoiceStore(fc),
 		WithAttestationService(attService),
 		WithStateGen(stateGen),
 		WithPayloadIDCache(cache.NewPayloadIDCache()),
 		WithClockSynchronizer(startup.NewClockSynchronizer()),
+		WithP2PBroadcaster(&mockAccesser{}),
 	}

 	chainService, err := NewService(ctx, opts...)
@@ -587,7 +588,9 @@ func (s *MockClockSetter) SetClock(g *startup.Clock) error {
 func TestNotifyIndex(t *testing.T) {
 	// Initialize a blobNotifierMap
 	bn := &blobNotifierMap{
-		seenIndex: make(map[[32]byte][fieldparams.MaxBlobsPerBlock]bool),
+		// TODO: Separate blobs from data columns
+		// seenIndex: make(map[[32]byte][]bool),
+		seenIndex: make(map[[32]byte][fieldparams.NumberOfColumns]bool),
 		notifiers: make(map[[32]byte]chan uint64),
 	}

@@ -596,7 +599,7 @@ func TestNotifyIndex(t *testing.T) {
 	copy(root[:], "exampleRoot")

 	// Test notifying a new index
-	bn.notifyIndex(root, 1)
+	bn.notifyIndex(root, 1, 1)
 	if !bn.seenIndex[root][1] {
 		t.Errorf("Index was not marked as seen")
 	}
@@ -607,13 +610,13 @@ func TestNotifyIndex(t *testing.T) {
 	}

 	// Test notifying an already seen index
-	bn.notifyIndex(root, 1)
+	bn.notifyIndex(root, 1, 1)
 	if len(bn.notifiers[root]) > 1 {
 		t.Errorf("Notifier channel should not receive multiple messages for the same index")
 	}

 	// Test notifying a new index again
-	bn.notifyIndex(root, 2)
+	bn.notifyIndex(root, 2, 1)
 	if !bn.seenIndex[root][2] {
 		t.Errorf("Index was not marked as seen")
 	}
--- a/beacon-chain/blockchain/setup_test.go
+++ b/beacon-chain/blockchain/setup_test.go
@@ -19,8 +19,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/blstoexec"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p"
+	p2pTesting "github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/testing"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stategen"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"google.golang.org/protobuf/proto"
@@ -45,6 +47,11 @@ 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 +72,11 @@ func (mb *mockBroadcaster) BroadcastBlob(_ context.Context, _ uint64, _ *ethpb.B
 	return nil
 }

+func (mb *mockBroadcaster) BroadcastDataColumn(_ context.Context, _ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+	mb.broadcastCalled = true
+	return nil
+}
+
 func (mb *mockBroadcaster) BroadcastBLSChanges(_ context.Context, _ []*ethpb.SignedBLSToExecutionChange) {
 }

@@ -122,6 +134,7 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
 		WithSyncChecker(mock.MockChecker{}),
 		WithExecutionEngineCaller(&mockExecution.EngineClient{}),
+		WithP2PBroadcaster(&mockAccesser{}),
 	}
 	// append the variadic opts so they override the defaults by being processed afterwards
 	opts = append(defOpts, opts...)
--- a/beacon-chain/blockchain/testing/mock.go
+++ b/beacon-chain/blockchain/testing/mock.go
@@ -702,6 +702,11 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 	return nil
 }

+// ReceiveDataColumn implements the same method in chain service
+func (*ChainService) ReceiveDataColumn(_ blocks.VerifiedRODataColumn) error {
+	return nil
+}
+
 // TargetRootForEpoch mocks the same method in the chain service
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil
--- a/beacon-chain/cache/BUILD.bazel
+++ b/beacon-chain/cache/BUILD.bazel
@@ -5,9 +5,11 @@ go_library(
    srcs = [
        "active_balance.go",
        "active_balance_disabled.go",  # keep
+        "attestation.go",
        "attestation_data.go",
        "balance_cache_key.go",
        "checkpoint_state.go",
+        "column_subnet_ids.go",
        "committee.go",
        "committee_disabled.go",  # keep
        "committees.go",
@@ -36,18 +38,21 @@ go_library(
    ],
    deps = [
        "//beacon-chain/forkchoice/types:go_default_library",
+        "//beacon-chain/operations/attestations/attmap:go_default_library",
        "//beacon-chain/state:go_default_library",
        "//cache/lru:go_default_library",
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
        "//container/slice:go_default_library",
+        "//crypto/bls:go_default_library",
        "//crypto/hash:go_default_library",
        "//crypto/rand:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//math:go_default_library",
        "//monitoring/tracing/trace:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/attestation:go_default_library",
        "//runtime/version:go_default_library",
        "@com_github_ethereum_go_ethereum//common:go_default_library",
        "@com_github_hashicorp_golang_lru//:go_default_library",
@@ -66,6 +71,7 @@ go_test(
    srcs = [
        "active_balance_test.go",
        "attestation_data_test.go",
+        "attestation_test.go",
        "cache_test.go",
        "checkpoint_state_test.go",
        "committee_fuzz_test.go",
@@ -88,14 +94,17 @@ go_test(
        "//config/fieldparams:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/primitives:go_default_library",
+        "//crypto/bls/blst:go_default_library",
        "//encoding/bytesutil:go_default_library",
        "//proto/prysm/v1alpha1:go_default_library",
+        "//proto/prysm/v1alpha1/attestation:go_default_library",
        "//testing/assert:go_default_library",
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
        "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
        "@com_github_google_gofuzz//:go_default_library",
        "@com_github_hashicorp_golang_lru//:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
        "@com_github_stretchr_testify//require:go_default_library",
        "@org_golang_google_protobuf//proto:go_default_library",
    ],
--- a/beacon-chain/cache/attestation.go
+++ b/beacon-chain/cache/attestation.go
@@ -0,0 +1,275 @@
+package cache
+
+import (
+	"sync"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/operations/attestations/attmap"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
+	log "github.com/sirupsen/logrus"
+)
+
+type attGroup struct {
+	slot primitives.Slot
+	atts []ethpb.Att
+}
+
+// AttestationCache holds a map of attGroup items that group together all attestations for a single slot.
+// When we add an attestation to the cache by calling Add, we either create a new group with this attestation
+// (if this is the first attestation for some slot) or two things can happen:
+//
+//   - If the attestation is unaggregated, we add its attestation bit to attestation bits of the first
+//     attestation in the group.
+//   - If the attestation is aggregated, we append it to the group. There should be no redundancy
+//     in the list because we ignore redundant aggregates in gossip.
+//
+// The first bullet point above means that we keep one aggregate attestation to which we keep appending bits
+// as new single-bit attestations arrive. This means that at any point during seconds 0-4 of a slot
+// we will have only one attestation for this slot in the cache.
+//
+// NOTE: This design in principle can result in worse aggregates since we lose the ability to aggregate some
+// single bit attestations in case of overlaps with incoming aggregates.
+//
+// The cache also keeps forkchoice attestations in a separate struct. These attestations are used for
+// forkchoice-related operations.
+type AttestationCache struct {
+	atts map[attestation.Id]*attGroup
+	sync.RWMutex
+	forkchoiceAtts *attmap.Attestations
+}
+
+// NewAttestationCache creates a new cache instance.
+func NewAttestationCache() *AttestationCache {
+	return &AttestationCache{
+		atts:           make(map[attestation.Id]*attGroup),
+		forkchoiceAtts: attmap.New(),
+	}
+}
+
+// Add does one of two things:
+//
+//   - For unaggregated attestations, it adds the attestation bit to attestation bits of the running aggregate,
+//     which is the first aggregate for the slot.
+//   - For aggregated attestations, it appends the attestation to the existing list of attestations for the slot.
+func (c *AttestationCache) Add(att ethpb.Att) error {
+	if att.IsNil() {
+		log.Debug("Attempted to add a nil attestation to the attestation cache")
+		return nil
+	}
+	if len(att.GetAggregationBits().BitIndices()) == 0 {
+		log.Debug("Attempted to add an attestation with 0 bits set to the attestation cache")
+		return nil
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	id, err := attestation.NewId(att, attestation.Data)
+	if err != nil {
+		return errors.Wrapf(err, "could not create attestation ID")
+	}
+
+	group := c.atts[id]
+	if group == nil {
+		group = &attGroup{
+			slot: att.GetData().Slot,
+			atts: []ethpb.Att{att},
+		}
+		c.atts[id] = group
+		return nil
+	}
+
+	if att.IsAggregated() {
+		group.atts = append(group.atts, att.Clone())
+		return nil
+	}
+
+	// This should never happen because we return early for a new group.
+	if len(group.atts) == 0 {
+		log.Error("Attestation group contains no attestations, skipping insertion")
+		return nil
+	}
+
+	a := group.atts[0]
+
+	// Indexing is safe because we have guarded against 0 bits set.
+	bit := att.GetAggregationBits().BitIndices()[0]
+	if a.GetAggregationBits().BitAt(uint64(bit)) {
+		return nil
+	}
+	sig, err := aggregateSig(a, att)
+	if err != nil {
+		return errors.Wrapf(err, "could not aggregate signatures")
+	}
+
+	a.GetAggregationBits().SetBitAt(uint64(bit), true)
+	a.SetSignature(sig)
+
+	return nil
+}
+
+// GetAll returns all attestations in the cache, excluding forkchoice attestations.
+func (c *AttestationCache) GetAll() []ethpb.Att {
+	c.RLock()
+	defer c.RUnlock()
+
+	var result []ethpb.Att
+	for _, group := range c.atts {
+		result = append(result, group.atts...)
+	}
+	return result
+}
+
+// Count returns the number of all attestations in the cache, excluding forkchoice attestations.
+func (c *AttestationCache) Count() int {
+	c.RLock()
+	defer c.RUnlock()
+
+	count := 0
+	for _, group := range c.atts {
+		count += len(group.atts)
+	}
+	return count
+}
+
+// DeleteCovered removes all attestations whose attestation bits are a proper subset of the passed-in attestation.
+func (c *AttestationCache) DeleteCovered(att ethpb.Att) error {
+	if att.IsNil() {
+		return nil
+	}
+
+	c.Lock()
+	defer c.Unlock()
+
+	id, err := attestation.NewId(att, attestation.Data)
+	if err != nil {
+		return errors.Wrapf(err, "could not create attestation ID")
+	}
+
+	group := c.atts[id]
+	if group == nil {
+		return nil
+	}
+
+	idx := 0
+	for _, a := range group.atts {
+		if covered, err := att.GetAggregationBits().Contains(a.GetAggregationBits()); err != nil {
+			return err
+		} else if !covered {
+			group.atts[idx] = a
+			idx++
+		}
+	}
+	group.atts = group.atts[:idx]
+
+	if len(group.atts) == 0 {
+		delete(c.atts, id)
+	}
+
+	return nil
+}
+
+// PruneBefore removes all attestations whose slot is earlier than the passed-in slot.
+func (c *AttestationCache) PruneBefore(slot primitives.Slot) uint64 {
+	c.Lock()
+	defer c.Unlock()
+
+	var pruneCount int
+	for id, group := range c.atts {
+		if group.slot < slot {
+			pruneCount += len(group.atts)
+			delete(c.atts, id)
+		}
+	}
+	return uint64(pruneCount)
+}
+
+// AggregateIsRedundant checks whether all attestation bits of the passed-in aggregate
+// are already included by any aggregate in the cache.
+func (c *AttestationCache) AggregateIsRedundant(att ethpb.Att) (bool, error) {
+	if att.IsNil() {
+		return true, nil
+	}
+
+	c.RLock()
+	defer c.RUnlock()
+
+	id, err := attestation.NewId(att, attestation.Data)
+	if err != nil {
+		return true, errors.Wrapf(err, "could not create attestation ID")
+	}
+
+	group := c.atts[id]
+	if group == nil {
+		return false, nil
+	}
+
+	for _, a := range group.atts {
+		if redundant, err := a.GetAggregationBits().Contains(att.GetAggregationBits()); err != nil {
+			return true, err
+		} else if redundant {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+// SaveForkchoiceAttestations saves forkchoice attestations.
+func (c *AttestationCache) SaveForkchoiceAttestations(att []ethpb.Att) error {
+	return c.forkchoiceAtts.SaveMany(att)
+}
+
+// ForkchoiceAttestations returns all forkchoice attestations.
+func (c *AttestationCache) ForkchoiceAttestations() []ethpb.Att {
+	return c.forkchoiceAtts.GetAll()
+}
+
+// DeleteForkchoiceAttestation deletes a forkchoice attestation.
+func (c *AttestationCache) DeleteForkchoiceAttestation(att ethpb.Att) error {
+	return c.forkchoiceAtts.Delete(att)
+}
+
+// GetBySlotAndCommitteeIndex returns all attestations in the cache that match the provided slot
+// and committee index. Forkchoice attestations are not returned.
+//
+// NOTE: This function cannot be declared as a method on the AttestationCache because it is a generic function.
+func GetBySlotAndCommitteeIndex[T ethpb.Att](c *AttestationCache, slot primitives.Slot, committeeIndex primitives.CommitteeIndex) []T {
+	c.RLock()
+	defer c.RUnlock()
+
+	var result []T
+
+	for _, group := range c.atts {
+		if len(group.atts) > 0 {
+			// We can safely compare the first attestation because all attestations in a group
+			// must have the same slot and committee index, since they are under the same key.
+			a, ok := group.atts[0].(T)
+			if ok && a.GetData().Slot == slot && a.CommitteeBitsVal().BitAt(uint64(committeeIndex)) {
+				for _, a := range group.atts {
+					a, ok := a.(T)
+					if ok {
+						result = append(result, a)
+					}
+				}
+			}
+		}
+	}
+
+	return result
+}
+
+func aggregateSig(agg ethpb.Att, att ethpb.Att) ([]byte, error) {
+	aggSig, err := bls.SignatureFromBytesNoValidation(agg.GetSignature())
+	if err != nil {
+		return nil, err
+	}
+	attSig, err := bls.SignatureFromBytesNoValidation(att.GetSignature())
+	if err != nil {
+		return nil, err
+	}
+	return bls.AggregateSignatures([]bls.Signature{aggSig, attSig}).Marshal(), nil
+}
--- a/beacon-chain/cache/attestation_data.go
+++ b/beacon-chain/cache/attestation_data.go
@@ -15,24 +15,24 @@ type AttestationConsensusData struct {
 	Source   forkchoicetypes.Checkpoint
 }

-// AttestationCache stores cached results of AttestationData requests.
-type AttestationCache struct {
+// AttestationDataCache stores cached results of AttestationData requests.
+type AttestationDataCache struct {
 	a *AttestationConsensusData
 	sync.RWMutex
 }

-// NewAttestationCache creates a new instance of AttestationCache.
-func NewAttestationCache() *AttestationCache {
-	return &AttestationCache{}
+// NewAttestationDataCache creates a new instance of AttestationDataCache.
+func NewAttestationDataCache() *AttestationDataCache {
+	return &AttestationDataCache{}
 }

 // Get retrieves cached attestation data, recording a cache hit or miss. This method is lock free.
-func (c *AttestationCache) Get() *AttestationConsensusData {
+func (c *AttestationDataCache) Get() *AttestationConsensusData {
 	return c.a
 }

 // Put adds a response to the cache. This method is lock free.
-func (c *AttestationCache) Put(a *AttestationConsensusData) error {
+func (c *AttestationDataCache) Put(a *AttestationConsensusData) error {
 	if a == nil {
 		return errors.New("attestation cannot be nil")
 	}
--- a/beacon-chain/cache/attestation_data_test.go
+++ b/beacon-chain/cache/attestation_data_test.go
@@ -9,7 +9,7 @@ import (
 )

 func TestAttestationCache_RoundTrip(t *testing.T) {
-	c := cache.NewAttestationCache()
+	c := cache.NewAttestationDataCache()

 	a := c.Get()
 	require.Nil(t, a)
--- a/beacon-chain/cache/attestation_test.go
+++ b/beacon-chain/cache/attestation_test.go
@@ -0,0 +1,353 @@
+package cache
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/go-bitfield"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls/blst"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1/attestation"
+	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestAdd(t *testing.T) {
+	k, err := blst.RandKey()
+	require.NoError(t, err)
+	sig := k.Sign([]byte{'X'})
+
+	t.Run("new ID", func(t *testing.T) {
+		t.Run("first ID ever", func(t *testing.T) {
+			c := NewAttestationCache()
+			ab := bitfield.NewBitlist(8)
+			ab.SetBitAt(0, true)
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: ab,
+				Signature:       sig.Marshal(),
+			}
+			id, err := attestation.NewId(att, attestation.Data)
+			require.NoError(t, err)
+			require.NoError(t, c.Add(att))
+
+			require.Equal(t, 1, len(c.atts))
+			group, ok := c.atts[id]
+			require.Equal(t, true, ok)
+			assert.Equal(t, primitives.Slot(123), group.slot)
+			require.Equal(t, 1, len(group.atts))
+			assert.DeepEqual(t, group.atts[0], att)
+		})
+		t.Run("other ID exists", func(t *testing.T) {
+			c := NewAttestationCache()
+			ab := bitfield.NewBitlist(8)
+			ab.SetBitAt(0, true)
+			existingAtt := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: ab,
+				Signature:       sig.Marshal(),
+			}
+			existingId, err := attestation.NewId(existingAtt, attestation.Data)
+			require.NoError(t, err)
+			c.atts[existingId] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: ab,
+				Signature:       sig.Marshal(),
+			}
+			id, err := attestation.NewId(att, attestation.Data)
+			require.NoError(t, err)
+			require.NoError(t, c.Add(att))
+
+			require.Equal(t, 2, len(c.atts))
+			group, ok := c.atts[id]
+			require.Equal(t, true, ok)
+			assert.Equal(t, primitives.Slot(123), group.slot)
+			require.Equal(t, 1, len(group.atts))
+			assert.DeepEqual(t, group.atts[0], att)
+		})
+	})
+	t.Run("aggregated", func(t *testing.T) {
+		c := NewAttestationCache()
+		existingAtt := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		id, err := attestation.NewId(existingAtt, attestation.Data)
+		require.NoError(t, err)
+		c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		require.NoError(t, c.Add(att))
+
+		require.Equal(t, 1, len(c.atts))
+		group, ok := c.atts[id]
+		require.Equal(t, true, ok)
+		assert.Equal(t, primitives.Slot(123), group.slot)
+		require.Equal(t, 2, len(group.atts))
+		assert.DeepEqual(t, group.atts[0], existingAtt)
+		assert.DeepEqual(t, group.atts[1], att)
+	})
+	t.Run("unaggregated - existing bit", func(t *testing.T) {
+		c := NewAttestationCache()
+		existingAtt := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		existingAtt.AggregationBits.SetBitAt(0, true)
+		id, err := attestation.NewId(existingAtt, attestation.Data)
+		require.NoError(t, err)
+		c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		require.NoError(t, c.Add(att))
+
+		require.Equal(t, 1, len(c.atts))
+		group, ok := c.atts[id]
+		require.Equal(t, true, ok)
+		assert.Equal(t, primitives.Slot(123), group.slot)
+		require.Equal(t, 1, len(group.atts))
+		assert.DeepEqual(t, []int{0}, group.atts[0].GetAggregationBits().BitIndices())
+	})
+	t.Run("unaggregated - new bit", func(t *testing.T) {
+		c := NewAttestationCache()
+		existingAtt := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		existingAtt.AggregationBits.SetBitAt(0, true)
+		id, err := attestation.NewId(existingAtt, attestation.Data)
+		require.NoError(t, err)
+		c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(1, true)
+		require.NoError(t, c.Add(att))
+
+		require.Equal(t, 1, len(c.atts))
+		group, ok := c.atts[id]
+		require.Equal(t, true, ok)
+		assert.Equal(t, primitives.Slot(123), group.slot)
+		require.Equal(t, 1, len(group.atts))
+		assert.DeepEqual(t, []int{0, 1}, group.atts[0].GetAggregationBits().BitIndices())
+	})
+}
+
+func TestGetAll(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}, &ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}}}
+
+	assert.Equal(t, 3, len(c.GetAll()))
+}
+
+func TestCount(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}, &ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{atts: []ethpb.Att{&ethpb.Attestation{}}}
+
+	assert.Equal(t, 3, c.Count())
+}
+
+func TestDeleteCovered(t *testing.T) {
+	k, err := blst.RandKey()
+	require.NoError(t, err)
+	sig := k.Sign([]byte{'X'})
+
+	att1 := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	att1.AggregationBits.SetBitAt(0, true)
+
+	att2 := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	att2.AggregationBits.SetBitAt(1, true)
+	att2.AggregationBits.SetBitAt(2, true)
+
+	att3 := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	att3.AggregationBits.SetBitAt(1, true)
+	att3.AggregationBits.SetBitAt(3, true)
+	att3.AggregationBits.SetBitAt(4, true)
+
+	c := NewAttestationCache()
+	id, err := attestation.NewId(att1, attestation.Data)
+	require.NoError(t, err)
+	c.atts[id] = &attGroup{slot: att1.Data.Slot, atts: []ethpb.Att{att1, att2, att3}}
+
+	t.Run("no matching group", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 456, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		att.AggregationBits.SetBitAt(2, true)
+		att.AggregationBits.SetBitAt(3, true)
+		att.AggregationBits.SetBitAt(4, true)
+		require.NoError(t, c.DeleteCovered(att))
+
+		assert.Equal(t, 3, len(c.atts[id].atts))
+	})
+	t.Run("covered atts deleted", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		att.AggregationBits.SetBitAt(3, true)
+		att.AggregationBits.SetBitAt(4, true)
+		require.NoError(t, c.DeleteCovered(att))
+
+		atts := c.atts[id].atts
+		require.Equal(t, 1, len(atts))
+		assert.DeepEqual(t, att2, atts[0])
+	})
+	t.Run("last att in group deleted", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+		att.AggregationBits.SetBitAt(1, true)
+		att.AggregationBits.SetBitAt(2, true)
+		att.AggregationBits.SetBitAt(3, true)
+		att.AggregationBits.SetBitAt(4, true)
+		require.NoError(t, c.DeleteCovered(att))
+
+		assert.Equal(t, 0, len(c.atts))
+	})
+}
+
+func TestPruneBefore(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{slot: 1, atts: []ethpb.Att{&ethpb.Attestation{}, &ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{slot: 3, atts: []ethpb.Att{&ethpb.Attestation{}}}
+	c.atts[bytesutil.ToBytes32([]byte("id3"))] = &attGroup{slot: 2, atts: []ethpb.Att{&ethpb.Attestation{}}}
+
+	count := c.PruneBefore(3)
+
+	require.Equal(t, 1, len(c.atts))
+	_, ok := c.atts[bytesutil.ToBytes32([]byte("id2"))]
+	assert.Equal(t, true, ok)
+	assert.Equal(t, uint64(3), count)
+}
+
+func TestAggregateIsRedundant(t *testing.T) {
+	k, err := blst.RandKey()
+	require.NoError(t, err)
+	sig := k.Sign([]byte{'X'})
+
+	c := NewAttestationCache()
+	existingAtt := &ethpb.Attestation{
+		Data:            &ethpb.AttestationData{Slot: 123, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+		AggregationBits: bitfield.NewBitlist(8),
+		Signature:       sig.Marshal(),
+	}
+	existingAtt.AggregationBits.SetBitAt(0, true)
+	existingAtt.AggregationBits.SetBitAt(1, true)
+	id, err := attestation.NewId(existingAtt, attestation.Data)
+	require.NoError(t, err)
+	c.atts[id] = &attGroup{slot: existingAtt.Data.Slot, atts: []ethpb.Att{existingAtt}}
+
+	t.Run("no matching group", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 456, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+
+		redundant, err := c.AggregateIsRedundant(att)
+		require.NoError(t, err)
+		assert.Equal(t, false, redundant)
+	})
+	t.Run("redundant", func(t *testing.T) {
+		att := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: existingAtt.Data.Slot, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+			AggregationBits: bitfield.NewBitlist(8),
+			Signature:       sig.Marshal(),
+		}
+		att.AggregationBits.SetBitAt(0, true)
+
+		redundant, err := c.AggregateIsRedundant(att)
+		require.NoError(t, err)
+		assert.Equal(t, true, redundant)
+	})
+	t.Run("not redundant", func(t *testing.T) {
+		t.Run("strictly better", func(t *testing.T) {
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: existingAtt.Data.Slot, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: bitfield.NewBitlist(8),
+				Signature:       sig.Marshal(),
+			}
+			att.AggregationBits.SetBitAt(0, true)
+			att.AggregationBits.SetBitAt(1, true)
+			att.AggregationBits.SetBitAt(2, true)
+
+			redundant, err := c.AggregateIsRedundant(att)
+			require.NoError(t, err)
+			assert.Equal(t, false, redundant)
+		})
+		t.Run("overlapping and new bits", func(t *testing.T) {
+			att := &ethpb.Attestation{
+				Data:            &ethpb.AttestationData{Slot: existingAtt.Data.Slot, BeaconBlockRoot: make([]byte, 32), Source: &ethpb.Checkpoint{Root: make([]byte, 32)}, Target: &ethpb.Checkpoint{Root: make([]byte, 32)}},
+				AggregationBits: bitfield.NewBitlist(8),
+				Signature:       sig.Marshal(),
+			}
+			att.AggregationBits.SetBitAt(0, true)
+			att.AggregationBits.SetBitAt(2, true)
+
+			redundant, err := c.AggregateIsRedundant(att)
+			require.NoError(t, err)
+			assert.Equal(t, false, redundant)
+		})
+	})
+}
+
+func TestGetBySlotAndCommitteeIndex(t *testing.T) {
+	c := NewAttestationCache()
+	c.atts[bytesutil.ToBytes32([]byte("id1"))] = &attGroup{slot: 1, atts: []ethpb.Att{&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 1, CommitteeIndex: 1}}, &ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 1, CommitteeIndex: 1}}}}
+	c.atts[bytesutil.ToBytes32([]byte("id2"))] = &attGroup{slot: 2, atts: []ethpb.Att{&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 2}}}}
+	c.atts[bytesutil.ToBytes32([]byte("id3"))] = &attGroup{slot: 1, atts: []ethpb.Att{&ethpb.Attestation{Data: &ethpb.AttestationData{Slot: 2, CommitteeIndex: 2}}}}
+
+	// committeeIndex has to be small enough to fit in the bitvector
+	atts := GetBySlotAndCommitteeIndex[*ethpb.Attestation](c, 1, 1)
+	require.Equal(t, 2, len(atts))
+	assert.Equal(t, primitives.Slot(1), atts[0].Data.Slot)
+	assert.Equal(t, primitives.Slot(1), atts[1].Data.Slot)
+	assert.Equal(t, primitives.CommitteeIndex(1), atts[0].Data.CommitteeIndex)
+	assert.Equal(t, primitives.CommitteeIndex(1), atts[1].Data.CommitteeIndex)
+}
--- a/beacon-chain/cache/column_subnet_ids.go
+++ b/beacon-chain/cache/column_subnet_ids.go
@@ -0,0 +1,70 @@
+package cache
+
+import (
+	"sync"
+	"time"
+
+	"github.com/patrickmn/go-cache"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+)
+
+type columnSubnetIDs struct {
+	colSubCache *cache.Cache
+	colSubLock  sync.RWMutex
+}
+
+// ColumnSubnetIDs for column subnet participants
+var ColumnSubnetIDs = newColumnSubnetIDs()
+
+const columnKey = "columns"
+
+func newColumnSubnetIDs() *columnSubnetIDs {
+	secondsPerSlot := params.BeaconConfig().SecondsPerSlot
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+	epochDuration := time.Duration(slotsPerEpoch.Mul(secondsPerSlot))
+
+	// Set the default duration of a column subnet subscription as the column expiry period.
+	minEpochsForDataColumnSidecarsRequest := time.Duration(params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest)
+	subLength := epochDuration * minEpochsForDataColumnSidecarsRequest
+
+	persistentCache := cache.New(subLength*time.Second, epochDuration*time.Second)
+	return &columnSubnetIDs{colSubCache: persistentCache}
+}
+
+// GetColumnSubnets retrieves the data column subnets.
+func (s *columnSubnetIDs) GetColumnSubnets() ([]uint64, bool, time.Time) {
+	s.colSubLock.RLock()
+	defer s.colSubLock.RUnlock()
+
+	id, duration, ok := s.colSubCache.GetWithExpiration(columnKey)
+	if !ok {
+		return nil, false, time.Time{}
+	}
+	// Retrieve indices from the cache.
+	idxs, ok := id.([]uint64)
+	if !ok {
+		return nil, false, time.Time{}
+	}
+
+	return idxs, ok, duration
+}
+
+// AddColumnSubnets adds the relevant data column subnets.
+func (s *columnSubnetIDs) AddColumnSubnets(colIdx []uint64) {
+	s.colSubLock.Lock()
+	defer s.colSubLock.Unlock()
+
+	s.colSubCache.Set(columnKey, colIdx, 0)
+}
+
+// EmptyAllCaches empties out all the related caches and flushes any stored
+// entries on them. This should only ever be used for testing, in normal
+// production, handling of the relevant subnets for each role is done
+// separately.
+func (s *columnSubnetIDs) EmptyAllCaches() {
+	// Clear the cache.
+	s.colSubLock.Lock()
+	defer s.colSubLock.Unlock()
+
+	s.colSubCache.Flush()
+}
--- a/beacon-chain/core/altair/epoch_spec_test.go
+++ b/beacon-chain/core/altair/epoch_spec_test.go
@@ -105,10 +105,9 @@ func TestProcessSlashings_NotSlashed(t *testing.T) {
 	}
 	s, err := state_native.InitializeFromProtoAltair(base)
 	require.NoError(t, err)
-	newState, err := epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplierAltair)
-	require.NoError(t, err)
+	require.NoError(t, epoch.ProcessSlashings(s))
 	wanted := params.BeaconConfig().MaxEffectiveBalance
-	assert.Equal(t, wanted, newState.Balances()[0], "Unexpected slashed balance")
+	assert.Equal(t, wanted, s.Balances()[0], "Unexpected slashed balance")
 }

 func TestProcessSlashings_SlashedLess(t *testing.T) {
@@ -176,9 +175,8 @@ func TestProcessSlashings_SlashedLess(t *testing.T) {
 			original := proto.Clone(tt.state)
 			s, err := state_native.InitializeFromProtoAltair(tt.state)
 			require.NoError(t, err)
-			newState, err := epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplierAltair)
-			require.NoError(t, err)
-			assert.Equal(t, tt.want, newState.Balances()[0], "ProcessSlashings({%v}) = newState; newState.Balances[0] = %d", original, newState.Balances()[0])
+			require.NoError(t, epoch.ProcessSlashings(s))
+			assert.Equal(t, tt.want, s.Balances()[0], "ProcessSlashings({%v}) = newState; newState.Balances[0] = %d", original, s.Balances()[0])
 		})
 	}
 }
@@ -192,6 +190,5 @@ func TestProcessSlashings_BadValue(t *testing.T) {
 	}
 	s, err := state_native.InitializeFromProtoAltair(base)
 	require.NoError(t, err)
-	_, err = epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplierAltair)
-	require.ErrorContains(t, "addition overflows", err)
+	require.ErrorContains(t, "addition overflows", epoch.ProcessSlashings(s))
 }
--- a/beacon-chain/core/altair/sync_committee.go
+++ b/beacon-chain/core/altair/sync_committee.go
@@ -2,6 +2,7 @@ package altair

 import (
 	"context"
+	"encoding/binary"
 	goErrors "errors"
 	"fmt"
 	"time"
@@ -22,8 +23,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )

-const maxRandomByte = uint64(1<<8 - 1)
-
 var (
 	ErrTooLate = errors.New("sync message is too late")
 )
@@ -91,19 +90,22 @@ func NextSyncCommittee(ctx context.Context, s state.BeaconState) (*ethpb.SyncCom
 //	"""
 //	epoch = Epoch(get_current_epoch(state) + 1)
 //
-//	MAX_RANDOM_BYTE = 2**8 - 1
+//	MAX_RANDOM_VALUE = 2**16 - 1  # [Modified in Electra]
 //	active_validator_indices = get_active_validator_indices(state, epoch)
 //	active_validator_count = uint64(len(active_validator_indices))
 //	seed = get_seed(state, epoch, DOMAIN_SYNC_COMMITTEE)
-//	i = 0
+//	i = uint64(0)
 //	sync_committee_indices: List[ValidatorIndex] = []
 //	while len(sync_committee_indices) < SYNC_COMMITTEE_SIZE:
 //	    shuffled_index = compute_shuffled_index(uint64(i % active_validator_count), active_validator_count, seed)
 //	    candidate_index = active_validator_indices[shuffled_index]
-//	    random_byte = hash(seed + uint_to_bytes(uint64(i // 32)))[i % 32]
+//	    # [Modified in Electra]
+//	    random_bytes = hash(seed + uint_to_bytes(i // 16))
+//	    offset = i % 16 * 2
+//	    random_value = bytes_to_uint64(random_bytes[offset:offset + 2])
 //	    effective_balance = state.validators[candidate_index].effective_balance
 //	    # [Modified in Electra:EIP7251]
-//	    if effective_balance * MAX_RANDOM_BYTE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_byte:
+//	    if effective_balance * MAX_RANDOM_VALUE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_value:
 //	        sync_committee_indices.append(candidate_index)
 //	    i += 1
 //	return sync_committee_indices
@@ -123,12 +125,11 @@ func NextSyncCommitteeIndices(ctx context.Context, s state.BeaconState) ([]primi
 	cIndices := make([]primitives.ValidatorIndex, 0, syncCommitteeSize)
 	hashFunc := hash.CustomSHA256Hasher()

-	maxEB := cfg.MaxEffectiveBalanceElectra
-	if s.Version() < version.Electra {
-		maxEB = cfg.MaxEffectiveBalance
-	}
+	// Preallocate buffers to avoid repeated allocations
+	seedBuffer := make([]byte, len(seed)+8)
+	copy(seedBuffer, seed[:])

-	for i := primitives.ValidatorIndex(0); uint64(len(cIndices)) < params.BeaconConfig().SyncCommitteeSize; i++ {
+	for i := primitives.ValidatorIndex(0); uint64(len(cIndices)) < syncCommitteeSize; i++ {
 		if ctx.Err() != nil {
 			return nil, ctx.Err()
 		}
@@ -137,18 +138,30 @@ func NextSyncCommitteeIndices(ctx context.Context, s state.BeaconState) ([]primi
 		if err != nil {
 			return nil, err
 		}
-
-		b := append(seed[:], bytesutil.Bytes8(uint64(i.Div(32)))...)
-		randomByte := hashFunc(b)[i%32]
 		cIndex := indices[sIndex]
 		v, err := s.ValidatorAtIndexReadOnly(cIndex)
 		if err != nil {
 			return nil, err
 		}
-
 		effectiveBal := v.EffectiveBalance()
-		if effectiveBal*maxRandomByte >= maxEB*uint64(randomByte) {
-			cIndices = append(cIndices, cIndex)
+
+		if s.Version() >= version.Electra {
+			// Use the preallocated seed buffer
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], uint64(i/16))
+			randomByte := hashFunc(seedBuffer)
+			offset := (i % 16) * 2
+			randomValue := uint64(randomByte[offset]) | uint64(randomByte[offset+1])<<8
+
+			if effectiveBal*fieldparams.MaxRandomValueElectra >= cfg.MaxEffectiveBalanceElectra*randomValue {
+				cIndices = append(cIndices, cIndex)
+			}
+		} else {
+			// Use the preallocated seed buffer
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], uint64(i/32))
+			randomByte := hashFunc(seedBuffer)[i%32]
+			if effectiveBal*fieldparams.MaxRandomByte >= cfg.MaxEffectiveBalance*uint64(randomByte) {
+				cIndices = append(cIndices, cIndex)
+			}
 		}
 	}

--- a/beacon-chain/core/altair/transition.go
+++ b/beacon-chain/core/altair/transition.go
@@ -69,12 +69,7 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	}

 	// Modified in Altair and Bellatrix.
-	proportionalSlashingMultiplier, err := state.ProportionalSlashingMultiplier()
-	if err != nil {
-		return err
-	}
-	state, err = e.ProcessSlashings(state, proportionalSlashingMultiplier)
-	if err != nil {
+	if err := e.ProcessSlashings(state); err != nil {
 		return err
 	}
 	state, err = e.ProcessEth1DataReset(state)
--- a/beacon-chain/core/blocks/exports_test.go
+++ b/beacon-chain/core/blocks/exports_test.go
@@ -1,5 +1,5 @@
 package blocks

 var ProcessBLSToExecutionChange = processBLSToExecutionChange
-
+var ErrInvalidBLSPrefix = errInvalidBLSPrefix
 var VerifyBlobCommitmentCount = verifyBlobCommitmentCount
--- a/beacon-chain/core/blocks/genesis.go
+++ b/beacon-chain/core/blocks/genesis.go
@@ -198,7 +198,7 @@ func NewGenesisBlockForState(ctx context.Context, st state.BeaconState) (interfa
 						SyncCommitteeBits:      make([]byte, fieldparams.SyncCommitteeLength/8),
 						SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
 					},
-					ExecutionPayload: &enginev1.ExecutionPayloadElectra{
+					ExecutionPayload: &enginev1.ExecutionPayloadDeneb{
 						ParentHash:    make([]byte, 32),
 						FeeRecipient:  make([]byte, 20),
 						StateRoot:     make([]byte, 32),
--- a/beacon-chain/core/blocks/payload.go
+++ b/beacon-chain/core/blocks/payload.go
@@ -8,10 +8,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensus_types "github.com/prysmaticlabs/prysm/v5/consensus-types"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
@@ -210,7 +211,7 @@ func ProcessPayload(st state.BeaconState, body interfaces.ReadOnlyBeaconBlockBod
 	if err != nil {
 		return err
 	}
-	if err := verifyBlobCommitmentCount(body); err != nil {
+	if err := verifyBlobCommitmentCount(st.Slot(), body); err != nil {
 		return err
 	}
 	if err := ValidatePayloadWhenMergeCompletes(st, payload); err != nil {
@@ -225,7 +226,7 @@ func ProcessPayload(st state.BeaconState, body interfaces.ReadOnlyBeaconBlockBod
 	return nil
 }

-func verifyBlobCommitmentCount(body interfaces.ReadOnlyBeaconBlockBody) error {
+func verifyBlobCommitmentCount(slot primitives.Slot, body interfaces.ReadOnlyBeaconBlockBody) error {
 	if body.Version() < version.Deneb {
 		return nil
 	}
@@ -233,7 +234,8 @@ func verifyBlobCommitmentCount(body interfaces.ReadOnlyBeaconBlockBody) error {
 	if err != nil {
 		return err
 	}
-	if len(kzgs) > field_params.MaxBlobsPerBlock {
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
+	if len(kzgs) > maxBlobsPerBlock {
 		return fmt.Errorf("too many kzg commitments in block: %d", len(kzgs))
 	}
 	return nil
--- a/beacon-chain/core/blocks/payload_test.go
+++ b/beacon-chain/core/blocks/payload_test.go
@@ -9,6 +9,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
 	consensusblocks "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -923,10 +924,10 @@ func TestVerifyBlobCommitmentCount(t *testing.T) {
 	b := &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{}}
 	rb, err := consensusblocks.NewBeaconBlock(b)
 	require.NoError(t, err)
-	require.NoError(t, blocks.VerifyBlobCommitmentCount(rb.Body()))
+	require.NoError(t, blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))

-	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, fieldparams.MaxBlobsPerBlock+1)}}
+	b = &ethpb.BeaconBlockDeneb{Body: &ethpb.BeaconBlockBodyDeneb{BlobKzgCommitments: make([][]byte, params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())+1)}}
 	rb, err = consensusblocks.NewBeaconBlock(b)
 	require.NoError(t, err)
-	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: %d", fieldparams.MaxBlobsPerBlock+1), blocks.VerifyBlobCommitmentCount(rb.Body()))
+	require.ErrorContains(t, fmt.Sprintf("too many kzg commitments in block: %d", params.BeaconConfig().MaxBlobsPerBlock(rb.Slot())+1), blocks.VerifyBlobCommitmentCount(rb.Slot(), rb.Body()))
 }
--- a/beacon-chain/core/blocks/signature.go
+++ b/beacon-chain/core/blocks/signature.go
@@ -96,6 +96,24 @@ func VerifyBlockHeaderSignature(beaconState state.BeaconState, header *ethpb.Sig
 	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
 }

+func VerifyBlockHeaderSignatureUsingCurrentFork(beaconState state.BeaconState, header *ethpb.SignedBeaconBlockHeader) error {
+	currentEpoch := slots.ToEpoch(header.Header.Slot)
+	fork, err := forks.Fork(currentEpoch)
+	if err != nil {
+		return err
+	}
+	domain, err := signing.Domain(fork, currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorsRoot())
+	if err != nil {
+		return err
+	}
+	proposer, err := beaconState.ValidatorAtIndex(header.Header.ProposerIndex)
+	if err != nil {
+		return err
+	}
+	proposerPubKey := proposer.PublicKey
+	return signing.VerifyBlockHeaderSigningRoot(header.Header, proposerPubKey, header.Signature, domain)
+}
+
 // VerifyBlockSignatureUsingCurrentFork verifies the proposer signature of a beacon block. This differs
 // from the above method by not using fork data from the state and instead retrieving it
 // via the respective epoch.
--- a/beacon-chain/core/blocks/withdrawals.go
+++ b/beacon-chain/core/blocks/withdrawals.go
@@ -100,8 +100,11 @@ func ValidateBLSToExecutionChange(st state.ReadOnlyBeaconState, signed *ethpb.Si
 	if err != nil {
 		return nil, err
 	}
+	if val == nil {
+		return nil, errors.Wrap(errInvalidWithdrawalCredentials, "validator is nil") // This should not be possible.
+	}
 	cred := val.WithdrawalCredentials
-	if cred[0] != params.BeaconConfig().BLSWithdrawalPrefixByte {
+	if len(cred) < 2 || cred[0] != params.BeaconConfig().BLSWithdrawalPrefixByte {
 		return nil, errInvalidBLSPrefix
 	}

--- a/beacon-chain/core/blocks/withdrawals_test.go
+++ b/beacon-chain/core/blocks/withdrawals_test.go
@@ -113,7 +113,42 @@ func TestProcessBLSToExecutionChange(t *testing.T) {
 		require.NoError(t, err)
 		require.DeepEqual(t, digest[:], val.WithdrawalCredentials)
 	})
+	t.Run("nil validator does not panic", func(t *testing.T) {
+		priv, err := bls.RandKey()
+		require.NoError(t, err)
+		pubkey := priv.PublicKey().Marshal()

+		message := &ethpb.BLSToExecutionChange{
+			ToExecutionAddress: []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13},
+			ValidatorIndex:     0,
+			FromBlsPubkey:      pubkey,
+		}
+
+		registry := []*ethpb.Validator{
+			nil,
+		}
+		st, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
+			Validators: registry,
+			Fork: &ethpb.Fork{
+				CurrentVersion:  params.BeaconConfig().GenesisForkVersion,
+				PreviousVersion: params.BeaconConfig().GenesisForkVersion,
+			},
+			Slot: params.BeaconConfig().SlotsPerEpoch * 5,
+		})
+		require.NoError(t, err)
+
+		signature, err := signing.ComputeDomainAndSign(st, time.CurrentEpoch(st), message, params.BeaconConfig().DomainBLSToExecutionChange, priv)
+		require.NoError(t, err)
+
+		signed := &ethpb.SignedBLSToExecutionChange{
+			Message:   message,
+			Signature: signature,
+		}
+		_, err = blocks.ValidateBLSToExecutionChange(st, signed)
+		// The state should return an empty validator, even when the validator object in the registry is
+		// nil. This error should return when the withdrawal credentials are invalid or too short.
+		require.ErrorIs(t, err, blocks.ErrInvalidBLSPrefix)
+	})
 	t.Run("non-existent validator", func(t *testing.T) {
 		priv, err := bls.RandKey()
 		require.NoError(t, err)
@@ -1117,7 +1152,7 @@ func TestProcessWithdrawals(t *testing.T) {
 						}
 						st, err = state_native.InitializeFromProtoUnsafeElectra(spb)
 						require.NoError(t, err)
-						p, err = consensusblocks.WrappedExecutionPayloadElectra(&enginev1.ExecutionPayloadElectra{Withdrawals: test.Args.Withdrawals})
+						p, err = consensusblocks.WrappedExecutionPayloadDeneb(&enginev1.ExecutionPayloadDeneb{Withdrawals: test.Args.Withdrawals})
 						require.NoError(t, err)
 					default:
 						t.Fatalf("Add a beacon state setup for version %s", version.String(fork))
--- a/beacon-chain/core/electra/churn_test.go
+++ b/beacon-chain/core/electra/churn_test.go
@@ -20,7 +20,7 @@ func createValidatorsWithTotalActiveBalance(totalBal primitives.Gwei) []*eth.Val
 	vals := make([]*eth.Validator, num)
 	for i := range vals {
 		wd := make([]byte, 32)
-		wd[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+		wd[0] = params.BeaconConfig().CompoundingWithdrawalPrefixByte
 		wd[31] = byte(i)

 		vals[i] = &eth.Validator{
--- a/beacon-chain/core/electra/consolidations.go
+++ b/beacon-chain/core/electra/consolidations.go
@@ -9,6 +9,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -37,8 +38,7 @@ import (
 //	        break
 //
 //	    # Calculate the consolidated balance
-//	    max_effective_balance = get_max_effective_balance(source_validator)
-//	    source_effective_balance = min(state.balances[pending_consolidation.source_index], max_effective_balance)
+//	    source_effective_balance = min(state.balances[pending_consolidation.source_index], source_validator.effective_balance)
 //
 //	    # Move active balance to target. Excess balance is withdrawable.
 //	    decrease_balance(state, pending_consolidation.source_index, source_effective_balance)
@@ -78,7 +78,7 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 		if err != nil {
 			return err
 		}
-		b := min(validatorBalance, helpers.ValidatorMaxEffectiveBalance(sourceValidator))
+		b := min(validatorBalance, sourceValidator.EffectiveBalance())

 		if err := helpers.DecreaseBalance(st, pc.SourceIndex, b); err != nil {
 			return err
@@ -141,8 +141,8 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 //	    if not (has_correct_credential and is_correct_source_address):
 //	        return
 //
-//	    # Verify that target has execution withdrawal credentials
-//	    if not has_execution_withdrawal_credential(target_validator):
+//	    # Verify that target has compounding withdrawal credentials
+//	    if not has_compounding_withdrawal_credential(target_validator):
 //	        return
 //
 //	    # Verify the source and the target are active
@@ -175,10 +175,6 @@ func ProcessPendingConsolidations(ctx context.Context, st state.BeaconState) err
 //	        source_index=source_index,
 //	        target_index=target_index
 //	    ))
-//
-//	    # Churn any target excess active balance of target and raise its max
-//	    if has_eth1_withdrawal_credential(target_validator):
-//	        switch_to_compounding_validator(state, target_index)
 func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, reqs []*enginev1.ConsolidationRequest) error {
 	if len(reqs) == 0 || st == nil {
 		return nil
@@ -238,13 +234,18 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 			return fmt.Errorf("failed to fetch source validator: %w", err) // This should never happen.
 		}

+		roSrcV, err := state_native.NewValidator(srcV)
+		if err != nil {
+			return err
+		}
+
 		tgtV, err := st.ValidatorAtIndexReadOnly(tgtIdx)
 		if err != nil {
 			return fmt.Errorf("failed to fetch target validator: %w", err) // This should never happen.
 		}

 		// Verify source withdrawal credentials
-		if !helpers.HasExecutionWithdrawalCredentials(srcV) {
+		if !roSrcV.HasExecutionWithdrawalCredentials() {
 			continue
 		}
 		// Confirm source_validator.withdrawal_credentials[12:] == consolidation_request.source_address
@@ -253,7 +254,7 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		}

 		// Target validator must have their withdrawal credentials set appropriately.
-		if !helpers.HasExecutionWithdrawalCredentials(tgtV) {
+		if !tgtV.HasCompoundingWithdrawalCredentials() {
 			continue
 		}

@@ -298,13 +299,6 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		if err := st.AppendPendingConsolidation(&eth.PendingConsolidation{SourceIndex: srcIdx, TargetIndex: tgtIdx}); err != nil {
 			return fmt.Errorf("failed to append pending consolidation: %w", err) // This should never happen.
 		}
-
-		if helpers.HasETH1WithdrawalCredential(tgtV) {
-			if err := SwitchToCompoundingValidator(st, tgtIdx); err != nil {
-				log.WithError(err).Error("failed to switch to compounding validator")
-				continue
-			}
-		}
 	}

 	return nil
@@ -376,7 +370,7 @@ func IsValidSwitchToCompoundingRequest(st state.BeaconState, req *enginev1.Conso
 		return false
 	}

-	if !helpers.HasETH1WithdrawalCredential(srcV) {
+	if !srcV.HasETH1WithdrawalCredentials() {
 		return false
 	}

--- a/beacon-chain/core/electra/consolidations_test.go
+++ b/beacon-chain/core/electra/consolidations_test.go
@@ -46,6 +46,7 @@ func TestProcessPendingConsolidations(t *testing.T) {
 					Validators: []*eth.Validator{
 						{
 							WithdrawalCredentials: []byte{0x01, 0xFF},
+							EffectiveBalance:      params.BeaconConfig().MinActivationBalance,
 						},
 						{
 							WithdrawalCredentials: []byte{0x01, 0xAB},
@@ -218,7 +219,7 @@ func TestProcessConsolidationRequests(t *testing.T) {
 				}
 				// Validator scenario setup. See comments in reqs section.
 				st.Validators[3].WithdrawalCredentials = bytesutil.Bytes32(0)
-				st.Validators[8].WithdrawalCredentials = bytesutil.Bytes32(0)
+				st.Validators[8].WithdrawalCredentials = bytesutil.Bytes32(1)
 				st.Validators[9].ActivationEpoch = params.BeaconConfig().FarFutureEpoch
 				st.Validators[12].ActivationEpoch = params.BeaconConfig().FarFutureEpoch
 				st.Validators[13].ExitEpoch = 10
@@ -246,7 +247,7 @@ func TestProcessConsolidationRequests(t *testing.T) {
 					SourcePubkey:  []byte("val_5"),
 					TargetPubkey:  []byte("val_6"),
 				},
-				// Target does not have their withdrawal credentials set appropriately.
+				// Target does not have their withdrawal credentials set appropriately. (Using eth1 address prefix)
 				{
 					SourceAddress: append(bytesutil.PadTo(nil, 19), byte(7)),
 					SourcePubkey:  []byte("val_7"),
--- a/beacon-chain/core/electra/deposits.go
+++ b/beacon-chain/core/electra/deposits.go
@@ -15,7 +15,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing/trace"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
@@ -273,7 +272,7 @@ func ProcessPendingDeposits(ctx context.Context, st state.BeaconState, activeBal
 	isChurnLimitReached := false

 	var pendingDepositsToBatchVerify []*ethpb.PendingDeposit
-	var pendingDepositsToPostpone []*eth.PendingDeposit
+	var pendingDepositsToPostpone []*ethpb.PendingDeposit

 	depBalToConsume, err := st.DepositBalanceToConsume()
 	if err != nil {
--- a/beacon-chain/core/electra/effective_balance_updates.go
+++ b/beacon-chain/core/electra/effective_balance_updates.go
@@ -3,7 +3,6 @@ package electra
 import (
 	"fmt"

-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -40,7 +39,7 @@ func ProcessEffectiveBalanceUpdates(st state.BeaconState) error {

 	// Update effective balances with hysteresis.
 	validatorFunc := func(idx int, val state.ReadOnlyValidator) (newVal *ethpb.Validator, err error) {
-		if val == nil {
+		if val.IsNil() {
 			return nil, fmt.Errorf("validator %d is nil in state", idx)
 		}
 		if idx >= len(bals) {
@@ -49,7 +48,7 @@ func ProcessEffectiveBalanceUpdates(st state.BeaconState) error {
 		balance := bals[idx]

 		effectiveBalanceLimit := params.BeaconConfig().MinActivationBalance
-		if helpers.HasCompoundingWithdrawalCredential(val) {
+		if val.HasCompoundingWithdrawalCredentials() {
 			effectiveBalanceLimit = params.BeaconConfig().MaxEffectiveBalanceElectra
 		}

--- a/beacon-chain/core/electra/effective_balance_updates_test.go
+++ b/beacon-chain/core/electra/effective_balance_updates_test.go
@@ -77,7 +77,7 @@ func TestProcessEffectiveBalnceUpdates(t *testing.T) {
 					Validators: []*eth.Validator{
 						{
 							EffectiveBalance:      params.BeaconConfig().MinActivationBalance / 2,
-							WithdrawalCredentials: nil,
+							WithdrawalCredentials: make([]byte, 32),
 						},
 					},
 					Balances: []uint64{
--- a/beacon-chain/core/electra/registry_updates.go
+++ b/beacon-chain/core/electra/registry_updates.go
@@ -18,23 +18,24 @@ import (
 //
 // Spec pseudocode definition:
 //
-//		def process_registry_updates(state: BeaconState) -> None:
-//		    # Process activation eligibility and ejections
-//		    for index, validator in enumerate(state.validators):
-//		        if is_eligible_for_activation_queue(validator):
-//		            validator.activation_eligibility_epoch = get_current_epoch(state) + 1
+//	def process_registry_updates(state: BeaconState) -> None:
+//	    # Process activation eligibility and ejections
+//	    for index, validator in enumerate(state.validators):
+//	        if is_eligible_for_activation_queue(validator):  # [Modified in Electra:EIP7251]
+//	            validator.activation_eligibility_epoch = get_current_epoch(state) + 1
 //
-//		        if (
-//		            is_active_validator(validator, get_current_epoch(state))
-//		            and validator.effective_balance <= EJECTION_BALANCE
-//		        ):
-//		            initiate_validator_exit(state, ValidatorIndex(index))
+//	        if (
+//	            is_active_validator(validator, get_current_epoch(state))
+//	            and validator.effective_balance <= EJECTION_BALANCE
+//	        ):
+//	            initiate_validator_exit(state, ValidatorIndex(index))  # [Modified in Electra:EIP7251]
 //
-//	         # Activate all eligible validators
-//	         activation_epoch = compute_activation_exit_epoch(get_current_epoch(state))
-//	         for validator in state.validators:
-//	             if is_eligible_for_activation(state, validator):
-//	                 validator.activation_epoch = activation_epoch
+//	    # Activate all eligible validators
+//	    # [Modified in Electra:EIP7251]
+//	    activation_epoch = compute_activation_exit_epoch(get_current_epoch(state))
+//	    for validator in state.validators:
+//	        if is_eligible_for_activation(state, validator):
+//	            validator.activation_epoch = activation_epoch
 func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) error {
 	currentEpoch := time.CurrentEpoch(st)
 	ejectionBal := params.BeaconConfig().EjectionBalance
@@ -90,8 +91,8 @@ func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) error {
 		}
 	}

+	// Activate all eligible validators.
 	for _, idx := range eligibleForActivation {
-		// Activate all eligible validators.
 		v, err := st.ValidatorAtIndex(idx)
 		if err != nil {
 			return err
--- a/beacon-chain/core/electra/transition.go
+++ b/beacon-chain/core/electra/transition.go
@@ -40,14 +40,17 @@ var (
 //	    process_justification_and_finalization(state)
 //	    process_inactivity_updates(state)
 //	    process_rewards_and_penalties(state)
-//	    process_registry_updates(state)
-//	    process_slashings(state)
+//	    process_registry_updates(state)  # [Modified in Electra:EIP7251]
+//	    process_slashings(state)  # [Modified in Electra:EIP7251]
 //	    process_eth1_data_reset(state)
-//	    process_pending_deposits(state)  # New in EIP7251
-//	    process_pending_consolidations(state)  # New in EIP7251
-//	    process_effective_balance_updates(state)
+//	    process_pending_deposits(state)  # [New in Electra:EIP7251]
+//	    process_pending_consolidations(state)  # [New in Electra:EIP7251]
+//	    process_effective_balance_updates(state)  # [Modified in Electra:EIP7251]
 //	    process_slashings_reset(state)
 //	    process_randao_mixes_reset(state)
+//	    process_historical_summaries_update(state)
+//	    process_participation_flag_updates(state)
+//	    process_sync_committee_updates(state)
 func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	_, span := trace.StartSpan(ctx, "electra.ProcessEpoch")
 	defer span.End()
@@ -75,24 +78,16 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	if err != nil {
 		return errors.Wrap(err, "could not process rewards and penalties")
 	}
-
 	if err := ProcessRegistryUpdates(ctx, state); err != nil {
 		return errors.Wrap(err, "could not process registry updates")
 	}
-
-	proportionalSlashingMultiplier, err := state.ProportionalSlashingMultiplier()
-	if err != nil {
-		return err
-	}
-	state, err = ProcessSlashings(state, proportionalSlashingMultiplier)
-	if err != nil {
+	if err := ProcessSlashings(state); err != nil {
 		return err
 	}
 	state, err = ProcessEth1DataReset(state)
 	if err != nil {
 		return err
 	}
-
 	if err = ProcessPendingDeposits(ctx, state, primitives.Gwei(bp.ActiveCurrentEpoch)); err != nil {
 		return err
 	}
@@ -102,7 +97,6 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	if err = ProcessEffectiveBalanceUpdates(state); err != nil {
 		return err
 	}
-
 	state, err = ProcessSlashingsReset(state)
 	if err != nil {
 		return err
@@ -115,17 +109,14 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	if err != nil {
 		return err
 	}
-
 	state, err = ProcessParticipationFlagUpdates(state)
 	if err != nil {
 		return err
 	}
-
 	_, err = ProcessSyncCommitteeUpdates(ctx, state)
 	if err != nil {
 		return err
 	}
-
 	return nil
 }

--- a/beacon-chain/core/electra/upgrade.go
+++ b/beacon-chain/core/electra/upgrade.go
@@ -194,7 +194,7 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 		if val.ActivationEpoch() == params.BeaconConfig().FarFutureEpoch {
 			preActivationIndices = append(preActivationIndices, primitives.ValidatorIndex(index))
 		}
-		if helpers.HasCompoundingWithdrawalCredential(val) {
+		if val.HasCompoundingWithdrawalCredentials() {
 			compoundWithdrawalIndices = append(compoundWithdrawalIndices, primitives.ValidatorIndex(index))
 		}
 		return nil
@@ -240,7 +240,7 @@ func UpgradeToElectra(beaconState state.BeaconState) (state.BeaconState, error)
 		InactivityScores:            inactivityScores,
 		CurrentSyncCommittee:        currentSyncCommittee,
 		NextSyncCommittee:           nextSyncCommittee,
-		LatestExecutionPayloadHeader: &enginev1.ExecutionPayloadHeaderElectra{
+		LatestExecutionPayloadHeader: &enginev1.ExecutionPayloadHeaderDeneb{
 			ParentHash:       payloadHeader.ParentHash(),
 			FeeRecipient:     payloadHeader.FeeRecipient(),
 			StateRoot:        payloadHeader.StateRoot(),
--- a/beacon-chain/core/electra/upgrade_test.go
+++ b/beacon-chain/core/electra/upgrade_test.go
@@ -102,7 +102,7 @@ func TestUpgradeToElectra(t *testing.T) {

 	header, err := mSt.LatestExecutionPayloadHeader()
 	require.NoError(t, err)
-	protoHeader, ok := header.Proto().(*enginev1.ExecutionPayloadHeaderElectra)
+	protoHeader, ok := header.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
 	require.Equal(t, true, ok)
 	prevHeader, err := preForkState.LatestExecutionPayloadHeader()
 	require.NoError(t, err)
@@ -111,7 +111,7 @@ func TestUpgradeToElectra(t *testing.T) {

 	wdRoot, err := prevHeader.WithdrawalsRoot()
 	require.NoError(t, err)
-	wanted := &enginev1.ExecutionPayloadHeaderElectra{
+	wanted := &enginev1.ExecutionPayloadHeaderDeneb{
 		ParentHash:       prevHeader.ParentHash(),
 		FeeRecipient:     prevHeader.FeeRecipient(),
 		StateRoot:        prevHeader.StateRoot(),
--- a/beacon-chain/core/electra/withdrawals.go
+++ b/beacon-chain/core/electra/withdrawals.go
@@ -116,7 +116,7 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 			return nil, err
 		}
 		// Verify withdrawal credentials
-		hasCorrectCredential := helpers.HasExecutionWithdrawalCredentials(validator)
+		hasCorrectCredential := validator.HasExecutionWithdrawalCredentials()
 		wc := validator.GetWithdrawalCredentials()
 		isCorrectSourceAddress := bytes.Equal(wc[12:], wr.SourceAddress)
 		if !hasCorrectCredential || !isCorrectSourceAddress {
@@ -165,7 +165,7 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 		hasExcessBalance := vBal > params.BeaconConfig().MinActivationBalance+pendingBalanceToWithdraw

 		// Only allow partial withdrawals with compounding withdrawal credentials
-		if helpers.HasCompoundingWithdrawalCredential(validator) && hasSufficientEffectiveBalance && hasExcessBalance {
+		if validator.HasCompoundingWithdrawalCredentials() && hasSufficientEffectiveBalance && hasExcessBalance {
 			// Spec definition:
 			//  to_withdraw = min(
 			//	  state.balances[index] - MIN_ACTIVATION_BALANCE - pending_balance_to_withdraw,
--- a/beacon-chain/core/epoch/epoch_processing.go
+++ b/beacon-chain/core/epoch/epoch_processing.go
@@ -141,29 +141,76 @@ func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) (state.Be
 	return st, nil
 }

-// ProcessSlashings processes the slashed validators during epoch processing,
+// ProcessSlashings processes the slashed validators during epoch processing. This is a state mutating method.
+//
+// Electra spec definition:
 //
 //	def process_slashings(state: BeaconState) -> None:
-//	  epoch = get_current_epoch(state)
-//	  total_balance = get_total_active_balance(state)
-//	  adjusted_total_slashing_balance = min(sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER, total_balance)
-//	  if state.version == electra:
-//		 increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from total balance to avoid uint64 overflow
-//	  penalty_per_effective_balance_increment = adjusted_total_slashing_balance // (total_balance // increment)
-//	  for index, validator in enumerate(state.validators):
-//	      if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch:
-//	          increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from penalty numerator to avoid uint64 overflow
-//	          penalty_numerator = validator.effective_balance // increment * adjusted_total_slashing_balance
-//	          penalty = penalty_numerator // total_balance * increment
-//	          if state.version == electra:
+//	    epoch = get_current_epoch(state)
+//	    total_balance = get_total_active_balance(state)
+//	    adjusted_total_slashing_balance = min(
+//	        sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER_BELLATRIX,
+//	        total_balance
+//	    )
+//	    increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from total balance to avoid uint64 overflow
+//	    penalty_per_effective_balance_increment = adjusted_total_slashing_balance // (total_balance // increment)
+//	    for index, validator in enumerate(state.validators):
+//	        if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch:
 //	            effective_balance_increments = validator.effective_balance // increment
+//	            # [Modified in Electra:EIP7251]
 //	            penalty = penalty_per_effective_balance_increment * effective_balance_increments
-//	          decrease_balance(state, ValidatorIndex(index), penalty)
-func ProcessSlashings(st state.BeaconState, slashingMultiplier uint64) (state.BeaconState, error) {
+//	            decrease_balance(state, ValidatorIndex(index), penalty)
+//
+// Bellatrix spec definition:
+//
+//	def process_slashings(state: BeaconState) -> None:
+//	    epoch = get_current_epoch(state)
+//	    total_balance = get_total_active_balance(state)
+//	    adjusted_total_slashing_balance = min(
+//	        sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER_BELLATRIX,  # [Modified in Bellatrix]
+//	        total_balance
+//	    )
+//	    for index, validator in enumerate(state.validators):
+//	        if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch:
+//	            increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from penalty numerator to avoid uint64 overflow
+//	            penalty_numerator = validator.effective_balance // increment * adjusted_total_slashing_balance
+//	            penalty = penalty_numerator // total_balance * increment
+//	            decrease_balance(state, ValidatorIndex(index), penalty)
+//
+// Altair spec definition:
+//
+//	def process_slashings(state: BeaconState) -> None:
+//	    epoch = get_current_epoch(state)
+//	    total_balance = get_total_active_balance(state)
+//	    adjusted_total_slashing_balance = min(sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER_ALTAIR, total_balance)
+//	    for index, validator in enumerate(state.validators):
+//	        if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch:
+//	            increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from penalty numerator to avoid uint64 overflow
+//	            penalty_numerator = validator.effective_balance // increment * adjusted_total_slashing_balance
+//	            penalty = penalty_numerator // total_balance * increment
+//	            decrease_balance(state, ValidatorIndex(index), penalty)
+//
+// Phase0 spec definition:
+//
+//	def process_slashings(state: BeaconState) -> None:
+//	    epoch = get_current_epoch(state)
+//	    total_balance = get_total_active_balance(state)
+//	    adjusted_total_slashing_balance = min(sum(state.slashings) * PROPORTIONAL_SLASHING_MULTIPLIER, total_balance)
+//	    for index, validator in enumerate(state.validators):
+//	        if validator.slashed and epoch + EPOCHS_PER_SLASHINGS_VECTOR // 2 == validator.withdrawable_epoch:
+//	            increment = EFFECTIVE_BALANCE_INCREMENT  # Factored out from penalty numerator to avoid uint64 overflow
+//	            penalty_numerator = validator.effective_balance // increment * adjusted_total_slashing_balance
+//	            penalty = penalty_numerator // total_balance * increment
+//	            decrease_balance(state, ValidatorIndex(index), penalty)
+func ProcessSlashings(st state.BeaconState) error {
+	slashingMultiplier, err := st.ProportionalSlashingMultiplier()
+	if err != nil {
+		return errors.Wrap(err, "could not get proportional slashing multiplier")
+	}
 	currentEpoch := time.CurrentEpoch(st)
 	totalBalance, err := helpers.TotalActiveBalance(st)
 	if err != nil {
-		return nil, errors.Wrap(err, "could not get total active balance")
+		return errors.Wrap(err, "could not get total active balance")
 	}

 	// Compute slashed balances in the current epoch
@@ -175,7 +222,7 @@ func ProcessSlashings(st state.BeaconState, slashingMultiplier uint64) (state.Be
 	for _, slashing := range slashings {
 		totalSlashing, err = math.Add64(totalSlashing, slashing)
 		if err != nil {
-			return nil, err
+			return err
 		}
 	}

@@ -209,14 +256,14 @@ func ProcessSlashings(st state.BeaconState, slashingMultiplier uint64) (state.Be
 		return nil
 	})
 	if err != nil {
-		return nil, err
+		return err
 	}
 	if changed {
 		if err := st.SetBalances(bals); err != nil {
-			return nil, err
+			return err
 		}
 	}
-	return st, nil
+	return nil
 }

 // ProcessEth1DataReset processes updates to ETH1 data votes during epoch processing.
--- a/beacon-chain/core/epoch/epoch_processing_test.go
+++ b/beacon-chain/core/epoch/epoch_processing_test.go
@@ -32,10 +32,9 @@ func TestProcessSlashings_NotSlashed(t *testing.T) {
 	}
 	s, err := state_native.InitializeFromProtoPhase0(base)
 	require.NoError(t, err)
-	newState, err := epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplier)
-	require.NoError(t, err)
+	require.NoError(t, epoch.ProcessSlashings(s))
 	wanted := params.BeaconConfig().MaxEffectiveBalance
-	assert.Equal(t, wanted, newState.Balances()[0], "Unexpected slashed balance")
+	assert.Equal(t, wanted, s.Balances()[0], "Unexpected slashed balance")
 }

 func TestProcessSlashings_SlashedLess(t *testing.T) {
@@ -111,9 +110,8 @@ func TestProcessSlashings_SlashedLess(t *testing.T) {
 			s, err := state_native.InitializeFromProtoPhase0(tt.state)
 			require.NoError(t, err)
 			helpers.ClearCache()
-			newState, err := epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplier)
-			require.NoError(t, err)
-			assert.Equal(t, tt.want, newState.Balances()[0], "ProcessSlashings({%v}) = newState; newState.Balances[0] = %d", original, newState.Balances()[0])
+			require.NoError(t, epoch.ProcessSlashings(s))
+			assert.Equal(t, tt.want, s.Balances()[0], "ProcessSlashings({%v}) = newState; newState.Balances[0] = %d", original, s.Balances()[0])
 		})
 	}
 }
@@ -365,8 +363,7 @@ func TestProcessSlashings_BadValue(t *testing.T) {
 	}
 	s, err := state_native.InitializeFromProtoPhase0(base)
 	require.NoError(t, err)
-	_, err = epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplier)
-	require.ErrorContains(t, "addition overflows", err)
+	require.ErrorContains(t, "addition overflows", epoch.ProcessSlashings(s))
 }

 func TestProcessHistoricalDataUpdate(t *testing.T) {
@@ -514,9 +511,8 @@ func TestProcessSlashings_SlashedElectra(t *testing.T) {
 			s, err := state_native.InitializeFromProtoElectra(tt.state)
 			require.NoError(t, err)
 			helpers.ClearCache()
-			newState, err := epoch.ProcessSlashings(s, params.BeaconConfig().ProportionalSlashingMultiplierBellatrix)
-			require.NoError(t, err)
-			assert.Equal(t, tt.want, newState.Balances()[0], "ProcessSlashings({%v}) = newState; newState.Balances[0] = %d", original, newState.Balances()[0])
+			require.NoError(t, epoch.ProcessSlashings(s))
+			assert.Equal(t, tt.want, s.Balances()[0], "ProcessSlashings({%v}); s.Balances[0] = %d", original, s.Balances()[0])
 		})
 	}
 }
--- a/beacon-chain/core/feed/operation/events.go
+++ b/beacon-chain/core/feed/operation/events.go
@@ -32,6 +32,9 @@ const (

 	// AttesterSlashingReceived is sent after an attester slashing is received from gossip or rpc
 	AttesterSlashingReceived = 8
+
+	// DataColumnSidecarReceived is sent after a data column sidecar is received from gossip or rpc.
+	DataColumnSidecarReceived = 9
 )

 // UnAggregatedAttReceivedData is the data sent with UnaggregatedAttReceived events.
@@ -77,3 +80,7 @@ type ProposerSlashingReceivedData struct {
 type AttesterSlashingReceivedData struct {
 	AttesterSlashing ethpb.AttSlashing
 }
+
+type DataColumnSidecarReceivedData struct {
+	DataColumn *blocks.VerifiedRODataColumn
+}
--- a/beacon-chain/core/fulu/BUILD.bazel
+++ b/beacon-chain/core/fulu/BUILD.bazel
@@ -0,0 +1,32 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["upgrade.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/fulu",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/core/time:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//beacon-chain/state/state-native:go_default_library",
+        "//config/params:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["upgrade_test.go"],
+    deps = [
+        ":go_default_library",
+        "//beacon-chain/core/time:go_default_library",
+        "//config/params: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",
+    ],
+)
--- a/beacon-chain/core/fulu/upgrade.go
+++ b/beacon-chain/core/fulu/upgrade.go
@@ -0,0 +1,175 @@
+package fulu
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+// 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
+func UpgradeToFulu(beaconState state.BeaconState) (state.BeaconState, error) {
+	currentSyncCommittee, err := beaconState.CurrentSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	nextSyncCommittee, err := beaconState.NextSyncCommittee()
+	if err != nil {
+		return nil, err
+	}
+	prevEpochParticipation, err := beaconState.PreviousEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	currentEpochParticipation, err := beaconState.CurrentEpochParticipation()
+	if err != nil {
+		return nil, err
+	}
+	inactivityScores, err := beaconState.InactivityScores()
+	if err != nil {
+		return nil, err
+	}
+	payloadHeader, err := beaconState.LatestExecutionPayloadHeader()
+	if err != nil {
+		return nil, err
+	}
+	txRoot, err := payloadHeader.TransactionsRoot()
+	if err != nil {
+		return nil, err
+	}
+	wdRoot, err := payloadHeader.WithdrawalsRoot()
+	if err != nil {
+		return nil, err
+	}
+	wi, err := beaconState.NextWithdrawalIndex()
+	if err != nil {
+		return nil, err
+	}
+	vi, err := beaconState.NextWithdrawalValidatorIndex()
+	if err != nil {
+		return nil, err
+	}
+	summaries, err := beaconState.HistoricalSummaries()
+	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
+	}
+	blobGasUsed, err := payloadHeader.BlobGasUsed()
+	if err != nil {
+		return nil, err
+	}
+	depositBalanceToConsume, err := beaconState.DepositBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	exitBalanceToConsume, err := beaconState.ExitBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	earliestExitEpoch, err := beaconState.EarliestExitEpoch()
+	if err != nil {
+		return nil, err
+	}
+	consolidationBalanceToConsume, err := beaconState.ConsolidationBalanceToConsume()
+	if err != nil {
+		return nil, err
+	}
+	earliestConsolidationEpoch, err := beaconState.EarliestConsolidationEpoch()
+	if err != nil {
+		return nil, err
+	}
+	pendingDeposits, err := beaconState.PendingDeposits()
+	if err != nil {
+		return nil, err
+	}
+	pendingPartialWithdrawals, err := beaconState.PendingPartialWithdrawals()
+	if err != nil {
+		return nil, err
+	}
+	pendingConsolidations, err := beaconState.PendingConsolidations()
+	if err != nil {
+		return nil, err
+	}
+
+	s := &ethpb.BeaconStateFulu{
+		GenesisTime:           beaconState.GenesisTime(),
+		GenesisValidatorsRoot: beaconState.GenesisValidatorsRoot(),
+		Slot:                  beaconState.Slot(),
+		Fork: &ethpb.Fork{
+			PreviousVersion: beaconState.Fork().CurrentVersion,
+			CurrentVersion:  params.BeaconConfig().FuluForkVersion,
+			Epoch:           time.CurrentEpoch(beaconState),
+		},
+		LatestBlockHeader:           beaconState.LatestBlockHeader(),
+		BlockRoots:                  beaconState.BlockRoots(),
+		StateRoots:                  beaconState.StateRoots(),
+		HistoricalRoots:             historicalRoots,
+		Eth1Data:                    beaconState.Eth1Data(),
+		Eth1DataVotes:               beaconState.Eth1DataVotes(),
+		Eth1DepositIndex:            beaconState.Eth1DepositIndex(),
+		Validators:                  beaconState.Validators(),
+		Balances:                    beaconState.Balances(),
+		RandaoMixes:                 beaconState.RandaoMixes(),
+		Slashings:                   beaconState.Slashings(),
+		PreviousEpochParticipation:  prevEpochParticipation,
+		CurrentEpochParticipation:   currentEpochParticipation,
+		JustificationBits:           beaconState.JustificationBits(),
+		PreviousJustifiedCheckpoint: beaconState.PreviousJustifiedCheckpoint(),
+		CurrentJustifiedCheckpoint:  beaconState.CurrentJustifiedCheckpoint(),
+		FinalizedCheckpoint:         beaconState.FinalizedCheckpoint(),
+		InactivityScores:            inactivityScores,
+		CurrentSyncCommittee:        currentSyncCommittee,
+		NextSyncCommittee:           nextSyncCommittee,
+		LatestExecutionPayloadHeader: &enginev1.ExecutionPayloadHeaderDeneb{
+			ParentHash:       payloadHeader.ParentHash(),
+			FeeRecipient:     payloadHeader.FeeRecipient(),
+			StateRoot:        payloadHeader.StateRoot(),
+			ReceiptsRoot:     payloadHeader.ReceiptsRoot(),
+			LogsBloom:        payloadHeader.LogsBloom(),
+			PrevRandao:       payloadHeader.PrevRandao(),
+			BlockNumber:      payloadHeader.BlockNumber(),
+			GasLimit:         payloadHeader.GasLimit(),
+			GasUsed:          payloadHeader.GasUsed(),
+			Timestamp:        payloadHeader.Timestamp(),
+			ExtraData:        payloadHeader.ExtraData(),
+			BaseFeePerGas:    payloadHeader.BaseFeePerGas(),
+			BlockHash:        payloadHeader.BlockHash(),
+			TransactionsRoot: txRoot,
+			WithdrawalsRoot:  wdRoot,
+			ExcessBlobGas:    excessBlobGas,
+			BlobGasUsed:      blobGasUsed,
+		},
+		NextWithdrawalIndex:          wi,
+		NextWithdrawalValidatorIndex: vi,
+		HistoricalSummaries:          summaries,
+
+		DepositRequestsStartIndex:     params.BeaconConfig().UnsetDepositRequestsStartIndex,
+		DepositBalanceToConsume:       depositBalanceToConsume,
+		ExitBalanceToConsume:          exitBalanceToConsume,
+		EarliestExitEpoch:             earliestExitEpoch,
+		ConsolidationBalanceToConsume: consolidationBalanceToConsume,
+		EarliestConsolidationEpoch:    earliestConsolidationEpoch,
+		PendingDeposits:               pendingDeposits,
+		PendingPartialWithdrawals:     pendingPartialWithdrawals,
+		PendingConsolidations:         pendingConsolidations,
+	}
+
+	// Need to cast the beaconState to use in helper functions
+	post, err := state_native.InitializeFromProtoUnsafeFulu(s)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to initialize post fulu beaconState")
+	}
+
+	return post, nil
+}
--- a/beacon-chain/core/fulu/upgrade_test.go
+++ b/beacon-chain/core/fulu/upgrade_test.go
@@ -0,0 +1,185 @@
+package fulu_test
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/fulu"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+)
+
+func TestUpgradeToFulu(t *testing.T) {
+	st, _ := util.DeterministicGenesisStateElectra(t, params.BeaconConfig().MaxValidatorsPerCommittee)
+	require.NoError(t, st.SetHistoricalRoots([][]byte{{1}}))
+	vals := st.Validators()
+	vals[0].ActivationEpoch = params.BeaconConfig().FarFutureEpoch
+	vals[1].WithdrawalCredentials = []byte{params.BeaconConfig().CompoundingWithdrawalPrefixByte}
+	require.NoError(t, st.SetValidators(vals))
+	bals := st.Balances()
+	bals[1] = params.BeaconConfig().MinActivationBalance + 1000
+	require.NoError(t, st.SetBalances(bals))
+
+	preForkState := st.Copy()
+	mSt, err := fulu.UpgradeToFulu(st)
+	require.NoError(t, err)
+
+	require.Equal(t, preForkState.GenesisTime(), mSt.GenesisTime())
+	require.DeepSSZEqual(t, preForkState.GenesisValidatorsRoot(), mSt.GenesisValidatorsRoot())
+	require.Equal(t, preForkState.Slot(), mSt.Slot())
+
+	f := mSt.Fork()
+	require.DeepSSZEqual(t, &ethpb.Fork{
+		PreviousVersion: st.Fork().CurrentVersion,
+		CurrentVersion:  params.BeaconConfig().FuluForkVersion,
+		Epoch:           time.CurrentEpoch(st),
+	}, f)
+
+	require.DeepSSZEqual(t, preForkState.LatestBlockHeader(), mSt.LatestBlockHeader())
+	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)
+	require.DeepEqual(t, hr1, hr2)
+
+	require.DeepSSZEqual(t, preForkState.Eth1Data(), mSt.Eth1Data())
+	require.DeepSSZEqual(t, preForkState.Eth1DataVotes(), mSt.Eth1DataVotes())
+	require.DeepSSZEqual(t, preForkState.Eth1DepositIndex(), mSt.Eth1DepositIndex())
+	require.DeepSSZEqual(t, preForkState.Validators(), mSt.Validators())
+	require.DeepSSZEqual(t, preForkState.Balances(), mSt.Balances())
+	require.DeepSSZEqual(t, preForkState.RandaoMixes(), mSt.RandaoMixes())
+	require.DeepSSZEqual(t, preForkState.Slashings(), mSt.Slashings())
+
+	numValidators := mSt.NumValidators()
+
+	p, err := mSt.PreviousEpochParticipation()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, make([]byte, numValidators), p)
+
+	p, err = mSt.CurrentEpochParticipation()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, make([]byte, numValidators), p)
+
+	require.DeepSSZEqual(t, preForkState.JustificationBits(), mSt.JustificationBits())
+	require.DeepSSZEqual(t, preForkState.PreviousJustifiedCheckpoint(), mSt.PreviousJustifiedCheckpoint())
+	require.DeepSSZEqual(t, preForkState.CurrentJustifiedCheckpoint(), mSt.CurrentJustifiedCheckpoint())
+	require.DeepSSZEqual(t, preForkState.FinalizedCheckpoint(), mSt.FinalizedCheckpoint())
+
+	s, err := mSt.InactivityScores()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
+
+	csc, err := mSt.CurrentSyncCommittee()
+	require.NoError(t, err)
+	psc, err := preForkState.CurrentSyncCommittee()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, psc, csc)
+
+	nsc, err := mSt.NextSyncCommittee()
+	require.NoError(t, err)
+	psc, err = preForkState.NextSyncCommittee()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, psc, nsc)
+
+	header, err := mSt.LatestExecutionPayloadHeader()
+	require.NoError(t, err)
+	protoHeader, ok := header.Proto().(*enginev1.ExecutionPayloadHeaderDeneb)
+	require.Equal(t, true, ok)
+	prevHeader, err := preForkState.LatestExecutionPayloadHeader()
+	require.NoError(t, err)
+	txRoot, err := prevHeader.TransactionsRoot()
+	require.NoError(t, err)
+	wdRoot, err := prevHeader.WithdrawalsRoot()
+	require.NoError(t, err)
+	wanted := &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       prevHeader.ParentHash(),
+		FeeRecipient:     prevHeader.FeeRecipient(),
+		StateRoot:        prevHeader.StateRoot(),
+		ReceiptsRoot:     prevHeader.ReceiptsRoot(),
+		LogsBloom:        prevHeader.LogsBloom(),
+		PrevRandao:       prevHeader.PrevRandao(),
+		BlockNumber:      prevHeader.BlockNumber(),
+		GasLimit:         prevHeader.GasLimit(),
+		GasUsed:          prevHeader.GasUsed(),
+		Timestamp:        prevHeader.Timestamp(),
+		ExtraData:        prevHeader.ExtraData(),
+		BaseFeePerGas:    prevHeader.BaseFeePerGas(),
+		BlockHash:        prevHeader.BlockHash(),
+		TransactionsRoot: txRoot,
+		WithdrawalsRoot:  wdRoot,
+	}
+	require.DeepEqual(t, wanted, protoHeader)
+
+	nwi, err := mSt.NextWithdrawalIndex()
+	require.NoError(t, err)
+	require.Equal(t, uint64(0), nwi)
+
+	lwvi, err := mSt.NextWithdrawalValidatorIndex()
+	require.NoError(t, err)
+	require.Equal(t, primitives.ValidatorIndex(0), lwvi)
+
+	summaries, err := mSt.HistoricalSummaries()
+	require.NoError(t, err)
+	require.Equal(t, 0, len(summaries))
+
+	preDepositRequestsStartIndex, err := preForkState.DepositRequestsStartIndex()
+	require.NoError(t, err)
+	postDepositRequestsStartIndex, err := mSt.DepositRequestsStartIndex()
+	require.NoError(t, err)
+	require.Equal(t, preDepositRequestsStartIndex, postDepositRequestsStartIndex)
+
+	preDepositBalanceToConsume, err := preForkState.DepositBalanceToConsume()
+	require.NoError(t, err)
+	postDepositBalanceToConsume, err := mSt.DepositBalanceToConsume()
+	require.NoError(t, err)
+	require.Equal(t, preDepositBalanceToConsume, postDepositBalanceToConsume)
+
+	preExitBalanceToConsume, err := preForkState.ExitBalanceToConsume()
+	require.NoError(t, err)
+	postExitBalanceToConsume, err := mSt.ExitBalanceToConsume()
+	require.NoError(t, err)
+	require.Equal(t, preExitBalanceToConsume, postExitBalanceToConsume)
+
+	preEarliestExitEpoch, err := preForkState.EarliestExitEpoch()
+	require.NoError(t, err)
+	postEarliestExitEpoch, err := mSt.EarliestExitEpoch()
+	require.NoError(t, err)
+	require.Equal(t, preEarliestExitEpoch, postEarliestExitEpoch)
+
+	preConsolidationBalanceToConsume, err := preForkState.ConsolidationBalanceToConsume()
+	require.NoError(t, err)
+	postConsolidationBalanceToConsume, err := mSt.ConsolidationBalanceToConsume()
+	require.NoError(t, err)
+	require.Equal(t, preConsolidationBalanceToConsume, postConsolidationBalanceToConsume)
+
+	preEarliesConsolidationEoch, err := preForkState.EarliestConsolidationEpoch()
+	require.NoError(t, err)
+	postEarliestConsolidationEpoch, err := mSt.EarliestConsolidationEpoch()
+	require.NoError(t, err)
+	require.Equal(t, preEarliesConsolidationEoch, postEarliestConsolidationEpoch)
+
+	prePendingDeposits, err := preForkState.PendingDeposits()
+	require.NoError(t, err)
+	postPendingDeposits, err := mSt.PendingDeposits()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, prePendingDeposits, postPendingDeposits)
+
+	prePendingPartialWithdrawals, err := preForkState.PendingPartialWithdrawals()
+	require.NoError(t, err)
+	postPendingPartialWithdrawals, err := mSt.PendingPartialWithdrawals()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, prePendingPartialWithdrawals, postPendingPartialWithdrawals)
+
+	prePendingConsolidations, err := preForkState.PendingConsolidations()
+	require.NoError(t, err)
+	postPendingConsolidations, err := mSt.PendingConsolidations()
+	require.NoError(t, err)
+	require.DeepSSZEqual(t, prePendingConsolidations, postPendingConsolidations)
+}
--- a/beacon-chain/core/helpers/BUILD.bazel
+++ b/beacon-chain/core/helpers/BUILD.bazel
@@ -25,7 +25,6 @@ go_library(
        "//beacon-chain/state: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",
        "//container/slice:go_default_library",
        "//container/trie:go_default_library",
--- a/beacon-chain/core/helpers/attestation.go
+++ b/beacon-chain/core/helpers/attestation.go
@@ -32,6 +32,9 @@ func ValidateNilAttestation(attestation ethpb.Att) error {
 	if attestation.GetData().Target == nil {
 		return errors.New("attestation's target can't be nil")
 	}
+	if attestation.IsSingle() {
+		return nil
+	}
 	if attestation.GetAggregationBits() == nil {
 		return errors.New("attestation's bitfield can't be nil")
 	}
@@ -67,12 +70,6 @@ func IsAggregator(committeeCount uint64, slotSig []byte) (bool, error) {
 	return binary.LittleEndian.Uint64(b[:8])%modulo == 0, nil
 }

-// IsAggregated returns true if the attestation is an aggregated attestation,
-// false otherwise.
-func IsAggregated(attestation ethpb.Att) bool {
-	return attestation.GetAggregationBits().Count() > 1
-}
-
 // ComputeSubnetForAttestation returns the subnet for which the provided attestation will be broadcasted to.
 // This differs from the spec definition by instead passing in the active validators indices in the attestation's
 // given epoch.
--- a/beacon-chain/core/helpers/attestation_test.go
+++ b/beacon-chain/core/helpers/attestation_test.go
@@ -308,6 +308,16 @@ func TestValidateNilAttestation(t *testing.T) {
 			},
 			errString: "",
 		},
+		{
+			name: "single attestation",
+			attestation: &ethpb.SingleAttestation{
+				Data: &ethpb.AttestationData{
+					Target: &ethpb.Checkpoint{},
+					Source: &ethpb.Checkpoint{},
+				},
+			},
+			errString: "",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
--- a/beacon-chain/core/helpers/beacon_committee_test.go
+++ b/beacon-chain/core/helpers/beacon_committee_test.go
@@ -97,6 +97,13 @@ func TestVerifyBitfieldLength_OK(t *testing.T) {
 	assert.NoError(t, helpers.VerifyBitfieldLength(bf, committeeSize), "Bitfield is not validated when it was supposed to be")
 }

+func TestVerifyBitfieldLength_Incorrect(t *testing.T) {
+	helpers.ClearCache()
+
+	bf := bitfield.NewBitlist(1)
+	require.ErrorContains(t, "wanted participants bitfield length 2, got: 1", helpers.VerifyBitfieldLength(bf, 2))
+}
+
 func TestCommitteeAssignments_CannotRetrieveFutureEpoch(t *testing.T) {
 	helpers.ClearCache()

--- a/beacon-chain/core/helpers/sync_committee_test.go
+++ b/beacon-chain/core/helpers/sync_committee_test.go
@@ -78,6 +78,7 @@ func TestIsCurrentEpochSyncCommittee_UsingCommittee(t *testing.T) {

 func TestIsCurrentEpochSyncCommittee_DoesNotExist(t *testing.T) {
 	helpers.ClearCache()
+	params.SetupTestConfigCleanup(t)

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

 func TestCurrentEpochSyncSubcommitteeIndices_DoesNotExist(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
 	helpers.ClearCache()

 	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)
--- a/beacon-chain/core/helpers/validators.go
+++ b/beacon-chain/core/helpers/validators.go
@@ -3,6 +3,7 @@ package helpers
 import (
 	"bytes"
 	"context"
+	"encoding/binary"

 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
@@ -11,8 +12,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
@@ -347,27 +348,33 @@ func BeaconProposerIndexAtSlot(ctx context.Context, state state.ReadOnlyBeaconSt
 // Spec pseudocode definition:
 //
 //	def compute_proposer_index(state: BeaconState, indices: Sequence[ValidatorIndex], seed: Bytes32) -> ValidatorIndex:
-//	  """
-//	  Return from ``indices`` a random index sampled by effective balance.
-//	  """
-//	  assert len(indices) > 0
-//	  MAX_RANDOM_BYTE = 2**8 - 1
-//	  i = uint64(0)
-//	  total = uint64(len(indices))
-//	  while True:
-//	      candidate_index = indices[compute_shuffled_index(i % total, total, seed)]
-//	      random_byte = hash(seed + uint_to_bytes(uint64(i // 32)))[i % 32]
-//	      effective_balance = state.validators[candidate_index].effective_balance
-//	      if effective_balance * MAX_RANDOM_BYTE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_byte: #[Modified in Electra:EIP7251]
-//	          return candidate_index
-//	      i += 1
+//	   """
+//	   Return from ``indices`` a random index sampled by effective balance.
+//	   """
+//	   assert len(indices) > 0
+//	   MAX_RANDOM_VALUE = 2**16 - 1  # [Modified in Electra]
+//	   i = uint64(0)
+//	   total = uint64(len(indices))
+//	   while True:
+//	       candidate_index = indices[compute_shuffled_index(i % total, total, seed)]
+//	       # [Modified in Electra]
+//	       random_bytes = hash(seed + uint_to_bytes(i // 16))
+//	       offset = i % 16 * 2
+//	       random_value = bytes_to_uint64(random_bytes[offset:offset + 2])
+//	       effective_balance = state.validators[candidate_index].effective_balance
+//	       # [Modified in Electra:EIP7251]
+//	       if effective_balance * MAX_RANDOM_VALUE >= MAX_EFFECTIVE_BALANCE_ELECTRA * random_value:
+//	           return candidate_index
+//	       i += 1
 func ComputeProposerIndex(bState state.ReadOnlyBeaconState, activeIndices []primitives.ValidatorIndex, seed [32]byte) (primitives.ValidatorIndex, error) {
 	length := uint64(len(activeIndices))
 	if length == 0 {
 		return 0, errors.New("empty active indices list")
 	}
-	maxRandomByte := uint64(1<<8 - 1)
 	hashFunc := hash.CustomSHA256Hasher()
+	beaconConfig := params.BeaconConfig()
+	seedBuffer := make([]byte, len(seed)+8)
+	copy(seedBuffer, seed[:])

 	for i := uint64(0); ; i++ {
 		candidateIndex, err := ComputeShuffledIndex(primitives.ValidatorIndex(i%length), length, seed, true /* shuffle */)
@@ -378,21 +385,28 @@ func ComputeProposerIndex(bState state.ReadOnlyBeaconState, activeIndices []prim
 		if uint64(candidateIndex) >= uint64(bState.NumValidators()) {
 			return 0, errors.New("active index out of range")
 		}
-		b := append(seed[:], bytesutil.Bytes8(i/32)...)
-		randomByte := hashFunc(b)[i%32]
+
 		v, err := bState.ValidatorAtIndexReadOnly(candidateIndex)
 		if err != nil {
 			return 0, err
 		}
 		effectiveBal := v.EffectiveBalance()
-
-		maxEB := params.BeaconConfig().MaxEffectiveBalance
 		if bState.Version() >= version.Electra {
-			maxEB = params.BeaconConfig().MaxEffectiveBalanceElectra
-		}
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], i/16)
+			randomByte := hashFunc(seedBuffer)
+			offset := (i % 16) * 2
+			randomValue := uint64(randomByte[offset]) | uint64(randomByte[offset+1])<<8

-		if effectiveBal*maxRandomByte >= maxEB*uint64(randomByte) {
-			return candidateIndex, nil
+			if effectiveBal*fieldparams.MaxRandomValueElectra >= beaconConfig.MaxEffectiveBalanceElectra*randomValue {
+				return candidateIndex, nil
+			}
+		} else {
+			binary.LittleEndian.PutUint64(seedBuffer[len(seed):], i/32)
+			randomByte := hashFunc(seedBuffer)[i%32]
+
+			if effectiveBal*fieldparams.MaxRandomByte >= beaconConfig.MaxEffectiveBalance*uint64(randomByte) {
+				return candidateIndex, nil
+			}
 		}
 	}
 }
@@ -500,63 +514,6 @@ func LastActivatedValidatorIndex(ctx context.Context, st state.ReadOnlyBeaconSta
 	return lastActivatedvalidatorIndex, nil
 }

-// hasETH1WithdrawalCredential returns whether the validator has an ETH1
-// Withdrawal prefix. It assumes that the caller has a lock on the state
-func HasETH1WithdrawalCredential(val interfaces.WithWithdrawalCredentials) bool {
-	if val == nil {
-		return false
-	}
-	return isETH1WithdrawalCredential(val.GetWithdrawalCredentials())
-}
-
-func isETH1WithdrawalCredential(creds []byte) bool {
-	return bytes.HasPrefix(creds, []byte{params.BeaconConfig().ETH1AddressWithdrawalPrefixByte})
-}
-
-// HasCompoundingWithdrawalCredential checks if the validator has a compounding withdrawal credential.
-// New in Electra EIP-7251: https://eips.ethereum.org/EIPS/eip-7251
-//
-// Spec definition:
-//
-//	def has_compounding_withdrawal_credential(validator: Validator) -> bool:
-//	    """
-//	    Check if ``validator`` has an 0x02 prefixed "compounding" withdrawal credential.
-//	    """
-//	    return is_compounding_withdrawal_credential(validator.withdrawal_credentials)
-func HasCompoundingWithdrawalCredential(v interfaces.WithWithdrawalCredentials) bool {
-	if v == nil {
-		return false
-	}
-	return IsCompoundingWithdrawalCredential(v.GetWithdrawalCredentials())
-}
-
-// IsCompoundingWithdrawalCredential checks if the credentials are a compounding withdrawal credential.
-//
-// Spec definition:
-//
-//	def is_compounding_withdrawal_credential(withdrawal_credentials: Bytes32) -> bool:
-//	    return withdrawal_credentials[:1] == COMPOUNDING_WITHDRAWAL_PREFIX
-func IsCompoundingWithdrawalCredential(creds []byte) bool {
-	return bytes.HasPrefix(creds, []byte{params.BeaconConfig().CompoundingWithdrawalPrefixByte})
-}
-
-// HasExecutionWithdrawalCredentials checks if the validator has an execution withdrawal credential or compounding credential.
-// New in Electra EIP-7251: https://eips.ethereum.org/EIPS/eip-7251
-//
-// Spec definition:
-//
-//	def has_execution_withdrawal_credential(validator: Validator) -> bool:
-//	    """
-//	    Check if ``validator`` has a 0x01 or 0x02 prefixed withdrawal credential.
-//	    """
-//	    return has_compounding_withdrawal_credential(validator) or has_eth1_withdrawal_credential(validator)
-func HasExecutionWithdrawalCredentials(v interfaces.WithWithdrawalCredentials) bool {
-	if v == nil {
-		return false
-	}
-	return HasCompoundingWithdrawalCredential(v) || HasETH1WithdrawalCredential(v)
-}
-
 // IsSameWithdrawalCredentials returns true if both validators have the same withdrawal credentials.
 //
 //	return a.withdrawal_credentials[12:] == b.withdrawal_credentials[12:]
@@ -591,10 +548,10 @@ func IsFullyWithdrawableValidator(val state.ReadOnlyValidator, balance uint64, e

 	// Electra / EIP-7251 logic
 	if fork >= version.Electra {
-		return HasExecutionWithdrawalCredentials(val) && val.WithdrawableEpoch() <= epoch
+		return val.HasExecutionWithdrawalCredentials() && val.WithdrawableEpoch() <= epoch
 	}

-	return HasETH1WithdrawalCredential(val) && val.WithdrawableEpoch() <= epoch
+	return val.HasETH1WithdrawalCredentials() && val.WithdrawableEpoch() <= epoch
 }

 // IsPartiallyWithdrawableValidator returns whether the validator is able to perform a
@@ -635,7 +592,7 @@ func isPartiallyWithdrawableValidatorElectra(val state.ReadOnlyValidator, balanc
 	hasMaxBalance := val.EffectiveBalance() == maxEB
 	hasExcessBalance := balance > maxEB

-	return HasExecutionWithdrawalCredentials(val) &&
+	return val.HasExecutionWithdrawalCredentials() &&
 		hasMaxBalance &&
 		hasExcessBalance
 }
@@ -655,7 +612,7 @@ func isPartiallyWithdrawableValidatorElectra(val state.ReadOnlyValidator, balanc
 func isPartiallyWithdrawableValidatorCapella(val state.ReadOnlyValidator, balance uint64, epoch primitives.Epoch) bool {
 	hasMaxBalance := val.EffectiveBalance() == params.BeaconConfig().MaxEffectiveBalance
 	hasExcessBalance := balance > params.BeaconConfig().MaxEffectiveBalance
-	return HasETH1WithdrawalCredential(val) && hasExcessBalance && hasMaxBalance
+	return val.HasETH1WithdrawalCredentials() && hasExcessBalance && hasMaxBalance
 }

 // ValidatorMaxEffectiveBalance returns the maximum effective balance for a validator.
@@ -671,7 +628,7 @@ func isPartiallyWithdrawableValidatorCapella(val state.ReadOnlyValidator, balanc
 //	    else:
 //	        return MIN_ACTIVATION_BALANCE
 func ValidatorMaxEffectiveBalance(val state.ReadOnlyValidator) uint64 {
-	if HasCompoundingWithdrawalCredential(val) {
+	if val.HasCompoundingWithdrawalCredentials() {
 		return params.BeaconConfig().MaxEffectiveBalanceElectra
 	}
 	return params.BeaconConfig().MinActivationBalance
--- a/beacon-chain/core/helpers/validators_test.go
+++ b/beacon-chain/core/helpers/validators_test.go
@@ -841,7 +841,6 @@ func computeProposerIndexWithValidators(validators []*ethpb.Validator, activeInd
 	if length == 0 {
 		return 0, errors.New("empty active indices list")
 	}
-	maxRandomByte := uint64(1<<8 - 1)
 	hashFunc := hash.CustomSHA256Hasher()

 	for i := uint64(0); ; i++ {
@@ -860,7 +859,7 @@ func computeProposerIndexWithValidators(validators []*ethpb.Validator, activeInd
 		if v != nil {
 			effectiveBal = v.EffectiveBalance
 		}
-		if effectiveBal*maxRandomByte >= params.BeaconConfig().MaxEffectiveBalance*uint64(randomByte) {
+		if effectiveBal*fieldparams.MaxRandomByte >= params.BeaconConfig().MaxEffectiveBalance*uint64(randomByte) {
 			return candidateIndex, nil
 		}
 	}
@@ -911,13 +910,15 @@ func TestProposerIndexFromCheckpoint(t *testing.T) {
 func TestHasETH1WithdrawalCredentials(t *testing.T) {
 	creds := []byte{0xFA, 0xCC}
 	v := &ethpb.Validator{WithdrawalCredentials: creds}
-	require.Equal(t, false, helpers.HasETH1WithdrawalCredential(v))
+	roV, err := state_native.NewValidator(v)
+	require.NoError(t, err)
+	require.Equal(t, false, roV.HasETH1WithdrawalCredentials())
 	creds = []byte{params.BeaconConfig().ETH1AddressWithdrawalPrefixByte, 0xCC}
 	v = &ethpb.Validator{WithdrawalCredentials: creds}
-	require.Equal(t, true, helpers.HasETH1WithdrawalCredential(v))
+	roV, err = state_native.NewValidator(v)
+	require.NoError(t, err)
+	require.Equal(t, true, roV.HasETH1WithdrawalCredentials())
 	// No Withdrawal cred
-	v = &ethpb.Validator{}
-	require.Equal(t, false, helpers.HasETH1WithdrawalCredential(v))
 }

 func TestHasCompoundingWithdrawalCredential(t *testing.T) {
@@ -932,11 +933,12 @@ func TestHasCompoundingWithdrawalCredential(t *testing.T) {
 		{"Does not have compounding withdrawal credential",
 			&ethpb.Validator{WithdrawalCredentials: bytesutil.PadTo([]byte{0x00}, 32)},
 			false},
-		{"Handles nil case", nil, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			assert.Equal(t, tt.want, helpers.HasCompoundingWithdrawalCredential(tt.validator))
+			roV, err := state_native.NewValidator(tt.validator)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, roV.HasCompoundingWithdrawalCredentials())
 		})
 	}
 }
@@ -956,11 +958,12 @@ func TestHasExecutionWithdrawalCredentials(t *testing.T) {
 		{"Does not have compounding withdrawal credential or eth1 withdrawal credential",
 			&ethpb.Validator{WithdrawalCredentials: bytesutil.PadTo([]byte{0x00}, 32)},
 			false},
-		{"Handles nil case", nil, false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			assert.Equal(t, tt.want, helpers.HasExecutionWithdrawalCredentials(tt.validator))
+			roV, err := state_native.NewValidator(tt.validator)
+			require.NoError(t, err)
+			assert.Equal(t, tt.want, roV.HasExecutionWithdrawalCredentials())
 		})
 	}
 }
--- a/beacon-chain/core/light-client/lightclient.go
+++ b/beacon-chain/core/light-client/lightclient.go
@@ -24,6 +24,8 @@ import (
 	"google.golang.org/protobuf/proto"
 )

+const ErrNotEnoughSyncCommitteeBits = "sync committee bits count is less than required"
+
 func NewLightClientFinalityUpdateFromBeaconState(
 	ctx context.Context,
 	currentSlot primitives.Slot,
@@ -84,7 +86,12 @@ func NewLightClientUpdateFromBeaconState(
 		return nil, errors.Wrap(err, "could not get sync aggregate")
 	}
 	if syncAggregate.SyncCommitteeBits.Count() < params.BeaconConfig().MinSyncCommitteeParticipants {
-		return nil, fmt.Errorf("invalid sync committee bits count %d", syncAggregate.SyncCommitteeBits.Count())
+		return nil, fmt.Errorf(
+			"%s (got %d, need %d)",
+			ErrNotEnoughSyncCommitteeBits,
+			syncAggregate.SyncCommitteeBits.Count(),
+			params.BeaconConfig().MinSyncCommitteeParticipants,
+		)
 	}

 	// assert state.slot == state.latest_block_header.slot
@@ -282,56 +289,247 @@ func CreateDefaultLightClientUpdate(currentSlot primitives.Slot, attestedState s
 	if currentEpoch < params.BeaconConfig().CapellaForkEpoch {
 		m = &pb.LightClientUpdateAltair{
 			AttestedHeader: &pb.LightClientHeaderAltair{
-				Beacon: &pb.BeaconBlockHeader{},
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
+				},
 			},
 			NextSyncCommittee:       nextSyncCommittee,
 			NextSyncCommitteeBranch: nextSyncCommitteeBranch,
 			FinalityBranch:          finalityBranch,
+			FinalizedHeader: &pb.LightClientHeaderAltair{
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
+				},
+			},
+			SyncAggregate: &pb.SyncAggregate{
+				SyncCommitteeBits:      make([]byte, 64),
+				SyncCommitteeSignature: make([]byte, 96),
+			},
 		}
 	} else if currentEpoch < params.BeaconConfig().DenebForkEpoch {
 		m = &pb.LightClientUpdateCapella{
 			AttestedHeader: &pb.LightClientHeaderCapella{
-				Beacon:          &pb.BeaconBlockHeader{},
-				Execution:       &enginev1.ExecutionPayloadHeaderCapella{},
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
+				},
+				Execution: &enginev1.ExecutionPayloadHeaderCapella{
+					ParentHash:       make([]byte, fieldparams.RootLength),
+					FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+					StateRoot:        make([]byte, fieldparams.RootLength),
+					ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+					LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+					PrevRandao:       make([]byte, fieldparams.RootLength),
+					ExtraData:        make([]byte, 0),
+					BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+					BlockHash:        make([]byte, fieldparams.RootLength),
+					TransactionsRoot: make([]byte, fieldparams.RootLength),
+					WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+				},
 				ExecutionBranch: executionBranch,
 			},
 			NextSyncCommittee:       nextSyncCommittee,
 			NextSyncCommitteeBranch: nextSyncCommitteeBranch,
 			FinalityBranch:          finalityBranch,
+			FinalizedHeader: &pb.LightClientHeaderCapella{
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
+				},
+				Execution: &enginev1.ExecutionPayloadHeaderCapella{
+					ParentHash:       make([]byte, fieldparams.RootLength),
+					FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+					StateRoot:        make([]byte, fieldparams.RootLength),
+					ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+					LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+					PrevRandao:       make([]byte, fieldparams.RootLength),
+					ExtraData:        make([]byte, 0),
+					BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+					BlockHash:        make([]byte, fieldparams.RootLength),
+					TransactionsRoot: make([]byte, fieldparams.RootLength),
+					WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+				},
+				ExecutionBranch: executionBranch,
+			},
+			SyncAggregate: &pb.SyncAggregate{
+				SyncCommitteeBits:      make([]byte, 64),
+				SyncCommitteeSignature: make([]byte, 96),
+			},
 		}
 	} else if currentEpoch < params.BeaconConfig().ElectraForkEpoch {
 		m = &pb.LightClientUpdateDeneb{
 			AttestedHeader: &pb.LightClientHeaderDeneb{
-				Beacon:          &pb.BeaconBlockHeader{},
-				Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
+				},
+				Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+					ParentHash:       make([]byte, fieldparams.RootLength),
+					FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+					StateRoot:        make([]byte, fieldparams.RootLength),
+					ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+					LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+					PrevRandao:       make([]byte, fieldparams.RootLength),
+					ExtraData:        make([]byte, 0),
+					BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+					BlockHash:        make([]byte, fieldparams.RootLength),
+					TransactionsRoot: make([]byte, fieldparams.RootLength),
+					WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+					GasLimit:         0,
+					GasUsed:          0,
+				},
 				ExecutionBranch: executionBranch,
 			},
 			NextSyncCommittee:       nextSyncCommittee,
 			NextSyncCommitteeBranch: nextSyncCommitteeBranch,
 			FinalityBranch:          finalityBranch,
+			FinalizedHeader: &pb.LightClientHeaderDeneb{
+				Beacon: &pb.BeaconBlockHeader{
+					ParentRoot: make([]byte, 32),
+					StateRoot:  make([]byte, 32),
+					BodyRoot:   make([]byte, 32),
+				},
+				Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+					ParentHash:       make([]byte, fieldparams.RootLength),
+					FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+					StateRoot:        make([]byte, fieldparams.RootLength),
+					ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+					LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+					PrevRandao:       make([]byte, fieldparams.RootLength),
+					ExtraData:        make([]byte, 0),
+					BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+					BlockHash:        make([]byte, fieldparams.RootLength),
+					TransactionsRoot: make([]byte, fieldparams.RootLength),
+					WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+					GasLimit:         0,
+					GasUsed:          0,
+				},
+				ExecutionBranch: executionBranch,
+			},
+			SyncAggregate: &pb.SyncAggregate{
+				SyncCommitteeBits:      make([]byte, 64),
+				SyncCommitteeSignature: make([]byte, 96),
+			},
 		}
 	} else {
 		if attestedState.Version() >= version.Electra {
 			m = &pb.LightClientUpdateElectra{
 				AttestedHeader: &pb.LightClientHeaderDeneb{
-					Beacon:          &pb.BeaconBlockHeader{},
-					Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
+					Beacon: &pb.BeaconBlockHeader{
+						ParentRoot: make([]byte, 32),
+						StateRoot:  make([]byte, 32),
+						BodyRoot:   make([]byte, 32),
+					},
+					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+						ParentHash:       make([]byte, fieldparams.RootLength),
+						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+						StateRoot:        make([]byte, fieldparams.RootLength),
+						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+						PrevRandao:       make([]byte, fieldparams.RootLength),
+						ExtraData:        make([]byte, 0),
+						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+						BlockHash:        make([]byte, fieldparams.RootLength),
+						TransactionsRoot: make([]byte, fieldparams.RootLength),
+						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+						GasLimit:         0,
+						GasUsed:          0,
+					},
 					ExecutionBranch: executionBranch,
 				},
 				NextSyncCommittee:       nextSyncCommittee,
 				NextSyncCommitteeBranch: nextSyncCommitteeBranch,
 				FinalityBranch:          finalityBranch,
+				FinalizedHeader: &pb.LightClientHeaderDeneb{
+					Beacon: &pb.BeaconBlockHeader{
+						ParentRoot: make([]byte, 32),
+						StateRoot:  make([]byte, 32),
+						BodyRoot:   make([]byte, 32),
+					},
+					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+						ParentHash:       make([]byte, fieldparams.RootLength),
+						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+						StateRoot:        make([]byte, fieldparams.RootLength),
+						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+						PrevRandao:       make([]byte, fieldparams.RootLength),
+						ExtraData:        make([]byte, 0),
+						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+						BlockHash:        make([]byte, fieldparams.RootLength),
+						TransactionsRoot: make([]byte, fieldparams.RootLength),
+						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+						GasLimit:         0,
+						GasUsed:          0,
+					},
+					ExecutionBranch: executionBranch,
+				},
+				SyncAggregate: &pb.SyncAggregate{
+					SyncCommitteeBits:      make([]byte, 64),
+					SyncCommitteeSignature: make([]byte, 96),
+				},
 			}
 		} else {
 			m = &pb.LightClientUpdateDeneb{
 				AttestedHeader: &pb.LightClientHeaderDeneb{
-					Beacon:          &pb.BeaconBlockHeader{},
-					Execution:       &enginev1.ExecutionPayloadHeaderDeneb{},
+					Beacon: &pb.BeaconBlockHeader{
+						ParentRoot: make([]byte, 32),
+						StateRoot:  make([]byte, 32),
+						BodyRoot:   make([]byte, 32),
+					},
+					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+						ParentHash:       make([]byte, fieldparams.RootLength),
+						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+						StateRoot:        make([]byte, fieldparams.RootLength),
+						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+						PrevRandao:       make([]byte, fieldparams.RootLength),
+						ExtraData:        make([]byte, 0),
+						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+						BlockHash:        make([]byte, fieldparams.RootLength),
+						TransactionsRoot: make([]byte, fieldparams.RootLength),
+						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+						GasLimit:         0,
+						GasUsed:          0,
+					},
 					ExecutionBranch: executionBranch,
 				},
 				NextSyncCommittee:       nextSyncCommittee,
 				NextSyncCommitteeBranch: nextSyncCommitteeBranch,
 				FinalityBranch:          finalityBranch,
+				FinalizedHeader: &pb.LightClientHeaderDeneb{
+					Beacon: &pb.BeaconBlockHeader{
+						ParentRoot: make([]byte, 32),
+						StateRoot:  make([]byte, 32),
+						BodyRoot:   make([]byte, 32),
+					},
+					Execution: &enginev1.ExecutionPayloadHeaderDeneb{
+						ParentHash:       make([]byte, fieldparams.RootLength),
+						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+						StateRoot:        make([]byte, fieldparams.RootLength),
+						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+						PrevRandao:       make([]byte, fieldparams.RootLength),
+						ExtraData:        make([]byte, 0),
+						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+						BlockHash:        make([]byte, fieldparams.RootLength),
+						TransactionsRoot: make([]byte, fieldparams.RootLength),
+						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+						GasLimit:         0,
+						GasUsed:          0,
+					},
+					ExecutionBranch: executionBranch,
+				},
+				SyncAggregate: &pb.SyncAggregate{
+					SyncCommitteeBits:      make([]byte, 64),
+					SyncCommitteeSignature: make([]byte, 96),
+				},
 			}
 		}
 	}
--- a/beacon-chain/core/light-client/lightclient_test.go
+++ b/beacon-chain/core/light-client/lightclient_test.go
@@ -697,7 +697,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 			excessBlobGas, err := payload.ExcessBlobGas()
 			require.NoError(t, err)

-			executionHeader := &v11.ExecutionPayloadHeaderElectra{
+			executionHeader := &v11.ExecutionPayloadHeaderDeneb{
 				ParentHash:       payload.ParentHash(),
 				FeeRecipient:     payload.FeeRecipient(),
 				StateRoot:        payload.StateRoot(),
@@ -762,7 +762,7 @@ func TestLightClient_BlockToLightClientHeader(t *testing.T) {
 			excessBlobGas, err := payload.ExcessBlobGas()
 			require.NoError(t, err)

-			executionHeader := &v11.ExecutionPayloadHeaderElectra{
+			executionHeader := &v11.ExecutionPayloadHeaderDeneb{
 				ParentHash:       payload.ParentHash(),
 				FeeRecipient:     payload.FeeRecipient(),
 				StateRoot:        payload.StateRoot(),
--- a/beacon-chain/core/peerdas/BUILD.bazel
+++ b/beacon-chain/core/peerdas/BUILD.bazel
@@ -0,0 +1,51 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "helpers.go",
+        "log.go",
+        "metrics.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
+        "//crypto/hash:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_holiman_uint256//:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@org_golang_x_sync//errgroup:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["helpers_test.go"],
+    deps = [
+        ":go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//testing/require:go_default_library",
+        "//testing/util:go_default_library",
+        "@com_github_consensys_gnark_crypto//ecc/bls12-381/fr:go_default_library",
+        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
+)
--- a/beacon-chain/core/peerdas/helpers.go
+++ b/beacon-chain/core/peerdas/helpers.go
@@ -0,0 +1,677 @@
+package peerdas
+
+import (
+	"context"
+	"encoding/binary"
+	"fmt"
+	"math"
+	"math/big"
+	"slices"
+	"time"
+
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sync/errgroup"
+
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/holiman/uint256"
+	errors "github.com/pkg/errors"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/kzg"
+
+	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+const (
+	CustodyGroupCountEnrKey = "cgc"
+)
+
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/p2p-interface.md#the-discovery-domain-discv5
+type Cgc uint64
+
+func (Cgc) ENRKey() string { return CustodyGroupCountEnrKey }
+
+var (
+	// Custom errors
+	errCustodyGroupCountTooLarge      = errors.New("custody group count too large")
+	errWrongComputedCustodyGroupCount = errors.New("wrong computed custody group count, should never happen")
+	errIndexTooLarge                  = errors.New("column index is larger than the specified columns count")
+	errMismatchLength                 = errors.New("mismatch in the length of the commitments and proofs")
+	errRecordNil                      = errors.New("record is nil")
+	errCannotLoadCustodyGroupCount    = errors.New("cannot load the custody group count from peer")
+
+	// maxUint256 is the maximum value of a uint256.
+	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
+)
+
+// CustodyGroups computes the custody groups the node should participate in for custody.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/das-core.md#get_custody_groups
+func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) (map[uint64]bool, 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
+	}
+
+	custodyGroups := make(map[uint64]bool, custodyGroupCount)
+	one := uint256.NewInt(1)
+
+	for currentId := new(uint256.Int).SetBytes(nodeId.Bytes()); uint64(len(custodyGroups)) < custodyGroupCount; currentId.Add(currentId, one) {
+		// Convert to big endian bytes.
+		currentIdBytesBigEndian := currentId.Bytes32()
+
+		// Convert to little endian.
+		currentIdBytesLittleEndian := bytesutil.ReverseByteOrder(currentIdBytesBigEndian[:])
+
+		// Hash the result.
+		hashedCurrentId := hash.Hash(currentIdBytesLittleEndian)
+
+		// Get the custody group ID.
+		custodyGroupId := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroup
+
+		// Add the custody group to the map.
+		custodyGroups[custodyGroupId] = true
+
+		// Overflow prevention.
+		if currentId.Cmp(maxUint256) == 0 {
+			currentId = uint256.NewInt(0)
+		}
+	}
+
+	// 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-alpha.10/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, errCustodyGroupCountTooLarge
+	}
+
+	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
+}
+
+// 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
+
+	if columnIndex >= numberOfColumns {
+		return 0, errIndexTooLarge
+	}
+
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroups
+
+	return columnIndex / columnsPerGroup, nil
+}
+
+// ComputeSubnetForDataColumnSidecar computes the subnet for a data column sidecar.
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#compute_subnet_for_data_column_sidecar
+func ComputeSubnetForDataColumnSidecar(columnIndex uint64) uint64 {
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+	return columnIndex % dataColumnSidecarSubnetCount
+}
+
+// CustodyColumns computes the columns the node should custody.
+func CustodyColumns(custodyGroups map[uint64]bool) (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, errCustodyGroupCountTooLarge
+		}
+
+		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
+}
+
+// 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
+}
+
+// DataColumnSidecars computes the data column sidecars from the signed block and blobs.
+// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/das-core.md#get_data_column_sidecars
+func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, blobs []kzg.Blob) ([]*ethpb.DataColumnSidecar, error) {
+	startTime := time.Now()
+	blobsCount := len(blobs)
+	if blobsCount == 0 {
+		return nil, nil
+	}
+
+	// Get the signed block header.
+	signedBlockHeader, err := signedBlock.Header()
+	if err != nil {
+		return nil, errors.Wrap(err, "signed block header")
+	}
+
+	// Get the block body.
+	block := signedBlock.Block()
+	blockBody := block.Body()
+
+	// Get the blob KZG commitments.
+	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// Compute the KZG commitments inclusion proof.
+	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
+	if err != nil {
+		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
+	}
+
+	// Compute cells and proofs.
+	cellsAndProofs := make([]kzg.CellsAndProofs, blobsCount)
+
+	eg, _ := errgroup.WithContext(context.Background())
+	for i := range blobs {
+		blobIndex := i
+		eg.Go(func() error {
+			blob := &blobs[blobIndex]
+			blobCellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(blob)
+			if err != nil {
+				return errors.Wrap(err, "compute cells and KZG proofs")
+			}
+
+			cellsAndProofs[blobIndex] = blobCellsAndProofs
+			return nil
+		})
+	}
+	if err := eg.Wait(); err != nil {
+		return nil, err
+	}
+
+	// Get the column sidecars.
+	sidecars := make([]*ethpb.DataColumnSidecar, 0, fieldparams.NumberOfColumns)
+	for columnIndex := uint64(0); columnIndex < fieldparams.NumberOfColumns; columnIndex++ {
+		column := make([]kzg.Cell, 0, blobsCount)
+		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
+
+		for rowIndex := 0; rowIndex < blobsCount; rowIndex++ {
+			cellsForRow := cellsAndProofs[rowIndex].Cells
+			proofsForRow := cellsAndProofs[rowIndex].Proofs
+
+			cell := cellsForRow[columnIndex]
+			column = append(column, cell)
+
+			kzgProof := proofsForRow[columnIndex]
+			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
+		}
+
+		columnBytes := make([][]byte, 0, blobsCount)
+		for i := range column {
+			columnBytes = append(columnBytes, column[i][:])
+		}
+
+		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
+		for _, kzgProof := range kzgProofOfColumn {
+			copiedProof := kzgProof
+			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, copiedProof[:])
+		}
+
+		sidecar := &ethpb.DataColumnSidecar{
+			ColumnIndex:                  columnIndex,
+			DataColumn:                   columnBytes,
+			KzgCommitments:               blobKzgCommitments,
+			KzgProof:                     kzgProofOfColumnBytes,
+			SignedBlockHeader:            signedBlockHeader,
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+
+		sidecars = append(sidecars, sidecar)
+	}
+	dataColumnComputationTime.Observe(float64(time.Since(startTime).Milliseconds()))
+	return sidecars, nil
+}
+
+// populateAndFilterIndices returns a sorted slices of indices, setting all indices if none are provided,
+// and filtering out indices higher than the blob count.
+func populateAndFilterIndices(indices map[uint64]bool, blobCount uint64) []uint64 {
+	// If no indices are provided, provide all blobs.
+	if len(indices) == 0 {
+		for i := range blobCount {
+			indices[i] = true
+		}
+	}
+
+	// Filter blobs index higher than the blob count.
+	filteredIndices := make(map[uint64]bool, len(indices))
+	for i := range indices {
+		if i < blobCount {
+			filteredIndices[i] = true
+		}
+	}
+
+	// Transform set to slice.
+	indicesSlice := make([]uint64, 0, len(filteredIndices))
+	for i := range filteredIndices {
+		indicesSlice = append(indicesSlice, i)
+	}
+
+	// Sort the indices.
+	slices.Sort[[]uint64](indicesSlice)
+
+	return indicesSlice
+}
+
+// Blobs extract blobs from `dataColumnsSidecar`.
+// This can be seen as the reciprocal function of DataColumnSidecars.
+// `dataColumnsSidecar` needs to contain the datacolumns corresponding to the non-extended matrix,
+// else an error will be returned.
+// (`dataColumnsSidecar` can contain extra columns, but they will be ignored.)
+func Blobs(indices map[uint64]bool, dataColumnsSidecar []*ethpb.DataColumnSidecar) ([]*blocks.VerifiedROBlob, error) {
+	columnCount := fieldparams.NumberOfColumns
+
+	neededColumnCount := columnCount / 2
+
+	// Check if all needed columns are present.
+	sliceIndexFromColumnIndex := make(map[uint64]int, len(dataColumnsSidecar))
+	for i := range dataColumnsSidecar {
+		dataColumnSideCar := dataColumnsSidecar[i]
+		columnIndex := dataColumnSideCar.ColumnIndex
+
+		if columnIndex < uint64(neededColumnCount) {
+			sliceIndexFromColumnIndex[columnIndex] = i
+		}
+	}
+
+	actualColumnCount := len(sliceIndexFromColumnIndex)
+
+	// Get missing columns.
+	if actualColumnCount < neededColumnCount {
+		missingColumns := make(map[int]bool, neededColumnCount-actualColumnCount)
+		for i := range neededColumnCount {
+			if _, ok := sliceIndexFromColumnIndex[uint64(i)]; !ok {
+				missingColumns[i] = true
+			}
+		}
+
+		missingColumnsSlice := make([]int, 0, len(missingColumns))
+		for i := range missingColumns {
+			missingColumnsSlice = append(missingColumnsSlice, i)
+		}
+
+		slices.Sort[[]int](missingColumnsSlice)
+		return nil, errors.Errorf("some columns are missing: %v", missingColumnsSlice)
+	}
+
+	// It is safe to retrieve the first column since we already checked that `dataColumnsSidecar` is not empty.
+	firstDataColumnSidecar := dataColumnsSidecar[0]
+
+	blobCount := uint64(len(firstDataColumnSidecar.DataColumn))
+
+	// Check all colums have te same length.
+	for i := range dataColumnsSidecar {
+		if uint64(len(dataColumnsSidecar[i].DataColumn)) != blobCount {
+			return nil, errors.Errorf("mismatch in the length of the data columns, expected %d, got %d", blobCount, len(dataColumnsSidecar[i].DataColumn))
+		}
+	}
+
+	// Reconstruct verified RO blobs from columns.
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
+
+	// Populate and filter indices.
+	indicesSlice := populateAndFilterIndices(indices, blobCount)
+
+	for _, blobIndex := range indicesSlice {
+		var blob kzg.Blob
+
+		// Compute the content of the blob.
+		for columnIndex := range neededColumnCount {
+			sliceIndex, ok := sliceIndexFromColumnIndex[uint64(columnIndex)]
+			if !ok {
+				return nil, errors.Errorf("missing column %d, this should never happen", columnIndex)
+			}
+
+			dataColumnSideCar := dataColumnsSidecar[sliceIndex]
+			cell := dataColumnSideCar.DataColumn[blobIndex]
+
+			for i := 0; i < len(cell); i++ {
+				blob[columnIndex*kzg.BytesPerCell+i] = cell[i]
+			}
+		}
+
+		// Retrieve the blob KZG commitment.
+		blobKZGCommitment := kzg.Commitment(firstDataColumnSidecar.KzgCommitments[blobIndex])
+
+		// Compute the blob KZG proof.
+		blobKzgProof, err := kzg.ComputeBlobKZGProof(&blob, blobKZGCommitment)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute blob KZG proof")
+		}
+
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    blobIndex,
+			Blob:                     blob[:],
+			KzgCommitment:            blobKZGCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        firstDataColumnSidecar.SignedBlockHeader,
+			CommitmentInclusionProof: firstDataColumnSidecar.KzgCommitmentsInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		if err != nil {
+			return nil, errors.Wrap(err, "new RO blob")
+		}
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	return verifiedROBlobs, nil
+}
+
+// DataColumnSidecarsForReconstruct is a TEMPORARY function until there is an official specification for it.
+// It is scheduled for deletion.
+func DataColumnSidecarsForReconstruct(
+	blobKzgCommitments [][]byte,
+	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
+	kzgCommitmentsInclusionProof [][]byte,
+	cellsAndProofs []kzg.CellsAndProofs,
+) ([]*ethpb.DataColumnSidecar, error) {
+	// Each CellsAndProofs corresponds to a Blob
+	// So we can get the BlobCount by checking the length of CellsAndProofs
+	blobsCount := len(cellsAndProofs)
+	if blobsCount == 0 {
+		return nil, nil
+	}
+
+	// Get the column sidecars.
+	sidecars := make([]*ethpb.DataColumnSidecar, 0, fieldparams.NumberOfColumns)
+	for columnIndex := uint64(0); columnIndex < fieldparams.NumberOfColumns; columnIndex++ {
+		column := make([]kzg.Cell, 0, blobsCount)
+		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
+
+		for rowIndex := 0; rowIndex < blobsCount; rowIndex++ {
+			cellsForRow := cellsAndProofs[rowIndex].Cells
+			proofsForRow := cellsAndProofs[rowIndex].Proofs
+
+			cell := cellsForRow[columnIndex]
+			column = append(column, cell)
+
+			kzgProof := proofsForRow[columnIndex]
+			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
+		}
+
+		columnBytes := make([][]byte, 0, blobsCount)
+		for i := range column {
+			columnBytes = append(columnBytes, column[i][:])
+		}
+
+		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
+		for _, kzgProof := range kzgProofOfColumn {
+			copiedProof := kzgProof
+			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, copiedProof[:])
+		}
+
+		sidecar := &ethpb.DataColumnSidecar{
+			ColumnIndex:                  columnIndex,
+			DataColumn:                   columnBytes,
+			KzgCommitments:               blobKzgCommitments,
+			KzgProof:                     kzgProofOfColumnBytes,
+			SignedBlockHeader:            signedBlockHeader,
+			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
+		}
+
+		sidecars = append(sidecars, sidecar)
+	}
+
+	return sidecars, nil
+}
+
+// VerifyDataColumnsSidecarKZGProofs verifies the provided KZG Proofs of data columns.
+func VerifyDataColumnsSidecarKZGProofs(sidecars []blocks.RODataColumn) (bool, error) {
+	// Retrieve the number of columns.
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	// Compute the total count.
+	count := 0
+	for _, sidecar := range sidecars {
+		count += len(sidecar.DataColumn)
+	}
+
+	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 {
+		// Check if the columns index is not too large
+		if sidecar.ColumnIndex >= numberOfColumns {
+			return false, errIndexTooLarge
+		}
+
+		// Check if the KZG commitments size and data column size match.
+		if len(sidecar.DataColumn) != len(sidecar.KzgCommitments) {
+			return false, errMismatchLength
+		}
+
+		// Check if the KZG proofs size and data column size match.
+		if len(sidecar.DataColumn) != len(sidecar.KzgProof) {
+			return false, errMismatchLength
+		}
+
+		for i := range sidecar.DataColumn {
+			commitments = append(commitments, kzg.Bytes48(sidecar.KzgCommitments[i]))
+			indices = append(indices, sidecar.ColumnIndex)
+			cells = append(cells, kzg.Cell(sidecar.DataColumn[i]))
+			proofs = append(proofs, kzg.Bytes48(sidecar.KzgProof[i]))
+		}
+	}
+
+	// Verify all the batch at once.
+	verified, err := kzg.VerifyCellKZGProofBatch(commitments, indices, cells, proofs)
+	if err != nil {
+		return false, errors.Wrap(err, "verify cell KZG proof batch")
+	}
+
+	return verified, nil
+}
+
+// CustodyGroupCount returns the number of groups the node should participate in for custody.
+func CustodyGroupCount() uint64 {
+	if flags.Get().SubscribeToAllSubnets {
+		return params.BeaconConfig().NumberOfCustodyGroups
+	}
+
+	return params.BeaconConfig().CustodyRequirement
+}
+
+// CustodyGroupSamplingSize returns the number of custody groups the node should sample from.
+// https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.10/specs/fulu/das-core.md#custody-sampling
+func CustodyGroupSamplingSize() uint64 {
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
+	custodyGroupCount := CustodyGroupCount()
+
+	return max(samplesPerSlot, custodyGroupCount)
+}
+
+// HypergeomCDF computes the hypergeometric cumulative distribution function.
+// https://en.wikipedia.org/wiki/Hypergeometric_distribution
+func HypergeomCDF(k, M, n, N uint64) float64 {
+	denominatorInt := new(big.Int).Binomial(int64(M), int64(N)) // lint:ignore uintcast
+	denominator := new(big.Float).SetInt(denominatorInt)
+
+	rBig := big.NewFloat(0)
+
+	for i := uint64(0); i < k+1; i++ {
+		a := new(big.Int).Binomial(int64(n), int64(i)) // lint:ignore uintcast
+		b := new(big.Int).Binomial(int64(M-n), int64(N-i))
+		numeratorInt := new(big.Int).Mul(a, b)
+		numerator := new(big.Float).SetInt(numeratorInt)
+		item := new(big.Float).Quo(numerator, denominator)
+		rBig.Add(rBig, item)
+	}
+
+	r, _ := rBig.Float64()
+
+	return r
+}
+
+// ExtendedSampleCount computes, for a given number of samples per slot and allowed failures the
+// number of samples we should actually query from peers.
+// TODO: Add link to the specification once it is available.
+func ExtendedSampleCount(samplesPerSlot, allowedFailures uint64) uint64 {
+	// Retrieve the columns count
+	columnsCount := params.BeaconConfig().NumberOfColumns
+
+	// If half of the columns are missing, we are able to reconstruct the data.
+	// If half of the columns + 1 are missing, we are not able to reconstruct the data.
+	// This is the smallest worst case.
+	worstCaseMissing := columnsCount/2 + 1
+
+	// Compute the false positive threshold.
+	falsePositiveThreshold := HypergeomCDF(0, columnsCount, worstCaseMissing, samplesPerSlot)
+
+	var sampleCount uint64
+
+	// Finally, compute the extended sample count.
+	for sampleCount = samplesPerSlot; sampleCount < columnsCount+1; sampleCount++ {
+		if HypergeomCDF(allowedFailures, columnsCount, worstCaseMissing, sampleCount) <= falsePositiveThreshold {
+			break
+		}
+	}
+
+	return sampleCount
+}
+
+// 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 cgc := record.Load(&cgc); cgc != nil {
+		return 0, errCannotLoadCustodyGroupCount
+	}
+
+	return uint64(cgc), nil
+}
+
+func CanSelfReconstruct(custodyGroupCount uint64) bool {
+	total := params.BeaconConfig().NumberOfCustodyGroups
+	// If total is odd, then we need total / 2 + 1 columns to reconstruct.
+	// If total is even, then we need total / 2 columns to reconstruct.
+	custodyGroupsNeeded := total/2 + total%2
+	return custodyGroupCount >= custodyGroupsNeeded
+}
+
+// RecoverCellsAndProofs recovers the cells and proofs from the data column sidecars.
+func RecoverCellsAndProofs(
+	dataColumnSideCars []*ethpb.DataColumnSidecar,
+	blockRoot [fieldparams.RootLength]byte,
+) ([]kzg.CellsAndProofs, error) {
+	var wg errgroup.Group
+
+	dataColumnSideCarsCount := len(dataColumnSideCars)
+
+	if dataColumnSideCarsCount == 0 {
+		return nil, errors.New("no data column sidecars")
+	}
+
+	// Check if all columns have the same length.
+	blobCount := len(dataColumnSideCars[0].DataColumn)
+	for _, sidecar := range dataColumnSideCars {
+		length := len(sidecar.DataColumn)
+
+		if length != blobCount {
+			return nil, errors.New("columns do not have the same length")
+		}
+	}
+
+	// Recover cells and compute proofs in parallel.
+	recoveredCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+
+	for blobIndex := 0; blobIndex < blobCount; blobIndex++ {
+		bIndex := blobIndex
+		wg.Go(func() error {
+			start := time.Now()
+
+			cellsIndices := make([]uint64, 0, dataColumnSideCarsCount)
+			cells := make([]kzg.Cell, 0, dataColumnSideCarsCount)
+
+			for _, sidecar := range dataColumnSideCars {
+				// Build the cell indices.
+				cellsIndices = append(cellsIndices, sidecar.ColumnIndex)
+
+				// Get the cell.
+				column := sidecar.DataColumn
+				cell := column[bIndex]
+
+				cells = append(cells, kzg.Cell(cell))
+			}
+
+			// Recover the cells and proofs for the corresponding blob
+			cellsAndProofs, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
+
+			if err != nil {
+				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", bIndex)
+			}
+
+			recoveredCellsAndProofs[bIndex] = cellsAndProofs
+			log.WithFields(logrus.Fields{
+				"elapsed": time.Since(start),
+				"index":   bIndex,
+				"root":    fmt.Sprintf("%x", blockRoot),
+			}).Debug("Recovered cells and proofs")
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, err
+	}
+
+	return recoveredCellsAndProofs, nil
+}
--- a/beacon-chain/core/peerdas/helpers_test.go
+++ b/beacon-chain/core/peerdas/helpers_test.go
@@ -0,0 +1,531 @@
+package peerdas_test
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"testing"
+
+	"github.com/consensys/gnark-crypto/ecc/bls12-381/fr"
+	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	"github.com/ethereum/go-ethereum/p2p/enr"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/kzg"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
+	"github.com/prysmaticlabs/prysm/v5/cmd/beacon-chain/flags"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/sirupsen/logrus"
+)
+
+func deterministicRandomness(seed int64) [32]byte {
+	// Converts an int64 to a byte slice
+	buf := new(bytes.Buffer)
+	err := binary.Write(buf, binary.BigEndian, seed)
+	if err != nil {
+		logrus.WithError(err).Error("Failed to write int64 to bytes buffer")
+		return [32]byte{}
+	}
+	bytes := buf.Bytes()
+
+	return sha256.Sum256(bytes)
+}
+
+// Returns a serialized random field element in big-endian
+func GetRandFieldElement(seed int64) [32]byte {
+	bytes := deterministicRandomness(seed)
+	var r fr.Element
+	r.SetBytes(bytes[:])
+
+	return GoKZG.SerializeScalar(r)
+}
+
+// Returns a random blob using the passed seed as entropy
+func GetRandBlob(seed int64) kzg.Blob {
+	var blob kzg.Blob
+	bytesPerBlob := GoKZG.ScalarsPerBlob * GoKZG.SerializedScalarSize
+	for i := 0; i < bytesPerBlob; i += GoKZG.SerializedScalarSize {
+		fieldElementBytes := GetRandFieldElement(seed + int64(i))
+		copy(blob[i:i+GoKZG.SerializedScalarSize], fieldElementBytes[:])
+	}
+	return blob
+}
+
+func GenerateCommitmentAndProof(blob *kzg.Blob) (*kzg.Commitment, *kzg.Proof, error) {
+	commitment, err := kzg.BlobToKZGCommitment(blob)
+	if err != nil {
+		return nil, nil, err
+	}
+	proof, err := kzg.ComputeBlobKZGProof(blob, commitment)
+	if err != nil {
+		return nil, nil, err
+	}
+	return &commitment, &proof, err
+}
+
+func TestVerifyDataColumnSidecarKZGProofs(t *testing.T) {
+	dbBlock := util.NewBeaconBlockDeneb()
+	require.NoError(t, kzg.Start())
+
+	var (
+		comms [][]byte
+		blobs []kzg.Blob
+	)
+	for i := int64(0); i < 6; i++ {
+		blob := GetRandBlob(i)
+		commitment, _, err := GenerateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+		comms = append(comms, commitment[:])
+		blobs = append(blobs, blob)
+	}
+
+	dbBlock.Block.Body.BlobKzgCommitments = comms
+	sBlock, err := blocks.NewSignedBeaconBlock(dbBlock)
+	require.NoError(t, err)
+	sCars, err := peerdas.DataColumnSidecars(sBlock, blobs)
+	require.NoError(t, err)
+
+	for i, sidecar := range sCars {
+		roCol, err := blocks.NewRODataColumn(sidecar)
+		require.NoError(t, err)
+		verified, err := peerdas.VerifyDataColumnsSidecarKZGProofs([]blocks.RODataColumn{roCol})
+		require.NoError(t, err)
+		require.Equal(t, true, verified, fmt.Sprintf("sidecar %d failed", i))
+	}
+}
+
+func TestDataColumnSidecars(t *testing.T) {
+	var expected []*ethpb.DataColumnSidecar = nil
+	actual, err := peerdas.DataColumnSidecars(nil, []kzg.Blob{})
+	require.NoError(t, err)
+
+	require.DeepSSZEqual(t, expected, actual)
+}
+
+func TestBlobs(t *testing.T) {
+	blobsIndice := map[uint64]bool{}
+
+	almostAllColumns := make([]*ethpb.DataColumnSidecar, 0, fieldparams.NumberOfColumns/2)
+	for i := 2; i < fieldparams.NumberOfColumns/2+2; i++ {
+		almostAllColumns = append(almostAllColumns, &ethpb.DataColumnSidecar{
+			ColumnIndex: uint64(i),
+		})
+	}
+
+	testCases := []struct {
+		name     string
+		input    []*ethpb.DataColumnSidecar
+		expected []*blocks.VerifiedROBlob
+		err      error
+	}{
+		{
+			name:     "empty input",
+			input:    []*ethpb.DataColumnSidecar{},
+			expected: nil,
+			err:      errors.New("some columns are missing: [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63]"),
+		},
+		{
+			name:     "missing columns",
+			input:    almostAllColumns,
+			expected: nil,
+			err:      errors.New("some columns are missing: [0 1]"),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			actual, err := peerdas.Blobs(blobsIndice, tc.input)
+			if tc.err != nil {
+				require.Equal(t, tc.err.Error(), err.Error())
+			} else {
+				require.NoError(t, err)
+			}
+			require.DeepSSZEqual(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestDataColumnsSidecarsBlobsRoundtrip(t *testing.T) {
+	const blobCount = 5
+	blobsIndex := map[uint64]bool{}
+
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Create a protobuf signed beacon block.
+	signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+	// Generate random blobs and their corresponding commitments and proofs.
+	blobs := make([]kzg.Blob, 0, blobCount)
+	blobKzgCommitments := make([]*kzg.Commitment, 0, blobCount)
+	blobKzgProofs := make([]*kzg.Proof, 0, blobCount)
+
+	for blobIndex := range blobCount {
+		// Create a random blob.
+		blob := GetRandBlob(int64(blobIndex))
+		blobs = append(blobs, blob)
+
+		// Generate a blobKZGCommitment for the blob.
+		blobKZGCommitment, proof, err := GenerateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+
+		blobKzgCommitments = append(blobKzgCommitments, blobKZGCommitment)
+		blobKzgProofs = append(blobKzgProofs, proof)
+	}
+
+	// Set the commitments into the block.
+	blobZkgCommitmentsBytes := make([][]byte, 0, blobCount)
+	for _, blobKZGCommitment := range blobKzgCommitments {
+		blobZkgCommitmentsBytes = append(blobZkgCommitmentsBytes, blobKZGCommitment[:])
+	}
+
+	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = blobZkgCommitmentsBytes
+
+	// Generate verified RO blobs.
+	verifiedROBlobs := make([]*blocks.VerifiedROBlob, 0, blobCount)
+
+	// Create a signed beacon block from the protobuf.
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+	require.NoError(t, err)
+
+	commitmentInclusionProof, err := blocks.MerkleProofKZGCommitments(signedBeaconBlock.Block().Body())
+	require.NoError(t, err)
+
+	for blobIndex := range blobCount {
+		blob := blobs[blobIndex]
+		blobKZGCommitment := blobKzgCommitments[blobIndex]
+		blobKzgProof := blobKzgProofs[blobIndex]
+
+		// Get the signed beacon block header.
+		signedBeaconBlockHeader, err := signedBeaconBlock.Header()
+		require.NoError(t, err)
+
+		blobSidecar := &ethpb.BlobSidecar{
+			Index:                    uint64(blobIndex),
+			Blob:                     blob[:],
+			KzgCommitment:            blobKZGCommitment[:],
+			KzgProof:                 blobKzgProof[:],
+			SignedBlockHeader:        signedBeaconBlockHeader,
+			CommitmentInclusionProof: commitmentInclusionProof,
+		}
+
+		roBlob, err := blocks.NewROBlob(blobSidecar)
+		require.NoError(t, err)
+
+		verifiedROBlob := blocks.NewVerifiedROBlob(roBlob)
+		verifiedROBlobs = append(verifiedROBlobs, &verifiedROBlob)
+	}
+
+	// Compute data columns sidecars from the signed beacon block and from the blobs.
+	dataColumnsSidecar, err := peerdas.DataColumnSidecars(signedBeaconBlock, blobs)
+	require.NoError(t, err)
+
+	// Compute the blobs from the data columns sidecar.
+	roundtripBlobs, err := peerdas.Blobs(blobsIndex, dataColumnsSidecar)
+	require.NoError(t, err)
+
+	// Check that the blobs are the same.
+	require.DeepSSZEqual(t, verifiedROBlobs, roundtripBlobs)
+}
+
+func TestCustodyGroupCount(t *testing.T) {
+	testCases := []struct {
+		name                  string
+		subscribeToAllSubnets bool
+		expected              uint64
+	}{
+		{
+			name:                  "subscribeToAllSubnets=false",
+			subscribeToAllSubnets: false,
+			expected:              params.BeaconConfig().CustodyRequirement,
+		},
+		{
+			name:                  "subscribeToAllSubnets=true",
+			subscribeToAllSubnets: true,
+			expected:              params.BeaconConfig().DataColumnSidecarSubnetCount,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Set flags.
+			resetFlags := flags.Get()
+			defer func() {
+				flags.Init(resetFlags)
+			}()
+
+			params.SetupTestConfigCleanup(t)
+			gFlags := new(flags.GlobalFlags)
+			gFlags.SubscribeToAllSubnets = tc.subscribeToAllSubnets
+			flags.Init(gFlags)
+
+			// Get the custody subnet count.
+			actual := peerdas.CustodyGroupCount()
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestHypergeomCDF(t *testing.T) {
+	// Test case from https://en.wikipedia.org/wiki/Hypergeometric_distribution
+	// Population size: 1000, number of successes in population: 500, sample size: 10, number of successes in sample: 5
+	// Expected result: 0.072
+	const (
+		expected = 0.0796665913283742
+		margin   = 0.000001
+	)
+
+	actual := peerdas.HypergeomCDF(5, 128, 65, 16)
+	require.Equal(t, true, expected-margin <= actual && actual <= expected+margin)
+}
+
+func TestExtendedSampleCount(t *testing.T) {
+	const samplesPerSlot = 16
+
+	testCases := []struct {
+		name                string
+		allowedMissings     uint64
+		extendedSampleCount uint64
+	}{
+		{name: "allowedMissings=0", allowedMissings: 0, extendedSampleCount: 16},
+		{name: "allowedMissings=1", allowedMissings: 1, extendedSampleCount: 20},
+		{name: "allowedMissings=2", allowedMissings: 2, extendedSampleCount: 24},
+		{name: "allowedMissings=3", allowedMissings: 3, extendedSampleCount: 27},
+		{name: "allowedMissings=4", allowedMissings: 4, extendedSampleCount: 29},
+		{name: "allowedMissings=5", allowedMissings: 5, extendedSampleCount: 32},
+		{name: "allowedMissings=6", allowedMissings: 6, extendedSampleCount: 35},
+		{name: "allowedMissings=7", allowedMissings: 7, extendedSampleCount: 37},
+		{name: "allowedMissings=8", allowedMissings: 8, extendedSampleCount: 40},
+		{name: "allowedMissings=9", allowedMissings: 9, extendedSampleCount: 42},
+		{name: "allowedMissings=10", allowedMissings: 10, extendedSampleCount: 44},
+		{name: "allowedMissings=11", allowedMissings: 11, extendedSampleCount: 47},
+		{name: "allowedMissings=12", allowedMissings: 12, extendedSampleCount: 49},
+		{name: "allowedMissings=13", allowedMissings: 13, extendedSampleCount: 51},
+		{name: "allowedMissings=14", allowedMissings: 14, extendedSampleCount: 53},
+		{name: "allowedMissings=15", allowedMissings: 15, extendedSampleCount: 55},
+		{name: "allowedMissings=16", allowedMissings: 16, extendedSampleCount: 57},
+		{name: "allowedMissings=17", allowedMissings: 17, extendedSampleCount: 59},
+		{name: "allowedMissings=18", allowedMissings: 18, extendedSampleCount: 61},
+		{name: "allowedMissings=19", allowedMissings: 19, extendedSampleCount: 63},
+		{name: "allowedMissings=20", allowedMissings: 20, extendedSampleCount: 65},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			result := peerdas.ExtendedSampleCount(samplesPerSlot, tc.allowedMissings)
+			require.Equal(t, tc.extendedSampleCount, result)
+		})
+	}
+}
+
+func TestCustodyGroupCountFromRecord(t *testing.T) {
+	const expected uint64 = 7
+
+	// Create an Ethereum record.
+	record := &enr.Record{}
+	record.Set(peerdas.Cgc(expected))
+
+	actual, err := peerdas.CustodyGroupCountFromRecord(record)
+	require.NoError(t, err)
+	require.Equal(t, expected, actual)
+}
+
+func TestCanSelfReconstruct(t *testing.T) {
+	testCases := []struct {
+		name                       string
+		totalNumberOfCustodyGroups uint64
+		custodyNumberOfGroups      uint64
+		expected                   bool
+	}{
+		{
+			name:                       "totalNumberOfCustodyGroups=64, custodyNumberOfGroups=31",
+			totalNumberOfCustodyGroups: 64,
+			custodyNumberOfGroups:      31,
+			expected:                   false,
+		},
+		{
+			name:                       "totalNumberOfCustodyGroups=64, custodyNumberOfGroups=32",
+			totalNumberOfCustodyGroups: 64,
+			custodyNumberOfGroups:      32,
+			expected:                   true,
+		},
+		{
+			name:                       "totalNumberOfCustodyGroups=65, custodyNumberOfGroups=32",
+			totalNumberOfCustodyGroups: 65,
+			custodyNumberOfGroups:      32,
+			expected:                   false,
+		},
+		{
+			name:                       "totalNumberOfCustodyGroups=63, custodyNumberOfGroups=33",
+			totalNumberOfCustodyGroups: 65,
+			custodyNumberOfGroups:      33,
+			expected:                   true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Set the total number of columns.
+			params.SetupTestConfigCleanup(t)
+			cfg := params.BeaconConfig().Copy()
+			cfg.NumberOfCustodyGroups = tc.totalNumberOfCustodyGroups
+			params.OverrideBeaconConfig(cfg)
+
+			// Check if reconstuction is possible.
+			actual := peerdas.CanSelfReconstruct(tc.custodyNumberOfGroups)
+			require.Equal(t, tc.expected, actual)
+		})
+	}
+}
+
+func TestReconstructionRoundTrip(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+
+	const blobCount = 5
+
+	var blockRoot [fieldparams.RootLength]byte
+
+	signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+	require.NoError(t, kzg.Start())
+
+	// Generate random blobs and their corresponding commitments.
+	var (
+		blobsKzgCommitments [][]byte
+		blobs               []kzg.Blob
+	)
+	for i := range blobCount {
+		blob := GetRandBlob(int64(i))
+		commitment, _, err := GenerateCommitmentAndProof(&blob)
+		require.NoError(t, err)
+
+		blobsKzgCommitments = append(blobsKzgCommitments, commitment[:])
+		blobs = append(blobs, blob)
+	}
+
+	// Generate a signed beacon block.
+	signedBeaconBlockPb.Block.Body.BlobKzgCommitments = blobsKzgCommitments
+	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+	require.NoError(t, err)
+
+	// Get the signed beacon block header.
+	signedBeaconBlockHeader, err := signedBeaconBlock.Header()
+	require.NoError(t, err)
+
+	// Convert data columns sidecars from signed block and blobs.
+	dataColumnSidecars, err := peerdas.DataColumnSidecars(signedBeaconBlock, blobs)
+	require.NoError(t, err)
+
+	// Create verified RO data columns.
+	verifiedRoDataColumns := make([]*blocks.VerifiedRODataColumn, 0, blobCount)
+	for _, dataColumnSidecar := range dataColumnSidecars {
+		roDataColumn, err := blocks.NewRODataColumn(dataColumnSidecar)
+		require.NoError(t, err)
+
+		verifiedRoDataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRoDataColumns = append(verifiedRoDataColumns, &verifiedRoDataColumn)
+	}
+
+	verifiedRoDataColumn := verifiedRoDataColumns[0]
+
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	var noDataColumns []*ethpb.DataColumnSidecar
+	dataColumnsWithDifferentLengths := []*ethpb.DataColumnSidecar{
+		{DataColumn: [][]byte{{}, {}}},
+		{DataColumn: [][]byte{{}}},
+	}
+	notEnoughDataColumns := dataColumnSidecars[:numberOfColumns/2-1]
+	originalDataColumns := dataColumnSidecars[:numberOfColumns/2]
+	extendedDataColumns := dataColumnSidecars[numberOfColumns/2:]
+	evenDataColumns := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns/2)
+	oddDataColumns := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns/2)
+	allDataColumns := dataColumnSidecars
+
+	for i, dataColumn := range dataColumnSidecars {
+		if i%2 == 0 {
+			evenDataColumns = append(evenDataColumns, dataColumn)
+		} else {
+			oddDataColumns = append(oddDataColumns, dataColumn)
+		}
+	}
+
+	testCases := []struct {
+		name               string
+		dataColumnsSidecar []*ethpb.DataColumnSidecar
+		isError            bool
+	}{
+		{
+			name:               "No data columns sidecars",
+			dataColumnsSidecar: noDataColumns,
+			isError:            true,
+		},
+		{
+			name:               "Data columns sidecar with different lengths",
+			dataColumnsSidecar: dataColumnsWithDifferentLengths,
+			isError:            true,
+		},
+		{
+			name:               "All columns are present (no actual need to reconstruct)",
+			dataColumnsSidecar: allDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only original columns are present",
+			dataColumnsSidecar: originalDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only extended columns are present",
+			dataColumnsSidecar: extendedDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only even columns are present",
+			dataColumnsSidecar: evenDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Only odd columns are present",
+			dataColumnsSidecar: oddDataColumns,
+			isError:            false,
+		},
+		{
+			name:               "Not enough columns to reconstruct",
+			dataColumnsSidecar: notEnoughDataColumns,
+			isError:            true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Recover cells and proofs from available data columns sidecars.
+			cellsAndProofs, err := peerdas.RecoverCellsAndProofs(tc.dataColumnsSidecar, blockRoot)
+			isError := (err != nil)
+			require.Equal(t, tc.isError, isError)
+
+			if isError {
+				return
+			}
+
+			// Recover all data columns sidecars from cells and proofs.
+			reconstructedDataColumnsSideCars, err := peerdas.DataColumnSidecarsForReconstruct(
+				blobsKzgCommitments,
+				signedBeaconBlockHeader,
+				verifiedRoDataColumn.KzgCommitmentsInclusionProof,
+				cellsAndProofs,
+			)
+
+			require.NoError(t, err)
+
+			expected := dataColumnSidecars
+			actual := reconstructedDataColumnsSideCars
+			require.DeepSSZEqual(t, expected, actual)
+		})
+	}
+}
--- a/beacon-chain/core/peerdas/log.go
+++ b/beacon-chain/core/peerdas/log.go
@@ -0,0 +1,5 @@
+package peerdas
+
+import "github.com/sirupsen/logrus"
+
+var log = logrus.WithField("prefix", "peerdas")
--- a/beacon-chain/core/peerdas/metrics.go
+++ b/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{100, 250, 500, 750, 1000, 1500, 2000, 4000, 8000, 12000, 16000},
+	},
+)
--- a/beacon-chain/core/time/slot_epoch.go
+++ b/beacon-chain/core/time/slot_epoch.go
@@ -53,6 +53,11 @@ func HigherEqualThanAltairVersionAndEpoch(s state.BeaconState, e primitives.Epoc
 	return s.Version() >= version.Altair && e >= params.BeaconConfig().AltairForkEpoch
 }

+// PeerDASIsActive checks whether peerDAS is active at the provided slot.
+func PeerDASIsActive(slot primitives.Slot) bool {
+	return params.FuluEnabled() && slots.ToEpoch(slot) >= params.BeaconConfig().FuluForkEpoch
+}
+
 // CanUpgradeToAltair returns true if the input `slot` can upgrade to Altair.
 // Spec code:
 // If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == ALTAIR_FORK_EPOCH
@@ -99,6 +104,15 @@ func CanUpgradeToElectra(slot primitives.Slot) bool {
 	return epochStart && electraEpoch
 }

+// CanUpgradeToFulu returns true if the input `slot` can upgrade to Fulu.
+// Spec code:
+// If state.slot % SLOTS_PER_EPOCH == 0 and compute_epoch_at_slot(state.slot) == FULU_FORK_EPOCH
+func CanUpgradeToFulu(slot primitives.Slot) bool {
+	epochStart := slots.IsEpochStart(slot)
+	fuluEpoch := slots.ToEpoch(slot) == params.BeaconConfig().FuluForkEpoch
+	return epochStart && fuluEpoch
+}
+
 // CanProcessEpoch checks the eligibility to process epoch.
 // The epoch can be processed at the end of the last slot of every epoch.
 //
--- a/beacon-chain/core/time/slot_epoch_test.go
+++ b/beacon-chain/core/time/slot_epoch_test.go
@@ -1,6 +1,7 @@
 package time_test

 import (
+	"fmt"
 	"testing"

 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
@@ -83,76 +84,6 @@ func TestNextEpoch_OK(t *testing.T) {
 	}
 }

-func TestCanUpgradeToAltair(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	bc := params.BeaconConfig()
-	bc.AltairForkEpoch = 5
-	params.OverrideBeaconConfig(bc)
-	tests := []struct {
-		name string
-		slot primitives.Slot
-		want bool
-	}{
-		{
-			name: "not epoch start",
-			slot: 1,
-			want: false,
-		},
-		{
-			name: "not altair epoch",
-			slot: params.BeaconConfig().SlotsPerEpoch,
-			want: false,
-		},
-		{
-			name: "altair epoch",
-			slot: primitives.Slot(params.BeaconConfig().AltairForkEpoch) * params.BeaconConfig().SlotsPerEpoch,
-			want: true,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := time.CanUpgradeToAltair(tt.slot); got != tt.want {
-				t.Errorf("canUpgradeToAltair() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
-func TestCanUpgradeBellatrix(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	bc := params.BeaconConfig()
-	bc.BellatrixForkEpoch = 5
-	params.OverrideBeaconConfig(bc)
-	tests := []struct {
-		name string
-		slot primitives.Slot
-		want bool
-	}{
-		{
-			name: "not epoch start",
-			slot: 1,
-			want: false,
-		},
-		{
-			name: "not bellatrix epoch",
-			slot: params.BeaconConfig().SlotsPerEpoch,
-			want: false,
-		},
-		{
-			name: "bellatrix epoch",
-			slot: primitives.Slot(params.BeaconConfig().BellatrixForkEpoch) * params.BeaconConfig().SlotsPerEpoch,
-			want: true,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := time.CanUpgradeToBellatrix(tt.slot); got != tt.want {
-				t.Errorf("CanUpgradeToBellatrix() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
-
 func TestCanProcessEpoch_TrueOnEpochsLastSlot(t *testing.T) {
 	tests := []struct {
 		slot            primitives.Slot
@@ -264,107 +195,79 @@ func TestAltairCompatible(t *testing.T) {
 	}
 }

-func TestCanUpgradeToCapella(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	bc := params.BeaconConfig()
-	bc.CapellaForkEpoch = 5
-	params.OverrideBeaconConfig(bc)
-	tests := []struct {
-		name string
-		slot primitives.Slot
-		want bool
-	}{
-		{
-			name: "not epoch start",
-			slot: 1,
-			want: false,
-		},
-		{
-			name: "not capella epoch",
-			slot: params.BeaconConfig().SlotsPerEpoch,
-			want: false,
-		},
-		{
-			name: "capella epoch",
-			slot: primitives.Slot(params.BeaconConfig().CapellaForkEpoch) * params.BeaconConfig().SlotsPerEpoch,
-			want: true,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := time.CanUpgradeToCapella(tt.slot); got != tt.want {
-				t.Errorf("CanUpgradeToCapella() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}
+func TestCanUpgradeTo(t *testing.T) {
+	beaconConfig := params.BeaconConfig()

-func TestCanUpgradeToDeneb(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	bc := params.BeaconConfig()
-	bc.DenebForkEpoch = 5
-	params.OverrideBeaconConfig(bc)
-	tests := []struct {
-		name string
-		slot primitives.Slot
-		want bool
+	outerTestCases := []struct {
+		name        string
+		forkEpoch   *primitives.Epoch
+		upgradeFunc func(primitives.Slot) bool
 	}{
 		{
-			name: "not epoch start",
-			slot: 1,
-			want: false,
+			name:        "Altair",
+			forkEpoch:   &beaconConfig.AltairForkEpoch,
+			upgradeFunc: time.CanUpgradeToAltair,
 		},
 		{
-			name: "not deneb epoch",
-			slot: params.BeaconConfig().SlotsPerEpoch,
-			want: false,
+			name:        "Bellatrix",
+			forkEpoch:   &beaconConfig.BellatrixForkEpoch,
+			upgradeFunc: time.CanUpgradeToBellatrix,
 		},
 		{
-			name: "deneb epoch",
-			slot: primitives.Slot(params.BeaconConfig().DenebForkEpoch) * params.BeaconConfig().SlotsPerEpoch,
-			want: true,
+			name:        "Capella",
+			forkEpoch:   &beaconConfig.CapellaForkEpoch,
+			upgradeFunc: time.CanUpgradeToCapella,
+		},
+		{
+			name:        "Deneb",
+			forkEpoch:   &beaconConfig.DenebForkEpoch,
+			upgradeFunc: time.CanUpgradeToDeneb,
+		},
+		{
+			name:        "Electra",
+			forkEpoch:   &beaconConfig.ElectraForkEpoch,
+			upgradeFunc: time.CanUpgradeToElectra,
+		},
+		{
+			name:        "Fulu",
+			forkEpoch:   &beaconConfig.FuluForkEpoch,
+			upgradeFunc: time.CanUpgradeToFulu,
 		},
 	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := time.CanUpgradeToDeneb(tt.slot); got != tt.want {
-				t.Errorf("CanUpgradeToDeneb() = %v, want %v", got, tt.want)
-			}
-		})
-	}
-}

-func TestCanUpgradeToElectra(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	bc := params.BeaconConfig()
-	bc.ElectraForkEpoch = 5
-	params.OverrideBeaconConfig(bc)
-	tests := []struct {
-		name string
-		slot primitives.Slot
-		want bool
-	}{
-		{
-			name: "not epoch start",
-			slot: 1,
-			want: false,
-		},
-		{
-			name: "not electra epoch",
-			slot: params.BeaconConfig().SlotsPerEpoch,
-			want: false,
-		},
-		{
-			name: "electra epoch",
-			slot: primitives.Slot(params.BeaconConfig().ElectraForkEpoch) * params.BeaconConfig().SlotsPerEpoch,
-			want: true,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			if got := time.CanUpgradeToElectra(tt.slot); got != tt.want {
-				t.Errorf("CanUpgradeToElectra() = %v, want %v", got, tt.want)
-			}
-		})
+	for _, otc := range outerTestCases {
+		params.SetupTestConfigCleanup(t)
+		*otc.forkEpoch = 5
+		params.OverrideBeaconConfig(beaconConfig)
+
+		innerTestCases := []struct {
+			name string
+			slot primitives.Slot
+			want bool
+		}{
+			{
+				name: "not epoch start",
+				slot: 1,
+				want: false,
+			},
+			{
+				name: fmt.Sprintf("not %s epoch", otc.name),
+				slot: params.BeaconConfig().SlotsPerEpoch,
+				want: false,
+			},
+			{
+				name: fmt.Sprintf("%s epoch", otc.name),
+				slot: primitives.Slot(*otc.forkEpoch) * params.BeaconConfig().SlotsPerEpoch,
+				want: true,
+			},
+		}
+
+		for _, itc := range innerTestCases {
+			t.Run(fmt.Sprintf("%s-%s", otc.name, itc.name), func(t *testing.T) {
+				if got := otc.upgradeFunc(itc.slot); got != itc.want {
+					t.Errorf("CanUpgradeTo%s() = %v, want %v", otc.name, got, itc.want)
+				}
+			})
+		}
 	}
 }
--- a/beacon-chain/core/transition/BUILD.bazel
+++ b/beacon-chain/core/transition/BUILD.bazel
@@ -23,6 +23,7 @@ go_library(
        "//beacon-chain/core/epoch:go_default_library",
        "//beacon-chain/core/epoch/precompute:go_default_library",
        "//beacon-chain/core/execution:go_default_library",
+        "//beacon-chain/core/fulu:go_default_library",
        "//beacon-chain/core/helpers:go_default_library",
        "//beacon-chain/core/time:go_default_library",
        "//beacon-chain/core/transition/interop:go_default_library",
--- a/beacon-chain/core/transition/transition.go
+++ b/beacon-chain/core/transition/transition.go
@@ -17,6 +17,7 @@ import (
 	e "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epoch"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epoch/precompute"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/execution"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/fulu"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
@@ -298,7 +299,7 @@ func ProcessSlotsCore(ctx context.Context, span trace.Span, state state.BeaconSt
 func ProcessEpoch(ctx context.Context, state state.BeaconState) (state.BeaconState, error) {
 	var err error
 	if time.CanProcessEpoch(state) {
-		if state.Version() == version.Electra {
+		if state.Version() >= version.Electra {
 			if err = electra.ProcessEpoch(ctx, state); err != nil {
 				return nil, errors.Wrap(err, fmt.Sprintf("could not process %s epoch", version.String(state.Version())))
 			}
@@ -322,9 +323,11 @@ func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconSta
 	defer span.End()

 	var err error
+
+	slot := state.Slot()
 	upgraded := false

-	if time.CanUpgradeToAltair(state.Slot()) {
+	if time.CanUpgradeToAltair(slot) {
 		state, err = altair.UpgradeToAltair(ctx, state)
 		if err != nil {
 			tracing.AnnotateError(span, err)
@@ -333,7 +336,7 @@ func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconSta
 		upgraded = true
 	}

-	if time.CanUpgradeToBellatrix(state.Slot()) {
+	if time.CanUpgradeToBellatrix(slot) {
 		state, err = execution.UpgradeToBellatrix(state)
 		if err != nil {
 			tracing.AnnotateError(span, err)
@@ -342,7 +345,7 @@ func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconSta
 		upgraded = true
 	}

-	if time.CanUpgradeToCapella(state.Slot()) {
+	if time.CanUpgradeToCapella(slot) {
 		state, err = capella.UpgradeToCapella(state)
 		if err != nil {
 			tracing.AnnotateError(span, err)
@@ -351,7 +354,7 @@ func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconSta
 		upgraded = true
 	}

-	if time.CanUpgradeToDeneb(state.Slot()) {
+	if time.CanUpgradeToDeneb(slot) {
 		state, err = deneb.UpgradeToDeneb(state)
 		if err != nil {
 			tracing.AnnotateError(span, err)
@@ -360,7 +363,7 @@ func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconSta
 		upgraded = true
 	}

-	if time.CanUpgradeToElectra(state.Slot()) {
+	if time.CanUpgradeToElectra(slot) {
 		state, err = electra.UpgradeToElectra(state)
 		if err != nil {
 			tracing.AnnotateError(span, err)
@@ -369,8 +372,17 @@ func UpgradeState(ctx context.Context, state state.BeaconState) (state.BeaconSta
 		upgraded = true
 	}

+	if time.CanUpgradeToFulu(slot) {
+		state, err = fulu.UpgradeToFulu(state)
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return nil, err
+		}
+		upgraded = true
+	}
+
 	if upgraded {
-		log.Debugf("upgraded state to %s", version.String(state.Version()))
+		log.WithField("version", version.String(state.Version())).Info("Upgraded state to")
 	}

 	return state, nil
--- a/beacon-chain/core/transition/transition_test.go
+++ b/beacon-chain/core/transition/transition_test.go
@@ -665,6 +665,20 @@ func TestProcessSlots_ThroughElectraEpoch(t *testing.T) {
 	require.Equal(t, params.BeaconConfig().SlotsPerEpoch*10, st.Slot())
 }

+func TestProcessSlots_ThroughFuluEpoch(t *testing.T) {
+	transition.SkipSlotCache.Disable()
+	params.SetupTestConfigCleanup(t)
+	conf := params.BeaconConfig()
+	conf.FuluForkEpoch = 5
+	params.OverrideBeaconConfig(conf)
+
+	st, _ := util.DeterministicGenesisStateElectra(t, params.BeaconConfig().MaxValidatorsPerCommittee)
+	st, err := transition.ProcessSlots(context.Background(), st, params.BeaconConfig().SlotsPerEpoch*10)
+	require.NoError(t, err)
+	require.Equal(t, version.Fulu, st.Version())
+	require.Equal(t, params.BeaconConfig().SlotsPerEpoch*10, st.Slot())
+}
+
 func TestProcessSlotsUsingNextSlotCache(t *testing.T) {
 	s, _ := util.DeterministicGenesisState(t, 1)
 	r := []byte{'a'}
--- a/beacon-chain/core/validators/slashing.go
+++ b/beacon-chain/core/validators/slashing.go
@@ -9,25 +9,35 @@ import (
 // SlashingParamsPerVersion returns the slashing parameters for the given state version.
 func SlashingParamsPerVersion(v int) (slashingQuotient, proposerRewardQuotient, whistleblowerRewardQuotient uint64, err error) {
 	cfg := params.BeaconConfig()
-	switch v {
-	case version.Phase0:
-		slashingQuotient = cfg.MinSlashingPenaltyQuotient
-		proposerRewardQuotient = cfg.ProposerRewardQuotient
-		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
-	case version.Altair:
-		slashingQuotient = cfg.MinSlashingPenaltyQuotientAltair
-		proposerRewardQuotient = cfg.ProposerRewardQuotient
-		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
-	case version.Bellatrix, version.Capella, version.Deneb:
-		slashingQuotient = cfg.MinSlashingPenaltyQuotientBellatrix
-		proposerRewardQuotient = cfg.ProposerRewardQuotient
-		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
-	case version.Electra:
+
+	if v >= version.Electra {
 		slashingQuotient = cfg.MinSlashingPenaltyQuotientElectra
 		proposerRewardQuotient = cfg.ProposerRewardQuotient
 		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotientElectra
-	default:
-		err = errors.New("unknown state version")
+		return
 	}
+
+	if v >= version.Bellatrix {
+		slashingQuotient = cfg.MinSlashingPenaltyQuotientBellatrix
+		proposerRewardQuotient = cfg.ProposerRewardQuotient
+		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
+		return
+	}
+
+	if v >= version.Altair {
+		slashingQuotient = cfg.MinSlashingPenaltyQuotientAltair
+		proposerRewardQuotient = cfg.ProposerRewardQuotient
+		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
+		return
+	}
+
+	if v >= version.Phase0 {
+		slashingQuotient = cfg.MinSlashingPenaltyQuotient
+		proposerRewardQuotient = cfg.ProposerRewardQuotient
+		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
+		return
+	}
+
+	err = errors.Errorf("unknown state version %s", version.String(v))
 	return
 }
--- a/beacon-chain/core/validators/validator_test.go
+++ b/beacon-chain/core/validators/validator_test.go
@@ -217,6 +217,7 @@ func TestSlashValidator_OK(t *testing.T) {
 }

 func TestSlashValidator_Electra(t *testing.T) {
+	helpers.ClearCache()
 	validatorCount := 100
 	registry := make([]*ethpb.Validator, 0, validatorCount)
 	balances := make([]uint64, 0, validatorCount)
--- a/beacon-chain/das/BUILD.bazel
+++ b/beacon-chain/das/BUILD.bazel
@@ -4,6 +4,7 @@ go_library(
    name = "go_default_library",
    srcs = [
        "availability.go",
+        "availability_columns.go",
        "cache.go",
        "iface.go",
        "mock.go",
@@ -11,6 +12,7 @@ go_library(
    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/das",
    visibility = ["//visibility:public"],
    deps = [
+        "//beacon-chain/core/peerdas:go_default_library",
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/verification:go_default_library",
        "//config/fieldparams:go_default_library",
@@ -20,6 +22,7 @@ go_library(
        "//runtime/logging:go_default_library",
        "//runtime/version:go_default_library",
        "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
    ],
@@ -28,6 +31,7 @@ go_library(
 go_test(
    name = "go_default_test",
    srcs = [
+        "availability_columns_test.go",
        "availability_test.go",
        "cache_test.go",
    ],
@@ -35,7 +39,7 @@ go_test(
    deps = [
        "//beacon-chain/db/filesystem:go_default_library",
        "//beacon-chain/verification:go_default_library",
-        "//config/fieldparams:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
        "//config/params:go_default_library",
        "//consensus-types/blocks:go_default_library",
        "//consensus-types/primitives:go_default_library",
@@ -43,6 +47,7 @@ go_test(
        "//testing/require:go_default_library",
        "//testing/util:go_default_library",
        "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
        "@com_github_pkg_errors//:go_default_library",
    ],
 )
--- a/beacon-chain/das/availability.go
+++ b/beacon-chain/das/availability.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"

+	"github.com/ethereum/go-ethereum/p2p/enode"
 	errors "github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
@@ -80,13 +81,13 @@ func (s *LazilyPersistentStore) Persist(current primitives.Slot, sc ...blocks.RO

 // IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
 // BlobSidecars already in the db are assumed to have been previously verified against the block.
-func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error {
+func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, _ enode.ID, current primitives.Slot, b blocks.ROBlock) error {
 	blockCommitments, err := commitmentsToCheck(b, current)
 	if err != nil {
-		return errors.Wrapf(err, "could check data availability for block %#x", b.Root())
+		return errors.Wrapf(err, "could not check data availability for block %#x", b.Root())
 	}
 	// Return early for blocks that are pre-deneb or which do not have any commitments.
-	if blockCommitments.count() == 0 {
+	if len(blockCommitments) == 0 {
 		return nil
 	}

@@ -106,7 +107,7 @@ func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, current pri
 	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
 	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
 	// ignore their response and decrease their peer score.
-	sidecars, err := entry.filter(root, blockCommitments)
+	sidecars, err := entry.filter(root, blockCommitments, b.Block().Slot())
 	if err != nil {
 		return errors.Wrap(err, "incomplete BlobSidecar batch")
 	}
@@ -137,22 +138,28 @@ func (s *LazilyPersistentStore) IsDataAvailable(ctx context.Context, current pri
 	return nil
 }

-func commitmentsToCheck(b blocks.ROBlock, current primitives.Slot) (safeCommitmentArray, error) {
-	var ar safeCommitmentArray
+func commitmentsToCheck(b blocks.ROBlock, current primitives.Slot) ([][]byte, error) {
 	if b.Version() < version.Deneb {
-		return ar, nil
+		return nil, nil
 	}
-	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+
+	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUEST
 	if !params.WithinDAPeriod(slots.ToEpoch(b.Block().Slot()), slots.ToEpoch(current)) {
-		return ar, nil
+		return nil, nil
 	}
-	kc, err := b.Block().Body().BlobKzgCommitments()
+
+	kzgCommitments, err := b.Block().Body().BlobKzgCommitments()
 	if err != nil {
-		return ar, err
+		return nil, err
 	}
-	if len(kc) > len(ar) {
-		return ar, errIndexOutOfBounds
+
+	maxBlobCount := params.BeaconConfig().MaxBlobsPerBlock(b.Block().Slot())
+	if len(kzgCommitments) > maxBlobCount {
+		return nil, errIndexOutOfBounds
 	}
-	copy(ar[:], kc)
-	return ar, nil
+
+	result := make([][]byte, len(kzgCommitments))
+	copy(result, kzgCommitments)
+
+	return result, nil
 }
--- a/beacon-chain/das/availability_columns.go
+++ b/beacon-chain/das/availability_columns.go
@@ -0,0 +1,190 @@
+package das
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/ethereum/go-ethereum/p2p/enode"
+	errors "github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/peerdas"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/db/filesystem"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	log "github.com/sirupsen/logrus"
+)
+
+// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
+// This implementation will hold any blobs passed to Persist until the IsDataAvailable is called for their
+// block, at which time they will undergo full verification and be saved to the disk.
+type LazilyPersistentStoreColumn struct {
+	store *filesystem.BlobStorage
+	cache *cache
+}
+
+func NewLazilyPersistentStoreColumn(store *filesystem.BlobStorage) *LazilyPersistentStoreColumn {
+	return &LazilyPersistentStoreColumn{
+		store: store,
+		cache: newCache(),
+	}
+}
+
+// Persist do nothing at the moment.
+// TODO: Very Ugly, change interface to allow for columns and blobs
+func (*LazilyPersistentStoreColumn) Persist(_ primitives.Slot, _ ...blocks.ROBlob) error {
+	return nil
+}
+
+// PersistColumns adds columns to the working column cache. columns stored in this cache will be persisted
+// for at least as long as the node is running. Once IsDataAvailable succeeds, all blobs referenced
+// by the given block are guaranteed to be persisted for the remainder of the retention period.
+func (s *LazilyPersistentStoreColumn) PersistColumns(current primitives.Slot, sc ...blocks.RODataColumn) error {
+	if len(sc) == 0 {
+		return nil
+	}
+	if len(sc) > 1 {
+		first := sc[0].BlockRoot()
+		for i := 1; i < len(sc); i++ {
+			if first != sc[i].BlockRoot() {
+				return errMixedRoots
+			}
+		}
+	}
+	if !params.WithinDAPeriod(slots.ToEpoch(sc[0].Slot()), slots.ToEpoch(current)) {
+		return nil
+	}
+	key := keyFromColumn(sc[0])
+	entry := s.cache.ensure(key)
+	for i := range sc {
+		if err := entry.stashColumns(&sc[i]); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
+// BlobSidecars already in the db are assumed to have been previously verified against the block.
+func (s *LazilyPersistentStoreColumn) IsDataAvailable(
+	ctx context.Context,
+	nodeID enode.ID,
+	currentSlot primitives.Slot,
+	block blocks.ROBlock,
+) error {
+	blockCommitments, err := fullCommitmentsToCheck(nodeID, block, currentSlot)
+	if err != nil {
+		return errors.Wrapf(err, "full commitments to check with block root `%#x` and current slot `%d`", block.Root(), currentSlot)
+	}
+
+	// Return early for blocks that do not have any commitments.
+	if blockCommitments.count() == 0 {
+		return nil
+	}
+
+	// Build the cache key for the block.
+	key := keyFromBlock(block)
+
+	// Retrieve the cache entry for the block, or create an empty one if it doesn't exist.
+	entry := s.cache.ensure(key)
+
+	// Delete the cache entry for the block at the end.
+	defer s.cache.delete(key)
+
+	// Get the root of the block.
+	blockRoot := block.Root()
+
+	// Wait for the summarizer to be ready before proceeding.
+	summarizer, err := s.store.WaitForSummarizer(ctx)
+	if err != nil {
+		log.
+			WithField("root", fmt.Sprintf("%#x", blockRoot)).
+			WithError(err).
+			Debug("Failed to receive BlobStorageSummarizer within IsDataAvailable")
+	} else {
+		// Get the summary for the block, and set it in the cache entry.
+		summary := summarizer.Summary(blockRoot)
+		entry.setDiskSummary(summary)
+	}
+
+	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
+	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
+	// ignore their response and decrease their peer score.
+	roDataColumns, err := entry.filterColumns(blockRoot, blockCommitments)
+	if err != nil {
+		return errors.Wrap(err, "incomplete DataColumnSidecar batch")
+	}
+
+	// Create verified RO data columns from RO data columns.
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumns))
+
+	for _, roDataColumn := range roDataColumns {
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
+	}
+
+	// Ensure that each column sidecar is written to disk.
+	for _, verifiedRODataColumn := range verifiedRODataColumns {
+		if err := s.store.SaveDataColumn(verifiedRODataColumn); err != nil {
+			return errors.Wrapf(err, "save data columns for index `%d` for block `%#x`", verifiedRODataColumn.ColumnIndex, blockRoot)
+		}
+	}
+
+	// All ColumnSidecars are persisted - data availability check succeeds.
+	return nil
+}
+
+// fullCommitmentsToCheck returns the commitments to check for a given block.
+func fullCommitmentsToCheck(nodeID enode.ID, block blocks.ROBlock, currentSlot primitives.Slot) (*safeCommitmentsArray, error) {
+	// Return early for blocks that are pre-Fulu.
+	if block.Version() < version.Fulu {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Compute the block epoch.
+	blockSlot := block.Block().Slot()
+	blockEpoch := slots.ToEpoch(blockSlot)
+
+	// Compute the current spoch.
+	currentEpoch := slots.ToEpoch(currentSlot)
+
+	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.
+	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Retrieve the KZG commitments for the block.
+	kzgCommitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	// Return early if there are no commitments in the block.
+	if len(kzgCommitments) == 0 {
+		return &safeCommitmentsArray{}, nil
+	}
+
+	// Retrieve the groups count.
+	custodyGroupCount := peerdas.CustodyGroupCount()
+
+	// Retrieve custody groups.
+	custodyGroups, err := peerdas.CustodyGroups(nodeID, custodyGroupCount)
+	if err != nil {
+		return nil, errors.Wrap(err, "custody groups")
+	}
+
+	// Retrieve custody columns.
+	custodyColumns, err := peerdas.CustodyColumns(custodyGroups)
+	if err != nil {
+		return nil, errors.Wrap(err, "custody columns")
+	}
+
+	// Create a safe commitments array for the custody columns.
+	commitmentsArray := &safeCommitmentsArray{}
+	for column := range custodyColumns {
+		commitmentsArray[column] = kzgCommitments
+	}
+
+	return commitmentsArray, nil
+}
--- a/Show More
+++ b/Show More