Add builder

Add wait until PTC duty

.github/workflows/changelog.yml

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

CHANGELOG.md

@@ -13,20 +13,12 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Light client support: Implement `ComputeFieldRootsForBlockBody`.
 - Light client support: Add light client database changes.
 - Light client support: Implement capella and deneb changes.
-- Light client support: Implement `BlockToLightClientHeader` function.
-- Light client support: Consensus types.
+- Light client support: Implement `BlockToLightClientHeaderXXX` functions upto Deneb
 - GetBeaconStateV2: add Electra case.
 - Implement [consensus-specs/3875](https://github.com/ethereum/consensus-specs/pull/3875)
-- Tests to ensure sepolia config matches the official upstream yaml
-- HTTP endpoint for PublishBlobs
-- GetBlockV2, GetBlindedBlock, ProduceBlockV2, ProduceBlockV3: add Electra case.
-- Add Electra support and tests for light client functions
-- fastssz version bump (better error messages).
-- SSE implementation that sheds stuck clients. [pr](https://github.com/prysmaticlabs/prysm/pull/14413)
 
 ### Changed
 
-- Electra: Updated interop genesis generator to support Electra.
 - `getLocalPayload` has been refactored to enable work in ePBS branch.
 - `TestNodeServer_GetPeer` and `TestNodeServer_ListPeers` test flakes resolved by iterating the whole peer list to find
   a match rather than taking the first peer in the map.
@@ -47,11 +39,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Updated k8s-io/client-go to v0.30.4 and k8s-io/apimachinery to v0.30.4
 - Migrated tracing library from opencensus to opentelemetry for both the beacon node and validator.
 - Refactored light client code to make it more readable and make future PRs easier.
-- Update light client helper functions to reference `dev` branch of CL specs
 - Updated Libp2p Dependencies to allow prysm to use gossipsub v1.2 .
-- Updated Sepolia bootnodes.
-- Make committee aware packing the default by deprecating `--enable-committee-aware-packing`.
-- Moved `ConvertKzgCommitmentToVersionedHash` to the `primitives` package.
 
 ### Deprecated
 - `--disable-grpc-gateway` flag is deprecated due to grpc gateway removal.
@@ -76,10 +64,7 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 - Core: Fixed slash processing causing extra hashing.
 - Core: Fixed extra allocations when processing slashings.
 - remove unneeded container in blob sidecar ssz response
-- Light client support: create finalized header based on finalizedBlock's version, not attestedBlock.
-- Light client support: fix light client attested header execution fields' wrong version bug.
 - Testing: added custom matcher for better push settings testing.
-- Registered `GetDepositSnapshot` Beacon API endpoint.
 
 ### Security
 

WORKSPACE

@@ -342,22 +342,6 @@ filegroup(
     url = "https://github.com/eth-clients/holesky/archive/874c199423ccd180607320c38cbaca05d9a1573a.tar.gz",  # 2024-06-18
 )
 
-http_archive(
-    name = "sepolia_testnet",
-    build_file_content = """
-filegroup(
-    name = "configs",
-    srcs = [
-        "metadata/config.yaml",
-    ],
-    visibility = ["//visibility:public"],
-)
-""",
-    integrity = "sha256-cY/UgpCcYEhQf7JefD65FI8tn/A+rAvKhcm2/qiVdqY=",
-    strip_prefix = "sepolia-f2c219a93c4491cee3d90c18f2f8e82aed850eab",
-    url = "https://github.com/eth-clients/sepolia/archive/f2c219a93c4491cee3d90c18f2f8e82aed850eab.tar.gz",  # 2024-09-19
-)
-
 http_archive(
     name = "com_google_protobuf",
     sha256 = "9bd87b8280ef720d3240514f884e56a712f2218f0d693b48050c836028940a42",

api/headers.go

@@ -1,7 +1,5 @@
 package api
 
-import "net/http"
-
 const (
 	VersionHeader                 = "Eth-Consensus-Version"
 	ExecutionPayloadBlindedHeader = "Eth-Execution-Payload-Blinded"
@@ -12,9 +10,3 @@ const (
 	EventStreamMediaType          = "text/event-stream"
 	KeepAlive                     = "keep-alive"
 )
-
-// SetSSEHeaders sets the headers needed for a server-sent event response.
-func SetSSEHeaders(w http.ResponseWriter) {
-	w.Header().Set("Content-Type", EventStreamMediaType)
-	w.Header().Set("Connection", KeepAlive)
-}

api/server/structs/BUILD.bazel

@@ -5,7 +5,6 @@ go_library(
     srcs = [
         "block.go",
         "conversions.go",
-        "conversions_blob.go",
         "conversions_block.go",
         "conversions_lightclient.go",
         "conversions_state.go",

api/server/structs/conversions.go

@@ -15,7 +15,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/math"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
-	ethv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 )
 
@@ -1509,37 +1508,3 @@ func PendingConsolidationsFromConsensus(cs []*eth.PendingConsolidation) []*Pendi
 	}
 	return consolidations
 }
-
-func HeadEventFromV1(event *ethv1.EventHead) *HeadEvent {
-	return &HeadEvent{
-		Slot:                      fmt.Sprintf("%d", event.Slot),
-		Block:                     hexutil.Encode(event.Block),
-		State:                     hexutil.Encode(event.State),
-		EpochTransition:           event.EpochTransition,
-		ExecutionOptimistic:       event.ExecutionOptimistic,
-		PreviousDutyDependentRoot: hexutil.Encode(event.PreviousDutyDependentRoot),
-		CurrentDutyDependentRoot:  hexutil.Encode(event.CurrentDutyDependentRoot),
-	}
-}
-
-func FinalizedCheckpointEventFromV1(event *ethv1.EventFinalizedCheckpoint) *FinalizedCheckpointEvent {
-	return &FinalizedCheckpointEvent{
-		Block:               hexutil.Encode(event.Block),
-		State:               hexutil.Encode(event.State),
-		Epoch:               fmt.Sprintf("%d", event.Epoch),
-		ExecutionOptimistic: event.ExecutionOptimistic,
-	}
-}
-
-func EventChainReorgFromV1(event *ethv1.EventChainReorg) *ChainReorgEvent {
-	return &ChainReorgEvent{
-		Slot:                fmt.Sprintf("%d", event.Slot),
-		Depth:               fmt.Sprintf("%d", event.Depth),
-		OldHeadBlock:        hexutil.Encode(event.OldHeadBlock),
-		NewHeadBlock:        hexutil.Encode(event.NewHeadBlock),
-		OldHeadState:        hexutil.Encode(event.OldHeadState),
-		NewHeadState:        hexutil.Encode(event.NewHeadState),
-		Epoch:               fmt.Sprintf("%d", event.Epoch),
-		ExecutionOptimistic: event.ExecutionOptimistic,
-	}
-}

api/server/structs/conversions_blob.go

@@ -1,61 +0,0 @@
-package structs
-
-import (
-	"strconv"
-
-	"github.com/prysmaticlabs/prysm/v5/api/server"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-)
-
-func (sc *Sidecar) ToConsensus() (*eth.BlobSidecar, error) {
-	if sc == nil {
-		return nil, errNilValue
-	}
-
-	index, err := strconv.ParseUint(sc.Index, 10, 64)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Index")
-	}
-
-	blob, err := bytesutil.DecodeHexWithLength(sc.Blob, 131072)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "Blob")
-	}
-
-	kzgCommitment, err := bytesutil.DecodeHexWithLength(sc.KzgCommitment, 48)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "KzgCommitment")
-	}
-
-	kzgProof, err := bytesutil.DecodeHexWithLength(sc.KzgProof, 48)
-	if err != nil {
-		return nil, server.NewDecodeError(err, "KzgProof")
-	}
-
-	header, err := sc.SignedBeaconBlockHeader.ToConsensus()
-	if err != nil {
-		return nil, server.NewDecodeError(err, "SignedBeaconBlockHeader")
-	}
-
-	// decode the commitment inclusion proof
-	var commitmentInclusionProof [][]byte
-	for _, proof := range sc.CommitmentInclusionProof {
-		proofBytes, err := bytesutil.DecodeHexWithLength(proof, 32)
-		if err != nil {
-			return nil, server.NewDecodeError(err, "CommitmentInclusionProof")
-		}
-		commitmentInclusionProof = append(commitmentInclusionProof, proofBytes)
-	}
-
-	bsc := &eth.BlobSidecar{
-		Index:                    index,
-		Blob:                     blob,
-		KzgCommitment:            kzgCommitment,
-		KzgProof:                 kzgProof,
-		SignedBlockHeader:        header,
-		CommitmentInclusionProof: commitmentInclusionProof,
-	}
-
-	return bsc, nil
-}

api/server/structs/conversions_block.go

@@ -20,9 +20,6 @@ import (
 var ErrUnsupportedConversion = errors.New("Could not determine api struct type to use for value")
 
 func (h *SignedBeaconBlockHeader) ToConsensus() (*eth.SignedBeaconBlockHeader, error) {
-	if h == nil {
-		return nil, errNilValue
-	}
 	msg, err := h.Message.ToConsensus()
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Message")
@@ -39,9 +36,6 @@ func (h *SignedBeaconBlockHeader) ToConsensus() (*eth.SignedBeaconBlockHeader, e
 }
 
 func (h *BeaconBlockHeader) ToConsensus() (*eth.BeaconBlockHeader, error) {
-	if h == nil {
-		return nil, errNilValue
-	}
 	s, err := strconv.ParseUint(h.Slot, 10, 64)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Slot")
@@ -2554,8 +2548,6 @@ func SignedBeaconBlockMessageJsoner(block interfaces.ReadOnlySignedBeaconBlock)
 		return SignedBlindedBeaconBlockDenebFromConsensus(pbStruct)
 	case *eth.SignedBeaconBlockDeneb:
 		return SignedBeaconBlockDenebFromConsensus(pbStruct)
-	case *eth.SignedBlindedBeaconBlockElectra:
-		return SignedBlindedBeaconBlockElectraFromConsensus(pbStruct)
 	case *eth.SignedBeaconBlockElectra:
 		return SignedBeaconBlockElectraFromConsensus(pbStruct)
 	default:

api/server/structs/conversions_lightclient.go

@@ -84,11 +84,6 @@ func syncAggregateToJSON(input *v1.SyncAggregate) *SyncAggregate {
 }
 
 func lightClientHeaderContainerToJSON(container *v2.LightClientHeaderContainer) (json.RawMessage, error) {
-	// In the case that a finalizedHeader is nil.
-	if container == nil {
-		return nil, nil
-	}
-
 	beacon, err := container.GetBeacon()
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get beacon block header")

api/server/structs/endpoints_blob.go

@@ -12,12 +12,3 @@ type Sidecar struct {
 	KzgProof                 string                   `json:"kzg_proof"`
 	CommitmentInclusionProof []string                 `json:"kzg_commitment_inclusion_proof"`
 }
-
-type BlobSidecars struct {
-	Sidecars []*Sidecar `json:"sidecars"`
-}
-
-type PublishBlobsRequest struct {
-	BlobSidecars *BlobSidecars `json:"blob_sidecars"`
-	BlockRoot    string        `json:"block_root"`
-}

async/event/BUILD.bazel

@@ -4,7 +4,6 @@ go_library(
     name = "go_default_library",
     srcs = [
         "feed.go",
-        "interface.go",
         "subscription.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/async/event",

async/event/feed.go

@@ -22,4 +22,3 @@ import (
 
 // Feed is a re-export of the go-ethereum event feed.
 type Feed = geth_event.Feed
-type Subscription = geth_event.Subscription

async/event/interface.go

@@ -1,8 +0,0 @@
-package event
-
-// SubscriberSender is an abstract representation of an *event.Feed
-// to use in describing types that accept or return an *event.Feed.
-type SubscriberSender interface {
-	Subscribe(channel interface{}) Subscription
-	Send(value interface{}) (nsent int)
-}

async/event/subscription.go

@@ -28,6 +28,25 @@ import (
 // request backoff time.
 const waitQuotient = 10
 
+// Subscription represents a stream of events. The carrier of the events is typically a
+// channel, but isn't part of the interface.
+//
+// Subscriptions can fail while established. Failures are reported through an error
+// channel. It receives a value if there is an issue with the subscription (e.g. the
+// network connection delivering the events has been closed). Only one value will ever be
+// sent.
+//
+// The error channel is closed when the subscription ends successfully (i.e. when the
+// source of events is closed). It is also closed when Unsubscribe is called.
+//
+// The Unsubscribe method cancels the sending of events. You must call Unsubscribe in all
+// cases to ensure that resources related to the subscription are released. It can be
+// called any number of times.
+type Subscription interface {
+	Err() <-chan error // returns the error channel
+	Unsubscribe()      // cancels sending of events, closing the error channel
+}
+
 // NewSubscription runs a producer function as a subscription in a new goroutine. The
 // channel given to the producer is closed when Unsubscribe is called. If fn returns an
 // error, it is sent on the subscription's error channel.

beacon-chain/blockchain/BUILD.bazel

@@ -6,6 +6,7 @@ go_library(
         "chain_info.go",
         "chain_info_forkchoice.go",
         "currently_syncing_block.go",
+        "currently_syncing_execution_payload_envelope.go",
         "defragment.go",
         "error.go",
         "execution_engine.go",
@@ -25,6 +26,8 @@ go_library(
         "receive_attestation.go",
         "receive_blob.go",
         "receive_block.go",
+        "receive_execution_payload_envelope.go",
+        "receive_payload_attestation_message.go",
         "service.go",
         "tracked_proposer.go",
         "weak_subjectivity_checks.go",
@@ -43,6 +46,7 @@ go_library(
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
+        "//beacon-chain/core/epbs:go_default_library",
         "//beacon-chain/core/epoch/precompute:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
@@ -97,6 +101,7 @@ go_library(
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
+        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_x_sync//errgroup:go_default_library",
     ],
 )
@@ -109,6 +114,7 @@ go_test(
         "chain_info_norace_test.go",
         "chain_info_test.go",
         "checktags_test.go",
+        "epbs_test.go",
         "error_test.go",
         "execution_engine_test.go",
         "forkchoice_update_execution_test.go",
@@ -124,6 +130,7 @@ go_test(
         "process_block_test.go",
         "receive_attestation_test.go",
         "receive_block_test.go",
+        "receive_execution_payload_envelope_test.go",
         "service_norace_test.go",
         "service_test.go",
         "setup_test.go",
@@ -177,6 +184,7 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//testing/util/random:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",

beacon-chain/blockchain/chain_info.go

@@ -42,7 +42,7 @@ type ForkchoiceFetcher interface {
 	GetProposerHead() [32]byte
 	SetForkChoiceGenesisTime(uint64)
 	UpdateHead(context.Context, primitives.Slot)
-	HighestReceivedBlockSlot() primitives.Slot
+	HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte)
 	ReceivedBlocksLastEpoch() (uint64, error)
 	InsertNode(context.Context, state.BeaconState, [32]byte) error
 	ForkChoiceDump(context.Context) (*forkchoice.Dump, error)
@@ -50,6 +50,8 @@ type ForkchoiceFetcher interface {
 	ProposerBoost() [32]byte
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 	IsCanonical(ctx context.Context, blockRoot [32]byte) (bool, error)
+	GetPTCVote(root [32]byte) primitives.PTCStatus
+	Weight(root [32]byte) (uint64, error)
 }
 
 // TimeFetcher retrieves the Ethereum consensus data that's related to time.
@@ -118,6 +120,12 @@ type OptimisticModeFetcher interface {
 	IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool, error)
 }
 
+// ExecutionPayloadFetcher defines a common interface that returns forkchoice
+// information about payload block hashes
+type ExecutionPayloadFetcher interface {
+	HashInForkchoice([32]byte) bool
+}
+
 // FinalizedCheckpt returns the latest finalized checkpoint from chain store.
 func (s *Service) FinalizedCheckpt() *ethpb.Checkpoint {
 	s.cfg.ForkChoiceStore.RLock()
@@ -399,6 +407,14 @@ func (s *Service) InForkchoice(root [32]byte) bool {
 	return s.cfg.ForkChoiceStore.HasNode(root)
 }
 
+// HashInForkchoice returns true if the given payload block hash is found in
+// forkchoice
+func (s *Service) HashInForkchoice(hash [32]byte) bool {
+	s.cfg.ForkChoiceStore.RLock()
+	defer s.cfg.ForkChoiceStore.RUnlock()
+	return s.cfg.ForkChoiceStore.HasHash(hash)
+}
+
 // IsOptimisticForRoot takes the root as argument instead of the current head
 // and returns true if it is optimistic.
 func (s *Service) IsOptimisticForRoot(ctx context.Context, root [32]byte) (bool, error) {

beacon-chain/blockchain/chain_info_forkchoice.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/forkchoice"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )
 
@@ -29,11 +30,11 @@ func (s *Service) SetForkChoiceGenesisTime(timestamp uint64) {
 	s.cfg.ForkChoiceStore.SetGenesisTime(timestamp)
 }
 
-// HighestReceivedBlockSlot returns the corresponding value from forkchoice
-func (s *Service) HighestReceivedBlockSlot() primitives.Slot {
+// HighestReceivedBlockSlotRoot returns the corresponding value from forkchoice
+func (s *Service) HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte) {
 	s.cfg.ForkChoiceStore.RLock()
 	defer s.cfg.ForkChoiceStore.RUnlock()
-	return s.cfg.ForkChoiceStore.HighestReceivedBlockSlot()
+	return s.cfg.ForkChoiceStore.HighestReceivedBlockSlotRoot()
 }
 
 // ReceivedBlocksLastEpoch returns the corresponding value from forkchoice
@@ -99,3 +100,30 @@ func (s *Service) ParentRoot(root [32]byte) ([32]byte, error) {
 	defer s.cfg.ForkChoiceStore.RUnlock()
 	return s.cfg.ForkChoiceStore.ParentRoot(root)
 }
+
+// GetPTCVote wraps a call to the corresponding method in forkchoice and checks
+// the currently syncing status
+// Warning: this method will return the current PTC status regardless of
+// timeliness. A client MUST call this method when about to submit a PTC
+// attestation, that is exactly at the threshold to submit the attestation.
+func (s *Service) GetPTCVote(root [32]byte) primitives.PTCStatus {
+	s.cfg.ForkChoiceStore.RLock()
+	f := s.cfg.ForkChoiceStore.GetPTCVote()
+	s.cfg.ForkChoiceStore.RUnlock()
+	if f != primitives.PAYLOAD_ABSENT {
+		return f
+	}
+	f, isSyncing := s.payloadBeingSynced.isSyncing(root)
+	if isSyncing {
+		return f
+	}
+	return primitives.PAYLOAD_ABSENT
+}
+
+// insertPayloadEnvelope wraps a locked call to the corresponding method in
+// forkchoice
+func (s *Service) insertPayloadEnvelope(envelope interfaces.ROExecutionPayloadEnvelope) error {
+	s.cfg.ForkChoiceStore.Lock()
+	defer s.cfg.ForkChoiceStore.Unlock()
+	return s.cfg.ForkChoiceStore.InsertPayloadEnvelope(envelope)
+}

beacon-chain/blockchain/currently_syncing_execution_payload_envelope.go

@@ -0,0 +1,36 @@
+package blockchain
+
+import (
+	"sync"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+)
+
+type currentlySyncingPayload struct {
+	sync.Mutex
+	roots map[[32]byte]primitives.PTCStatus
+}
+
+func (b *currentlySyncingPayload) set(envelope interfaces.ROExecutionPayloadEnvelope) {
+	b.Lock()
+	defer b.Unlock()
+	if envelope.PayloadWithheld() {
+		b.roots[envelope.BeaconBlockRoot()] = primitives.PAYLOAD_WITHHELD
+	} else {
+		b.roots[envelope.BeaconBlockRoot()] = primitives.PAYLOAD_PRESENT
+	}
+}
+
+func (b *currentlySyncingPayload) unset(root [32]byte) {
+	b.Lock()
+	defer b.Unlock()
+	delete(b.roots, root)
+}
+
+func (b *currentlySyncingPayload) isSyncing(root [32]byte) (status primitives.PTCStatus, isSyncing bool) {
+	b.Lock()
+	defer b.Unlock()
+	status, isSyncing = b.roots[root]
+	return
+}

beacon-chain/blockchain/epbs_test.go

@@ -0,0 +1,18 @@
+package blockchain
+
+import (
+	"testing"
+
+	doublylinkedtree "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestServiceGetPTCVote(t *testing.T) {
+	c := &currentlySyncingPayload{roots: make(map[[32]byte]primitives.PTCStatus)}
+	s := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, payloadBeingSynced: c}
+	r := [32]byte{'r'}
+	require.Equal(t, primitives.PAYLOAD_ABSENT, s.GetPTCVote(r))
+	c.roots[r] = primitives.PAYLOAD_WITHHELD
+	require.Equal(t, primitives.PAYLOAD_WITHHELD, s.GetPTCVote(r))
+}

beacon-chain/blockchain/error.go

@@ -30,6 +30,9 @@ var (
 	ErrNotCheckpoint = errors.New("not a checkpoint in forkchoice")
 	// ErrNilHead is returned when no head is present in the blockchain service.
 	ErrNilHead = errors.New("nil head")
+	// errInvalidValidatorIndex is returned when a validator index is
+	// invalid or unexpected
+	errInvalidValidatorIndex = errors.New("invalid validator index")
 )
 
 var errMaxBlobsExceeded = errors.New("Expected commitments in block exceeds MAX_BLOBS_PER_BLOCK")

beacon-chain/blockchain/execution_engine_test.go

@@ -1056,8 +1056,8 @@ func TestService_removeInvalidBlockAndState(t *testing.T) {
 
 	require.NoError(t, service.removeInvalidBlockAndState(ctx, [][32]byte{r1, r2}))
 
-	require.Equal(t, false, service.hasBlock(ctx, r1))
-	require.Equal(t, false, service.hasBlock(ctx, r2))
+	require.Equal(t, false, service.chainHasBlock(ctx, r1))
+	require.Equal(t, false, service.chainHasBlock(ctx, r2))
 	require.Equal(t, false, service.cfg.BeaconDB.HasStateSummary(ctx, r1))
 	require.Equal(t, false, service.cfg.BeaconDB.HasStateSummary(ctx, r2))
 	has, err := service.cfg.StateGen.HasState(ctx, r1)

beacon-chain/blockchain/metrics.go

@@ -182,6 +182,10 @@ var (
 		Name: "chain_service_processing_milliseconds",
 		Help: "Total time to call a chain service in ReceiveBlock()",
 	})
+	executionEngineProcessingTime = promauto.NewSummary(prometheus.SummaryOpts{
+		Name: "execution_engine_processing_milliseconds",
+		Help: "Total time to process an execution payload envelope in ReceiveExecutionPayloadEnvelope()",
+	})
 	dataAvailWaitedTime = promauto.NewSummary(prometheus.SummaryOpts{
 		Name: "da_waited_time_milliseconds",
 		Help: "Total time spent waiting for a data availability check in ReceiveBlock()",

beacon-chain/blockchain/options.go

@@ -1,6 +1,8 @@
 package blockchain
 
 import (
+	"sync"
+
 	"github.com/prysmaticlabs/prysm/v5/async/event"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
@@ -69,6 +71,22 @@ func WithDepositCache(c cache.DepositCache) Option {
 	}
 }
 
+// WithPayloadAttestationCache for payload attestation cache.
+func WithPayloadAttestationCache(c *cache.PayloadAttestationCache) Option {
+	return func(s *Service) error {
+		s.cfg.PayloadAttestationCache = c
+		return nil
+	}
+}
+
+// WithPayloadEnvelopeCache for payload envelope cache.
+func WithPayloadEnvelopeCache(c *sync.Map) Option {
+	return func(s *Service) error {
+		s.cfg.PayloadEnvelopeCache = c
+		return nil
+	}
+}
+
 // WithPayloadIDCache for payload ID cache.
 func WithPayloadIDCache(c *cache.PayloadIDCache) Option {
 	return func(s *Service) error {

beacon-chain/blockchain/process_attestation.go

@@ -97,7 +97,7 @@ func (s *Service) OnAttestation(ctx context.Context, a ethpb.Att, disparity time
 	// We assume trusted attestation in this function has verified signature.
 
 	// Update forkchoice store with the new attestation for updating weight.
-	s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indexedAtt.GetAttestingIndices(), bytesutil.ToBytes32(a.GetData().BeaconBlockRoot), a.GetData().Target.Epoch)
+	s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indexedAtt.GetAttestingIndices(), bytesutil.ToBytes32(a.GetData().BeaconBlockRoot), a.GetData().Slot)
 
 	return nil
 }

beacon-chain/blockchain/process_block.go

@@ -375,7 +375,7 @@ 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)
+			s.cfg.ForkChoiceStore.ProcessAttestation(ctx, indices, r, a.GetData().Slot)
 		} else if err := s.cfg.AttPool.SaveBlockAttestation(a); err != nil {
 			return err
 		}

beacon-chain/blockchain/process_block_helpers.go

@@ -162,10 +162,6 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 	postState state.BeaconState) (int, error) {
 	// Get attested state
 	attestedRoot := signed.Block().ParentRoot()
-	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
-	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested block")
-	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get attested state")
@@ -187,7 +183,6 @@ func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed inte
 		postState,
 		signed,
 		attestedState,
-		attestedBlock,
 		finalizedBlock,
 	)
 
@@ -213,10 +208,6 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 	postState state.BeaconState) (int, error) {
 	// Get attested state
 	attestedRoot := signed.Block().ParentRoot()
-	attestedBlock, err := s.cfg.BeaconDB.Block(ctx, attestedRoot)
-	if err != nil {
-		return 0, errors.Wrap(err, "could not get attested block")
-	}
 	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get attested state")
@@ -227,7 +218,6 @@ func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed in
 		postState,
 		signed,
 		attestedState,
-		attestedBlock,
 	)
 
 	if err != nil {

beacon-chain/blockchain/receive_attestation.go

@@ -177,7 +177,7 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 		}
 
 		hasState := s.cfg.BeaconDB.HasStateSummary(ctx, bytesutil.ToBytes32(a.GetData().BeaconBlockRoot))
-		hasBlock := s.hasBlock(ctx, bytesutil.ToBytes32(a.GetData().BeaconBlockRoot))
+		hasBlock := s.chainHasBlock(ctx, bytesutil.ToBytes32(a.GetData().BeaconBlockRoot))
 		if !(hasState && hasBlock) {
 			continue
 		}

beacon-chain/blockchain/receive_block.go

@@ -39,18 +39,30 @@ var epochsSinceFinalityExpandCache = primitives.Epoch(4)
 // BlockReceiver interface defines the methods of chain service for receiving and processing new blocks.
 type BlockReceiver interface {
 	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte, avs das.AvailabilityStore) error
+	ReceiveExecutionPayloadEnvelope(ctx context.Context, env interfaces.ROExecutionPayloadEnvelope, avs das.AvailabilityStore) error
 	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock, avs das.AvailabilityStore) error
 	HasBlock(ctx context.Context, root [32]byte) bool
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 	BlockBeingSynced([32]byte) bool
 }
 
+// PayloadAttestationReceiver defines methods of the chain service for receiving
+// and processing new payload attestations and payload attestation messages
+type PayloadAttestationReceiver interface {
+	ReceivePayloadAttestationMessage(ctx context.Context, a *ethpb.PayloadAttestationMessage) error
+}
+
 // BlobReceiver interface defines the methods of chain service for receiving new
 // blobs
 type BlobReceiver interface {
 	ReceiveBlob(context.Context, blocks.VerifiedROBlob) error
 }
 
+// ExecutionPayloadReceiver interface defines the methods of chain service for receiving `ROExecutionPayloadEnvelope`.
+type ExecutionPayloadReceiver interface {
+	ReceiveExecutionPayloadEnvelope(ctx context.Context, envelope interfaces.ROExecutionPayloadEnvelope, _ das.AvailabilityStore) error
+}
+
 // SlashingReceiver interface defines the methods of chain service for receiving validated slashing over the wire.
 type SlashingReceiver interface {
 	ReceiveAttesterSlashing(ctx context.Context, slashing ethpb.AttSlashing)

beacon-chain/blockchain/receive_execution_payload_envelope.go

@@ -0,0 +1,152 @@
+package blockchain
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epbs"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/execution"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
+	"golang.org/x/sync/errgroup"
+)
+
+// ReceiveExecutionPayloadEnvelope is a function that defines the operations (minus pubsub)
+// that are performed on a received execution payload envelope. The operations consist of:
+//  1. Validate the payload, apply state transition.
+//  2. Apply fork choice to the processed payload
+//  3. Save latest head info
+func (s *Service) ReceiveExecutionPayloadEnvelope(ctx context.Context, envelope interfaces.ROExecutionPayloadEnvelope, _ das.AvailabilityStore) error {
+	receivedTime := time.Now()
+	root := envelope.BeaconBlockRoot()
+	s.payloadBeingSynced.set(envelope)
+	defer s.payloadBeingSynced.unset(root)
+
+	preState, err := s.getPayloadEnvelopePrestate(ctx, envelope)
+	if err != nil {
+		return errors.Wrap(err, "could not get prestate")
+	}
+
+	eg, _ := errgroup.WithContext(ctx)
+	var postState state.BeaconState
+	eg.Go(func() error {
+		if err := epbs.ValidatePayloadStateTransition(ctx, preState, envelope); err != nil {
+			return errors.Wrap(err, "failed to validate consensus state transition function")
+		}
+		return nil
+	})
+	var isValidPayload bool
+	eg.Go(func() error {
+		var err error
+		isValidPayload, err = s.validateExecutionOnEnvelope(ctx, envelope)
+		if err != nil {
+			return errors.Wrap(err, "could not notify the engine of the new payload")
+		}
+		return nil
+	})
+
+	if err := eg.Wait(); err != nil {
+		return err
+	}
+	_ = isValidPayload
+	_ = postState
+	daStartTime := time.Now()
+	// TODO: Add DA check
+	daWaitedTime := time.Since(daStartTime)
+	dataAvailWaitedTime.Observe(float64(daWaitedTime.Milliseconds()))
+	// TODO: Add Head update, cache handling, postProcessing
+	if err := s.insertPayloadEnvelope(envelope); err != nil {
+		return errors.Wrap(err, "could not insert payload to forkchoice")
+	}
+	timeWithoutDaWait := time.Since(receivedTime) - daWaitedTime
+	executionEngineProcessingTime.Observe(float64(timeWithoutDaWait.Milliseconds()))
+	return nil
+}
+
+// notifyNewPayload signals execution engine on a new payload.
+// It returns true if the EL has returned VALID for the block
+func (s *Service) notifyNewEnvelope(ctx context.Context, envelope interfaces.ROExecutionPayloadEnvelope) (bool, error) {
+	ctx, span := trace.StartSpan(ctx, "blockChain.notifyNewPayload")
+	defer span.End()
+
+	payload, err := envelope.Execution()
+	if err != nil {
+		return false, errors.Wrap(err, "could not get execution payload")
+	}
+
+	versionedHashes := envelope.VersionedHashes()
+	root := envelope.BeaconBlockRoot()
+	parentRoot, err := s.ParentRoot(root)
+	if err != nil {
+		return false, errors.Wrap(err, "could not get parent block root")
+	}
+	pr := common.Hash(parentRoot)
+	lastValidHash, err := s.cfg.ExecutionEngineCaller.NewPayload(ctx, payload, versionedHashes, &pr)
+	switch {
+	case err == nil:
+		newPayloadValidNodeCount.Inc()
+		return true, nil
+	case errors.Is(err, execution.ErrAcceptedSyncingPayloadStatus):
+		newPayloadOptimisticNodeCount.Inc()
+		log.WithFields(logrus.Fields{
+			"payloadBlockHash": fmt.Sprintf("%#x", bytesutil.Trunc(payload.BlockHash())),
+		}).Info("Called new payload with optimistic block")
+		return false, nil
+	case errors.Is(err, execution.ErrInvalidPayloadStatus):
+		lvh := bytesutil.ToBytes32(lastValidHash)
+		return false, invalidBlock{
+			error:         ErrInvalidPayload,
+			lastValidHash: lvh,
+		}
+	default:
+		return false, errors.WithMessage(ErrUndefinedExecutionEngineError, err.Error())
+	}
+}
+
+// validateExecutionOnEnvelope notifies the engine of the incoming execution payload and returns true if the payload is valid
+func (s *Service) validateExecutionOnEnvelope(ctx context.Context, e interfaces.ROExecutionPayloadEnvelope) (bool, error) {
+	isValidPayload, err := s.notifyNewEnvelope(ctx, e)
+	if err == nil {
+		return isValidPayload, nil
+	}
+	blockRoot := e.BeaconBlockRoot()
+	parentRoot, rootErr := s.ParentRoot(blockRoot)
+	if rootErr != nil {
+		return false, errors.Wrap(rootErr, "could not get parent block root")
+	}
+	s.cfg.ForkChoiceStore.Lock()
+	err = s.handleInvalidExecutionError(ctx, err, blockRoot, parentRoot)
+	s.cfg.ForkChoiceStore.Unlock()
+	return false, err
+}
+
+func (s *Service) getPayloadEnvelopePrestate(ctx context.Context, e interfaces.ROExecutionPayloadEnvelope) (state.BeaconState, error) {
+	ctx, span := trace.StartSpan(ctx, "blockChain.getPayloadEnvelopePreState")
+	defer span.End()
+
+	// Verify incoming payload has a valid pre state.
+	root := e.BeaconBlockRoot()
+	// Verify the referred block is known to forkchoice
+	if !s.InForkchoice(root) {
+		return nil, errors.New("Cannot import execution payload envelope for unknown block")
+	}
+	if err := s.verifyBlkPreState(ctx, root); err != nil {
+		return nil, errors.Wrap(err, "could not verify payload prestate")
+	}
+
+	preState, err := s.cfg.StateGen.StateByRoot(ctx, root)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get pre state")
+	}
+	if preState == nil || preState.IsNil() {
+		return nil, errors.Wrap(err, "nil pre state")
+	}
+	return preState, nil
+}

beacon-chain/blockchain/receive_execution_payload_envelope_test.go

@@ -0,0 +1,99 @@
+package blockchain
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
+	mockExecution "github.com/prysmaticlabs/prysm/v5/beacon-chain/execution/testing"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func Test_getPayloadEnvelopePrestate(t *testing.T) {
+	service, tr := minimalTestService(t)
+	ctx, fcs := tr.ctx, tr.fcs
+
+	gs, _ := util.DeterministicGenesisStateEpbs(t, 32)
+	require.NoError(t, service.saveGenesisData(ctx, gs))
+	require.NoError(t, fcs.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Root: service.originBlockRoot}))
+
+	p := random.ExecutionPayloadEnvelope(t)
+	p.BeaconBlockRoot = service.originBlockRoot[:]
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+
+	_, err = service.getPayloadEnvelopePrestate(ctx, e)
+	require.NoError(t, err)
+}
+
+func Test_notifyNewEnvelope(t *testing.T) {
+	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	ctx, fcs := tr.ctx, tr.fcs
+	gs, _ := util.DeterministicGenesisStateEpbs(t, 32)
+	require.NoError(t, service.saveGenesisData(ctx, gs))
+	require.NoError(t, fcs.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Root: service.originBlockRoot}))
+	p := random.ExecutionPayloadEnvelope(t)
+	p.BeaconBlockRoot = service.originBlockRoot[:]
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	engine := &mockExecution.EngineClient{}
+	service.cfg.ExecutionEngineCaller = engine
+	isValidPayload, err := service.notifyNewEnvelope(ctx, e)
+	require.NoError(t, err)
+	require.Equal(t, true, isValidPayload)
+}
+
+func Test_validateExecutionOnEnvelope(t *testing.T) {
+	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	ctx, fcs := tr.ctx, tr.fcs
+	gs, _ := util.DeterministicGenesisStateEpbs(t, 32)
+	require.NoError(t, service.saveGenesisData(ctx, gs))
+	require.NoError(t, fcs.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Root: service.originBlockRoot}))
+	p := random.ExecutionPayloadEnvelope(t)
+	p.BeaconBlockRoot = service.originBlockRoot[:]
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	engine := &mockExecution.EngineClient{}
+	service.cfg.ExecutionEngineCaller = engine
+	isValidPayload, err := service.validateExecutionOnEnvelope(ctx, e)
+	require.NoError(t, err)
+	require.Equal(t, true, isValidPayload)
+}
+
+func Test_ReceiveExecutionPayloadEnvelope(t *testing.T) {
+	service, tr := minimalTestService(t, WithPayloadIDCache(cache.NewPayloadIDCache()))
+	ctx, fcs := tr.ctx, tr.fcs
+	gs, _ := util.DeterministicGenesisStateEpbs(t, 32)
+	require.NoError(t, service.saveGenesisData(ctx, gs))
+	require.NoError(t, fcs.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Root: service.originBlockRoot}))
+	post := gs.Copy()
+	p := &enginev1.ExecutionPayloadEnvelope{
+		Payload: &enginev1.ExecutionPayloadElectra{
+			ParentHash: make([]byte, 32),
+			BlockHash:  make([]byte, 32),
+		},
+		BeaconBlockRoot:    service.originBlockRoot[:],
+		BlobKzgCommitments: make([][]byte, 0),
+		StateRoot:          make([]byte, 32),
+	}
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	das := &das.MockAvailabilityStore{}
+
+	blockHeader := post.LatestBlockHeader()
+	prevStateRoot, err := post.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	blockHeader.StateRoot = prevStateRoot[:]
+	require.NoError(t, post.SetLatestBlockHeader(blockHeader))
+	stRoot, err := post.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	p.StateRoot = stRoot[:]
+	engine := &mockExecution.EngineClient{}
+	service.cfg.ExecutionEngineCaller = engine
+	require.NoError(t, service.ReceiveExecutionPayloadEnvelope(ctx, e, das))
+}

beacon-chain/blockchain/receive_payload_attestation_message.go

@@ -0,0 +1,33 @@
+package blockchain
+
+import (
+	"context"
+	"slices"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+func (s *Service) ReceivePayloadAttestationMessage(ctx context.Context, a *eth.PayloadAttestationMessage) error {
+	if err := helpers.ValidateNilPayloadAttestationMessage(a); err != nil {
+		return err
+	}
+	root := [32]byte(a.Data.BeaconBlockRoot)
+	st, err := s.HeadStateReadOnly(ctx)
+	if err != nil {
+		return err
+	}
+	ptc, err := helpers.GetPayloadTimelinessCommittee(ctx, st, a.Data.Slot)
+	if err != nil {
+		return err
+	}
+	idx := slices.Index(ptc, a.ValidatorIndex)
+	if idx == -1 {
+		return errInvalidValidatorIndex
+	}
+	if s.cfg.PayloadAttestationCache.Seen(root, uint64(primitives.ValidatorIndex(idx))) {
+		return nil
+	}
+	return s.cfg.PayloadAttestationCache.Add(a, uint64(idx))
+}

beacon-chain/blockchain/service.go

@@ -65,6 +65,7 @@ type Service struct {
 	syncComplete                  chan struct{}
 	blobNotifiers                 *blobNotifierMap
 	blockBeingSynced              *currentlySyncingBlock
+	payloadBeingSynced            *currentlySyncingPayload
 	blobStorage                   *filesystem.BlobStorage
 	lastPublishedLightClientEpoch primitives.Epoch
 }
@@ -75,6 +76,8 @@ type config struct {
 	ChainStartFetcher       execution.ChainStartFetcher
 	BeaconDB                db.HeadAccessDatabase
 	DepositCache            cache.DepositCache
+	PayloadAttestationCache *cache.PayloadAttestationCache
+	PayloadEnvelopeCache    *sync.Map
 	PayloadIDCache          *cache.PayloadIDCache
 	TrackedValidatorsCache  *cache.TrackedValidatorsCache
 	AttPool                 attestations.Pool
@@ -179,6 +182,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 		blobNotifiers:        bn,
 		cfg:                  &config{},
 		blockBeingSynced:     &currentlySyncingBlock{roots: make(map[[32]byte]struct{})},
+		payloadBeingSynced:   &currentlySyncingPayload{roots: make(map[[32]byte]primitives.PTCStatus)},
 	}
 	for _, opt := range opts {
 		if err := opt(srv); err != nil {
@@ -544,7 +548,7 @@ func (s *Service) saveGenesisData(ctx context.Context, genesisState state.Beacon
 // 2.) Check DB.
 // Checking 1.) is ten times faster than checking 2.)
 // this function requires a lock in forkchoice
-func (s *Service) hasBlock(ctx context.Context, root [32]byte) bool {
+func (s *Service) chainHasBlock(ctx context.Context, root [32]byte) bool {
 	if s.cfg.ForkChoiceStore.HasNode(root) {
 		return true
 	}

beacon-chain/blockchain/service_test.go

@@ -382,8 +382,8 @@ func TestHasBlock_ForkChoiceAndDB_DoublyLinkedTree(t *testing.T) {
 	require.NoError(t, err)
 	require.NoError(t, s.cfg.ForkChoiceStore.InsertNode(ctx, beaconState, r))
 
-	assert.Equal(t, false, s.hasBlock(ctx, [32]byte{}), "Should not have block")
-	assert.Equal(t, true, s.hasBlock(ctx, r), "Should have block")
+	assert.Equal(t, false, s.chainHasBlock(ctx, [32]byte{}), "Should not have block")
+	assert.Equal(t, true, s.chainHasBlock(ctx, r), "Should have block")
 }
 
 func TestServiceStop_SaveCachedBlocks(t *testing.T) {

beacon-chain/blockchain/setup_test.go

@@ -32,7 +32,7 @@ type mockBeaconNode struct {
 }
 
 // StateFeed mocks the same method in the beacon node.
-func (mbn *mockBeaconNode) StateFeed() event.SubscriberSender {
+func (mbn *mockBeaconNode) StateFeed() *event.Feed {
 	mbn.mu.Lock()
 	defer mbn.mu.Unlock()
 	if mbn.stateFeed == nil {

beacon-chain/blockchain/testing/BUILD.bazel

@@ -3,7 +3,10 @@ load("@prysm//tools/go:def.bzl", "go_library")
 go_library(
     name = "go_default_library",
     testonly = True,
-    srcs = ["mock.go"],
+    srcs = [
+        "mock.go",
+        "mock_epbs.go",
+    ],
     importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/testing",
     visibility = [
         "//beacon-chain:__subpackages__",

beacon-chain/blockchain/testing/mock.go

@@ -37,44 +37,50 @@ var ErrNilState = errors.New("nil state")
 
 // ChainService defines the mock interface for testing
 type ChainService struct {
-	NotFinalized                bool
-	Optimistic                  bool
-	ValidAttestation            bool
-	ValidatorsRoot              [32]byte
-	PublicKey                   [fieldparams.BLSPubkeyLength]byte
-	FinalizedCheckPoint         *ethpb.Checkpoint
-	CurrentJustifiedCheckPoint  *ethpb.Checkpoint
-	PreviousJustifiedCheckPoint *ethpb.Checkpoint
-	Slot                        *primitives.Slot // Pointer because 0 is a useful value, so checking against it can be incorrect.
-	Balance                     *precompute.Balance
-	CanonicalRoots              map[[32]byte]bool
-	Fork                        *ethpb.Fork
-	ETH1Data                    *ethpb.Eth1Data
-	InitSyncBlockRoots          map[[32]byte]bool
-	DB                          db.Database
-	State                       state.BeaconState
-	Block                       interfaces.ReadOnlySignedBeaconBlock
-	VerifyBlkDescendantErr      error
-	stateNotifier               statefeed.Notifier
-	BlocksReceived              []interfaces.ReadOnlySignedBeaconBlock
-	SyncCommitteeIndices        []primitives.CommitteeIndex
-	blockNotifier               blockfeed.Notifier
-	opNotifier                  opfeed.Notifier
-	Root                        []byte
-	SyncCommitteeDomain         []byte
-	SyncSelectionProofDomain    []byte
-	SyncContributionProofDomain []byte
-	SyncCommitteePubkeys        [][]byte
-	Genesis                     time.Time
-	ForkChoiceStore             forkchoice.ForkChoicer
-	ReceiveBlockMockErr         error
-	OptimisticCheckRootReceived [32]byte
-	FinalizedRoots              map[[32]byte]bool
-	OptimisticRoots             map[[32]byte]bool
-	BlockSlot                   primitives.Slot
-	SyncingRoot                 [32]byte
-	Blobs                       []blocks.VerifiedROBlob
-	TargetRoot                  [32]byte
+	NotFinalized                        bool
+	Optimistic                          bool
+	ValidAttestation                    bool
+	ValidatorsRoot                      [32]byte
+	PublicKey                           [fieldparams.BLSPubkeyLength]byte
+	FinalizedCheckPoint                 *ethpb.Checkpoint
+	CurrentJustifiedCheckPoint          *ethpb.Checkpoint
+	PreviousJustifiedCheckPoint         *ethpb.Checkpoint
+	Slot                                *primitives.Slot // Pointer because 0 is a useful value, so checking against it can be incorrect.
+	Balance                             *precompute.Balance
+	CanonicalRoots                      map[[32]byte]bool
+	Fork                                *ethpb.Fork
+	ETH1Data                            *ethpb.Eth1Data
+	InitSyncBlockRoots                  map[[32]byte]bool
+	DB                                  db.Database
+	State                               state.BeaconState
+	Block                               interfaces.ReadOnlySignedBeaconBlock
+	ExecutionPayloadEnvelope            interfaces.ROExecutionPayloadEnvelope
+	VerifyBlkDescendantErr              error
+	stateNotifier                       statefeed.Notifier
+	BlocksReceived                      []interfaces.ReadOnlySignedBeaconBlock
+	SyncCommitteeIndices                []primitives.CommitteeIndex
+	blockNotifier                       blockfeed.Notifier
+	opNotifier                          opfeed.Notifier
+	Root                                []byte
+	SyncCommitteeDomain                 []byte
+	SyncSelectionProofDomain            []byte
+	SyncContributionProofDomain         []byte
+	SyncCommitteePubkeys                [][]byte
+	Genesis                             time.Time
+	ForkChoiceStore                     forkchoice.ForkChoicer
+	ReceiveBlockMockErr                 error
+	ReceiveEnvelopeMockErr              error
+	OptimisticCheckRootReceived         [32]byte
+	FinalizedRoots                      map[[32]byte]bool
+	OptimisticRoots                     map[[32]byte]bool
+	BlockSlot                           primitives.Slot
+	SyncingRoot                         [32]byte
+	Blobs                               []blocks.VerifiedROBlob
+	TargetRoot                          [32]byte
+	HighestReceivedSlot                 primitives.Slot
+	HighestReceivedRoot                 [32]byte
+	PayloadStatus                       primitives.PTCStatus
+	ReceivePayloadAttestationMessageErr error
 }
 
 func (s *ChainService) Ancestor(ctx context.Context, root []byte, slot primitives.Slot) ([]byte, error) {
@@ -98,44 +104,6 @@ func (s *ChainService) BlockNotifier() blockfeed.Notifier {
 	return s.blockNotifier
 }
 
-type EventFeedWrapper struct {
-	feed       *event.Feed
-	subscribed chan struct{} // this channel is closed once a subscription is made
-}
-
-func (w *EventFeedWrapper) Subscribe(channel interface{}) event.Subscription {
-	select {
-	case <-w.subscribed:
-		break // already closed
-	default:
-		close(w.subscribed)
-	}
-	return w.feed.Subscribe(channel)
-}
-
-func (w *EventFeedWrapper) Send(value interface{}) int {
-	return w.feed.Send(value)
-}
-
-// WaitForSubscription allows test to wait for the feed to have a subscription before beginning to send events.
-func (w *EventFeedWrapper) WaitForSubscription(ctx context.Context) error {
-	select {
-	case <-w.subscribed:
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
-	}
-}
-
-var _ event.SubscriberSender = &EventFeedWrapper{}
-
-func NewEventFeedWrapper() *EventFeedWrapper {
-	return &EventFeedWrapper{
-		feed:       new(event.Feed),
-		subscribed: make(chan struct{}),
-	}
-}
-
 // MockBlockNotifier mocks the block notifier.
 type MockBlockNotifier struct {
 	feed *event.Feed
@@ -169,7 +137,7 @@ func (msn *MockStateNotifier) ReceivedEvents() []*feed.Event {
 }
 
 // StateFeed returns a state feed.
-func (msn *MockStateNotifier) StateFeed() event.SubscriberSender {
+func (msn *MockStateNotifier) StateFeed() *event.Feed {
 	msn.feedLock.Lock()
 	defer msn.feedLock.Unlock()
 
@@ -197,23 +165,6 @@ func (msn *MockStateNotifier) StateFeed() event.SubscriberSender {
 	return msn.feed
 }
 
-// NewSimpleStateNotifier makes a state feed without the custom mock feed machinery.
-func NewSimpleStateNotifier() *MockStateNotifier {
-	return &MockStateNotifier{feed: new(event.Feed)}
-}
-
-type SimpleNotifier struct {
-	Feed event.SubscriberSender
-}
-
-func (n *SimpleNotifier) StateFeed() event.SubscriberSender {
-	return n.Feed
-}
-
-func (n *SimpleNotifier) OperationFeed() event.SubscriberSender {
-	return n.Feed
-}
-
 // OperationNotifier mocks the same method in the chain service.
 func (s *ChainService) OperationNotifier() opfeed.Notifier {
 	if s.opNotifier == nil {
@@ -228,7 +179,7 @@ type MockOperationNotifier struct {
 }
 
 // OperationFeed returns an operation feed.
-func (mon *MockOperationNotifier) OperationFeed() event.SubscriberSender {
+func (mon *MockOperationNotifier) OperationFeed() *event.Feed {
 	if mon.feed == nil {
 		mon.feed = new(event.Feed)
 	}
@@ -622,12 +573,12 @@ func (s *ChainService) ReceivedBlocksLastEpoch() (uint64, error) {
 	return 0, nil
 }
 
-// HighestReceivedBlockSlot mocks the same method in the chain service
-func (s *ChainService) HighestReceivedBlockSlot() primitives.Slot {
+// HighestReceivedBlockSlotRoot mocks the same method in the chain service
+func (s *ChainService) HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte) {
 	if s.ForkChoiceStore != nil {
-		return s.ForkChoiceStore.HighestReceivedBlockSlot()
+		return s.ForkChoiceStore.HighestReceivedBlockSlotRoot()
 	}
-	return 0
+	return s.HighestReceivedSlot, s.HighestReceivedRoot
 }
 
 // InsertNode mocks the same method in the chain service
@@ -687,3 +638,17 @@ func (c *ChainService) ReceiveBlob(_ context.Context, b blocks.VerifiedROBlob) e
 func (c *ChainService) TargetRootForEpoch(_ [32]byte, _ primitives.Epoch) ([32]byte, error) {
 	return c.TargetRoot, nil
 }
+
+// HashInForkchoice mocks the same method in the chain service
+func (c *ChainService) HashInForkchoice([32]byte) bool {
+	return false
+}
+
+// ReceivePayloadAttestationMessage mocks the same method in the chain service
+func (c *ChainService) ReceivePayloadAttestationMessage(_ context.Context, _ *ethpb.PayloadAttestationMessage) error {
+	return c.ReceivePayloadAttestationMessageErr
+}
+
+func (c *ChainService) GetPTCVote(root [32]byte) primitives.PTCStatus {
+	return c.PayloadStatus
+}

beacon-chain/blockchain/testing/mock_epbs.go

@@ -0,0 +1,25 @@
+package testing
+
+import (
+	"context"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/das"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+)
+
+// ReceiveExecutionPayloadEnvelope mocks the  method in chain service.
+func (s *ChainService) ReceiveExecutionPayloadEnvelope(ctx context.Context, env interfaces.ROExecutionPayloadEnvelope, _ das.AvailabilityStore) error {
+	if s.ReceiveBlockMockErr != nil {
+		return s.ReceiveBlockMockErr
+	}
+	if s.State == nil {
+		return ErrNilState
+	}
+	if s.State.Slot() == env.Slot() {
+		if err := s.State.SetLatestFullSlot(s.State.Slot()); err != nil {
+			return err
+		}
+	}
+	s.ExecutionPayloadEnvelope = env
+	return nil
+}

beacon-chain/cache/BUILD.bazel

@@ -15,11 +15,13 @@ go_library(
         "doc.go",
         "error.go",
         "interfaces.go",
+        "payload_attestation.go",
         "payload_id.go",
         "proposer_indices.go",
         "proposer_indices_disabled.go",  # keep
         "proposer_indices_type.go",
         "registration.go",
+        "signed_execution_header.go",
         "skip_slot_cache.go",
         "subnet_ids.go",
         "sync_committee.go",
@@ -42,11 +44,13 @@ go_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/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
@@ -70,10 +74,12 @@ go_test(
         "checkpoint_state_test.go",
         "committee_fuzz_test.go",
         "committee_test.go",
+        "payload_attestation_test.go",
         "payload_id_test.go",
         "private_access_test.go",
         "proposer_indices_test.go",
         "registration_test.go",
+        "signed_execution_header_test.go",
         "skip_slot_cache_test.go",
         "subnet_ids_test.go",
         "sync_committee_head_state_test.go",
@@ -88,7 +94,9 @@ go_test(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",

beacon-chain/cache/payload_attestation.go

@@ -0,0 +1,132 @@
+package cache
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+var errNilPayloadAttestationMessage = errors.New("nil Payload Attestation Message")
+
+// PayloadAttestationCache keeps a map of all the PTC votes that were seen,
+// already aggregated. The key is the beacon block root.
+type PayloadAttestationCache struct {
+	root         [32]byte
+	attestations [primitives.PAYLOAD_INVALID_STATUS]*eth.PayloadAttestation
+	sync.Mutex
+}
+
+// Seen returns true if a vote for the given Beacon Block Root has already been processed
+// for this Payload Timeliness Committee index. This will return true even if
+// the Payload status differs.
+func (p *PayloadAttestationCache) Seen(root [32]byte, idx uint64) bool {
+	p.Lock()
+	defer p.Unlock()
+	if p.root != root {
+		return false
+	}
+	for _, agg := range p.attestations {
+		if agg == nil {
+			continue
+		}
+		if agg.AggregationBits.BitAt(idx) {
+			return true
+		}
+	}
+	return false
+}
+
+// messageToPayloadAttestation creates a PayloadAttestation with a single
+// aggregated bit from the passed PayloadAttestationMessage
+func messageToPayloadAttestation(att *eth.PayloadAttestationMessage, idx uint64) *eth.PayloadAttestation {
+	bits := primitives.NewPayloadAttestationAggregationBits()
+	bits.SetBitAt(idx, true)
+	data := &eth.PayloadAttestationData{
+		BeaconBlockRoot: bytesutil.SafeCopyBytes(att.Data.BeaconBlockRoot),
+		Slot:            att.Data.Slot,
+		PayloadStatus:   att.Data.PayloadStatus,
+	}
+	return &eth.PayloadAttestation{
+		AggregationBits: bits,
+		Data:            data,
+		Signature:       bytesutil.SafeCopyBytes(att.Signature),
+	}
+}
+
+// aggregateSigFromMessage returns the aggregated signature from a Payload
+// Attestation by adding the passed signature in the PayloadAttestationMessage,
+// no signature validation is performed.
+func aggregateSigFromMessage(aggregated *eth.PayloadAttestation, message *eth.PayloadAttestationMessage) ([]byte, error) {
+	aggSig, err := bls.SignatureFromBytesNoValidation(aggregated.Signature)
+	if err != nil {
+		return nil, err
+	}
+	sig, err := bls.SignatureFromBytesNoValidation(message.Signature)
+	if err != nil {
+		return nil, err
+	}
+	return bls.AggregateSignatures([]bls.Signature{aggSig, sig}).Marshal(), nil
+}
+
+// Add adds a PayloadAttestationMessage to the internal cache of aggregated
+// PayloadAttestations.
+// If the index has already been seen for this attestation status the function does nothing.
+// If the root is not the cached root, the function will clear the previous cache
+// This function assumes that the message has already been validated. In
+// particular that the signature is valid and that the block root corresponds to
+// the given slot in the attestation data.
+func (p *PayloadAttestationCache) Add(att *eth.PayloadAttestationMessage, idx uint64) error {
+	if att == nil || att.Data == nil || att.Data.BeaconBlockRoot == nil {
+		return errNilPayloadAttestationMessage
+	}
+	p.Lock()
+	defer p.Unlock()
+	root := [32]byte(att.Data.BeaconBlockRoot)
+	if p.root != root {
+		p.root = root
+		p.attestations = [primitives.PAYLOAD_INVALID_STATUS]*eth.PayloadAttestation{}
+	}
+	agg := p.attestations[att.Data.PayloadStatus]
+	if agg == nil {
+		p.attestations[att.Data.PayloadStatus] = messageToPayloadAttestation(att, idx)
+		return nil
+	}
+	if agg.AggregationBits.BitAt(idx) {
+		return nil
+	}
+	sig, err := aggregateSigFromMessage(agg, att)
+	if err != nil {
+		return err
+	}
+	agg.Signature = sig
+	agg.AggregationBits.SetBitAt(idx, true)
+	return nil
+}
+
+// Get returns the aggregated PayloadAttestation for the given root and status
+// if the root doesn't exist or status is invalid, the function returns nil.
+func (p *PayloadAttestationCache) Get(root [32]byte, status primitives.PTCStatus) *eth.PayloadAttestation {
+	p.Lock()
+	defer p.Unlock()
+
+	if p.root != root {
+		return nil
+	}
+	if status >= primitives.PAYLOAD_INVALID_STATUS {
+		return nil
+	}
+
+	return eth.CopyPayloadAttestation(p.attestations[status])
+}
+
+// Clear clears the internal map
+func (p *PayloadAttestationCache) Clear() {
+	p.Lock()
+	defer p.Unlock()
+	p.root = [32]byte{}
+	p.attestations = [primitives.PAYLOAD_INVALID_STATUS]*eth.PayloadAttestation{}
+}

beacon-chain/cache/payload_attestation_test.go

@@ -0,0 +1,143 @@
+package cache
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestPayloadAttestationCache(t *testing.T) {
+	p := &PayloadAttestationCache{}
+
+	//Test Has seen
+	root := [32]byte{'r'}
+	idx := uint64(5)
+	require.Equal(t, false, p.Seen(root, idx))
+
+	// Test Add
+	msg := &eth.PayloadAttestationMessage{
+		Signature: bls.NewAggregateSignature().Marshal(),
+		Data: &eth.PayloadAttestationData{
+			BeaconBlockRoot: root[:],
+			Slot:            1,
+			PayloadStatus:   primitives.PAYLOAD_PRESENT,
+		},
+	}
+
+	// Add new root
+	require.NoError(t, p.Add(msg, idx))
+	require.Equal(t, true, p.Seen(root, idx))
+	require.Equal(t, root, p.root)
+	att := p.attestations[primitives.PAYLOAD_PRESENT]
+	indices := att.AggregationBits.BitIndices()
+	require.DeepEqual(t, []int{int(idx)}, indices)
+	singleSig := bytesutil.SafeCopyBytes(msg.Signature)
+	require.DeepEqual(t, singleSig, att.Signature)
+
+	// Test Seen
+	require.Equal(t, true, p.Seen(root, idx))
+	require.Equal(t, false, p.Seen(root, idx+1))
+
+	// Add another attestation on the same data
+	msg2 := &eth.PayloadAttestationMessage{
+		Signature: bls.NewAggregateSignature().Marshal(),
+		Data:      att.Data,
+	}
+	idx2 := uint64(7)
+	require.NoError(t, p.Add(msg2, idx2))
+	att = p.attestations[primitives.PAYLOAD_PRESENT]
+	indices = att.AggregationBits.BitIndices()
+	require.DeepEqual(t, []int{int(idx), int(idx2)}, indices)
+	require.DeepNotEqual(t, att.Signature, msg.Signature)
+
+	// Try again the same index
+	require.NoError(t, p.Add(msg2, idx2))
+	att2 := p.attestations[primitives.PAYLOAD_PRESENT]
+	indices = att.AggregationBits.BitIndices()
+	require.DeepEqual(t, []int{int(idx), int(idx2)}, indices)
+	require.DeepEqual(t, att, att2)
+
+	// Test Seen
+	require.Equal(t, true, p.Seen(root, idx2))
+	require.Equal(t, false, p.Seen(root, idx2+1))
+
+	// Add another payload status for a different payload status
+	msg3 := &eth.PayloadAttestationMessage{
+		Signature: bls.NewAggregateSignature().Marshal(),
+		Data: &eth.PayloadAttestationData{
+			BeaconBlockRoot: root[:],
+			Slot:            1,
+			PayloadStatus:   primitives.PAYLOAD_WITHHELD,
+		},
+	}
+	idx3 := uint64(17)
+
+	require.NoError(t, p.Add(msg3, idx3))
+	att3 := p.attestations[primitives.PAYLOAD_WITHHELD]
+	indices3 := att3.AggregationBits.BitIndices()
+	require.DeepEqual(t, []int{int(idx3)}, indices3)
+	require.DeepEqual(t, singleSig, att3.Signature)
+
+	// Add a different root
+	root2 := [32]byte{'s'}
+	msg.Data.BeaconBlockRoot = root2[:]
+	require.NoError(t, p.Add(msg, idx))
+	require.Equal(t, root2, p.root)
+	require.Equal(t, true, p.Seen(root2, idx))
+	require.Equal(t, false, p.Seen(root, idx))
+	att = p.attestations[primitives.PAYLOAD_PRESENT]
+	indices = att.AggregationBits.BitIndices()
+	require.DeepEqual(t, []int{int(idx)}, indices)
+}
+
+func TestPayloadAttestationCache_Get(t *testing.T) {
+	root := [32]byte{1, 2, 3}
+	wrongRoot := [32]byte{4, 5, 6}
+	status := primitives.PAYLOAD_PRESENT
+	invalidStatus := primitives.PAYLOAD_INVALID_STATUS
+
+	cache := &PayloadAttestationCache{
+		root: root,
+		attestations: [primitives.PAYLOAD_INVALID_STATUS]*eth.PayloadAttestation{
+			{
+				Signature: []byte{1},
+			},
+			{
+				Signature: []byte{2},
+			},
+			{
+				Signature: []byte{3},
+			},
+		},
+	}
+
+	t.Run("valid root and status", func(t *testing.T) {
+		result := cache.Get(root, status)
+		require.NotNil(t, result, "Expected a non-nil result")
+		require.DeepEqual(t, cache.attestations[status], result)
+	})
+
+	t.Run("invalid root", func(t *testing.T) {
+		result := cache.Get(wrongRoot, status)
+		require.IsNil(t, result)
+	})
+
+	t.Run("status out of bound", func(t *testing.T) {
+		result := cache.Get(root, invalidStatus)
+		require.IsNil(t, result)
+	})
+
+	t.Run("no attestation", func(t *testing.T) {
+		emptyCache := &PayloadAttestationCache{
+			root:         root,
+			attestations: [primitives.PAYLOAD_INVALID_STATUS]*eth.PayloadAttestation{},
+		}
+
+		result := emptyCache.Get(root, status)
+		require.IsNil(t, result)
+	})
+}

beacon-chain/cache/signed_execution_header.go

@@ -0,0 +1,76 @@
+package cache
+
+import (
+	"bytes"
+	"sync"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+)
+
+// ExecutionPayloadHeaders is used  by the sync service to store signed execution payload headers after they pass validation,
+// and filter out subsequent headers with lower value.
+// The signed header from this cache could be used by the proposer when proposing the next slot.
+type ExecutionPayloadHeaders struct {
+	headers map[primitives.Slot][]*enginev1.SignedExecutionPayloadHeader
+	sync.RWMutex
+}
+
+func NewExecutionPayloadHeaders() *ExecutionPayloadHeaders {
+	return &ExecutionPayloadHeaders{
+		headers: make(map[primitives.Slot][]*enginev1.SignedExecutionPayloadHeader),
+	}
+}
+
+// SaveSignedExecutionPayloadHeader saves the signed execution payload header to the cache.
+// The cache stores headers for up to two slots. If the input slot is higher than the lowest slot
+// currently in the cache, the lowest slot is removed to make space for the new header.
+// Only the highest value header for a given parent block hash will be stored.
+// This function assumes caller already checks header's slot is current or next slot, it doesn't account for slot validation.
+func (c *ExecutionPayloadHeaders) SaveSignedExecutionPayloadHeader(header *enginev1.SignedExecutionPayloadHeader) {
+	c.Lock()
+	defer c.Unlock()
+
+	for s := range c.headers {
+		if s+1 < header.Message.Slot {
+			delete(c.headers, s)
+		}
+	}
+
+	// Add or update the header in the map
+	if _, ok := c.headers[header.Message.Slot]; !ok {
+		c.headers[header.Message.Slot] = []*enginev1.SignedExecutionPayloadHeader{header}
+	} else {
+		found := false
+		for i, h := range c.headers[header.Message.Slot] {
+			if bytes.Equal(h.Message.ParentBlockHash, header.Message.ParentBlockHash) && bytes.Equal(h.Message.ParentBlockRoot, header.Message.ParentBlockRoot) {
+				if header.Message.Value > h.Message.Value {
+					c.headers[header.Message.Slot][i] = header
+				}
+				found = true
+				break
+			}
+		}
+		if !found {
+			c.headers[header.Message.Slot] = append(c.headers[header.Message.Slot], header)
+		}
+	}
+}
+
+// SignedExecutionPayloadHeader returns the signed payload header for the given slot and parent block hash and block root.
+// Returns nil if the header is not found.
+// This should be used when the caller wants the header to match parent block hash and parent block root such as proposer choosing a header to propose.
+func (c *ExecutionPayloadHeaders) SignedExecutionPayloadHeader(slot primitives.Slot, parentBlockHash []byte, parentBlockRoot []byte) *enginev1.SignedExecutionPayloadHeader {
+	c.RLock()
+	defer c.RUnlock()
+
+	if headers, ok := c.headers[slot]; ok {
+		for _, header := range headers {
+			if bytes.Equal(header.Message.ParentBlockHash, parentBlockHash) && bytes.Equal(header.Message.ParentBlockRoot, parentBlockRoot) {
+				return header
+			}
+		}
+	}
+
+	return nil
+}

beacon-chain/cache/signed_execution_header_test.go

@@ -0,0 +1,243 @@
+package cache
+
+import (
+	"testing"
+
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func Test_SaveSignedExecutionPayloadHeader(t *testing.T) {
+	t.Run("First header should be added to cache", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				Value:           100,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header)
+		require.Equal(t, 1, len(c.headers))
+		require.Equal(t, header, c.headers[1][0])
+	})
+
+	t.Run("Second header with higher slot should be added, and both slots should be in cache", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header1 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				Value:           100,
+			},
+		}
+		header2 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           100,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header1)
+		c.SaveSignedExecutionPayloadHeader(header2)
+		require.Equal(t, 2, len(c.headers))
+		require.Equal(t, header1, c.headers[1][0])
+		require.Equal(t, header2, c.headers[2][0])
+	})
+
+	t.Run("Third header with higher slot should replace the oldest slot", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header1 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				Value:           100,
+			},
+		}
+		header2 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           100,
+			},
+		}
+		header3 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            3,
+				ParentBlockHash: []byte("parent3"),
+				Value:           100,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header1)
+		c.SaveSignedExecutionPayloadHeader(header2)
+		c.SaveSignedExecutionPayloadHeader(header3)
+		require.Equal(t, 2, len(c.headers))
+		require.Equal(t, header2, c.headers[2][0])
+		require.Equal(t, header3, c.headers[3][0])
+	})
+
+	t.Run("Header with same slot but higher value should replace the existing one", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header1 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           100,
+			},
+		}
+		header2 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           200,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header1)
+		c.SaveSignedExecutionPayloadHeader(header2)
+		require.Equal(t, 1, len(c.headers[2]))
+		require.Equal(t, header2, c.headers[2][0])
+	})
+
+	t.Run("Header with different parent block hash should be appended to the same slot", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header1 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent1"),
+				Value:           100,
+			},
+		}
+		header2 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           200,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header1)
+		c.SaveSignedExecutionPayloadHeader(header2)
+		require.Equal(t, 2, len(c.headers[2]))
+		require.Equal(t, header1, c.headers[2][0])
+		require.Equal(t, header2, c.headers[2][1])
+	})
+}
+
+func TestSignedExecutionPayloadHeader(t *testing.T) {
+	t.Run("Return header when slot and parentBlockHash match", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				ParentBlockRoot: []byte("root1"),
+				Value:           100,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header)
+		result := c.SignedExecutionPayloadHeader(1, []byte("parent1"), []byte("root1"))
+		require.NotNil(t, result)
+		require.Equal(t, header, result)
+	})
+
+	t.Run("Return nil when no matching slot and parentBlockHash", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				ParentBlockRoot: []byte("root1"),
+				Value:           100,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header)
+		result := c.SignedExecutionPayloadHeader(2, []byte("parent2"), []byte("root1"))
+		require.IsNil(t, result)
+	})
+
+	t.Run("Return nil when no matching slot and parentBlockRoot", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				ParentBlockRoot: []byte("root1"),
+				Value:           100,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header)
+		result := c.SignedExecutionPayloadHeader(2, []byte("parent1"), []byte("root2"))
+		require.IsNil(t, result)
+	})
+
+	t.Run("Return header when there are two slots in the cache and a match is found", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header1 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				Value:           100,
+			},
+		}
+		header2 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           200,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header1)
+		c.SaveSignedExecutionPayloadHeader(header2)
+
+		// Check for the first header
+		result1 := c.SignedExecutionPayloadHeader(1, []byte("parent1"), []byte{})
+		require.NotNil(t, result1)
+		require.Equal(t, header1, result1)
+
+		// Check for the second header
+		result2 := c.SignedExecutionPayloadHeader(2, []byte("parent2"), []byte{})
+		require.NotNil(t, result2)
+		require.Equal(t, header2, result2)
+	})
+
+	t.Run("Return nil when slot is evicted from cache", func(t *testing.T) {
+		c := NewExecutionPayloadHeaders()
+		header1 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            1,
+				ParentBlockHash: []byte("parent1"),
+				Value:           100,
+			},
+		}
+		header2 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            2,
+				ParentBlockHash: []byte("parent2"),
+				Value:           200,
+			},
+		}
+		header3 := &enginev1.SignedExecutionPayloadHeader{
+			Message: &enginev1.ExecutionPayloadHeaderEPBS{
+				Slot:            3,
+				ParentBlockHash: []byte("parent3"),
+				Value:           300,
+			},
+		}
+		c.SaveSignedExecutionPayloadHeader(header1)
+		c.SaveSignedExecutionPayloadHeader(header2)
+		c.SaveSignedExecutionPayloadHeader(header3)
+
+		// The first slot should be evicted, so result should be nil
+		result := c.SignedExecutionPayloadHeader(1, []byte("parent1"), []byte{})
+		require.IsNil(t, result)
+
+		// The second slot should still be present
+		result = c.SignedExecutionPayloadHeader(2, []byte("parent2"), []byte{})
+		require.NotNil(t, result)
+		require.Equal(t, header2, result)
+
+		// The third slot should be present
+		result = c.SignedExecutionPayloadHeader(3, []byte("parent3"), []byte{})
+		require.NotNil(t, result)
+		require.Equal(t, header3, result)
+	})
+}

beacon-chain/core/blocks/BUILD.bazel

@@ -107,6 +107,7 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//testing/util/random:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_google_gofuzz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",

beacon-chain/core/blocks/genesis.go

@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v5/encoding/ssz"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 )
@@ -222,6 +223,42 @@ func NewGenesisBlockForState(ctx context.Context, st state.BeaconState) (interfa
 			},
 			Signature: params.BeaconConfig().EmptySignature[:],
 		})
+	case *ethpb.BeaconStateEPBS:
+		kzgs := make([][]byte, 0)
+		kzgRoot, err := ssz.KzgCommitmentsRoot(kzgs)
+		if err != nil {
+			return nil, err
+		}
+		return blocks.NewSignedBeaconBlock(&ethpb.SignedBeaconBlockEpbs{
+			Block: &ethpb.BeaconBlockEpbs{
+				ParentRoot: params.BeaconConfig().ZeroHash[:],
+				StateRoot:  root[:],
+				Body: &ethpb.BeaconBlockBodyEpbs{
+					RandaoReveal: make([]byte, 96),
+					Eth1Data: &ethpb.Eth1Data{
+						DepositRoot: make([]byte, 32),
+						BlockHash:   make([]byte, 32),
+					},
+					Graffiti: make([]byte, 32),
+					SyncAggregate: &ethpb.SyncAggregate{
+						SyncCommitteeBits:      make([]byte, fieldparams.SyncCommitteeLength/8),
+						SyncCommitteeSignature: make([]byte, fieldparams.BLSSignatureLength),
+					},
+					SignedExecutionPayloadHeader: &enginev1.SignedExecutionPayloadHeader{
+						Message: &enginev1.ExecutionPayloadHeaderEPBS{
+							ParentBlockHash:        make([]byte, 32),
+							ParentBlockRoot:        make([]byte, 32),
+							BlockHash:              make([]byte, 32),
+							BlobKzgCommitmentsRoot: kzgRoot[:],
+						},
+						Signature: make([]byte, 96),
+					},
+					BlsToExecutionChanges: make([]*ethpb.SignedBLSToExecutionChange, 0),
+					PayloadAttestations:   make([]*ethpb.PayloadAttestation, 0),
+				},
+			},
+			Signature: params.BeaconConfig().EmptySignature[:],
+		})
 	default:
 		return nil, ErrUnrecognizedState
 	}

beacon-chain/core/blocks/payload.go

@@ -239,12 +239,47 @@ func verifyBlobCommitmentCount(body interfaces.ReadOnlyBeaconBlockBody) error {
 // GetBlockPayloadHash returns the hash of the execution payload of the block
 func GetBlockPayloadHash(blk interfaces.ReadOnlyBeaconBlock) ([32]byte, error) {
 	var payloadHash [32]byte
-	if IsPreBellatrixVersion(blk.Version()) {
-		return payloadHash, nil
+	if blk.Version() >= version.EPBS {
+		header, err := blk.Body().SignedExecutionPayloadHeader()
+		if err != nil {
+			return payloadHash, err
+		}
+		payload, err := header.Header()
+		if err != nil {
+			return payloadHash, err
+		}
+		return payload.BlockHash(), nil
 	}
-	payload, err := blk.Body().Execution()
-	if err != nil {
-		return payloadHash, err
+	if blk.Version() >= version.Bellatrix {
+		payload, err := blk.Body().Execution()
+		if err != nil {
+			return payloadHash, err
+		}
+		return bytesutil.ToBytes32(payload.BlockHash()), nil
 	}
-	return bytesutil.ToBytes32(payload.BlockHash()), nil
+	return payloadHash, nil
+}
+
+// GetBlockParentHash returns the hash of the parent execution payload
+func GetBlockParentHash(blk interfaces.ReadOnlyBeaconBlock) ([32]byte, error) {
+	var parentHash [32]byte
+	if blk.Version() >= version.EPBS {
+		header, err := blk.Body().SignedExecutionPayloadHeader()
+		if err != nil {
+			return parentHash, err
+		}
+		payload, err := header.Header()
+		if err != nil {
+			return parentHash, err
+		}
+		return payload.ParentBlockHash(), nil
+	}
+	if blk.Version() >= version.Bellatrix {
+		payload, err := blk.Body().Execution()
+		if err != nil {
+			return parentHash, err
+		}
+		return bytesutil.ToBytes32(payload.ParentHash()), nil
+	}
+	return parentHash, nil
 }

beacon-chain/core/blocks/withdrawals.go

@@ -14,8 +14,8 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
 	"github.com/prysmaticlabs/prysm/v5/crypto/hash"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v5/encoding/ssz"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 )
@@ -115,15 +115,97 @@ func ValidateBLSToExecutionChange(st state.ReadOnlyBeaconState, signed *ethpb.Si
 	return val, nil
 }
 
+func checkWithdrawalsAgainstPayload(
+	executionData interfaces.ExecutionData,
+	numExpected int,
+	expectedRoot [32]byte,
+) error {
+	var wdRoot [32]byte
+	if executionData.IsBlinded() {
+		r, err := executionData.WithdrawalsRoot()
+		if err != nil {
+			return errors.Wrap(err, "could not get withdrawals root")
+		}
+		copy(wdRoot[:], r)
+	} else {
+		wds, err := executionData.Withdrawals()
+		if err != nil {
+			return errors.Wrap(err, "could not get withdrawals")
+		}
+
+		if len(wds) != numExpected {
+			return fmt.Errorf("execution payload header has %d withdrawals when %d were expected", len(wds), numExpected)
+		}
+
+		wdRoot, err = ssz.WithdrawalSliceRoot(wds, fieldparams.MaxWithdrawalsPerPayload)
+		if err != nil {
+			return errors.Wrap(err, "could not get withdrawals root")
+		}
+	}
+	if expectedRoot != wdRoot {
+		return fmt.Errorf("expected withdrawals root %#x, got %#x", expectedRoot, wdRoot)
+	}
+	return nil
+}
+
+func processWithdrawalStateTransition(
+	st state.BeaconState,
+	expectedWithdrawals []*enginev1.Withdrawal,
+	partialWithdrawalsCount uint64,
+) (err error) {
+	for _, withdrawal := range expectedWithdrawals {
+		err := helpers.DecreaseBalance(st, withdrawal.ValidatorIndex, withdrawal.Amount)
+		if err != nil {
+			return errors.Wrap(err, "could not decrease balance")
+		}
+	}
+	if st.Version() >= version.Electra {
+		if err := st.DequeuePartialWithdrawals(partialWithdrawalsCount); err != nil {
+			return fmt.Errorf("unable to dequeue partial withdrawals from state: %w", err)
+		}
+	}
+
+	if len(expectedWithdrawals) > 0 {
+		if err := st.SetNextWithdrawalIndex(expectedWithdrawals[len(expectedWithdrawals)-1].Index + 1); err != nil {
+			return errors.Wrap(err, "could not set next withdrawal index")
+		}
+	}
+	var nextValidatorIndex primitives.ValidatorIndex
+	if uint64(len(expectedWithdrawals)) < params.BeaconConfig().MaxWithdrawalsPerPayload {
+		nextValidatorIndex, err = st.NextWithdrawalValidatorIndex()
+		if err != nil {
+			return errors.Wrap(err, "could not get next withdrawal validator index")
+		}
+		nextValidatorIndex += primitives.ValidatorIndex(params.BeaconConfig().MaxValidatorsPerWithdrawalsSweep)
+		nextValidatorIndex = nextValidatorIndex % primitives.ValidatorIndex(st.NumValidators())
+	} else {
+		nextValidatorIndex = expectedWithdrawals[len(expectedWithdrawals)-1].ValidatorIndex + 1
+		if nextValidatorIndex == primitives.ValidatorIndex(st.NumValidators()) {
+			nextValidatorIndex = 0
+		}
+	}
+	if err := st.SetNextWithdrawalValidatorIndex(nextValidatorIndex); err != nil {
+		return errors.Wrap(err, "could not set next withdrawal validator index")
+	}
+	return nil
+}
+
 // ProcessWithdrawals processes the validator withdrawals from the provided execution payload
 // into the beacon state.
 //
 // Spec pseudocode definition:
 //
 //	def process_withdrawals(state: BeaconState, payload: ExecutionPayload) -> None:
+//		if state.fork.current_version >= EIP7732_FORK_VERSION :
+//			if not is_parent_block_full(state): # [New in EIP-7732]
+//		 		return
+//
 //	    expected_withdrawals, partial_withdrawals_count = get_expected_withdrawals(state)  # [Modified in Electra:EIP7251]
 //
-//	    assert len(payload.withdrawals) == len(expected_withdrawals)
+//		if state.fork.current_version >= EIP7732_FORK_VERSION :
+//			state.latest_withdrawals_root = hash_tree_root(expected_withdrawals) # [New in EIP-7732]
+//		else :
+//	    	assert len(payload.withdrawals) == len(expected_withdrawals)
 //
 //	    for expected_withdrawal, withdrawal in zip(expected_withdrawals, payload.withdrawals):
 //	        assert withdrawal == expected_withdrawal
@@ -148,76 +230,39 @@ func ValidateBLSToExecutionChange(st state.ReadOnlyBeaconState, signed *ethpb.Si
 //	        next_validator_index = ValidatorIndex(next_index % len(state.validators))
 //	        state.next_withdrawal_validator_index = next_validator_index
 func ProcessWithdrawals(st state.BeaconState, executionData interfaces.ExecutionData) (state.BeaconState, error) {
+	if st.Version() >= version.EPBS {
+		IsParentBlockFull, err := st.IsParentBlockFull()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not check if parent block is full")
+		}
+
+		if !IsParentBlockFull {
+			return nil, nil
+		}
+	}
+
 	expectedWithdrawals, partialWithdrawalsCount, err := st.ExpectedWithdrawals()
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get expected withdrawals")
 	}
 
-	var wdRoot [32]byte
-	if executionData.IsBlinded() {
-		r, err := executionData.WithdrawalsRoot()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals root")
-		}
-		wdRoot = bytesutil.ToBytes32(r)
-	} else {
-		wds, err := executionData.Withdrawals()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals")
-		}
-
-		if len(wds) != len(expectedWithdrawals) {
-			return nil, fmt.Errorf("execution payload header has %d withdrawals when %d were expected", len(wds), len(expectedWithdrawals))
-		}
-
-		wdRoot, err = ssz.WithdrawalSliceRoot(wds, fieldparams.MaxWithdrawalsPerPayload)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get withdrawals root")
-		}
-	}
-
 	expectedRoot, err := ssz.WithdrawalSliceRoot(expectedWithdrawals, fieldparams.MaxWithdrawalsPerPayload)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get expected withdrawals root")
 	}
-	if expectedRoot != wdRoot {
-		return nil, fmt.Errorf("expected withdrawals root %#x, got %#x", expectedRoot, wdRoot)
-	}
 
-	for _, withdrawal := range expectedWithdrawals {
-		err := helpers.DecreaseBalance(st, withdrawal.ValidatorIndex, withdrawal.Amount)
+	if st.Version() >= version.EPBS {
+		err = st.SetLastWithdrawalsRoot(expectedRoot[:])
 		if err != nil {
-			return nil, errors.Wrap(err, "could not decrease balance")
+			return nil, errors.Wrap(err, "could not set withdrawals root")
 		}
-	}
-
-	if st.Version() >= version.Electra {
-		if err := st.DequeuePartialWithdrawals(partialWithdrawalsCount); err != nil {
-			return nil, fmt.Errorf("unable to dequeue partial withdrawals from state: %w", err)
-		}
-	}
-
-	if len(expectedWithdrawals) > 0 {
-		if err := st.SetNextWithdrawalIndex(expectedWithdrawals[len(expectedWithdrawals)-1].Index + 1); err != nil {
-			return nil, errors.Wrap(err, "could not set next withdrawal index")
-		}
-	}
-	var nextValidatorIndex primitives.ValidatorIndex
-	if uint64(len(expectedWithdrawals)) < params.BeaconConfig().MaxWithdrawalsPerPayload {
-		nextValidatorIndex, err = st.NextWithdrawalValidatorIndex()
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get next withdrawal validator index")
-		}
-		nextValidatorIndex += primitives.ValidatorIndex(params.BeaconConfig().MaxValidatorsPerWithdrawalsSweep)
-		nextValidatorIndex = nextValidatorIndex % primitives.ValidatorIndex(st.NumValidators())
 	} else {
-		nextValidatorIndex = expectedWithdrawals[len(expectedWithdrawals)-1].ValidatorIndex + 1
-		if nextValidatorIndex == primitives.ValidatorIndex(st.NumValidators()) {
-			nextValidatorIndex = 0
+		if err := checkWithdrawalsAgainstPayload(executionData, len(expectedWithdrawals), expectedRoot); err != nil {
+			return nil, err
 		}
 	}
-	if err := st.SetNextWithdrawalValidatorIndex(nextValidatorIndex); err != nil {
-		return nil, errors.Wrap(err, "could not set next withdrawal validator index")
+	if err := processWithdrawalStateTransition(st, expectedWithdrawals, partialWithdrawalsCount); err != nil {
+		return nil, err
 	}
 	return st, nil
 }

beacon-chain/core/blocks/withdrawals_test.go

@@ -22,6 +22,7 @@ import (
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )
 
@@ -1132,13 +1133,407 @@ func TestProcessWithdrawals(t *testing.T) {
 						checkPostState(t, test.Control, post)
 					}
 					params.BeaconConfig().MaxValidatorsPerWithdrawalsSweep = saved
-
 				})
 			}
 		})
 	}
 }
 
+func TestProcessWithdrawalsEPBS(t *testing.T) {
+	const (
+		currentEpoch             = primitives.Epoch(10)
+		epochInFuture            = primitives.Epoch(12)
+		epochInPast              = primitives.Epoch(8)
+		numValidators            = 128
+		notWithdrawableIndex     = 127
+		notPartiallyWithdrawable = 126
+		maxSweep                 = uint64(80)
+	)
+	maxEffectiveBalance := params.BeaconConfig().MaxEffectiveBalance
+
+	type args struct {
+		Name                            string
+		NextWithdrawalValidatorIndex    primitives.ValidatorIndex
+		NextWithdrawalIndex             uint64
+		FullWithdrawalIndices           []primitives.ValidatorIndex
+		PendingPartialWithdrawalIndices []primitives.ValidatorIndex
+		Withdrawals                     []*enginev1.Withdrawal
+		PendingPartialWithdrawals       []*ethpb.PendingPartialWithdrawal // Electra
+		LatestBlockHash                 []byte                            // EIP-7732
+	}
+	type control struct {
+		NextWithdrawalValidatorIndex primitives.ValidatorIndex
+		NextWithdrawalIndex          uint64
+		Balances                     map[uint64]uint64
+	}
+	type Test struct {
+		Args    args
+		Control control
+	}
+	executionAddress := func(i primitives.ValidatorIndex) []byte {
+		wc := make([]byte, 20)
+		wc[19] = byte(i)
+		return wc
+	}
+	withdrawalAmount := func(i primitives.ValidatorIndex) uint64 {
+		return maxEffectiveBalance + uint64(i)*100000
+	}
+	fullWithdrawal := func(i primitives.ValidatorIndex, idx uint64) *enginev1.Withdrawal {
+		return &enginev1.Withdrawal{
+			Index:          idx,
+			ValidatorIndex: i,
+			Address:        executionAddress(i),
+			Amount:         withdrawalAmount(i),
+		}
+	}
+	PendingPartialWithdrawal := func(i primitives.ValidatorIndex, idx uint64) *enginev1.Withdrawal {
+		return &enginev1.Withdrawal{
+			Index:          idx,
+			ValidatorIndex: i,
+			Address:        executionAddress(i),
+			Amount:         withdrawalAmount(i) - maxEffectiveBalance,
+		}
+	}
+	tests := []Test{
+		{
+			Args: args{
+				Name:                         "success no withdrawals",
+				NextWithdrawalValidatorIndex: 10,
+				NextWithdrawalIndex:          3,
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 90,
+				NextWithdrawalIndex:          3,
+			},
+		},
+		{
+			Args: args{
+				Name:                         "success one full withdrawal",
+				NextWithdrawalIndex:          3,
+				NextWithdrawalValidatorIndex: 5,
+				FullWithdrawalIndices:        []primitives.ValidatorIndex{70},
+				Withdrawals: []*enginev1.Withdrawal{
+					fullWithdrawal(70, 3),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 85,
+				NextWithdrawalIndex:          4,
+				Balances:                     map[uint64]uint64{70: 0},
+			},
+		},
+		{
+			Args: args{
+				Name:                            "success one partial withdrawal",
+				NextWithdrawalIndex:             21,
+				NextWithdrawalValidatorIndex:    120,
+				PendingPartialWithdrawalIndices: []primitives.ValidatorIndex{7},
+				Withdrawals: []*enginev1.Withdrawal{
+					PendingPartialWithdrawal(7, 21),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 72,
+				NextWithdrawalIndex:          22,
+				Balances:                     map[uint64]uint64{7: maxEffectiveBalance},
+			},
+		},
+		{
+			Args: args{
+				Name:                         "success many full withdrawals",
+				NextWithdrawalIndex:          22,
+				NextWithdrawalValidatorIndex: 4,
+				FullWithdrawalIndices:        []primitives.ValidatorIndex{7, 19, 28, 1},
+				Withdrawals: []*enginev1.Withdrawal{
+					fullWithdrawal(7, 22), fullWithdrawal(19, 23), fullWithdrawal(28, 24),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 84,
+				NextWithdrawalIndex:          25,
+				Balances:                     map[uint64]uint64{7: 0, 19: 0, 28: 0},
+			},
+		},
+		{
+			Args: args{
+				Name:                         "less than max sweep at end",
+				NextWithdrawalIndex:          22,
+				NextWithdrawalValidatorIndex: 4,
+				FullWithdrawalIndices:        []primitives.ValidatorIndex{80, 81, 82, 83},
+				Withdrawals: []*enginev1.Withdrawal{
+					fullWithdrawal(80, 22), fullWithdrawal(81, 23), fullWithdrawal(82, 24),
+					fullWithdrawal(83, 25),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 84,
+				NextWithdrawalIndex:          26,
+				Balances:                     map[uint64]uint64{80: 0, 81: 0, 82: 0, 83: 0},
+			},
+		},
+		{
+			Args: args{
+				Name:                         "less than max sweep and beginning",
+				NextWithdrawalIndex:          22,
+				NextWithdrawalValidatorIndex: 4,
+				FullWithdrawalIndices:        []primitives.ValidatorIndex{4, 5, 6},
+				Withdrawals: []*enginev1.Withdrawal{
+					fullWithdrawal(4, 22), fullWithdrawal(5, 23), fullWithdrawal(6, 24),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 84,
+				NextWithdrawalIndex:          25,
+				Balances:                     map[uint64]uint64{4: 0, 5: 0, 6: 0},
+			},
+		},
+		{
+			Args: args{
+				Name:                            "success many partial withdrawals",
+				NextWithdrawalIndex:             22,
+				NextWithdrawalValidatorIndex:    4,
+				PendingPartialWithdrawalIndices: []primitives.ValidatorIndex{7, 19, 28},
+				Withdrawals: []*enginev1.Withdrawal{
+					PendingPartialWithdrawal(7, 22), PendingPartialWithdrawal(19, 23), PendingPartialWithdrawal(28, 24),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 84,
+				NextWithdrawalIndex:          25,
+				Balances: map[uint64]uint64{
+					7:  maxEffectiveBalance,
+					19: maxEffectiveBalance,
+					28: maxEffectiveBalance,
+				},
+			},
+		},
+		{
+			Args: args{
+				Name:                            "success many withdrawals",
+				NextWithdrawalIndex:             22,
+				NextWithdrawalValidatorIndex:    88,
+				FullWithdrawalIndices:           []primitives.ValidatorIndex{7, 19, 28},
+				PendingPartialWithdrawalIndices: []primitives.ValidatorIndex{2, 1, 89, 15},
+				Withdrawals: []*enginev1.Withdrawal{
+					PendingPartialWithdrawal(89, 22), PendingPartialWithdrawal(1, 23), PendingPartialWithdrawal(2, 24),
+					fullWithdrawal(7, 25), PendingPartialWithdrawal(15, 26), fullWithdrawal(19, 27),
+					fullWithdrawal(28, 28),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 40,
+				NextWithdrawalIndex:          29,
+				Balances: map[uint64]uint64{
+					7: 0, 19: 0, 28: 0,
+					2: maxEffectiveBalance, 1: maxEffectiveBalance, 89: maxEffectiveBalance,
+					15: maxEffectiveBalance,
+				},
+			},
+		},
+		{
+			Args: args{
+				Name:                            "success many withdrawals with pending partial withdrawals in state",
+				NextWithdrawalIndex:             22,
+				NextWithdrawalValidatorIndex:    88,
+				FullWithdrawalIndices:           []primitives.ValidatorIndex{7, 19, 28},
+				PendingPartialWithdrawalIndices: []primitives.ValidatorIndex{2, 1, 89, 15},
+				Withdrawals: []*enginev1.Withdrawal{
+					PendingPartialWithdrawal(89, 22), PendingPartialWithdrawal(1, 23), PendingPartialWithdrawal(2, 24),
+					fullWithdrawal(7, 25), PendingPartialWithdrawal(15, 26), fullWithdrawal(19, 27),
+					fullWithdrawal(28, 28),
+				},
+				PendingPartialWithdrawals: []*ethpb.PendingPartialWithdrawal{
+					{
+						Index:  11,
+						Amount: withdrawalAmount(11) - maxEffectiveBalance,
+					},
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 40,
+				NextWithdrawalIndex:          29,
+				Balances: map[uint64]uint64{
+					7: 0, 19: 0, 28: 0,
+					2: maxEffectiveBalance, 1: maxEffectiveBalance, 89: maxEffectiveBalance,
+					15: maxEffectiveBalance,
+				},
+			},
+		},
+
+		{
+			Args: args{
+				Name:                         "success more than max fully withdrawals",
+				NextWithdrawalIndex:          22,
+				NextWithdrawalValidatorIndex: 0,
+				FullWithdrawalIndices:        []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6, 7, 8, 9, 21, 22, 23, 24, 25, 26, 27, 29, 35, 89},
+				Withdrawals: []*enginev1.Withdrawal{
+					fullWithdrawal(1, 22), fullWithdrawal(2, 23), fullWithdrawal(3, 24),
+					fullWithdrawal(4, 25), fullWithdrawal(5, 26), fullWithdrawal(6, 27),
+					fullWithdrawal(7, 28), fullWithdrawal(8, 29), fullWithdrawal(9, 30),
+					fullWithdrawal(21, 31), fullWithdrawal(22, 32), fullWithdrawal(23, 33),
+					fullWithdrawal(24, 34), fullWithdrawal(25, 35), fullWithdrawal(26, 36),
+					fullWithdrawal(27, 37),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 28,
+				NextWithdrawalIndex:          38,
+				Balances: map[uint64]uint64{
+					1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0, 9: 0,
+					21: 0, 22: 0, 23: 0, 24: 0, 25: 0, 26: 0, 27: 0,
+				},
+			},
+		},
+		{
+			Args: args{
+				Name:                            "success more than max partially withdrawals",
+				NextWithdrawalIndex:             22,
+				NextWithdrawalValidatorIndex:    0,
+				PendingPartialWithdrawalIndices: []primitives.ValidatorIndex{1, 2, 3, 4, 5, 6, 7, 8, 9, 21, 22, 23, 24, 25, 26, 27, 29, 35, 89},
+				Withdrawals: []*enginev1.Withdrawal{
+					PendingPartialWithdrawal(1, 22), PendingPartialWithdrawal(2, 23), PendingPartialWithdrawal(3, 24),
+					PendingPartialWithdrawal(4, 25), PendingPartialWithdrawal(5, 26), PendingPartialWithdrawal(6, 27),
+					PendingPartialWithdrawal(7, 28), PendingPartialWithdrawal(8, 29), PendingPartialWithdrawal(9, 30),
+					PendingPartialWithdrawal(21, 31), PendingPartialWithdrawal(22, 32), PendingPartialWithdrawal(23, 33),
+					PendingPartialWithdrawal(24, 34), PendingPartialWithdrawal(25, 35), PendingPartialWithdrawal(26, 36),
+					PendingPartialWithdrawal(27, 37),
+				},
+			},
+			Control: control{
+				NextWithdrawalValidatorIndex: 28,
+				NextWithdrawalIndex:          38,
+				Balances: map[uint64]uint64{
+					1:  maxEffectiveBalance,
+					2:  maxEffectiveBalance,
+					3:  maxEffectiveBalance,
+					4:  maxEffectiveBalance,
+					5:  maxEffectiveBalance,
+					6:  maxEffectiveBalance,
+					7:  maxEffectiveBalance,
+					8:  maxEffectiveBalance,
+					9:  maxEffectiveBalance,
+					21: maxEffectiveBalance,
+					22: maxEffectiveBalance,
+					23: maxEffectiveBalance,
+					24: maxEffectiveBalance,
+					25: maxEffectiveBalance,
+					26: maxEffectiveBalance,
+					27: maxEffectiveBalance,
+				},
+			},
+		},
+		{
+			Args: args{
+				Name:                         "Parent Node is not full",
+				NextWithdrawalIndex:          22,
+				NextWithdrawalValidatorIndex: 4,
+				FullWithdrawalIndices:        []primitives.ValidatorIndex{7, 19, 28, 1},
+				Withdrawals: []*enginev1.Withdrawal{
+					fullWithdrawal(7, 22), fullWithdrawal(19, 23), fullWithdrawal(28, 24),
+				},
+				LatestBlockHash: []byte{1, 2, 3},
+			},
+		},
+	}
+
+	checkPostState := func(t *testing.T, expected control, st state.BeaconState) {
+		l, err := st.NextWithdrawalValidatorIndex()
+		require.NoError(t, err)
+		require.Equal(t, expected.NextWithdrawalValidatorIndex, l)
+
+		n, err := st.NextWithdrawalIndex()
+		require.NoError(t, err)
+		require.Equal(t, expected.NextWithdrawalIndex, n)
+		balances := st.Balances()
+		for idx, bal := range expected.Balances {
+			require.Equal(t, bal, balances[idx])
+		}
+	}
+
+	prepareValidators := func(st state.BeaconState, arguments args) error {
+		validators := make([]*ethpb.Validator, numValidators)
+		if err := st.SetBalances(make([]uint64, numValidators)); err != nil {
+			return err
+		}
+		for i := range validators {
+			v := &ethpb.Validator{}
+			v.EffectiveBalance = maxEffectiveBalance
+			v.WithdrawableEpoch = epochInFuture
+			v.WithdrawalCredentials = make([]byte, 32)
+			v.WithdrawalCredentials[31] = byte(i)
+			if err := st.UpdateBalancesAtIndex(primitives.ValidatorIndex(i), v.EffectiveBalance-uint64(rand.Intn(1000))); err != nil {
+				return err
+			}
+			validators[i] = v
+		}
+		for _, idx := range arguments.FullWithdrawalIndices {
+			if idx != notWithdrawableIndex {
+				validators[idx].WithdrawableEpoch = epochInPast
+			}
+			if err := st.UpdateBalancesAtIndex(idx, withdrawalAmount(idx)); err != nil {
+				return err
+			}
+			validators[idx].WithdrawalCredentials[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+		}
+		for _, idx := range arguments.PendingPartialWithdrawalIndices {
+			validators[idx].WithdrawalCredentials[0] = params.BeaconConfig().ETH1AddressWithdrawalPrefixByte
+			if err := st.UpdateBalancesAtIndex(idx, withdrawalAmount(idx)); err != nil {
+				return err
+			}
+		}
+		return st.SetValidators(validators)
+	}
+
+	for _, test := range tests {
+		t.Run(test.Args.Name, func(t *testing.T) {
+			saved := params.BeaconConfig().MaxValidatorsPerWithdrawalsSweep
+			params.BeaconConfig().MaxValidatorsPerWithdrawalsSweep = maxSweep
+			if test.Args.Withdrawals == nil {
+				test.Args.Withdrawals = make([]*enginev1.Withdrawal, 0)
+			}
+			if test.Args.FullWithdrawalIndices == nil {
+				test.Args.FullWithdrawalIndices = make([]primitives.ValidatorIndex, 0)
+			}
+			if test.Args.PendingPartialWithdrawalIndices == nil {
+				test.Args.PendingPartialWithdrawalIndices = make([]primitives.ValidatorIndex, 0)
+			}
+			slot, err := slots.EpochStart(currentEpoch)
+			require.NoError(t, err)
+			var st state.BeaconState
+			var p interfaces.ExecutionData
+			spb := &ethpb.BeaconStateEPBS{
+				Slot:                         slot,
+				NextWithdrawalValidatorIndex: test.Args.NextWithdrawalValidatorIndex,
+				NextWithdrawalIndex:          test.Args.NextWithdrawalIndex,
+				PendingPartialWithdrawals:    test.Args.PendingPartialWithdrawals,
+				LatestExecutionPayloadHeader: &enginev1.ExecutionPayloadHeaderEPBS{
+					BlockHash: []byte{},
+				},
+				LatestBlockHash: test.Args.LatestBlockHash,
+			}
+			st, err = state_native.InitializeFromProtoUnsafeEpbs(spb)
+			require.NoError(t, err)
+			env := random.ExecutionPayloadEnvelope(t)
+			env.Payload.Withdrawals = test.Args.Withdrawals
+			wp, err := consensusblocks.WrappedROExecutionPayloadEnvelope(env)
+			require.NoError(t, err)
+			p, err = wp.Execution()
+			require.NoError(t, err)
+			err = prepareValidators(st, test.Args)
+			require.NoError(t, err)
+			post, err := blocks.ProcessWithdrawals(st, p)
+			if test.Args.Name == "Parent Node is not full" {
+				require.IsNil(t, post)
+				require.IsNil(t, err)
+			} else {
+				require.NoError(t, err)
+				checkPostState(t, test.Control, post)
+			}
+			params.BeaconConfig().MaxValidatorsPerWithdrawalsSweep = saved
+		})
+	}
+}
+
 func TestProcessBLSToExecutionChanges(t *testing.T) {
 	spb := &ethpb.BeaconStateCapella{
 		Fork: &ethpb.Fork{

beacon-chain/core/epbs/BUILD.bazel

@@ -0,0 +1,38 @@
+load("@prysm//tools/go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "attestation.go",
+        "execution_payload_envelope.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epbs",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/core/electra:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
+        "//proto/engine/v1:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = [
+        "attestation_test.go",
+        "execution_payload_envelope_test.go",
+    ],
+    embed = [":go_default_library"],
+    deps = [
+        "//beacon-chain/core/altair:go_default_library",
+        "//beacon-chain/state/state-native:go_default_library",
+        "//config/params:go_default_library",
+        "//consensus-types/blocks: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",
+        "//testing/util/random:go_default_library",
+    ],
+)

beacon-chain/core/epbs/attestation.go

@@ -0,0 +1,13 @@
+package epbs
+
+import (
+	"fmt"
+)
+
+// RemoveValidatorFlag removes validator flag from existing one.
+func RemoveValidatorFlag(flag, flagPosition uint8) (uint8, error) {
+	if flagPosition > 7 {
+		return flag, fmt.Errorf("flag position %d exceeds length", flagPosition)
+	}
+	return flag & ^(1 << flagPosition), nil
+}

beacon-chain/core/epbs/attestation_test.go

@@ -0,0 +1,93 @@
+package epbs_test
+
+import (
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/altair"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/epbs"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestValidatorFlag_Remove(t *testing.T) {
+	tests := []struct {
+		name          string
+		add           []uint8
+		remove        []uint8
+		expectedTrue  []uint8
+		expectedFalse []uint8
+	}{
+		{
+			name:          "none",
+			add:           []uint8{},
+			remove:        []uint8{},
+			expectedTrue:  []uint8{},
+			expectedFalse: []uint8{params.BeaconConfig().TimelySourceFlagIndex, params.BeaconConfig().TimelyTargetFlagIndex, params.BeaconConfig().TimelyHeadFlagIndex},
+		},
+		{
+			name:          "source",
+			add:           []uint8{params.BeaconConfig().TimelySourceFlagIndex},
+			remove:        []uint8{params.BeaconConfig().TimelySourceFlagIndex},
+			expectedTrue:  []uint8{},
+			expectedFalse: []uint8{params.BeaconConfig().TimelySourceFlagIndex, params.BeaconConfig().TimelyTargetFlagIndex, params.BeaconConfig().TimelyHeadFlagIndex},
+		},
+		{
+			name:          "source, target",
+			add:           []uint8{params.BeaconConfig().TimelySourceFlagIndex, params.BeaconConfig().TimelyTargetFlagIndex},
+			remove:        []uint8{params.BeaconConfig().TimelySourceFlagIndex},
+			expectedTrue:  []uint8{params.BeaconConfig().TimelyTargetFlagIndex},
+			expectedFalse: []uint8{params.BeaconConfig().TimelySourceFlagIndex, params.BeaconConfig().TimelyHeadFlagIndex},
+		},
+		{
+			name:          "source, target, head",
+			add:           []uint8{params.BeaconConfig().TimelySourceFlagIndex, params.BeaconConfig().TimelyTargetFlagIndex, params.BeaconConfig().TimelyHeadFlagIndex},
+			remove:        []uint8{params.BeaconConfig().TimelyTargetFlagIndex, params.BeaconConfig().TimelyHeadFlagIndex},
+			expectedTrue:  []uint8{params.BeaconConfig().TimelySourceFlagIndex},
+			expectedFalse: []uint8{params.BeaconConfig().TimelyTargetFlagIndex, params.BeaconConfig().TimelyHeadFlagIndex},
+		},
+	}
+	var err error
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			flag := uint8(0)
+
+			// Add flags.
+			for _, flagPosition := range test.add {
+				flag, err = altair.AddValidatorFlag(flag, flagPosition)
+				require.NoError(t, err)
+
+				has, err := altair.HasValidatorFlag(flag, flagPosition)
+				require.NoError(t, err)
+				require.Equal(t, true, has)
+			}
+
+			// Remove flags.
+			for _, flagPosition := range test.remove {
+				flag, err = epbs.RemoveValidatorFlag(flag, flagPosition)
+				require.NoError(t, err)
+			}
+
+			// Check if flags are set correctly.
+			for _, flagPosition := range test.expectedTrue {
+				has, err := altair.HasValidatorFlag(flag, flagPosition)
+				require.NoError(t, err)
+				require.Equal(t, true, has)
+			}
+			for _, flagPosition := range test.expectedFalse {
+				has, err := altair.HasValidatorFlag(flag, flagPosition)
+				require.NoError(t, err)
+				require.Equal(t, false, has)
+			}
+		})
+	}
+}
+
+func TestValidatorFlag_Remove_ExceedsLength(t *testing.T) {
+	_, err := epbs.RemoveValidatorFlag(0, 8)
+	require.ErrorContains(t, "flag position 8 exceeds length", err)
+}
+
+func TestValidatorFlag_Remove_NotSet(t *testing.T) {
+	_, err := epbs.RemoveValidatorFlag(0, 1)
+	require.NoError(t, err)
+}

beacon-chain/core/epbs/execution_payload_envelope.go

@@ -0,0 +1,126 @@
+package epbs
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/electra"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+)
+
+// ValidatePayloadStateTransition performs the process_execution_payload
+// function.
+func ValidatePayloadStateTransition(
+	ctx context.Context,
+	preState state.BeaconState,
+	envelope interfaces.ROExecutionPayloadEnvelope,
+) error {
+	if err := validateAgainstHeader(ctx, preState, envelope); err != nil {
+		return err
+	}
+	committedHeader, err := preState.LatestExecutionPayloadHeaderEPBS()
+	if err != nil {
+		return err
+	}
+	if err := validateAgainstCommittedBid(committedHeader, envelope); err != nil {
+		return err
+	}
+	if err := ProcessPayloadStateTransition(ctx, preState, envelope); err != nil {
+		return err
+	}
+	return checkPostStateRoot(ctx, preState, envelope)
+}
+
+func ProcessPayloadStateTransition(
+	ctx context.Context,
+	preState state.BeaconState,
+	envelope interfaces.ROExecutionPayloadEnvelope,
+) error {
+	er := envelope.ExecutionRequests()
+	preState, err := electra.ProcessDepositRequests(ctx, preState, er.Deposits)
+	if err != nil {
+		return errors.Wrap(err, "could not process deposit receipts")
+	}
+	preState, err = electra.ProcessWithdrawalRequests(ctx, preState, er.Withdrawals)
+	if err != nil {
+		return errors.Wrap(err, "could not process ercution layer withdrawal requests")
+	}
+	if err := electra.ProcessConsolidationRequests(ctx, preState, er.Consolidations); err != nil {
+		return errors.Wrap(err, "could not process consolidation requests")
+	}
+	payload, err := envelope.Execution()
+	if err != nil {
+		return errors.Wrap(err, "could not get execution payload")
+	}
+	if err := preState.SetLatestBlockHash(payload.BlockHash()); err != nil {
+		return err
+	}
+	return preState.SetLatestFullSlot(preState.Slot())
+}
+
+func validateAgainstHeader(
+	ctx context.Context,
+	preState state.BeaconState,
+	envelope interfaces.ROExecutionPayloadEnvelope,
+) error {
+	blockHeader := preState.LatestBlockHeader()
+	if blockHeader == nil {
+		return errors.New("invalid nil latest block header")
+	}
+	if len(blockHeader.StateRoot) == 0 || [32]byte(blockHeader.StateRoot) == [32]byte{} {
+		prevStateRoot, err := preState.HashTreeRoot(ctx)
+		if err != nil {
+			return errors.Wrap(err, "could not compute previous state root")
+		}
+		blockHeader.StateRoot = prevStateRoot[:]
+		if err := preState.SetLatestBlockHeader(blockHeader); err != nil {
+			return errors.Wrap(err, "could not set latest block header")
+		}
+	}
+	blockHeaderRoot, err := blockHeader.HashTreeRoot()
+	if err != nil {
+		return err
+	}
+	beaconBlockRoot := envelope.BeaconBlockRoot()
+	if blockHeaderRoot != beaconBlockRoot {
+		return fmt.Errorf("beacon block root does not match previous header, got: %#x wanted: %#x", beaconBlockRoot, blockHeaderRoot)
+	}
+	return nil
+}
+
+func validateAgainstCommittedBid(
+	committedHeader *enginev1.ExecutionPayloadHeaderEPBS,
+	envelope interfaces.ROExecutionPayloadEnvelope,
+) error {
+	builderIndex := envelope.BuilderIndex()
+	if committedHeader.BuilderIndex != builderIndex {
+		return errors.New("builder index does not match committed header")
+	}
+	kzgRoot, err := envelope.BlobKzgCommitmentsRoot()
+	if err != nil {
+		return err
+	}
+	if [32]byte(committedHeader.BlobKzgCommitmentsRoot) != kzgRoot {
+		return errors.New("blob KZG commitments root does not match committed header")
+	}
+	return nil
+}
+
+func checkPostStateRoot(
+	ctx context.Context,
+	preState state.BeaconState,
+	envelope interfaces.ROExecutionPayloadEnvelope,
+) error {
+	stateRoot, err := preState.HashTreeRoot(ctx)
+	if err != nil {
+		return err
+	}
+	envelopeStateRoot := envelope.StateRoot()
+	if stateRoot != envelopeStateRoot {
+		return errors.New("state root mismatch")
+	}
+	return nil
+}

beacon-chain/core/epbs/execution_payload_envelope_test.go

@@ -0,0 +1,108 @@
+package epbs
+
+import (
+	"context"
+	"testing"
+
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	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"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func TestProcessPayloadStateTransition(t *testing.T) {
+	bh := [32]byte{'h'}
+	p := random.ExecutionPayloadEnvelope(t)
+	p.Payload.BlockHash = bh[:]
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	validators := make([]*ethpb.Validator, 0)
+	stpb := &ethpb.BeaconStateEPBS{Slot: 3, Validators: validators}
+	st, err := state_native.InitializeFromProtoUnsafeEpbs(stpb)
+	require.NoError(t, err)
+	ctx := context.Background()
+
+	lbh, err := st.LatestBlockHash()
+	require.NoError(t, err)
+	require.Equal(t, [32]byte{}, [32]byte(lbh))
+
+	require.NoError(t, ProcessPayloadStateTransition(ctx, st, e))
+
+	lbh, err = st.LatestBlockHash()
+	require.NoError(t, err)
+	require.Equal(t, bh, [32]byte(lbh))
+
+	lfs, err := st.LatestFullSlot()
+	require.NoError(t, err)
+	require.Equal(t, lfs, st.Slot())
+}
+
+func Test_validateAgainstHeader(t *testing.T) {
+	bh := [32]byte{'h'}
+	payload := &enginev1.ExecutionPayloadElectra{BlockHash: bh[:]}
+	p := random.ExecutionPayloadEnvelope(t)
+	p.Payload = payload
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	stpb := &ethpb.BeaconStateEPBS{Slot: 3}
+	st, err := state_native.InitializeFromProtoUnsafeEpbs(stpb)
+	require.NoError(t, err)
+	ctx := context.Background()
+	require.ErrorContains(t, "invalid nil latest block header", validateAgainstHeader(ctx, st, e))
+
+	prest, _ := util.DeterministicGenesisStateEpbs(t, 64)
+	br := [32]byte{'r'}
+	p.BeaconBlockRoot = br[:]
+	require.ErrorContains(t, "beacon block root does not match previous header", validateAgainstHeader(ctx, prest, e))
+
+	header := prest.LatestBlockHeader()
+	require.NoError(t, err)
+	headerRoot, err := header.HashTreeRoot()
+	require.NoError(t, err)
+	p.BeaconBlockRoot = headerRoot[:]
+	require.NoError(t, validateAgainstHeader(ctx, prest, e))
+}
+
+func Test_validateAgainstCommittedBid(t *testing.T) {
+	payload := &enginev1.ExecutionPayloadElectra{}
+	p := random.ExecutionPayloadEnvelope(t)
+	p.Payload = payload
+	p.BuilderIndex = 1
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	h := &enginev1.ExecutionPayloadHeaderEPBS{}
+	require.ErrorContains(t, "builder index does not match committed header", validateAgainstCommittedBid(h, e))
+
+	h.BuilderIndex = 1
+	p.BlobKzgCommitments = make([][]byte, 6)
+	for i := range p.BlobKzgCommitments {
+		p.BlobKzgCommitments[i] = make([]byte, 48)
+	}
+	h.BlobKzgCommitmentsRoot = make([]byte, 32)
+	require.ErrorContains(t, "blob KZG commitments root does not match committed header", validateAgainstCommittedBid(h, e))
+
+	root, err := e.BlobKzgCommitmentsRoot()
+	require.NoError(t, err)
+	h.BlobKzgCommitmentsRoot = root[:]
+	require.NoError(t, validateAgainstCommittedBid(h, e))
+}
+
+func TestCheckPostStateRoot(t *testing.T) {
+	payload := &enginev1.ExecutionPayloadElectra{}
+	p := random.ExecutionPayloadEnvelope(t)
+	p.Payload = payload
+	p.BuilderIndex = 1
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	ctx := context.Background()
+	st, _ := util.DeterministicGenesisStateEpbs(t, 64)
+	p.StateRoot = make([]byte, 32)
+	require.ErrorContains(t, "state root mismatch", checkPostStateRoot(ctx, st, e))
+	root, err := st.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	p.StateRoot = root[:]
+	require.NoError(t, checkPostStateRoot(ctx, st, e))
+}

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

@@ -4,5 +4,5 @@ import "github.com/prysmaticlabs/prysm/v5/async/event"
 
 // Notifier interface defines the methods of the service that provides beacon block operation updates to consumers.
 type Notifier interface {
-	OperationFeed() event.SubscriberSender
+	OperationFeed() *event.Feed
 }

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

@@ -4,5 +4,5 @@ import "github.com/prysmaticlabs/prysm/v5/async/event"
 
 // Notifier interface defines the methods of the service that provides state updates to consumers.
 type Notifier interface {
-	StateFeed() event.SubscriberSender
+	StateFeed() *event.Feed
 }

beacon-chain/core/helpers/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "block.go",
         "genesis.go",
         "metrics.go",
+        "payload_attestation.go",
         "randao.go",
         "rewards_penalties.go",
         "shuffle.go",
@@ -20,11 +21,13 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//beacon-chain/cache:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/epbs:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//container/slice:go_default_library",
@@ -53,6 +56,8 @@ go_test(
         "attestation_test.go",
         "beacon_committee_test.go",
         "block_test.go",
+        "exports_test.go",
+        "payload_attestation_test.go",
         "private_access_fuzz_noop_test.go",  # keep
         "private_access_test.go",
         "randao_test.go",
@@ -63,26 +68,33 @@ go_test(
         "validators_test.go",
         "weak_subjectivity_test.go",
     ],
+    data = glob(["testdata/**"]),
     embed = [":go_default_library"],
     shard_count = 2,
     tags = ["CI_race_detection"],
     deps = [
         "//beacon-chain/cache:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/epbs: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",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//testing/util/random:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",

beacon-chain/core/helpers/beacon_committee.go

@@ -213,6 +213,7 @@ type CommitteeAssignment struct {
 	Committee      []primitives.ValidatorIndex
 	AttesterSlot   primitives.Slot
 	CommitteeIndex primitives.CommitteeIndex
+	PtcSlot        primitives.Slot
 }
 
 // verifyAssignmentEpoch verifies if the given epoch is valid for assignment based on the provided state.
@@ -294,7 +295,7 @@ func CommitteeAssignments(ctx context.Context, state state.BeaconState, epoch pr
 	if err := verifyAssignmentEpoch(epoch, state); err != nil {
 		return nil, err
 	}
-	startSlot, err := slots.EpochStart(epoch)
+	slot, err := slots.EpochStart(epoch)
 	if err != nil {
 		return nil, err
 	}
@@ -303,14 +304,17 @@ func CommitteeAssignments(ctx context.Context, state state.BeaconState, epoch pr
 		vals[v] = struct{}{}
 	}
 	assignments := make(map[primitives.ValidatorIndex]*CommitteeAssignment)
+
+	committees, err := BeaconCommittees(ctx, state, slot)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not compute beacon committees")
+	}
+	ptcPerSlot, ptcMembersPerCommittee := PtcAllocation(len(committees))
 	// Compute committee assignments for each slot in the epoch.
-	for slot := startSlot; slot < startSlot+params.BeaconConfig().SlotsPerEpoch; slot++ {
-		committees, err := BeaconCommittees(ctx, state, slot)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not compute beacon committees")
-		}
+	endSlot := slot + params.BeaconConfig().SlotsPerEpoch
+	for {
 		for j, committee := range committees {
-			for _, vIndex := range committee {
+			for i, vIndex := range committee {
 				if _, ok := vals[vIndex]; !ok { // Skip if the validator is not in the provided validators slice.
 					continue
 				}
@@ -320,8 +324,19 @@ func CommitteeAssignments(ctx context.Context, state state.BeaconState, epoch pr
 				assignments[vIndex].Committee = committee
 				assignments[vIndex].AttesterSlot = slot
 				assignments[vIndex].CommitteeIndex = primitives.CommitteeIndex(j)
+				if uint64(j) < ptcPerSlot && uint64(i) < ptcMembersPerCommittee {
+					assignments[vIndex].PtcSlot = slot
+				}
 			}
 		}
+		slot++
+		if slot == endSlot {
+			break
+		}
+		committees, err = BeaconCommittees(ctx, state, slot)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not compute beacon committees")
+		}
 	}
 	return assignments, nil
 }

beacon-chain/core/helpers/beacon_committee_test.go

@@ -3,6 +3,7 @@ package helpers_test
 import (
 	"context"
 	"fmt"
+	"slices"
 	"strconv"
 	"testing"
 
@@ -10,6 +11,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/container/slice"
@@ -722,15 +724,26 @@ func TestCommitteeIndices(t *testing.T) {
 	assert.DeepEqual(t, []primitives.CommitteeIndex{0, 1, 3}, indices)
 }
 
-func TestAttestationCommittees(t *testing.T) {
-	validators := make([]*ethpb.Validator, params.BeaconConfig().SlotsPerEpoch.Mul(params.BeaconConfig().TargetCommitteeSize))
+func TestCommitteeAssignments_PTC(t *testing.T) {
+	helpers.ClearCache()
+	// Create 10 committees. Total 40960 validators.
+	committeeCount := uint64(10)
+	validatorCount := committeeCount * params.BeaconConfig().TargetCommitteeSize * uint64(params.BeaconConfig().SlotsPerEpoch)
+	validators := make([]*ethpb.Validator, validatorCount)
+	validatorIndices := make([]primitives.ValidatorIndex, validatorCount)
+
 	for i := 0; i < len(validators); i++ {
+		k := make([]byte, 48)
+		copy(k, strconv.Itoa(i))
 		validators[i] = &ethpb.Validator{
-			ExitEpoch: params.BeaconConfig().FarFutureEpoch,
+			PublicKey:             k,
+			WithdrawalCredentials: make([]byte, 32),
+			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
 		}
+		validatorIndices[i] = primitives.ValidatorIndex(i)
 	}
 
-	state, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
+	state, err := state_native.InitializeFromProtoEpbs(&ethpb.BeaconStateEPBS{
 		Validators:  validators,
 		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
 	})
@@ -754,6 +767,31 @@ func TestAttestationCommittees(t *testing.T) {
 		assert.Equal(t, params.BeaconConfig().TargetCommitteeSize, uint64(len(committees[0])))
 		assert.Equal(t, params.BeaconConfig().TargetCommitteeSize, uint64(len(committees[1])))
 	})
+	as, err := helpers.CommitteeAssignments(context.Background(), state, 1, validatorIndices)
+	require.NoError(t, err)
+
+	// Capture all the slots and all the validator index that belonged in a PTC using a map for verification later.
+	slotValidatorMap := make(map[primitives.Slot][]primitives.ValidatorIndex)
+	for i, a := range as {
+		slotValidatorMap[a.PtcSlot] = append(slotValidatorMap[a.PtcSlot], i)
+	}
+
+	// Verify that all the slots have the correct number of PTC.
+	for s, v := range slotValidatorMap {
+		if s == 0 {
+			continue
+		}
+		// Make sure all the PTC are the correct size from the map.
+		require.Equal(t, len(v), field_params.PTCSize)
+
+		// Get the actual PTC from the beacon state using the helper function
+		ptc, err := helpers.GetPayloadTimelinessCommittee(context.Background(), state, s)
+		require.NoError(t, err)
+		for _, index := range ptc {
+			i := slices.Index(v, index)
+			require.NotEqual(t, -1, i) // PTC not found from the assignment map
+		}
+	}
 }
 
 func TestBeaconCommittees(t *testing.T) {

beacon-chain/core/helpers/exports_test.go

@@ -0,0 +1,12 @@
+package helpers
+
+var (
+	ErrNilMessage            = errNilMessage
+	ErrNilData               = errNilData
+	ErrNilBeaconBlockRoot    = errNilBeaconBlockRoot
+	ErrNilPayloadAttestation = errNilPayloadAttestation
+	ErrNilSignature          = errNilSignature
+	ErrNilAggregationBits    = errNilAggregationBits
+	ErrPreEPBSState          = errPreEPBSState
+	ErrCommitteeOverflow     = errCommitteeOverflow
+)

beacon-chain/core/helpers/payload_attestation.go

@@ -0,0 +1,296 @@
+package helpers
+
+import (
+	"context"
+	"slices"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
+	"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/epbs"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/math"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+)
+
+var (
+	errNilMessage            = errors.New("nil PayloadAttestationMessage")
+	errNilData               = errors.New("nil PayloadAttestationData")
+	errNilBeaconBlockRoot    = errors.New("nil BeaconBlockRoot")
+	errNilPayloadAttestation = errors.New("nil PayloadAttestation")
+	errNilSignature          = errors.New("nil Signature")
+	errNilAggregationBits    = errors.New("nil AggregationBits")
+	errPreEPBSState          = errors.New("beacon state pre ePBS fork")
+	errCommitteeOverflow     = errors.New("beacon committee of insufficient size")
+)
+
+// ValidateNilPayloadAttestationData checks if any composite field of the
+// payload attestation data is nil
+func ValidateNilPayloadAttestationData(data *eth.PayloadAttestationData) error {
+	if data == nil {
+		return errNilData
+	}
+	if data.BeaconBlockRoot == nil {
+		return errNilBeaconBlockRoot
+	}
+	return nil
+}
+
+// ValidateNilPayloadAttestationMessage checks if any composite field of the
+// payload attestation message is nil
+func ValidateNilPayloadAttestationMessage(att *eth.PayloadAttestationMessage) error {
+	if att == nil {
+		return errNilMessage
+	}
+	if att.Signature == nil {
+		return errNilSignature
+	}
+	return ValidateNilPayloadAttestationData(att.Data)
+}
+
+// ValidateNilPayloadAttestation checks if any composite field of the
+// payload attestation is nil
+func ValidateNilPayloadAttestation(att *eth.PayloadAttestation) error {
+	if att == nil {
+		return errNilPayloadAttestation
+	}
+	if att.AggregationBits == nil {
+		return errNilAggregationBits
+	}
+	if att.Signature == nil {
+		return errNilSignature
+	}
+	return ValidateNilPayloadAttestationData(att.Data)
+}
+
+// InPayloadTimelinessCommittee returns whether the given index belongs to the
+// PTC computed from the passed state.
+func InPayloadTimelinessCommittee(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot, idx primitives.ValidatorIndex) (bool, error) {
+	ptc, err := GetPayloadTimelinessCommittee(ctx, state, slot)
+	if err != nil {
+		return false, err
+	}
+	for _, i := range ptc {
+		if i == idx {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// GetPayloadTimelinessCommittee returns the PTC for the given slot, computed from the passed state as in the
+// spec function `get_ptc`.
+func GetPayloadTimelinessCommittee(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot) (indices []primitives.ValidatorIndex, err error) {
+	if state.Version() < version.EPBS {
+		return nil, errPreEPBSState
+	}
+	committees, err := BeaconCommittees(ctx, state, slot)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get beacon committees")
+	}
+	committeesPerSlot, membersPerCommittee := PtcAllocation(len(committees))
+	for i, committee := range committees {
+		if uint64(i) >= committeesPerSlot {
+			return
+		}
+		if uint64(len(committee)) < membersPerCommittee {
+			return nil, errCommitteeOverflow
+		}
+		indices = append(indices, committee[:membersPerCommittee]...)
+	}
+	return
+}
+
+// PtcAllocation returns:
+// 1. The number of beacon committees that PTC will borrow from in a slot.
+// 2. The number of validators that PTC will borrow from in a beacon committee.
+func PtcAllocation(slotCommittees int) (committeesPerSlot, membersPerCommittee uint64) {
+	committeesPerSlot = math.LargestPowerOfTwo(math.Min(uint64(slotCommittees), fieldparams.PTCSize))
+	membersPerCommittee = fieldparams.PTCSize / committeesPerSlot
+	return
+}
+
+// GetPayloadAttestingIndices returns the set of attester indices corresponding to the given PayloadAttestation.
+//
+// Spec pseudocode definition:
+//
+//	def get_payload_attesting_indices(state: BeaconState, slot: Slot,
+//		payload_attestation: PayloadAttestation) -> Set[ValidatorIndex]:
+//	"""
+//	Return the set of attesting indices corresponding to ``payload_attestation``.
+//	"""
+//	ptc = get_ptc(state, slot)
+//	return set(index for i, index in enumerate(ptc) if payload_attestation.aggregation_bits[i])
+func GetPayloadAttestingIndices(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot, att *eth.PayloadAttestation) (indices []primitives.ValidatorIndex, err error) {
+	if state.Version() < version.EPBS {
+		return nil, errPreEPBSState
+	}
+
+	ptc, err := GetPayloadTimelinessCommittee(ctx, state, slot)
+	if err != nil {
+		return nil, err
+	}
+
+	for i, validatorIndex := range ptc {
+		if att.AggregationBits.BitAt(uint64(i)) {
+			indices = append(indices, validatorIndex)
+		}
+	}
+
+	return
+}
+
+// GetIndexedPayloadAttestation replaces a PayloadAttestation's AggregationBits with sorted AttestingIndices and returns an IndexedPayloadAttestation.
+//
+// Spec pseudocode definition:
+//
+//	def get_indexed_payload_attestation(state: BeaconState, slot: Slot,
+//		payload_attestation: PayloadAttestation) -> IndexedPayloadAttestation:
+//	"""
+//	Return the indexed payload attestation corresponding to ``payload_attestation``.
+//	"""
+//	attesting_indices = get_payload_attesting_indices(state, slot, payload_attestation)
+//
+//	return IndexedPayloadAttestation(
+//	attesting_indices=sorted(attesting_indices),
+//	data=payload_attestation.data,
+//	signature=payload_attestation.signature,
+//	)
+func GetIndexedPayloadAttestation(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot, att *eth.PayloadAttestation) (*epbs.IndexedPayloadAttestation, error) {
+	if state.Version() < version.EPBS {
+		return nil, errPreEPBSState
+	}
+
+	attestingIndices, err := GetPayloadAttestingIndices(ctx, state, slot, att)
+	if err != nil {
+		return nil, err
+	}
+
+	slices.Sort(attestingIndices)
+
+	return &epbs.IndexedPayloadAttestation{
+		AttestingIndices: attestingIndices,
+		Data:             att.Data,
+		Signature:        att.Signature,
+	}, nil
+}
+
+// IsValidIndexedPayloadAttestation validates the given IndexedPayloadAttestation.
+//
+// Spec pseudocode definition:
+//
+//	def is_valid_indexed_payload_attestation(
+//		state: BeaconState,
+//		indexed_payload_attestation: IndexedPayloadAttestation) -> bool:
+//	"""
+//	Check if ``indexed_payload_attestation`` is not empty, has sorted and unique indices and has
+//	a valid aggregate signature.
+//	"""
+//	# Verify the data is valid
+//	if indexed_payload_attestation.data.payload_status >= PAYLOAD_INVALID_STATUS:
+//		return False
+//
+//	# Verify indices are sorted and unique
+//	indices = indexed_payload_attestation.attesting_indices
+//	if len(indices) == 0 or not indices == sorted(set(indices)):
+//		return False
+//
+//	# Verify aggregate signature
+//	pubkeys = [state.validators[i].pubkey for i in indices]
+//	domain = get_domain(state, DOMAIN_PTC_ATTESTER, None)
+//	signing_root = compute_signing_root(indexed_payload_attestation.data, domain)
+//	return bls.FastAggregateVerify(pubkeys, signing_root, indexed_payload_attestation.signature)
+func IsValidIndexedPayloadAttestation(state state.ReadOnlyBeaconState, att *epbs.IndexedPayloadAttestation) (bool, error) {
+	if state.Version() < version.EPBS {
+		return false, errPreEPBSState
+	}
+
+	// Verify the data is valid.
+	if att.Data.PayloadStatus >= primitives.PAYLOAD_INVALID_STATUS {
+		return false, nil
+	}
+
+	// Verify indices are sorted and unique.
+	indices := att.AttestingIndices
+	slices.Sort(indices)
+	if len(indices) == 0 || !slices.Equal(att.AttestingIndices, indices) {
+		return false, nil
+	}
+
+	// Verify aggregate signature.
+	publicKeys := make([]bls.PublicKey, len(indices))
+	for i, index := range indices {
+		validator, err := state.ValidatorAtIndexReadOnly(index)
+		if err != nil {
+			return false, err
+		}
+
+		publicKeyBytes := validator.PublicKey()
+		publicKey, err := bls.PublicKeyFromBytes(publicKeyBytes[:])
+		if err != nil {
+			return false, err
+		}
+
+		publicKeys[i] = publicKey
+	}
+
+	domain, err := signing.Domain(
+		state.Fork(),
+		slots.ToEpoch(state.Slot()),
+		params.BeaconConfig().DomainPTCAttester,
+		state.GenesisValidatorsRoot(),
+	)
+	if err != nil {
+		return false, err
+	}
+
+	signingRoot, err := signing.ComputeSigningRoot(att.Data, domain)
+	if err != nil {
+		return false, err
+	}
+
+	signature, err := bls.SignatureFromBytes(att.Signature)
+	if err != nil {
+		return false, err
+	}
+
+	return signature.FastAggregateVerify(publicKeys, signingRoot), nil
+}
+
+// ValidatePayloadAttestationMessageSignature verifies the signature of a
+// payload attestation message.
+func ValidatePayloadAttestationMessageSignature(ctx context.Context, st state.ReadOnlyBeaconState, msg *eth.PayloadAttestationMessage) error {
+	if err := ValidateNilPayloadAttestationMessage(msg); err != nil {
+		return err
+	}
+	val, err := st.ValidatorAtIndex(msg.ValidatorIndex)
+	if err != nil {
+		return err
+	}
+	pub, err := bls.PublicKeyFromBytes(val.PublicKey)
+	if err != nil {
+		return err
+	}
+	sig, err := bls.SignatureFromBytes(msg.Signature)
+	if err != nil {
+		return err
+	}
+	currentEpoch := slots.ToEpoch(st.Slot())
+	domain, err := signing.Domain(st.Fork(), currentEpoch, params.BeaconConfig().DomainPTCAttester, st.GenesisValidatorsRoot())
+	if err != nil {
+		return err
+	}
+	root, err := signing.ComputeSigningRoot(msg.Data, domain)
+	if err != nil {
+		return err
+	}
+	if !sig.Verify(pub, root[:]) {
+		return signing.ErrSigFailedToVerify
+	}
+	return nil
+}

beacon-chain/core/helpers/payload_attestation_test.go

@@ -0,0 +1,363 @@
+package helpers_test
+
+import (
+	"context"
+	"slices"
+	"strconv"
+	"testing"
+
+	"github.com/prysmaticlabs/go-bitfield"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/epbs"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/crypto/rand"
+	"github.com/prysmaticlabs/prysm/v5/math"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	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/prysmaticlabs/prysm/v5/testing/util/random"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+)
+
+func TestValidateNilPayloadAttestation(t *testing.T) {
+	require.ErrorIs(t, helpers.ErrNilData, helpers.ValidateNilPayloadAttestationData(nil))
+	data := &eth.PayloadAttestationData{}
+	require.ErrorIs(t, helpers.ErrNilBeaconBlockRoot, helpers.ValidateNilPayloadAttestationData(data))
+	data.BeaconBlockRoot = make([]byte, 32)
+	require.NoError(t, helpers.ValidateNilPayloadAttestationData(data))
+
+	require.ErrorIs(t, helpers.ErrNilMessage, helpers.ValidateNilPayloadAttestationMessage(nil))
+	message := &eth.PayloadAttestationMessage{}
+	require.ErrorIs(t, helpers.ErrNilSignature, helpers.ValidateNilPayloadAttestationMessage(message))
+	message.Signature = make([]byte, 96)
+	require.ErrorIs(t, helpers.ErrNilData, helpers.ValidateNilPayloadAttestationMessage(message))
+	message.Data = data
+	require.NoError(t, helpers.ValidateNilPayloadAttestationMessage(message))
+
+	require.ErrorIs(t, helpers.ErrNilPayloadAttestation, helpers.ValidateNilPayloadAttestation(nil))
+	att := &eth.PayloadAttestation{}
+	require.ErrorIs(t, helpers.ErrNilAggregationBits, helpers.ValidateNilPayloadAttestation(att))
+	att.AggregationBits = bitfield.NewBitvector512()
+	require.ErrorIs(t, helpers.ErrNilSignature, helpers.ValidateNilPayloadAttestation(att))
+	att.Signature = message.Signature
+	require.ErrorIs(t, helpers.ErrNilData, helpers.ValidateNilPayloadAttestation(att))
+	att.Data = data
+	require.NoError(t, helpers.ValidateNilPayloadAttestation(att))
+}
+
+func TestGetPayloadTimelinessCommittee(t *testing.T) {
+	helpers.ClearCache()
+
+	// Create 10 committees
+	committeeCount := uint64(10)
+	validatorCount := committeeCount * params.BeaconConfig().TargetCommitteeSize * uint64(params.BeaconConfig().SlotsPerEpoch)
+	validators := make([]*ethpb.Validator, validatorCount)
+
+	for i := 0; i < len(validators); i++ {
+		k := make([]byte, 48)
+		copy(k, strconv.Itoa(i))
+		validators[i] = &ethpb.Validator{
+			PublicKey:             k,
+			WithdrawalCredentials: make([]byte, 32),
+			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
+		}
+	}
+
+	state, err := state_native.InitializeFromProtoEpbs(random.BeaconState(t))
+	require.NoError(t, err)
+	require.NoError(t, state.SetValidators(validators))
+	require.NoError(t, state.SetSlot(200))
+
+	ctx := context.Background()
+	indices, err := helpers.BeaconCommitteeFromState(ctx, state, state.Slot(), 1)
+	require.NoError(t, err)
+	require.Equal(t, 128, len(indices))
+
+	epoch := slots.ToEpoch(state.Slot())
+	activeCount, err := helpers.ActiveValidatorCount(ctx, state, epoch)
+	require.NoError(t, err)
+	require.Equal(t, uint64(40960), activeCount)
+
+	computedCommitteeCount := helpers.SlotCommitteeCount(activeCount)
+	require.Equal(t, committeeCount, computedCommitteeCount)
+	committeesPerSlot := math.LargestPowerOfTwo(math.Min(committeeCount, fieldparams.PTCSize))
+	require.Equal(t, uint64(8), committeesPerSlot)
+
+	ptc, err := helpers.GetPayloadTimelinessCommittee(ctx, state, state.Slot())
+	require.NoError(t, err)
+	require.Equal(t, fieldparams.PTCSize, len(ptc))
+
+	committee1, err := helpers.BeaconCommitteeFromState(ctx, state, state.Slot(), 0)
+	require.NoError(t, err)
+
+	require.DeepEqual(t, committee1[:64], ptc[:64])
+}
+
+func Test_PtcAllocation(t *testing.T) {
+	tests := []struct {
+		committeeCount     int
+		memberPerCommittee uint64
+		committeesPerSlot  uint64
+	}{
+		{1, 512, 1},
+		{4, 128, 4},
+		{128, 4, 128},
+		{512, 1, 512},
+		{1024, 1, 512},
+	}
+
+	for _, test := range tests {
+		committeesPerSlot, memberPerCommittee := helpers.PtcAllocation(test.committeeCount)
+		if memberPerCommittee != test.memberPerCommittee {
+			t.Errorf("memberPerCommittee(%d) = %d; expected %d", test.committeeCount, memberPerCommittee, test.memberPerCommittee)
+		}
+		if committeesPerSlot != test.committeesPerSlot {
+			t.Errorf("committeesPerSlot(%d) = %d; expected %d", test.committeeCount, committeesPerSlot, test.committeesPerSlot)
+		}
+	}
+}
+
+func TestGetPayloadAttestingIndices(t *testing.T) {
+	helpers.ClearCache()
+
+	// Create 10 committees. Total 40960 validators.
+	committeeCount := uint64(10)
+	validatorCount := committeeCount * params.BeaconConfig().TargetCommitteeSize * uint64(params.BeaconConfig().SlotsPerEpoch)
+	validators := make([]*ethpb.Validator, validatorCount)
+
+	for i := 0; i < len(validators); i++ {
+		pubkey := make([]byte, 48)
+		copy(pubkey, strconv.Itoa(i))
+		validators[i] = &ethpb.Validator{
+			PublicKey:             pubkey,
+			WithdrawalCredentials: make([]byte, 32),
+			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
+		}
+	}
+
+	// Create a beacon state.
+	state, err := state_native.InitializeFromProtoEpbs(&ethpb.BeaconStateEPBS{
+		Validators:  validators,
+		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
+	})
+	require.NoError(t, err)
+
+	// Get PTC.
+	ptc, err := helpers.GetPayloadTimelinessCommittee(context.Background(), state, state.Slot())
+	require.NoError(t, err)
+	require.Equal(t, fieldparams.PTCSize, len(ptc))
+
+	// Generate random indices. PTC members at the corresponding indices are considered attested.
+	randGen := rand.NewDeterministicGenerator()
+	attesterCount := randGen.Intn(fieldparams.PTCSize) + 1
+	indices := randGen.Perm(fieldparams.PTCSize)[:attesterCount]
+	slices.Sort(indices)
+	require.Equal(t, attesterCount, len(indices))
+
+	// Create a PayloadAttestation with AggregationBits set true at the indices.
+	aggregationBits := bitfield.NewBitvector512()
+	for _, index := range indices {
+		aggregationBits.SetBitAt(uint64(index), true)
+	}
+
+	payloadAttestation := &eth.PayloadAttestation{
+		AggregationBits: aggregationBits,
+		Data: &eth.PayloadAttestationData{
+			BeaconBlockRoot: make([]byte, 32),
+		},
+		Signature: make([]byte, 96),
+	}
+
+	// Get attesting indices.
+	attesters, err := helpers.GetPayloadAttestingIndices(context.Background(), state, state.Slot(), payloadAttestation)
+	require.NoError(t, err)
+	require.Equal(t, len(indices), len(attesters))
+
+	// Check if each attester equals to the PTC member at the corresponding index.
+	for i, index := range indices {
+		require.Equal(t, attesters[i], ptc[index])
+	}
+}
+
+func TestGetIndexedPayloadAttestation(t *testing.T) {
+	helpers.ClearCache()
+
+	// Create 10 committees. Total 40960 validators.
+	committeeCount := uint64(10)
+	validatorCount := committeeCount * params.BeaconConfig().TargetCommitteeSize * uint64(params.BeaconConfig().SlotsPerEpoch)
+	validators := make([]*ethpb.Validator, validatorCount)
+
+	for i := 0; i < len(validators); i++ {
+		publicKey := make([]byte, 48)
+		copy(publicKey, strconv.Itoa(i))
+		validators[i] = &ethpb.Validator{
+			PublicKey:             publicKey,
+			WithdrawalCredentials: make([]byte, 32),
+			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
+		}
+	}
+
+	// Create a beacon state.
+	state, err := state_native.InitializeFromProtoEpbs(&ethpb.BeaconStateEPBS{
+		Validators:  validators,
+		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
+	})
+	require.NoError(t, err)
+
+	// Get PTC.
+	ptc, err := helpers.GetPayloadTimelinessCommittee(context.Background(), state, state.Slot())
+	require.NoError(t, err)
+	require.Equal(t, fieldparams.PTCSize, len(ptc))
+
+	// Generate random indices. PTC members at the corresponding indices are considered attested.
+	randGen := rand.NewDeterministicGenerator()
+	attesterCount := randGen.Intn(fieldparams.PTCSize) + 1
+	indices := randGen.Perm(fieldparams.PTCSize)[:attesterCount]
+	slices.Sort(indices)
+	require.Equal(t, attesterCount, len(indices))
+
+	// Create a PayloadAttestation with AggregationBits set true at the indices.
+	aggregationBits := bitfield.NewBitvector512()
+	for _, index := range indices {
+		aggregationBits.SetBitAt(uint64(index), true)
+	}
+
+	payloadAttestation := &eth.PayloadAttestation{
+		AggregationBits: aggregationBits,
+		Data: &eth.PayloadAttestationData{
+			BeaconBlockRoot: make([]byte, 32),
+		},
+		Signature: make([]byte, 96),
+	}
+
+	// Get attesting indices.
+	ctx := context.Background()
+	attesters, err := helpers.GetPayloadAttestingIndices(ctx, state, state.Slot(), payloadAttestation)
+	require.NoError(t, err)
+	require.Equal(t, len(indices), len(attesters))
+
+	// Get an IndexedPayloadAttestation.
+	indexedPayloadAttestation, err := helpers.GetIndexedPayloadAttestation(ctx, state, state.Slot(), payloadAttestation)
+	require.NoError(t, err)
+	require.Equal(t, len(indices), len(indexedPayloadAttestation.AttestingIndices))
+	require.DeepEqual(t, payloadAttestation.Data, indexedPayloadAttestation.Data)
+	require.DeepEqual(t, payloadAttestation.Signature, indexedPayloadAttestation.Signature)
+
+	// Check if the attesting indices are the same.
+	slices.Sort(attesters) // GetIndexedPayloadAttestation sorts attesting indices.
+	require.DeepEqual(t, attesters, indexedPayloadAttestation.AttestingIndices)
+}
+
+func TestIsValidIndexedPayloadAttestation(t *testing.T) {
+	helpers.ClearCache()
+
+	// Create validators.
+	validatorCount := uint64(350)
+	validators := make([]*ethpb.Validator, validatorCount)
+	_, secretKeys, err := util.DeterministicDepositsAndKeys(validatorCount)
+	require.NoError(t, err)
+
+	for i := 0; i < len(validators); i++ {
+		validators[i] = &ethpb.Validator{
+			PublicKey:             secretKeys[i].PublicKey().Marshal(),
+			WithdrawalCredentials: make([]byte, 32),
+			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
+		}
+	}
+
+	// Create a beacon state.
+	state, err := state_native.InitializeFromProtoEpbs(&ethpb.BeaconStateEPBS{
+		Validators: validators,
+		Fork: &ethpb.Fork{
+			Epoch:           0,
+			CurrentVersion:  params.BeaconConfig().GenesisForkVersion,
+			PreviousVersion: params.BeaconConfig().GenesisForkVersion,
+		},
+		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
+	})
+	require.NoError(t, err)
+
+	// Define test cases.
+	tests := []struct {
+		attestation *epbs.IndexedPayloadAttestation
+	}{
+		{
+			attestation: &epbs.IndexedPayloadAttestation{
+				AttestingIndices: []primitives.ValidatorIndex{1},
+				Data: &eth.PayloadAttestationData{
+					BeaconBlockRoot: make([]byte, fieldparams.RootLength),
+				},
+				Signature: make([]byte, fieldparams.BLSSignatureLength),
+			},
+		},
+		{
+			attestation: &epbs.IndexedPayloadAttestation{
+				AttestingIndices: []primitives.ValidatorIndex{13, 19},
+				Data: &eth.PayloadAttestationData{
+					BeaconBlockRoot: make([]byte, fieldparams.RootLength),
+				},
+				Signature: make([]byte, fieldparams.BLSSignatureLength),
+			},
+		},
+		{
+			attestation: &epbs.IndexedPayloadAttestation{
+				AttestingIndices: []primitives.ValidatorIndex{123, 234, 345},
+				Data: &eth.PayloadAttestationData{
+					BeaconBlockRoot: make([]byte, fieldparams.RootLength),
+				},
+				Signature: make([]byte, fieldparams.BLSSignatureLength),
+			},
+		},
+		{
+			attestation: &epbs.IndexedPayloadAttestation{
+				AttestingIndices: []primitives.ValidatorIndex{38, 46, 54, 62, 70, 78, 86, 194},
+				Data: &eth.PayloadAttestationData{
+					BeaconBlockRoot: make([]byte, fieldparams.RootLength),
+				},
+				Signature: make([]byte, fieldparams.BLSSignatureLength),
+			},
+		},
+		{
+			attestation: &epbs.IndexedPayloadAttestation{
+				AttestingIndices: []primitives.ValidatorIndex{5},
+				Data: &eth.PayloadAttestationData{
+					BeaconBlockRoot: make([]byte, fieldparams.RootLength),
+				},
+				Signature: make([]byte, fieldparams.BLSSignatureLength),
+			},
+		},
+	}
+
+	// Run test cases.
+	for _, test := range tests {
+		signatures := make([]bls.Signature, len(test.attestation.AttestingIndices))
+		for i, index := range test.attestation.AttestingIndices {
+			signedBytes, err := signing.ComputeDomainAndSign(
+				state,
+				slots.ToEpoch(test.attestation.Data.Slot),
+				test.attestation.Data,
+				params.BeaconConfig().DomainPTCAttester,
+				secretKeys[index],
+			)
+			require.NoError(t, err)
+
+			signature, err := bls.SignatureFromBytes(signedBytes)
+			require.NoError(t, err)
+
+			signatures[i] = signature
+		}
+
+		aggregatedSignature := bls.AggregateSignatures(signatures)
+		test.attestation.Signature = aggregatedSignature.Marshal()
+
+		isValid, err := helpers.IsValidIndexedPayloadAttestation(state, test.attestation)
+		require.NoError(t, err)
+		require.Equal(t, true, isValid)
+	}
+}

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

@@ -12,10 +12,12 @@ go_library(
         "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/eth/v2:go_default_library",
+        "//proto/migration:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -27,13 +29,11 @@ go_test(
     srcs = ["lightclient_test.go"],
     deps = [
         ":go_default_library",
-        "//config/fieldparams:go_default_library",
-        "//consensus-types:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
-        "//encoding/ssz:go_default_library",
+        "//consensus-types/primitives:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
     ],
 )

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

@@ -13,11 +13,15 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/encoding/ssz"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	v11 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpbv1 "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
+	"github.com/prysmaticlabs/prysm/v5/proto/migration"
 	"github.com/prysmaticlabs/prysm/v5/runtime/version"
 	"github.com/prysmaticlabs/prysm/v5/time/slots"
+
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 )
 
 const (
@@ -25,6 +29,16 @@ const (
 	executionBranchNumOfLeaves = 4
 )
 
+// createLightClientFinalityUpdate - implements https://github.com/ethereum/consensus-specs/blob/3d235740e5f1e641d3b160c8688f26e7dc5a1894/specs/altair/light-client/full-node.md#create_light_client_finality_update
+// def create_light_client_finality_update(update: LightClientUpdate) -> LightClientFinalityUpdate:
+//
+//	return LightClientFinalityUpdate(
+//	    attested_header=update.attested_header,
+//	    finalized_header=update.finalized_header,
+//	    finality_branch=update.finality_branch,
+//	    sync_aggregate=update.sync_aggregate,
+//	    signature_slot=update.signature_slot,
+//	)
 func createLightClientFinalityUpdate(update *ethpbv2.LightClientUpdate) *ethpbv2.LightClientFinalityUpdate {
 	finalityUpdate := &ethpbv2.LightClientFinalityUpdate{
 		AttestedHeader:  update.AttestedHeader,
@@ -37,6 +51,14 @@ func createLightClientFinalityUpdate(update *ethpbv2.LightClientUpdate) *ethpbv2
 	return finalityUpdate
 }
 
+// createLightClientOptimisticUpdate - implements https://github.com/ethereum/consensus-specs/blob/3d235740e5f1e641d3b160c8688f26e7dc5a1894/specs/altair/light-client/full-node.md#create_light_client_optimistic_update
+// def create_light_client_optimistic_update(update: LightClientUpdate) -> LightClientOptimisticUpdate:
+//
+//	return LightClientOptimisticUpdate(
+//	    attested_header=update.attested_header,
+//	    sync_aggregate=update.sync_aggregate,
+//	    signature_slot=update.signature_slot,
+//	)
 func createLightClientOptimisticUpdate(update *ethpbv2.LightClientUpdate) *ethpbv2.LightClientOptimisticUpdate {
 	optimisticUpdate := &ethpbv2.LightClientOptimisticUpdate{
 		AttestedHeader: update.AttestedHeader,
@@ -52,10 +74,9 @@ func NewLightClientFinalityUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
-	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 	finalizedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*ethpbv2.LightClientFinalityUpdate, error) {
-	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, finalizedBlock)
+	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, finalizedBlock)
 	if err != nil {
 		return nil, err
 	}
@@ -68,9 +89,8 @@ func NewLightClientOptimisticUpdateFromBeaconState(
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
-	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 ) (*ethpbv2.LightClientOptimisticUpdate, error) {
-	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, nil)
+	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -78,12 +98,68 @@ func NewLightClientOptimisticUpdateFromBeaconState(
 	return createLightClientOptimisticUpdate(update), nil
 }
 
+// NewLightClientUpdateFromBeaconState implements https://github.com/ethereum/consensus-specs/blob/d70dcd9926a4bbe987f1b4e65c3e05bd029fcfb8/specs/altair/light-client/full-node.md#create_light_client_update
+// def create_light_client_update(state: BeaconState,
+//
+//	                           block: SignedBeaconBlock,
+//	                           attested_state: BeaconState,
+//	                           finalized_block: Optional[SignedBeaconBlock]) -> LightClientUpdate:
+//	assert compute_epoch_at_slot(attested_state.slot) >= ALTAIR_FORK_EPOCH
+//	assert sum(block.message.body.sync_aggregate.sync_committee_bits) >= MIN_SYNC_COMMITTEE_PARTICIPANTS
+//
+//	assert state.slot == state.latest_block_header.slot
+//	header = state.latest_block_header.copy()
+//	header.state_root = hash_tree_root(state)
+//	assert hash_tree_root(header) == hash_tree_root(block.message)
+//	update_signature_period = compute_sync_committee_period(compute_epoch_at_slot(block.message.slot))
+//
+//	assert attested_state.slot == attested_state.latest_block_header.slot
+//	attested_header = attested_state.latest_block_header.copy()
+//	attested_header.state_root = hash_tree_root(attested_state)
+//	assert hash_tree_root(attested_header) == block.message.parent_root
+//	update_attested_period = compute_sync_committee_period(compute_epoch_at_slot(attested_header.slot))
+//
+//	# `next_sync_committee` is only useful if the message is signed by the current sync committee
+//	if update_attested_period == update_signature_period:
+//	    next_sync_committee = attested_state.next_sync_committee
+//	    next_sync_committee_branch = compute_merkle_proof_for_state(attested_state, NEXT_SYNC_COMMITTEE_INDEX)
+//	else:
+//	    next_sync_committee = SyncCommittee()
+//	    next_sync_committee_branch = [Bytes32() for _ in range(floorlog2(NEXT_SYNC_COMMITTEE_INDEX))]
+//
+//	# Indicate finality whenever possible
+//	if finalized_block is not None:
+//	    if finalized_block.message.slot != GENESIS_SLOT:
+//	        finalized_header = BeaconBlockHeader(
+//	            slot=finalized_block.message.slot,
+//	            proposer_index=finalized_block.message.proposer_index,
+//	            parent_root=finalized_block.message.parent_root,
+//	            state_root=finalized_block.message.state_root,
+//	            body_root=hash_tree_root(finalized_block.message.body),
+//	        )
+//	        assert hash_tree_root(finalized_header) == attested_state.finalized_checkpoint.root
+//	    else:
+//	        assert attested_state.finalized_checkpoint.root == Bytes32()
+//	        finalized_header = BeaconBlockHeader()
+//	    finality_branch = compute_merkle_proof_for_state(attested_state, FINALIZED_ROOT_INDEX)
+//	else:
+//	    finalized_header = BeaconBlockHeader()
+//	    finality_branch = [Bytes32() for _ in range(floorlog2(FINALIZED_ROOT_INDEX))]
+//
+//	return LightClientUpdate(
+//	    attested_header=attested_header,
+//	    next_sync_committee=next_sync_committee,
+//	    next_sync_committee_branch=next_sync_committee_branch,
+//	    finalized_header=finalized_header,
+//	    finality_branch=finality_branch,
+//	    sync_aggregate=block.message.body.sync_aggregate,
+//	    signature_slot=block.message.slot,
+//	)
 func NewLightClientUpdateFromBeaconState(
 	ctx context.Context,
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
-	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
 	finalizedBlock interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientUpdate, error) {
 	// assert compute_epoch_at_slot(attested_state.slot) >= ALTAIR_FORK_EPOCH
 	attestedEpoch := slots.ToEpoch(attestedState.Slot())
@@ -147,30 +223,73 @@ func NewLightClientUpdateFromBeaconState(
 	if err != nil {
 		return nil, errors.Wrap(err, "could not get attested header root")
 	}
-	attestedBlockRoot, err := attestedBlock.Block().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get attested block root")
-	}
-	// assert hash_tree_root(attested_header) == hash_tree_root(attested_block.message) == block.message.parent_root
-	if attestedHeaderRoot != block.Block().ParentRoot() || attestedHeaderRoot != attestedBlockRoot {
-		return nil, fmt.Errorf("attested header root %#x not equal to block parent root %#x or attested block root %#x", attestedHeaderRoot, block.Block().ParentRoot(), attestedBlockRoot)
+	if attestedHeaderRoot != block.Block().ParentRoot() {
+		return nil, fmt.Errorf("attested header root %#x not equal to block parent root %#x", attestedHeaderRoot, block.Block().ParentRoot())
 	}
 
-	// update_attested_period = compute_sync_committee_period_at_slot(attested_block.message.slot)
-	updateAttestedPeriod := slots.SyncCommitteePeriod(slots.ToEpoch(attestedBlock.Block().Slot()))
+	// update_attested_period = compute_sync_committee_period(compute_epoch_at_slot(attested_header.slot))
+	updateAttestedPeriod := slots.SyncCommitteePeriod(slots.ToEpoch(attestedHeader.Slot))
 
 	// update = LightClientUpdate()
-	result, err := createDefaultLightClientUpdate()
+	result, err := createDefaultLightClientUpdate(block.Block().Version())
 	if err != nil {
 		return nil, errors.Wrap(err, "could not create default light client update")
 	}
 
 	// update.attested_header = block_to_light_client_header(attested_block)
-	attestedLightClientHeader, err := BlockToLightClientHeader(attestedBlock)
-	if err != nil {
-		return nil, errors.Wrap(err, "could not get attested light client header")
+	blockHeader := &ethpbv1.BeaconBlockHeader{
+		Slot:          attestedHeader.Slot,
+		ProposerIndex: attestedHeader.ProposerIndex,
+		ParentRoot:    attestedHeader.ParentRoot,
+		StateRoot:     attestedHeader.StateRoot,
+		BodyRoot:      attestedHeader.BodyRoot,
+	}
+	switch block.Block().Version() {
+	case version.Altair, version.Bellatrix:
+		result.AttestedHeader = &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
+				HeaderAltair: &ethpbv2.LightClientHeader{Beacon: blockHeader},
+			},
+		}
+	case version.Capella:
+		executionPayloadHeader, err := getExecutionPayloadHeaderCapella(block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get execution payload header")
+		}
+		executionPayloadProof, err := blocks.PayloadProof(ctx, block.Block())
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get execution payload proof")
+		}
+		result.AttestedHeader = &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
+				HeaderCapella: &ethpbv2.LightClientHeaderCapella{
+					Beacon:          blockHeader,
+					Execution:       executionPayloadHeader,
+					ExecutionBranch: executionPayloadProof,
+				},
+			},
+		}
+	case version.Deneb:
+		executionPayloadHeader, err := getExecutionPayloadHeaderDeneb(block)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get execution payload header")
+		}
+		executionPayloadProof, err := blocks.PayloadProof(ctx, block.Block())
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get execution payload proof")
+		}
+		result.AttestedHeader = &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
+				HeaderDeneb: &ethpbv2.LightClientHeaderDeneb{
+					Beacon:          blockHeader,
+					Execution:       executionPayloadHeader,
+					ExecutionBranch: executionPayloadProof,
+				},
+			},
+		}
+	default:
+		return nil, fmt.Errorf("unsupported block version %s", version.String(block.Block().Version()))
 	}
-	result.AttestedHeader = attestedLightClientHeader
 
 	// if update_attested_period == update_signature_period
 	if updateAttestedPeriod == updateSignaturePeriod {
@@ -200,11 +319,70 @@ func NewLightClientUpdateFromBeaconState(
 		// if finalized_block.message.slot != GENESIS_SLOT
 		if finalizedBlock.Block().Slot() != 0 {
 			// update.finalized_header = block_to_light_client_header(finalized_block)
-			finalizedLightClientHeader, err := BlockToLightClientHeader(finalizedBlock)
+			v1alpha1FinalizedHeader, err := finalizedBlock.Header()
 			if err != nil {
-				return nil, errors.Wrap(err, "could not get finalized light client header")
+				return nil, errors.Wrap(err, "could not get finalized header")
+			}
+			finalizedHeader := migration.V1Alpha1SignedHeaderToV1(v1alpha1FinalizedHeader).GetMessage()
+			finalizedHeaderRoot, err := finalizedHeader.HashTreeRoot()
+			if err != nil {
+				return nil, errors.Wrap(err, "could not get finalized header root")
+			}
+			switch block.Block().Version() {
+			case version.Altair, version.Bellatrix:
+				result.FinalizedHeader = &ethpbv2.LightClientHeaderContainer{
+					Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
+						HeaderAltair: &ethpbv2.LightClientHeader{Beacon: finalizedHeader},
+					},
+				}
+			case version.Capella:
+				executionPayloadHeader, err := getExecutionPayloadHeaderCapella(finalizedBlock)
+				if err != nil {
+					return nil, errors.Wrap(err, "could not get execution payload header")
+				}
+				executionPayloadProof, err := blocks.PayloadProof(ctx, finalizedBlock.Block())
+				if err != nil {
+					return nil, errors.Wrap(err, "could not get execution payload proof")
+				}
+				result.FinalizedHeader = &ethpbv2.LightClientHeaderContainer{
+					Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
+						HeaderCapella: &ethpbv2.LightClientHeaderCapella{
+							Beacon:          finalizedHeader,
+							Execution:       executionPayloadHeader,
+							ExecutionBranch: executionPayloadProof,
+						},
+					},
+				}
+			case version.Deneb:
+				executionPayloadHeader, err := getExecutionPayloadHeaderDeneb(finalizedBlock)
+				if err != nil {
+					return nil, errors.Wrap(err, "could not get execution payload header")
+				}
+				executionPayloadProof, err := blocks.PayloadProof(ctx, finalizedBlock.Block())
+				if err != nil {
+					return nil, errors.Wrap(err, "could not get execution payload proof")
+				}
+				result.FinalizedHeader = &ethpbv2.LightClientHeaderContainer{
+					Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
+						HeaderDeneb: &ethpbv2.LightClientHeaderDeneb{
+							Beacon:          finalizedHeader,
+							Execution:       executionPayloadHeader,
+							ExecutionBranch: executionPayloadProof,
+						},
+					},
+				}
+			default:
+				return nil, fmt.Errorf("unsupported block version %s", version.String(block.Block().Version()))
+			}
+
+			// assert hash_tree_root(update.finalized_header.beacon) == attested_state.finalized_checkpoint.root
+			if finalizedHeaderRoot != bytesutil.ToBytes32(attestedState.FinalizedCheckpoint().Root) {
+				return nil, fmt.Errorf(
+					"finalized header root %#x not equal to attested finalized checkpoint root %#x",
+					finalizedHeaderRoot,
+					bytesutil.ToBytes32(attestedState.FinalizedCheckpoint().Root),
+				)
 			}
-			result.FinalizedHeader = finalizedLightClientHeader
 		} else {
 			// assert attested_state.finalized_checkpoint.root == Bytes32()
 			if !bytes.Equal(attestedState.FinalizedCheckpoint().Root, make([]byte, 32)) {
@@ -233,7 +411,7 @@ func NewLightClientUpdateFromBeaconState(
 	return result, nil
 }
 
-func createDefaultLightClientUpdate() (*ethpbv2.LightClientUpdate, error) {
+func createDefaultLightClientUpdate(v int) (*ethpbv2.LightClientUpdate, error) {
 	syncCommitteeSize := params.BeaconConfig().SyncCommitteeSize
 	pubKeys := make([][]byte, syncCommitteeSize)
 	for i := uint64(0); i < syncCommitteeSize; i++ {
@@ -243,26 +421,218 @@ func createDefaultLightClientUpdate() (*ethpbv2.LightClientUpdate, error) {
 		Pubkeys:         pubKeys,
 		AggregatePubkey: make([]byte, fieldparams.BLSPubkeyLength),
 	}
-	nextSyncCommitteeBranch := make([][]byte, fieldparams.SyncCommitteeBranchDepth)
-	for i := 0; i < fieldparams.SyncCommitteeBranchDepth; i++ {
+	nextSyncCommitteeBranch := make([][]byte, fieldparams.NextSyncCommitteeBranchDepth)
+	for i := 0; i < fieldparams.NextSyncCommitteeBranchDepth; i++ {
 		nextSyncCommitteeBranch[i] = make([]byte, fieldparams.RootLength)
 	}
 	executionBranch := make([][]byte, executionBranchNumOfLeaves)
 	for i := 0; i < executionBranchNumOfLeaves; i++ {
 		executionBranch[i] = make([]byte, 32)
 	}
+	finalizedBlockHeader := &ethpbv1.BeaconBlockHeader{
+		Slot:          0,
+		ProposerIndex: 0,
+		ParentRoot:    make([]byte, 32),
+		StateRoot:     make([]byte, 32),
+		BodyRoot:      make([]byte, 32),
+	}
 	finalityBranch := make([][]byte, FinalityBranchNumOfLeaves)
 	for i := 0; i < FinalityBranchNumOfLeaves; i++ {
 		finalityBranch[i] = make([]byte, 32)
 	}
 
+	var finalizedHeader *ethpbv2.LightClientHeaderContainer
+	switch v {
+	case version.Altair, version.Bellatrix:
+		finalizedHeader = &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
+				HeaderAltair: &ethpbv2.LightClientHeader{
+					Beacon: finalizedBlockHeader,
+				},
+			},
+		}
+	case version.Capella:
+		finalizedHeader = &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
+				HeaderCapella: &ethpbv2.LightClientHeaderCapella{
+					Beacon:          finalizedBlockHeader,
+					Execution:       createEmptyExecutionPayloadHeaderCapella(),
+					ExecutionBranch: executionBranch,
+				},
+			},
+		}
+	case version.Deneb:
+		finalizedHeader = &ethpbv2.LightClientHeaderContainer{
+			Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
+				HeaderDeneb: &ethpbv2.LightClientHeaderDeneb{
+					Beacon:          finalizedBlockHeader,
+					Execution:       createEmptyExecutionPayloadHeaderDeneb(),
+					ExecutionBranch: executionBranch,
+				},
+			},
+		}
+	default:
+		return nil, fmt.Errorf("unsupported block version %s", version.String(v))
+	}
+
 	return &ethpbv2.LightClientUpdate{
 		NextSyncCommittee:       nextSyncCommittee,
 		NextSyncCommitteeBranch: nextSyncCommitteeBranch,
+		FinalizedHeader:         finalizedHeader,
 		FinalityBranch:          finalityBranch,
 	}, nil
 }
 
+func createEmptyExecutionPayloadHeaderCapella() *enginev1.ExecutionPayloadHeaderCapella {
+	return &enginev1.ExecutionPayloadHeaderCapella{
+		ParentHash:       make([]byte, 32),
+		FeeRecipient:     make([]byte, 20),
+		StateRoot:        make([]byte, 32),
+		ReceiptsRoot:     make([]byte, 32),
+		LogsBloom:        make([]byte, 256),
+		PrevRandao:       make([]byte, 32),
+		BlockNumber:      0,
+		GasLimit:         0,
+		GasUsed:          0,
+		Timestamp:        0,
+		ExtraData:        make([]byte, 32),
+		BaseFeePerGas:    make([]byte, 32),
+		BlockHash:        make([]byte, 32),
+		TransactionsRoot: make([]byte, 32),
+		WithdrawalsRoot:  make([]byte, 32),
+	}
+}
+
+func createEmptyExecutionPayloadHeaderDeneb() *enginev1.ExecutionPayloadHeaderDeneb {
+	return &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       make([]byte, 32),
+		FeeRecipient:     make([]byte, 20),
+		StateRoot:        make([]byte, 32),
+		ReceiptsRoot:     make([]byte, 32),
+		LogsBloom:        make([]byte, 256),
+		PrevRandao:       make([]byte, 32),
+		BlockNumber:      0,
+		GasLimit:         0,
+		GasUsed:          0,
+		Timestamp:        0,
+		ExtraData:        make([]byte, 32),
+		BaseFeePerGas:    make([]byte, 32),
+		BlockHash:        make([]byte, 32),
+		TransactionsRoot: make([]byte, 32),
+		WithdrawalsRoot:  make([]byte, 32),
+	}
+}
+
+func getExecutionPayloadHeaderCapella(block interfaces.ReadOnlySignedBeaconBlock) (*enginev1.ExecutionPayloadHeaderCapella, error) {
+	payloadInterface, err := block.Block().Body().Execution()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get execution data")
+	}
+	transactionsRoot, err := payloadInterface.TransactionsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		transactions, err := payloadInterface.Transactions()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions")
+		}
+		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions root")
+		}
+		transactionsRoot = transactionsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get transactions root")
+	}
+	withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		withdrawals, err := payloadInterface.Withdrawals()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals")
+		}
+		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals root")
+		}
+		withdrawalsRoot = withdrawalsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get withdrawals root")
+	}
+
+	execution := &enginev1.ExecutionPayloadHeaderCapella{
+		ParentHash:       payloadInterface.ParentHash(),
+		FeeRecipient:     payloadInterface.FeeRecipient(),
+		StateRoot:        payloadInterface.StateRoot(),
+		ReceiptsRoot:     payloadInterface.ReceiptsRoot(),
+		LogsBloom:        payloadInterface.LogsBloom(),
+		PrevRandao:       payloadInterface.PrevRandao(),
+		BlockNumber:      payloadInterface.BlockNumber(),
+		GasLimit:         payloadInterface.GasLimit(),
+		GasUsed:          payloadInterface.GasUsed(),
+		Timestamp:        payloadInterface.Timestamp(),
+		ExtraData:        payloadInterface.ExtraData(),
+		BaseFeePerGas:    payloadInterface.BaseFeePerGas(),
+		BlockHash:        payloadInterface.BlockHash(),
+		TransactionsRoot: transactionsRoot,
+		WithdrawalsRoot:  withdrawalsRoot,
+	}
+
+	return execution, nil
+}
+
+func getExecutionPayloadHeaderDeneb(block interfaces.ReadOnlySignedBeaconBlock) (*enginev1.ExecutionPayloadHeaderDeneb, error) {
+	payloadInterface, err := block.Block().Body().Execution()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get execution data")
+	}
+	transactionsRoot, err := payloadInterface.TransactionsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		transactions, err := payloadInterface.Transactions()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions")
+		}
+		transactionsRootArray, err := ssz.TransactionsRoot(transactions)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get transactions root")
+		}
+		transactionsRoot = transactionsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get transactions root")
+	}
+	withdrawalsRoot, err := payloadInterface.WithdrawalsRoot()
+	if errors.Is(err, consensus_types.ErrUnsupportedField) {
+		withdrawals, err := payloadInterface.Withdrawals()
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals")
+		}
+		withdrawalsRootArray, err := ssz.WithdrawalSliceRoot(withdrawals, fieldparams.MaxWithdrawalsPerPayload)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not get withdrawals root")
+		}
+		withdrawalsRoot = withdrawalsRootArray[:]
+	} else if err != nil {
+		return nil, errors.Wrap(err, "could not get withdrawals root")
+	}
+
+	execution := &enginev1.ExecutionPayloadHeaderDeneb{
+		ParentHash:       payloadInterface.ParentHash(),
+		FeeRecipient:     payloadInterface.FeeRecipient(),
+		StateRoot:        payloadInterface.StateRoot(),
+		ReceiptsRoot:     payloadInterface.ReceiptsRoot(),
+		LogsBloom:        payloadInterface.LogsBloom(),
+		PrevRandao:       payloadInterface.PrevRandao(),
+		BlockNumber:      payloadInterface.BlockNumber(),
+		GasLimit:         payloadInterface.GasLimit(),
+		GasUsed:          payloadInterface.GasUsed(),
+		Timestamp:        payloadInterface.Timestamp(),
+		ExtraData:        payloadInterface.ExtraData(),
+		BaseFeePerGas:    payloadInterface.BaseFeePerGas(),
+		BlockHash:        payloadInterface.BlockHash(),
+		TransactionsRoot: transactionsRoot,
+		WithdrawalsRoot:  withdrawalsRoot,
+	}
+
+	return execution, nil
+}
+
 func ComputeTransactionsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 	transactionsRoot, err := payload.TransactionsRoot()
 	if errors.Is(err, consensus_types.ErrUnsupportedField) {
@@ -299,45 +669,8 @@ func ComputeWithdrawalsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 	return withdrawalsRoot, nil
 }
 
-func BlockToLightClientHeader(block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderContainer, error) {
-	switch block.Version() {
-	case version.Altair, version.Bellatrix:
-		altairHeader, err := blockToLightClientHeaderAltair(block)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get header")
-		}
-		return &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderAltair{
-				HeaderAltair: altairHeader,
-			},
-		}, nil
-	case version.Capella:
-		capellaHeader, err := blockToLightClientHeaderCapella(context.Background(), block)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get capella header")
-		}
-		return &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderCapella{
-				HeaderCapella: capellaHeader,
-			},
-		}, nil
-	case version.Deneb, version.Electra:
-		denebHeader, err := blockToLightClientHeaderDeneb(context.Background(), block)
-		if err != nil {
-			return nil, errors.Wrap(err, "could not get header")
-		}
-		return &ethpbv2.LightClientHeaderContainer{
-			Header: &ethpbv2.LightClientHeaderContainer_HeaderDeneb{
-				HeaderDeneb: denebHeader,
-			},
-		}, nil
-	default:
-		return nil, fmt.Errorf("unsupported block version %s", version.String(block.Version()))
-	}
-}
-
-func blockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeader, error) {
-	if block.Version() < version.Altair {
+func BlockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeader, error) {
+	if block.Version() != version.Altair {
 		return nil, fmt.Errorf("block version is %s instead of Altair", version.String(block.Version()))
 	}
 
@@ -359,8 +692,8 @@ func blockToLightClientHeaderAltair(block interfaces.ReadOnlySignedBeaconBlock)
 	}, nil
 }
 
-func blockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderCapella, error) {
-	if block.Version() < version.Capella {
+func BlockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderCapella, error) {
+	if block.Version() != version.Capella {
 		return nil, fmt.Errorf("block version is %s instead of Capella", version.String(block.Version()))
 	}
 
@@ -421,9 +754,9 @@ func blockToLightClientHeaderCapella(ctx context.Context, block interfaces.ReadO
 	}, nil
 }
 
-func blockToLightClientHeaderDeneb(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderDeneb, error) {
-	if block.Version() < version.Deneb {
-		return nil, fmt.Errorf("block version is %s instead of Deneb/Electra", version.String(block.Version()))
+func BlockToLightClientHeaderDeneb(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (*ethpbv2.LightClientHeaderDeneb, error) {
+	if block.Version() != version.Deneb {
+		return nil, fmt.Errorf("block version is %s instead of Deneb", version.String(block.Version()))
 	}
 
 	payload, err := block.Block().Body().Execution()

beacon-chain/core/validators/slashing.go

@@ -22,7 +22,7 @@ func SlashingParamsPerVersion(v int) (slashingQuotient, proposerRewardQuotient,
 		slashingQuotient = cfg.MinSlashingPenaltyQuotientBellatrix
 		proposerRewardQuotient = cfg.ProposerRewardQuotient
 		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotient
-	case version.Electra:
+	case version.Electra, version.EPBS:
 		slashingQuotient = cfg.MinSlashingPenaltyQuotientElectra
 		proposerRewardQuotient = cfg.ProposerRewardQuotient
 		whistleblowerRewardQuotient = cfg.WhistleBlowerRewardQuotientElectra

beacon-chain/db/iface/interface.go

@@ -25,6 +25,7 @@ import (
 type ReadOnlyDatabase interface {
 	// Block related methods.
 	Block(ctx context.Context, blockRoot [32]byte) (interfaces.ReadOnlySignedBeaconBlock, error)
+	SignedExecutionPayloadHeader(ctx context.Context, blockRoot [32]byte) (interfaces.ROSignedExecutionPayloadHeader, error)
 	Blocks(ctx context.Context, f *filters.QueryFilter) ([]interfaces.ReadOnlySignedBeaconBlock, [][32]byte, error)
 	BlockRoots(ctx context.Context, f *filters.QueryFilter) ([][32]byte, error)
 	BlocksBySlot(ctx context.Context, slot primitives.Slot) ([]interfaces.ReadOnlySignedBeaconBlock, error)
@@ -55,6 +56,7 @@ type ReadOnlyDatabase interface {
 	DepositContractAddress(ctx context.Context) ([]byte, error)
 	// ExecutionChainData operations.
 	ExecutionChainData(ctx context.Context) (*ethpb.ETH1ChainData, error)
+	SignedBlindPayloadEnvelope(ctx context.Context, blockRoot []byte) (*ethpb.SignedBlindPayloadEnvelope, error)
 	// Fee recipients operations.
 	FeeRecipientByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (common.Address, error)
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
@@ -92,6 +94,7 @@ type NoHeadAccessDatabase interface {
 	SaveDepositContractAddress(ctx context.Context, addr common.Address) error
 	// SaveExecutionChainData operations.
 	SaveExecutionChainData(ctx context.Context, data *ethpb.ETH1ChainData) error
+	SaveBlindPayloadEnvelope(ctx context.Context, envelope *ethpb.SignedBlindPayloadEnvelope) error
 	// Run any required database migrations.
 	RunMigrations(ctx context.Context) error
 	// Fee recipients operations.

beacon-chain/db/kv/BUILD.bazel

@@ -6,10 +6,12 @@ go_library(
         "archived_point.go",
         "backfill.go",
         "backup.go",
+        "blind_payload_envelope.go",
         "blocks.go",
         "checkpoint.go",
         "deposit_contract.go",
         "encoding.go",
+        "epbs.go",
         "error.go",
         "execution_chain.go",
         "finalized_block_roots.go",
@@ -70,6 +72,7 @@ go_library(
         "@com_github_schollz_progressbar_v3//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@io_etcd_go_bbolt//:go_default_library",
+        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )
@@ -80,10 +83,12 @@ go_test(
         "archived_point_test.go",
         "backfill_test.go",
         "backup_test.go",
+        "blind_payload_envelope_test.go",
         "blocks_test.go",
         "checkpoint_test.go",
         "deposit_contract_test.go",
         "encoding_test.go",
+        "epbs_test.go",
         "execution_chain_test.go",
         "finalized_block_roots_test.go",
         "genesis_test.go",
@@ -124,6 +129,7 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//testing/util/random:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_golang_snappy//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",

beacon-chain/db/kv/blind_payload_envelope.go

@@ -0,0 +1,45 @@
+package kv
+
+import (
+	"context"
+
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	bolt "go.etcd.io/bbolt"
+	"go.opencensus.io/trace"
+)
+
+// SaveBlindPayloadEnvelope saves a signed execution payload envelope blind in the database.
+func (s *Store) SaveBlindPayloadEnvelope(ctx context.Context, env *ethpb.SignedBlindPayloadEnvelope) error {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.SaveBlindPayloadEnvelope")
+	defer span.End()
+
+	enc, err := encode(ctx, env)
+	if err != nil {
+		return err
+	}
+
+	r := env.Message.BeaconBlockRoot
+	err = s.db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(executionPayloadEnvelopeBucket)
+		return bucket.Put(r, enc)
+	})
+
+	return err
+}
+
+// SignedBlindPayloadEnvelope retrieves a signed execution payload envelope blind from the database.
+func (s *Store) SignedBlindPayloadEnvelope(ctx context.Context, blockRoot []byte) (*ethpb.SignedBlindPayloadEnvelope, error) {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.SignedBlindPayloadEnvelope")
+	defer span.End()
+
+	env := &ethpb.SignedBlindPayloadEnvelope{}
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(executionPayloadEnvelopeBucket)
+		enc := bkt.Get(blockRoot)
+		if enc == nil {
+			return ErrNotFound
+		}
+		return decode(ctx, enc, env)
+	})
+	return env, err
+}

beacon-chain/db/kv/blind_payload_envelope_test.go

@@ -0,0 +1,23 @@
+package kv
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func TestStore_SignedBlindPayloadEnvelope(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	_, err := db.SignedBlindPayloadEnvelope(ctx, []byte("test"))
+	require.ErrorIs(t, err, ErrNotFound)
+
+	env := random.SignedBlindPayloadEnvelope(t)
+	err = db.SaveBlindPayloadEnvelope(ctx, env)
+	require.NoError(t, err)
+	got, err := db.SignedBlindPayloadEnvelope(ctx, env.Message.BeaconBlockRoot)
+	require.NoError(t, err)
+	require.DeepEqual(t, got, env)
+}

beacon-chain/db/kv/blocks.go

@@ -823,6 +823,11 @@ func unmarshalBlock(_ context.Context, enc []byte) (interfaces.ReadOnlySignedBea
 		if err := rawBlock.UnmarshalSSZ(enc[len(electraBlindKey):]); err != nil {
 			return nil, errors.Wrap(err, "could not unmarshal blinded Electra block")
 		}
+	case hasEpbsKey(enc):
+		rawBlock = &ethpb.SignedBeaconBlockEpbs{}
+		if err := rawBlock.UnmarshalSSZ(enc[len(epbsKey):]); err != nil {
+			return nil, errors.Wrap(err, "could not unmarshal EPBS block")
+		}
 	default:
 		// Marshal block bytes to phase 0 beacon block.
 		rawBlock = &ethpb.SignedBeaconBlock{}
@@ -852,6 +857,8 @@ func encodeBlock(blk interfaces.ReadOnlySignedBeaconBlock) ([]byte, error) {
 
 func keyForBlock(blk interfaces.ReadOnlySignedBeaconBlock) ([]byte, error) {
 	switch blk.Version() {
+	case version.EPBS:
+		return epbsKey, nil
 	case version.Electra:
 		if blk.IsBlinded() {
 			return electraBlindKey, nil

beacon-chain/db/kv/blocks_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -146,6 +147,17 @@ var blockTests = []struct {
 			}
 			return blocks.NewSignedBeaconBlock(b)
 		}},
+	{
+		name: "epbs",
+		newBlock: func(slot primitives.Slot, root []byte) (interfaces.ReadOnlySignedBeaconBlock, error) {
+			b := random.SignedBeaconBlock(&testing.T{})
+			b.Block.Slot = slot
+			if root != nil {
+				b.Block.ParentRoot = root
+			}
+			return blocks.NewSignedBeaconBlock(b)
+		},
+	},
 }
 
 func TestStore_SaveBlock_NoDuplicates(t *testing.T) {
@@ -202,7 +214,7 @@ func TestStore_BlocksCRUD(t *testing.T) {
 			retrievedBlock, err = db.Block(ctx, blockRoot)
 			require.NoError(t, err)
 			wanted := retrievedBlock
-			if retrievedBlock.Version() >= version.Bellatrix {
+			if retrievedBlock.Version() >= version.Bellatrix && retrievedBlock.Version() < version.EPBS {
 				wanted, err = retrievedBlock.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -390,7 +402,7 @@ func TestStore_BlocksCRUD_NoCache(t *testing.T) {
 			require.NoError(t, err)
 
 			wanted := blk
-			if blk.Version() >= version.Bellatrix {
+			if blk.Version() >= version.Bellatrix && blk.Version() < version.EPBS {
 				wanted, err = blk.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -609,7 +621,7 @@ func TestStore_SaveBlock_CanGetHighestAt(t *testing.T) {
 			b, err := db.Block(ctx, root)
 			require.NoError(t, err)
 			wanted := block1
-			if block1.Version() >= version.Bellatrix {
+			if block1.Version() >= version.Bellatrix && block1.Version() < version.EPBS {
 				wanted, err = wanted.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -627,7 +639,7 @@ func TestStore_SaveBlock_CanGetHighestAt(t *testing.T) {
 			b, err = db.Block(ctx, root)
 			require.NoError(t, err)
 			wanted2 := block2
-			if block2.Version() >= version.Bellatrix {
+			if block2.Version() >= version.Bellatrix && block2.Version() < version.EPBS {
 				wanted2, err = block2.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -645,7 +657,7 @@ func TestStore_SaveBlock_CanGetHighestAt(t *testing.T) {
 			b, err = db.Block(ctx, root)
 			require.NoError(t, err)
 			wanted = block3
-			if block3.Version() >= version.Bellatrix {
+			if block3.Version() >= version.Bellatrix && block3.Version() < version.EPBS {
 				wanted, err = wanted.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -681,7 +693,7 @@ func TestStore_GenesisBlock_CanGetHighestAt(t *testing.T) {
 			b, err := db.Block(ctx, root)
 			require.NoError(t, err)
 			wanted := block1
-			if block1.Version() >= version.Bellatrix {
+			if block1.Version() >= version.Bellatrix && block1.Version() < version.EPBS {
 				wanted, err = block1.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -698,7 +710,7 @@ func TestStore_GenesisBlock_CanGetHighestAt(t *testing.T) {
 			b, err = db.Block(ctx, root)
 			require.NoError(t, err)
 			wanted = genesisBlock
-			if genesisBlock.Version() >= version.Bellatrix {
+			if genesisBlock.Version() >= version.Bellatrix && genesisBlock.Version() < version.EPBS {
 				wanted, err = genesisBlock.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -715,7 +727,7 @@ func TestStore_GenesisBlock_CanGetHighestAt(t *testing.T) {
 			b, err = db.Block(ctx, root)
 			require.NoError(t, err)
 			wanted = genesisBlock
-			if genesisBlock.Version() >= version.Bellatrix {
+			if genesisBlock.Version() >= version.Bellatrix && genesisBlock.Version() < version.EPBS {
 				wanted, err = genesisBlock.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -811,7 +823,7 @@ func TestStore_BlocksBySlot_BlockRootsBySlot(t *testing.T) {
 			require.NoError(t, err)
 
 			wanted := b1
-			if b1.Version() >= version.Bellatrix {
+			if b1.Version() >= version.Bellatrix && b1.Version() < version.EPBS {
 				wanted, err = b1.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -827,7 +839,7 @@ func TestStore_BlocksBySlot_BlockRootsBySlot(t *testing.T) {
 				t.Fatalf("Expected 2 blocks, received %d blocks", len(retrievedBlocks))
 			}
 			wanted = b2
-			if b2.Version() >= version.Bellatrix {
+			if b2.Version() >= version.Bellatrix && b2.Version() < version.EPBS {
 				wanted, err = b2.ToBlinded()
 				require.NoError(t, err)
 			}
@@ -837,7 +849,7 @@ func TestStore_BlocksBySlot_BlockRootsBySlot(t *testing.T) {
 			require.NoError(t, err)
 			assert.Equal(t, true, proto.Equal(wantedPb, retrieved0Pb), "Wanted: %v, received: %v", retrievedBlocks[0], wanted)
 			wanted = b3
-			if b3.Version() >= version.Bellatrix {
+			if b3.Version() >= version.Bellatrix && b3.Version() < version.EPBS {
 				wanted, err = b3.ToBlinded()
 				require.NoError(t, err)
 			}

beacon-chain/db/kv/encoding.go

@@ -78,6 +78,8 @@ func isSSZStorageFormat(obj interface{}) bool {
 		return true
 	case *ethpb.VoluntaryExit:
 		return true
+	case *ethpb.SignedBlindPayloadEnvelope:
+		return true
 	case *ethpb.ValidatorRegistrationV1:
 		return true
 	default:

beacon-chain/db/kv/epbs.go

@@ -0,0 +1,18 @@
+package kv
+
+import (
+	"context"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+)
+
+func (s *Store) SignedExecutionPayloadHeader(ctx context.Context, blockRoot [32]byte) (interfaces.ROSignedExecutionPayloadHeader, error) {
+	b, err := s.Block(ctx, blockRoot)
+	if err != nil {
+		return nil, err
+	}
+	if b.IsNil() {
+		return nil, ErrNotFound
+	}
+	return b.Block().Body().SignedExecutionPayloadHeader()
+}

beacon-chain/db/kv/epbs_test.go

@@ -0,0 +1,28 @@
+package kv
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func Test_SignedExecutionPayloadHeader(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+
+	b := random.SignedBeaconBlock(t)
+	blk, err := blocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	blockRoot, err := blk.Block().HashTreeRoot()
+	require.NoError(t, err)
+
+	require.NoError(t, db.SaveBlock(ctx, blk))
+	retrievedHeader, err := db.SignedExecutionPayloadHeader(ctx, blockRoot)
+	require.NoError(t, err)
+	wantedHeader, err := blk.Block().Body().SignedExecutionPayloadHeader()
+	require.NoError(t, err)
+	require.DeepEqual(t, wantedHeader, retrievedHeader)
+}

beacon-chain/db/kv/key.go

@@ -65,3 +65,10 @@ func hasElectraBlindKey(enc []byte) bool {
 	}
 	return bytes.Equal(enc[:len(electraBlindKey)], electraBlindKey)
 }
+
+func hasEpbsKey(enc []byte) bool {
+	if len(epbsKey) >= len(enc) {
+		return false
+	}
+	return bytes.Equal(enc[:len(epbsKey)], epbsKey)
+}

beacon-chain/db/kv/kv.go

@@ -119,6 +119,9 @@ var Buckets = [][]byte{
 
 	feeRecipientBucket,
 	registrationBucket,
+
+	// ePBS
+	executionPayloadEnvelopeBucket,
 }
 
 // KVStoreOption is a functional option that modifies a kv.Store.

beacon-chain/db/kv/schema.go

@@ -7,15 +7,16 @@ package kv
 // it easy to scan for keys that have a certain shard number as a prefix and return those
 // corresponding attestations.
 var (
-	blocksBucket          = []byte("blocks")
-	stateBucket           = []byte("state")
-	stateSummaryBucket    = []byte("state-summary")
-	chainMetadataBucket   = []byte("chain-metadata")
-	checkpointBucket      = []byte("check-point")
-	powchainBucket        = []byte("powchain")
-	stateValidatorsBucket = []byte("state-validators")
-	feeRecipientBucket    = []byte("fee-recipient")
-	registrationBucket    = []byte("registration")
+	blocksBucket                   = []byte("blocks")
+	stateBucket                    = []byte("state")
+	stateSummaryBucket             = []byte("state-summary")
+	chainMetadataBucket            = []byte("chain-metadata")
+	checkpointBucket               = []byte("check-point")
+	powchainBucket                 = []byte("powchain")
+	stateValidatorsBucket          = []byte("state-validators")
+	feeRecipientBucket             = []byte("fee-recipient")
+	registrationBucket             = []byte("registration")
+	executionPayloadEnvelopeBucket = []byte("execution-payload-envelope")
 
 	// Light Client Updates Bucket
 	lightClientUpdatesBucket = []byte("light-client-updates")
@@ -53,6 +54,7 @@ var (
 	denebBlindKey              = []byte("blind-deneb")
 	electraKey                 = []byte("electra")
 	electraBlindKey            = []byte("blind-electra")
+	epbsKey                    = []byte("epbs")
 
 	// block root included in the beacon state used by weak subjectivity initial sync
 	originCheckpointBlockRootKey = []byte("origin-checkpoint-block-root")

beacon-chain/db/kv/state.go

@@ -252,6 +252,10 @@ func (s *Store) saveStatesEfficientInternal(ctx context.Context, tx *bolt.Tx, bl
 			if err := s.processElectra(ctx, rawType, rt[:], bucket, valIdxBkt, validatorKeys[i]); err != nil {
 				return err
 			}
+		case *ethpb.BeaconStateEPBS:
+			if err := s.processEPBS(ctx, rawType, rt[:], bucket, valIdxBkt, validatorKeys[i]); err != nil {
+				return err
+			}
 		default:
 			return errors.New("invalid state type")
 		}
@@ -367,6 +371,24 @@ func (s *Store) processElectra(ctx context.Context, pbState *ethpb.BeaconStateEl
 	return nil
 }
 
+func (s *Store) processEPBS(ctx context.Context, pbState *ethpb.BeaconStateEPBS, rootHash []byte, bucket, valIdxBkt *bolt.Bucket, validatorKey []byte) error {
+	valEntries := pbState.Validators
+	pbState.Validators = make([]*ethpb.Validator, 0)
+	rawObj, err := pbState.MarshalSSZ()
+	if err != nil {
+		return err
+	}
+	encodedState := snappy.Encode(nil, append(epbsKey, rawObj...))
+	if err := bucket.Put(rootHash, encodedState); err != nil {
+		return err
+	}
+	pbState.Validators = valEntries
+	if err := valIdxBkt.Put(rootHash, validatorKey); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (s *Store) storeValidatorEntriesSeparately(ctx context.Context, tx *bolt.Tx, validatorsEntries map[string]*ethpb.Validator) error {
 	valBkt := tx.Bucket(stateValidatorsBucket)
 	for hashStr, validatorEntry := range validatorsEntries {
@@ -516,6 +538,19 @@ func (s *Store) unmarshalState(_ context.Context, enc []byte, validatorEntries [
 	}
 
 	switch {
+	case hasEpbsKey(enc):
+		protoState := &ethpb.BeaconStateEPBS{}
+		if err := protoState.UnmarshalSSZ(enc[len(epbsKey):]); err != nil {
+			return nil, errors.Wrap(err, "failed to unmarshal encoding for EPBS")
+		}
+		ok, err := s.isStateValidatorMigrationOver()
+		if err != nil {
+			return nil, err
+		}
+		if ok {
+			protoState.Validators = validatorEntries
+		}
+		return statenative.InitializeFromProtoEpbs(protoState)
 	case hasElectraKey(enc):
 		protoState := &ethpb.BeaconStateElectra{}
 		if err := protoState.UnmarshalSSZ(enc[len(electraKey):]); err != nil {
@@ -675,6 +710,19 @@ func marshalState(ctx context.Context, st state.ReadOnlyBeaconState) ([]byte, er
 			return nil, err
 		}
 		return snappy.Encode(nil, append(electraKey, rawObj...)), nil
+	case *ethpb.BeaconStateEPBS:
+		rState, ok := st.ToProtoUnsafe().(*ethpb.BeaconStateEPBS)
+		if !ok {
+			return nil, errors.New("non valid inner state")
+		}
+		if rState == nil {
+			return nil, errors.New("nil state")
+		}
+		rawObj, err := rState.MarshalSSZ()
+		if err != nil {
+			return nil, err
+		}
+		return snappy.Encode(nil, append(epbsKey, rawObj...)), nil
 	default:
 		return nil, errors.New("invalid inner state")
 	}

beacon-chain/db/kv/state_test.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	statenative "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
 	"github.com/prysmaticlabs/prysm/v5/config/features"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
@@ -20,6 +21,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
 	bolt "go.etcd.io/bbolt"
 )
 
@@ -156,6 +158,16 @@ func TestState_CanSaveRetrieve(t *testing.T) {
 			},
 			rootSeed: 'E',
 		},
+		{
+			name: "epbs",
+			s: func() state.BeaconState {
+				stPb := random.BeaconState(t)
+				st, err := statenative.InitializeFromProtoUnsafeEpbs(stPb)
+				require.NoError(t, err)
+				return st
+			},
+			rootSeed: 'F',
+		},
 	}
 
 	db := setupDB(t)
@@ -1110,6 +1122,26 @@ func TestDenebState_CanDelete(t *testing.T) {
 	require.Equal(t, state.ReadOnlyBeaconState(nil), savedS, "Unsaved state should've been nil")
 }
 
+func TestEpbsState_CanDelete(t *testing.T) {
+	db := setupDB(t)
+
+	r := [32]byte{'A'}
+
+	require.Equal(t, false, db.HasState(context.Background(), r))
+
+	s := random.BeaconState(t)
+	st, err := statenative.InitializeFromProtoUnsafeEpbs(s)
+	require.NoError(t, err)
+
+	require.NoError(t, db.SaveState(context.Background(), st, r))
+	require.Equal(t, true, db.HasState(context.Background(), r))
+
+	require.NoError(t, db.DeleteState(context.Background(), r))
+	savedS, err := db.State(context.Background(), r)
+	require.NoError(t, err)
+	require.Equal(t, state.ReadOnlyBeaconState(nil), savedS, "Unsaved state should've been nil")
+}
+
 func TestStateDeneb_CanSaveRetrieveValidatorEntries(t *testing.T) {
 	db := setupDB(t)
 

beacon-chain/execution/service_test.go

@@ -73,7 +73,7 @@ type goodNotifier struct {
 	MockStateFeed *event.Feed
 }
 
-func (g *goodNotifier) StateFeed() event.SubscriberSender {
+func (g *goodNotifier) StateFeed() *event.Feed {
 	if g.MockStateFeed == nil {
 		g.MockStateFeed = new(event.Feed)
 	}

beacon-chain/forkchoice/BUILD.bazel

@@ -19,6 +19,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//consensus-types/forkchoice:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],

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

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "doc.go",
+        "epbs.go",
         "errors.go",
         "forkchoice.go",
         "last_root.go",
@@ -31,6 +32,7 @@ go_library(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/forkchoice:go_default_library",
+        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
@@ -47,6 +49,7 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "epbs_test.go",
         "ffg_update_test.go",
         "forkchoice_test.go",
         "last_root_test.go",
@@ -66,6 +69,7 @@ go_test(
         "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/forkchoice:go_default_library",
@@ -78,5 +82,6 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
     ],
 )

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

@@ -0,0 +1,80 @@
+package doublylinkedtree
+
+import (
+	"time"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+)
+
+func (n *Node) isParentFull() bool {
+	// Finalized checkpoint is considered full
+	if n.parent == nil || n.parent.parent == nil {
+		return true
+	}
+	return n.parent.payloadHash != [32]byte{}
+}
+
+func (f *ForkChoice) GetPTCVote() primitives.PTCStatus {
+	highestNode := f.store.highestReceivedNode
+	if highestNode == nil {
+		return primitives.PAYLOAD_ABSENT
+	}
+	if slots.CurrentSlot(f.store.genesisTime) > highestNode.slot {
+		return primitives.PAYLOAD_ABSENT
+	}
+	if highestNode.payloadHash == [32]byte{} {
+		return primitives.PAYLOAD_ABSENT
+	}
+	if highestNode.withheld {
+		return primitives.PAYLOAD_WITHHELD
+	}
+	return primitives.PAYLOAD_PRESENT
+}
+
+// InsertPayloadEnvelope adds a full node to forkchoice from the given payload
+// envelope.
+func (f *ForkChoice) InsertPayloadEnvelope(envelope interfaces.ROExecutionPayloadEnvelope) error {
+	s := f.store
+	b, ok := s.nodeByRoot[envelope.BeaconBlockRoot()]
+	if !ok {
+		return ErrNilNode
+	}
+	e, err := envelope.Execution()
+	if err != nil {
+		return err
+	}
+	hash := [32]byte(e.BlockHash())
+	if _, ok = s.nodeByPayload[hash]; ok {
+		// We ignore nodes with the give payload hash already included
+		return nil
+	}
+	n := &Node{
+		slot:                     b.slot,
+		root:                     b.root,
+		payloadHash:              hash,
+		parent:                   b.parent,
+		target:                   b.target,
+		children:                 make([]*Node, 0),
+		justifiedEpoch:           b.justifiedEpoch,
+		unrealizedJustifiedEpoch: b.unrealizedJustifiedEpoch,
+		finalizedEpoch:           b.finalizedEpoch,
+		unrealizedFinalizedEpoch: b.unrealizedFinalizedEpoch,
+		timestamp:                uint64(time.Now().Unix()),
+		ptcVote:                  make([]primitives.PTCStatus, 0),
+		withheld:                 envelope.PayloadWithheld(),
+		optimistic:               true,
+	}
+	if n.parent != nil {
+		n.parent.children = append(n.parent.children, n)
+	}
+	s.nodeByPayload[hash] = n
+	processedPayloadCount.Inc()
+	payloadCount.Set(float64(len(s.nodeByPayload)))
+
+	if b.slot == s.highestReceivedNode.slot {
+		s.highestReceivedNode = n
+	}
+	return nil
+}

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

@@ -0,0 +1,213 @@
+package doublylinkedtree
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+)
+
+func TestStore_Insert_PayloadContent(t *testing.T) {
+	ctx := context.Background()
+	f := setup(0, 0)
+	s := f.store
+	// The tree root is full
+	fr := [32]byte{}
+	n := s.nodeByRoot[fr]
+	require.Equal(t, true, n.isParentFull())
+
+	// Insert a child with a payload
+	cr := [32]byte{'a'}
+	cp := [32]byte{'p'}
+	n, err := s.insert(ctx, 1, cr, fr, cp, fr, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, true, n.isParentFull())
+	require.Equal(t, s.treeRootNode, n.parent)
+	require.Equal(t, s.nodeByRoot[cr], n)
+
+	// Insert a grandchild without a payload
+	gr := [32]byte{'b'}
+	gn, err := s.insert(ctx, 2, gr, cr, fr, cp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, true, gn.isParentFull())
+	require.Equal(t, n, gn.parent)
+
+	// Insert the payload of the same grandchild
+	gp := [32]byte{'q'}
+	gfn, err := s.insert(ctx, 2, gr, cr, gp, cp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, true, gfn.isParentFull())
+	require.Equal(t, n, gfn.parent)
+
+	// Insert an empty great grandchild based on empty
+	ggr := [32]byte{'c'}
+	ggn, err := s.insert(ctx, 3, ggr, gr, fr, cp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, false, ggn.isParentFull())
+	require.Equal(t, gn, ggn.parent)
+
+	// Insert an empty great grandchild based on full
+	ggfr := [32]byte{'d'}
+	ggfn, err := s.insert(ctx, 3, ggfr, gr, fr, gp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, gfn, ggfn.parent)
+	require.Equal(t, true, ggfn.isParentFull())
+
+	// Insert the payload for the great grandchild based on empty
+	ggp := [32]byte{'r'}
+	n, err = s.insert(ctx, 3, ggr, gr, ggp, cp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, false, n.isParentFull())
+	require.Equal(t, gn, n.parent)
+
+	// Insert the payload for the great grandchild based on full
+	ggfp := [32]byte{'s'}
+	n, err = s.insert(ctx, 3, ggfr, gr, ggfp, gp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, true, n.isParentFull())
+	require.Equal(t, gfn, n.parent)
+
+	// Reinsert an empty node
+	ggfn2, err := s.insert(ctx, 3, ggfr, gr, fr, gp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, ggfn, ggfn2)
+
+	// Reinsert a full node
+	n2, err := s.insert(ctx, 3, ggfr, gr, ggfp, gp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, n, n2)
+}
+
+func TestStore_Insert_PayloadEnvelope(t *testing.T) {
+	ctx := context.Background()
+	f := setup(0, 0)
+	s := f.store
+	// The tree root is full
+	fr := [32]byte{}
+	n := s.nodeByRoot[fr]
+	require.Equal(t, true, n.isParentFull())
+
+	// Insert a child
+	cr := [32]byte{'a'}
+	cp := [32]byte{'p'}
+	n, err := s.insert(ctx, 1, cr, fr, [32]byte{}, fr, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, true, n.isParentFull())
+	require.Equal(t, s.treeRootNode, n.parent)
+	require.Equal(t, s.nodeByRoot[cr], n)
+	// Insert its payload
+	p := &enginev1.ExecutionPayloadEnvelope{
+		Payload: &enginev1.ExecutionPayloadElectra{
+			BlockHash: cp[:],
+		},
+		BeaconBlockRoot:    cr[:],
+		PayloadWithheld:    false,
+		StateRoot:          fr[:],
+		BlobKzgCommitments: make([][]byte, 0),
+	}
+	e, err := blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	require.NoError(t, f.InsertPayloadEnvelope(e))
+	np := s.nodeByPayload[cp]
+	require.Equal(t, np.root, n.root)
+	require.NotEqual(t, np, n)
+
+	// Insert a grandchild without a payload, it's parent is the full node,
+	// which is not the empty node
+	gr := [32]byte{'b'}
+	gn, err := s.insert(ctx, 2, gr, cr, fr, cp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, true, gn.isParentFull())
+	require.Equal(t, np, gn.parent)
+
+	// Insert the payload of the same grandchild
+	gp := [32]byte{'q'}
+	p = &enginev1.ExecutionPayloadEnvelope{
+		Payload: &enginev1.ExecutionPayloadElectra{
+			BlockHash: gp[:],
+		},
+		BeaconBlockRoot:    gr[:],
+		PayloadWithheld:    false,
+		StateRoot:          fr[:],
+		BlobKzgCommitments: make([][]byte, 0),
+	}
+	e, err = blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	require.NoError(t, f.InsertPayloadEnvelope(e))
+	gfn := s.nodeByPayload[gp]
+	require.Equal(t, true, gfn.isParentFull())
+	require.Equal(t, np, gfn.parent)
+
+	// Insert an empty great grandchild based on empty
+	ggr := [32]byte{'c'}
+	ggn, err := s.insert(ctx, 3, ggr, gr, fr, cp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, false, ggn.isParentFull())
+	require.Equal(t, gn, ggn.parent)
+
+	// Insert an empty great grandchild based on full
+	ggfr := [32]byte{'d'}
+	ggfn, err := s.insert(ctx, 3, ggfr, gr, fr, gp, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, gfn, ggfn.parent)
+	require.Equal(t, true, ggfn.isParentFull())
+
+	// Insert the payload for the great grandchild based on empty
+	ggp := [32]byte{'r'}
+	p = &enginev1.ExecutionPayloadEnvelope{
+		Payload: &enginev1.ExecutionPayloadElectra{
+			BlockHash: ggp[:],
+		},
+		BeaconBlockRoot:    ggr[:],
+		PayloadWithheld:    false,
+		StateRoot:          fr[:],
+		BlobKzgCommitments: make([][]byte, 0),
+	}
+	e, err = blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	require.NoError(t, f.InsertPayloadEnvelope(e))
+	n = s.nodeByPayload[ggp]
+	require.Equal(t, false, n.isParentFull())
+	require.Equal(t, gn, n.parent)
+
+	// Insert the payload for the great grandchild based on full
+	ggfp := [32]byte{'s'}
+	p = &enginev1.ExecutionPayloadEnvelope{
+		Payload: &enginev1.ExecutionPayloadElectra{
+			BlockHash: ggfp[:],
+		},
+		BeaconBlockRoot:    ggfr[:],
+		PayloadWithheld:    false,
+		StateRoot:          fr[:],
+		BlobKzgCommitments: make([][]byte, 0),
+	}
+	e, err = blocks.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	require.NoError(t, f.InsertPayloadEnvelope(e))
+	n = s.nodeByPayload[ggfp]
+	require.Equal(t, true, n.isParentFull())
+	require.Equal(t, gfn, n.parent)
+}
+
+func TestGetPTCVote(t *testing.T) {
+	ctx := context.Background()
+	f := setup(0, 0)
+	s := f.store
+	require.NotNil(t, s.highestReceivedNode)
+	fr := [32]byte{}
+
+	// Insert a child with a payload
+	cr := [32]byte{'a'}
+	cp := [32]byte{'p'}
+	n, err := s.insert(ctx, 1, cr, fr, cp, fr, 0, 0)
+	require.NoError(t, err)
+	require.Equal(t, n, s.highestReceivedNode)
+	require.Equal(t, primitives.PAYLOAD_ABSENT, f.GetPTCVote())
+	driftGenesisTime(f, 1, 0)
+	require.Equal(t, primitives.PAYLOAD_PRESENT, f.GetPTCVote())
+	n.withheld = true
+	require.Equal(t, primitives.PAYLOAD_WITHHELD, f.GetPTCVote())
+}

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

@@ -80,7 +80,7 @@ func (f *ForkChoice) Head(
 
 // ProcessAttestation processes attestation for vote accounting, it iterates around validator indices
 // and update their votes accordingly.
-func (f *ForkChoice) ProcessAttestation(ctx context.Context, validatorIndices []uint64, blockRoot [32]byte, targetEpoch primitives.Epoch) {
+func (f *ForkChoice) ProcessAttestation(ctx context.Context, validatorIndices []uint64, blockRoot [32]byte, attSlot primitives.Slot) {
 	_, span := trace.StartSpan(ctx, "doublyLinkedForkchoice.ProcessAttestation")
 	defer span.End()
 
@@ -94,9 +94,9 @@ func (f *ForkChoice) ProcessAttestation(ctx context.Context, validatorIndices []
 		newVote := f.votes[index].nextRoot == params.BeaconConfig().ZeroHash &&
 			f.votes[index].currentRoot == params.BeaconConfig().ZeroHash
 
-		// Vote gets updated if it's newly allocated or high target epoch.
-		if newVote || targetEpoch > f.votes[index].nextEpoch {
-			f.votes[index].nextEpoch = targetEpoch
+		// Vote gets updated if it's newly allocated or higher attestation slot.
+		if newVote || attSlot > f.votes[index].slot {
+			f.votes[index].slot = attSlot
 			f.votes[index].nextRoot = blockRoot
 		}
 	}
@@ -115,8 +115,14 @@ func (f *ForkChoice) InsertNode(ctx context.Context, state state.BeaconState, ro
 		return errNilBlockHeader
 	}
 	parentRoot := bytesutil.ToBytes32(bh.ParentRoot)
-	var payloadHash [32]byte
-	if state.Version() >= version.Bellatrix {
+	var payloadHash, parentHash [32]byte
+	if state.Version() >= version.EPBS {
+		latestHash, err := state.LatestBlockHash()
+		if err != nil {
+			return err
+		}
+		copy(parentHash[:], latestHash)
+	} else if state.Version() >= version.Bellatrix {
 		ph, err := state.LatestExecutionPayloadHeader()
 		if err != nil {
 			return err
@@ -135,7 +141,7 @@ func (f *ForkChoice) InsertNode(ctx context.Context, state state.BeaconState, ro
 		return errInvalidNilCheckpoint
 	}
 	finalizedEpoch := fc.Epoch
-	node, err := f.store.insert(ctx, slot, root, parentRoot, payloadHash, justifiedEpoch, finalizedEpoch)
+	node, err := f.store.insert(ctx, slot, root, parentRoot, payloadHash, parentHash, justifiedEpoch, finalizedEpoch)
 	if err != nil {
 		return err
 	}
@@ -170,6 +176,13 @@ func (f *ForkChoice) HasNode(root [32]byte) bool {
 	return ok
 }
 
+// HasHash returns true if the node with the given payload hash exists in fork choice store,
+// false else wise.
+func (f *ForkChoice) HasHash(hash [32]byte) bool {
+	_, ok := f.store.nodeByPayload[hash]
+	return ok
+}
+
 // IsCanonical returns true if the given root is part of the canonical chain.
 func (f *ForkChoice) IsCanonical(root [32]byte) bool {
 	node, ok := f.store.nodeByRoot[root]
@@ -490,8 +503,12 @@ func (f *ForkChoice) InsertChain(ctx context.Context, chain []*forkchoicetypes.B
 		if err != nil {
 			return err
 		}
+		parentHash, err := blocks.GetBlockParentHash(b)
+		if err != nil {
+			return err
+		}
 		if _, err := f.store.insert(ctx,
-			b.Slot(), r, parentRoot, payloadHash,
+			b.Slot(), r, parentRoot, payloadHash, parentHash,
 			chain[i].JustifiedCheckpoint.Epoch, chain[i].FinalizedCheckpoint.Epoch); err != nil {
 			return err
 		}
@@ -691,3 +708,62 @@ func (f *ForkChoice) ParentRoot(root [32]byte) ([32]byte, error) {
 	}
 	return n.parent.root, nil
 }
+
+// UpdateVotesOnPayloadAttestation processes a new aggregated
+// payload attestation message and updates
+// the Payload Timeliness Committee (PTC) votes for the corresponding block.
+func (s *Store) updateVotesOnPayloadAttestation(
+	payloadAttestation *ethpb.PayloadAttestation) error {
+	// Extract the attestation data and convert the beacon block root to a 32-byte array
+	data := payloadAttestation.Data
+	blockRoot := bytesutil.ToBytes32(data.BeaconBlockRoot)
+
+	// Check if the block exists in the store
+	node, ok := s.nodeByRoot[blockRoot]
+	if !ok || node == nil {
+		return ErrNilNode
+	}
+
+	// Update the PTC votes based on the attestation
+	// We only set the vote if it hasn't been set before
+	// to handle potential equivocations
+	for i := uint64(0); i < fieldparams.PTCSize; i++ {
+		if payloadAttestation.AggregationBits.BitAt(i) && node.ptcVote[i] == primitives.PAYLOAD_ABSENT {
+			node.ptcVote[i] = data.PayloadStatus
+		}
+	}
+
+	return nil
+}
+
+// updatePayloadBoosts checks the PTC votes for a given node and updates
+// the payload reveal and withhold boost roots if the necessary thresholds are met.
+func (s *Store) updatePayloadBoosts(node *Node) {
+	presentCount := 0
+	withheldCount := 0
+
+	// Count the number of PRESENT and WITHHELD votes
+	for _, vote := range node.ptcVote {
+		if vote == primitives.PAYLOAD_PRESENT {
+			presentCount++
+		} else if vote == primitives.PAYLOAD_WITHHELD {
+			withheldCount++
+		}
+	}
+
+	// If the number of PRESENT votes exceeds the threshold,
+	// update the payload reveal boost root
+	if presentCount > int(params.BeaconConfig().PayloadTimelyThreshold) {
+		s.payloadRevealBoostRoot = node.root
+		return
+	}
+	// If the number of WITHHELD votes exceeds the threshold,
+	// update the payload reveal boost root
+	if withheldCount > int(params.BeaconConfig().PayloadTimelyThreshold) {
+		if node.parent != nil {
+			s.payloadWithholdBoostRoot = node.parent.root
+			// A node is considered "full" if it has a non-zero payload hash
+			s.payloadWithholdBoostFull = node.parent.payloadHash != [32]byte{}
+		}
+	}
+}

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

@@ -6,14 +6,17 @@ import (
 	"testing"
 	"time"
 
+	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v5/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	"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/crypto/hash"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
 	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
@@ -22,7 +25,8 @@ import (
 )
 
 // prepareForkchoiceState prepares a beacon State with the given data to mock
-// insert into forkchoice
+// insert into forkchoice. This method prepares full states and blocks for
+// bellatrix, it cannot be used for ePBS tests.
 func prepareForkchoiceState(
 	_ context.Context,
 	slot primitives.Slot,
@@ -61,6 +65,14 @@ func prepareForkchoiceState(
 	return st, blockRoot, err
 }
 
+// Helper function to set all bits in a Bitvector512
+func setAllBits(bv bitfield.Bitvector512) bitfield.Bitvector512 {
+	for i := 0; i < len(bv); i++ {
+		bv[i] = 0xFF
+	}
+	return bv
+}
+
 func TestForkChoice_UpdateBalancesPositiveChange(t *testing.T) {
 	f := setup(0, 0)
 	ctx := context.Background()
@@ -887,3 +899,227 @@ func TestForkchoiceParentRoot(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, zeroHash, root)
 }
+
+func TestStore_UpdateVotesOnPayloadAttestation(t *testing.T) {
+	tests := []struct {
+		name               string
+		setupStore         func(*Store)
+		payloadAttestation *ethpb.PayloadAttestation
+		wantErr            bool
+		expectedPTCVotes   []primitives.PTCStatus
+		expectedBoosts     func(*Store) bool
+	}{
+		{
+			name:       "Unknown block root",
+			setupStore: func(_ *Store) {},
+			payloadAttestation: &ethpb.PayloadAttestation{
+				Data: &ethpb.PayloadAttestationData{
+					BeaconBlockRoot: []byte{1, 2, 3},
+				},
+			},
+			wantErr: true,
+		},
+		{
+			name: "Update PTC votes - all present",
+			setupStore: func(s *Store) {
+				root := [32]byte{1, 2, 3}
+				s.nodeByRoot[root] = &Node{root: root, ptcVote: make([]primitives.PTCStatus, fieldparams.PTCSize)}
+			},
+			payloadAttestation: &ethpb.PayloadAttestation{
+				Data: &ethpb.PayloadAttestationData{
+					BeaconBlockRoot: []byte{1, 2, 3},
+					PayloadStatus:   primitives.PAYLOAD_PRESENT,
+				},
+				AggregationBits: setAllBits(bitfield.NewBitvector512()),
+			},
+			expectedPTCVotes: func() []primitives.PTCStatus {
+				return makeVotes(fieldparams.PTCSize, primitives.PAYLOAD_PRESENT)
+			}(),
+			expectedBoosts: noBoosts,
+		},
+		{
+			name: "Update PTC votes - all withheld",
+			setupStore: func(s *Store) {
+				root := [32]byte{4, 5, 6}
+				s.nodeByRoot[root] = &Node{root: root, ptcVote: make([]primitives.PTCStatus, fieldparams.PTCSize)}
+			},
+			payloadAttestation: &ethpb.PayloadAttestation{
+				Data: &ethpb.PayloadAttestationData{
+					BeaconBlockRoot: []byte{4, 5, 6},
+					PayloadStatus:   primitives.PAYLOAD_WITHHELD,
+				},
+				AggregationBits: setAllBits(bitfield.NewBitvector512()),
+			},
+			expectedPTCVotes: func() []primitives.PTCStatus {
+				return makeVotes(fieldparams.PTCSize, primitives.PAYLOAD_WITHHELD)
+			}(),
+			expectedBoosts: noBoosts,
+		},
+		{
+			name: "Update PTC votes - partial attestation",
+			setupStore: func(s *Store) {
+				root := [32]byte{7, 8, 9}
+				s.nodeByRoot[root] = &Node{root: root, ptcVote: make([]primitives.PTCStatus, fieldparams.PTCSize)}
+			},
+			payloadAttestation: &ethpb.PayloadAttestation{
+				Data: &ethpb.PayloadAttestationData{
+					BeaconBlockRoot: []byte{7, 8, 9},
+					PayloadStatus:   primitives.PAYLOAD_PRESENT,
+				},
+				AggregationBits: func() bitfield.Bitvector512 {
+					bits := bitfield.NewBitvector512()
+					for i := 0; i < fieldparams.PTCSize/2; i++ {
+						bits.SetBitAt(uint64(i), true)
+					}
+					return bits
+				}(),
+			},
+			expectedPTCVotes: func() []primitives.PTCStatus {
+				votes := make([]primitives.PTCStatus, fieldparams.PTCSize)
+				for i := 0; i < fieldparams.PTCSize/2; i++ {
+					votes[i] = primitives.PAYLOAD_PRESENT
+				}
+				return votes
+			}(),
+			expectedBoosts: noBoosts,
+		},
+		{
+			name: "Update PTC votes - no change for already set votes",
+			setupStore: func(s *Store) {
+				root := [32]byte{10, 11, 12}
+				votes := make([]primitives.PTCStatus, fieldparams.PTCSize)
+				for i := range votes {
+					if i%2 == 0 {
+						votes[i] = primitives.PAYLOAD_PRESENT
+					}
+				}
+				s.nodeByRoot[root] = &Node{root: root, ptcVote: votes}
+			},
+			payloadAttestation: &ethpb.PayloadAttestation{
+				Data: &ethpb.PayloadAttestationData{
+					BeaconBlockRoot: []byte{10, 11, 12},
+					PayloadStatus:   primitives.PAYLOAD_WITHHELD,
+				},
+				AggregationBits: setAllBits(bitfield.NewBitvector512()),
+			},
+			expectedPTCVotes: func() []primitives.PTCStatus {
+				votes := make([]primitives.PTCStatus, fieldparams.PTCSize)
+				for i := range votes {
+					if i%2 == 0 {
+						votes[i] = primitives.PAYLOAD_PRESENT
+					} else {
+						votes[i] = primitives.PAYLOAD_WITHHELD
+					}
+				}
+				return votes
+			}(),
+			expectedBoosts: noBoosts,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := &Store{
+				nodeByRoot: make(map[[32]byte]*Node),
+			}
+			tt.setupStore(s)
+
+			err := s.updateVotesOnPayloadAttestation(tt.payloadAttestation)
+
+			if tt.wantErr {
+				require.ErrorIs(t, err, ErrNilNode, "Expected ErrNilNode")
+			} else {
+				require.NoError(t, err)
+				node := s.nodeByRoot[bytesutil.ToBytes32(tt.payloadAttestation.Data.BeaconBlockRoot)]
+				assert.DeepEqual(t, tt.expectedPTCVotes, node.ptcVote, "Unexpected PTC votes")
+				assert.Equal(t, tt.expectedBoosts(s), true, "Unexpected boost values")
+			}
+		})
+	}
+}
+
+func makeVotes(count int, status primitives.PTCStatus) []primitives.PTCStatus {
+	votes := make([]primitives.PTCStatus, fieldparams.PTCSize)
+	for i := 0; i < count; i++ {
+		votes[i] = status
+	}
+	return votes
+}
+
+func noBoosts(s *Store) bool {
+	return s.payloadRevealBoostRoot == [32]byte{} &&
+		s.payloadWithholdBoostRoot == [32]byte{} &&
+		!s.payloadWithholdBoostFull
+}
+
+func TestStore_UpdatePayloadBoosts(t *testing.T) {
+	tests := []struct {
+		name                  string
+		setupNode             func(*Node)
+		expectedRevealBoost   [32]byte
+		expectedWithholdBoost [32]byte
+		expectedWithholdFull  bool
+	}{
+		{
+			name: "No boost",
+			setupNode: func(n *Node) {
+				n.ptcVote = make([]primitives.PTCStatus, fieldparams.PTCSize)
+			},
+		},
+		{
+			name: "Reveal boost",
+			setupNode: func(n *Node) {
+				n.root = [32]byte{1, 2, 3}
+				n.ptcVote = make([]primitives.PTCStatus, fieldparams.PTCSize)
+				for i := 0; i < int(params.BeaconConfig().PayloadTimelyThreshold)+1; i++ {
+					n.ptcVote[i] = primitives.PAYLOAD_PRESENT
+				}
+			},
+			expectedRevealBoost: [32]byte{1, 2, 3},
+		},
+		{
+			name: "Withhold boost",
+			setupNode: func(n *Node) {
+				n.ptcVote = make([]primitives.PTCStatus, fieldparams.PTCSize)
+				for i := 0; i < int(params.BeaconConfig().PayloadTimelyThreshold)+1; i++ {
+					n.ptcVote[i] = primitives.PAYLOAD_WITHHELD
+				}
+				n.parent = &Node{root: [32]byte{4, 5, 6}, payloadHash: [32]byte{7, 8, 9}}
+			},
+			expectedWithholdBoost: [32]byte{4, 5, 6},
+			expectedWithholdFull:  true,
+		},
+		{
+			name: "Reveal boost with early return",
+			setupNode: func(n *Node) {
+				n.root = [32]byte{1, 2, 3}
+				n.ptcVote = make([]primitives.PTCStatus, fieldparams.PTCSize)
+				for i := 0; i < int(params.BeaconConfig().PayloadTimelyThreshold)+1; i++ {
+					n.ptcVote[i] = primitives.PAYLOAD_PRESENT
+				}
+				// Set up conditions for withhold boost, which should not be applied due to early return
+				n.parent = &Node{root: [32]byte{4, 5, 6}, payloadHash: [32]byte{7, 8, 9}}
+				for i := int(params.BeaconConfig().PayloadTimelyThreshold) + 1; i < fieldparams.PTCSize; i++ {
+					n.ptcVote[i] = primitives.PAYLOAD_WITHHELD
+				}
+			},
+			expectedRevealBoost:   [32]byte{1, 2, 3},
+			expectedWithholdBoost: [32]byte{}, // Should remain zero due to early return
+			expectedWithholdFull:  false,      // Should remain false due to early return
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := &Store{}
+			n := &Node{}
+			tt.setupNode(n)
+
+			s.updatePayloadBoosts(n)
+
+			assert.Equal(t, tt.expectedRevealBoost, s.payloadRevealBoostRoot, "Unexpected reveal boost root")
+			assert.Equal(t, tt.expectedWithholdBoost, s.payloadWithholdBoostRoot, "Unexpected withhold boost root")
+			assert.Equal(t, tt.expectedWithholdFull, s.payloadWithholdBoostFull, "Unexpected withhold full status")
+		})
+	}
+}

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

@@ -18,7 +18,13 @@ var (
 	nodeCount = promauto.NewGauge(
 		prometheus.GaugeOpts{
 			Name: "doublylinkedtree_node_count",
-			Help: "The number of nodes in the doubly linked tree based store structure.",
+			Help: "The number of nodes for blocks in the doubly linked tree based store structure.",
+		},
+	)
+	payloadCount = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "doublylinkedtree_payload_count",
+			Help: "The number of nodes for execution payloads in the doubly linked tree based store structure.",
 		},
 	)
 	headChangesCount = promauto.NewCounter(
@@ -39,6 +45,12 @@ var (
 			Help: "The number of times a block is processed for fork choice.",
 		},
 	)
+	processedPayloadCount = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "doublylinkedtree_payload_processed_count",
+			Help: "The number of times an execution payload is processed for fork choice.",
+		},
+	)
 	processedAttestationCount = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "doublylinkedtree_attestation_processed_count",

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

@@ -9,6 +9,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
 )
 
 // Helper function to simulate the block being on time or delayed for proposer
@@ -61,7 +62,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		)
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-		f.ProcessAttestation(ctx, []uint64{0}, newRoot, fEpoch)
+		fSlot, err := slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, []uint64{0}, newRoot, fSlot)
 		headRoot, err = f.Head(ctx)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 1")
@@ -87,7 +90,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		)
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-		f.ProcessAttestation(ctx, []uint64{1}, newRoot, fEpoch)
+		fSlot, err = slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, []uint64{1}, newRoot, fSlot)
 		headRoot, err = f.Head(ctx)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 2")
@@ -115,7 +120,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		)
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-		f.ProcessAttestation(ctx, []uint64{2}, newRoot, fEpoch)
+		fSlot, err = slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, []uint64{2}, newRoot, fSlot)
 		headRoot, err = f.Head(ctx)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 3")
@@ -144,7 +151,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		)
 		require.NoError(t, err)
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
-		f.ProcessAttestation(ctx, []uint64{3}, newRoot, fEpoch)
+		fSlot, err = slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, []uint64{3}, newRoot, fSlot)
 		headRoot, err = f.Head(ctx)
 		require.NoError(t, err)
 		assert.Equal(t, newRoot, headRoot, "Incorrect head for justified epoch at slot 3")
@@ -174,7 +183,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 
 		// Regression: process attestations for C, check that it
 		// becomes head, we need two attestations to have C.weight = 30 > 24 = D.weight
-		f.ProcessAttestation(ctx, []uint64{4, 5}, indexToHash(3), fEpoch)
+		fSlot, err = slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, []uint64{4, 5}, indexToHash(3), fSlot)
 		headRoot, err = f.Head(ctx)
 		require.NoError(t, err)
 		assert.Equal(t, indexToHash(3), headRoot, "Incorrect head for justified epoch at slot 4")
@@ -235,10 +246,14 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 
 		// The maliciously withheld block has one vote.
 		votes := []uint64{1}
-		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fEpoch)
+		fSlot, err := slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fSlot)
 		// The honest block has one vote.
 		votes = []uint64{2}
-		f.ProcessAttestation(ctx, votes, honestBlock, fEpoch)
+		fSlot, err = slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, votes, honestBlock, fSlot)
 
 		// Ensure the head is STILL C, the honest block, as the honest block had proposer boost.
 		r, err = f.Head(ctx)
@@ -304,7 +319,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// An attestation is received for B that has more voting power than C with the proposer boost,
 		// allowing B to then become the head if their attestation has enough adversarial votes.
 		votes := []uint64{1, 2}
-		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fEpoch)
+		fSlot, err := slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, votes, maliciouslyWithheldBlock, fSlot)
 
 		// Expect the head to have switched to B.
 		r, err = f.Head(ctx)
@@ -379,7 +396,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 
 		// An attestation for C is received at slot N+3.
 		votes := []uint64{1}
-		f.ProcessAttestation(ctx, votes, c, fEpoch)
+		fSlot, err := slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, votes, c, fSlot)
 
 		// A block D, building on B, is received at slot N+3. It should not be able to win without boosting.
 		dSlot := primitives.Slot(3)
@@ -419,7 +438,9 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		require.NoError(t, f.InsertNode(ctx, state, blkRoot))
 
 		votes = []uint64{2}
-		f.ProcessAttestation(ctx, votes, d2, fEpoch)
+		fSlot, err = slots.EpochStart(fEpoch)
+		require.NoError(t, err)
+		f.ProcessAttestation(ctx, votes, d2, fSlot)
 		// Ensure D becomes the head thanks to boosting.
 		r, err = f.Head(ctx)
 		require.NoError(t, err)

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

@@ -62,20 +62,32 @@ func (s *Store) head(ctx context.Context) ([32]byte, error) {
 
 // insert registers a new block node to the fork choice store's node list.
 // It then updates the new node's parent with the best child and descendant node.
-func (s *Store) insert(ctx context.Context,
+func (s *Store) insert(
+	ctx context.Context,
 	slot primitives.Slot,
-	root, parentRoot, payloadHash [fieldparams.RootLength]byte,
-	justifiedEpoch, finalizedEpoch primitives.Epoch) (*Node, error) {
+	root, parentRoot, payloadHash, parentHash [fieldparams.RootLength]byte,
+	justifiedEpoch, finalizedEpoch primitives.Epoch,
+) (*Node, error) {
 	ctx, span := trace.StartSpan(ctx, "doublyLinkedForkchoice.insert")
 	defer span.End()
 
 	// Return if the block has been inserted into Store before.
-	if n, ok := s.nodeByRoot[root]; ok {
-		return n, nil
+	n, rootPresent := s.nodeByRoot[root]
+	m, hashPresent := s.nodeByPayload[payloadHash]
+	if rootPresent {
+		if payloadHash == [32]byte{} {
+			return n, nil
+		}
+		if hashPresent {
+			return m, nil
+		}
 	}
-
 	parent := s.nodeByRoot[parentRoot]
-	n := &Node{
+	fullParent := s.nodeByPayload[parentHash]
+	if fullParent != nil && parent != nil && fullParent.root == parent.root {
+		parent = fullParent
+	}
+	n = &Node{
 		slot:                     slot,
 		root:                     root,
 		parent:                   parent,
@@ -99,17 +111,22 @@ func (s *Store) insert(ctx context.Context,
 		}
 	}
 
-	s.nodeByPayload[payloadHash] = n
-	s.nodeByRoot[root] = n
 	if parent == nil {
 		if s.treeRootNode == nil {
 			s.treeRootNode = n
 			s.headNode = n
 			s.highestReceivedNode = n
-		} else {
+		} else if s.treeRootNode.root != n.root {
 			return n, errInvalidParentRoot
 		}
-	} else {
+	}
+	if !rootPresent {
+		s.nodeByRoot[root] = n
+	}
+	if !hashPresent {
+		s.nodeByPayload[payloadHash] = n
+	}
+	if parent != nil {
 		parent.children = append(parent.children, n)
 		// Apply proposer boost
 		timeNow := uint64(time.Now().Unix())
@@ -232,12 +249,12 @@ func (s *Store) tips() ([][32]byte, []primitives.Slot) {
 	return roots, slots
 }
 
-// HighestReceivedBlockSlot returns the highest slot received by the forkchoice
-func (f *ForkChoice) HighestReceivedBlockSlot() primitives.Slot {
+// HighestReceivedBlockSlotRoot returns the highest slot and root received by the forkchoice
+func (f *ForkChoice) HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte) {
 	if f.store.highestReceivedNode == nil {
-		return 0
+		return 0, [32]byte{}
 	}
-	return f.store.highestReceivedNode.slot
+	return f.store.highestReceivedNode.slot, f.store.highestReceivedNode.root
 }
 
 // HighestReceivedBlockSlotDelay returns the number of slots that the highest

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

@@ -133,7 +133,7 @@ func TestStore_Insert(t *testing.T) {
 	fc := &forkchoicetypes.Checkpoint{Epoch: 0}
 	s := &Store{nodeByRoot: nodeByRoot, treeRootNode: treeRootNode, nodeByPayload: nodeByPayload, justifiedCheckpoint: jc, finalizedCheckpoint: fc, highestReceivedNode: &Node{}}
 	payloadHash := [32]byte{'a'}
-	_, err := s.insert(context.Background(), 100, indexToHash(100), indexToHash(0), payloadHash, 1, 1)
+	_, err := s.insert(context.Background(), 100, indexToHash(100), indexToHash(0), payloadHash, payloadHash, 1, 1)
 	require.NoError(t, err)
 	assert.Equal(t, 2, len(s.nodeByRoot), "Did not insert block")
 	assert.Equal(t, (*Node)(nil), treeRootNode.parent, "Incorrect parent")
@@ -327,107 +327,116 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 
 	// Make sure it doesn't underflow
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-1*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
-	_, err := s.insert(context.Background(), 1, [32]byte{'a'}, b, b, 1, 1)
+	_, err := s.insert(context.Background(), 1, [32]byte{'a'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	count, err := f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
-	require.Equal(t, primitives.Slot(1), f.HighestReceivedBlockSlot())
+	slot, _ := f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(1), slot)
 	require.Equal(t, primitives.Slot(0), f.HighestReceivedBlockDelay())
 
 	// 64
 	// Received block last epoch is 1
-	_, err = s.insert(context.Background(), 64, [32]byte{'A'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 64, [32]byte{'A'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration((-64*int64(params.BeaconConfig().SecondsPerSlot))-1) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
-	require.Equal(t, primitives.Slot(64), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(64), slot)
 	require.Equal(t, primitives.Slot(0), f.HighestReceivedBlockDelay())
 
 	// 64 65
 	// Received block last epoch is 2
-	_, err = s.insert(context.Background(), 65, [32]byte{'B'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 65, [32]byte{'B'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-66*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(2), count)
-	require.Equal(t, primitives.Slot(65), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(65), slot)
 	require.Equal(t, primitives.Slot(1), f.HighestReceivedBlockDelay())
 
 	// 64 65 66
 	// Received block last epoch is 3
-	_, err = s.insert(context.Background(), 66, [32]byte{'C'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 66, [32]byte{'C'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-66*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(3), count)
-	require.Equal(t, primitives.Slot(66), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(66), slot)
 
 	// 64 65 66
 	//       98
 	// Received block last epoch is 1
-	_, err = s.insert(context.Background(), 98, [32]byte{'D'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 98, [32]byte{'D'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-98*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
-	require.Equal(t, primitives.Slot(98), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(98), slot)
 
 	// 64 65 66
 	//       98
 	//              132
 	// Received block last epoch is 1
-	_, err = s.insert(context.Background(), 132, [32]byte{'E'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 132, [32]byte{'E'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-132*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
-	require.Equal(t, primitives.Slot(132), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(132), slot)
 
 	// 64 65 66
 	//       98
 	//              132
 	//       99
 	// Received block last epoch is still 1. 99 is outside the window
-	_, err = s.insert(context.Background(), 99, [32]byte{'F'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 99, [32]byte{'F'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-132*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
-	require.Equal(t, primitives.Slot(132), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(132), slot)
 
 	// 64 65 66
 	//       98
 	//              132
 	//       99 100
 	// Received block last epoch is still 1. 100 is at the same position as 132
-	_, err = s.insert(context.Background(), 100, [32]byte{'G'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 100, [32]byte{'G'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-132*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
-	require.Equal(t, primitives.Slot(132), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(132), slot)
 
 	// 64 65 66
 	//       98
 	//              132
 	//       99 100 101
 	// Received block last epoch is 2. 101 is within the window
-	_, err = s.insert(context.Background(), 101, [32]byte{'H'}, b, b, 1, 1)
+	_, err = s.insert(context.Background(), 101, [32]byte{'H'}, b, b, b, 1, 1)
 	require.NoError(t, err)
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-132*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(2), count)
-	require.Equal(t, primitives.Slot(132), f.HighestReceivedBlockSlot())
+	slot, _ = f.HighestReceivedBlockSlotRoot()
+	require.Equal(t, primitives.Slot(132), slot)
 
 	s.genesisTime = uint64(time.Now().Add(time.Duration(-134*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()

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

@@ -41,6 +41,9 @@ type Store struct {
 	highestReceivedNode           *Node                                      // The highest slot node.
 	receivedBlocksLastEpoch       [fieldparams.SlotsPerEpoch]primitives.Slot // Using `highestReceivedSlot`. The slot of blocks received in the last epoch.
 	allTipsAreInvalid             bool                                       // tracks if all tips are not viable for head
+	payloadWithholdBoostRoot      [fieldparams.RootLength]byte               // the root of the block that receives the withhold boost
+	payloadWithholdBoostFull      bool                                       // Indicator of whether the block receiving the withhold boost is full or empty
+	payloadRevealBoostRoot        [fieldparams.RootLength]byte               // the root of the block that receives the reveal boost
 }
 
 // Node defines the individual block which includes its block parent, ancestor and how much weight accounted for it.
@@ -59,13 +62,15 @@ type Node struct {
 	balance                  uint64                       // the balance that voted for this node directly
 	weight                   uint64                       // weight of this node: the total balance including children
 	bestDescendant           *Node                        // bestDescendant node of this node.
-	optimistic               bool                         // whether the block has been fully validated or not
 	timestamp                uint64                       // The timestamp when the node was inserted.
+	ptcVote                  []primitives.PTCStatus       // tracks the Payload Timeliness Committee (PTC) votes for the node
+	withheld                 bool                         // whether the builder sent a withheld message for this payload
+	optimistic               bool                         // whether the block has been fully validated or not
 }
 
 // Vote defines an individual validator's vote.
 type Vote struct {
 	currentRoot [fieldparams.RootLength]byte // current voting root.
 	nextRoot    [fieldparams.RootLength]byte // next voting root.
-	nextEpoch   primitives.Epoch             // epoch of next voting period.
+	slot        primitives.Slot              // slot of the last vote by this validator
 }

beacon-chain/forkchoice/interfaces.go

@@ -7,6 +7,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
 	forkchoice2 "github.com/prysmaticlabs/prysm/v5/consensus-types/forkchoice"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 )
 
@@ -21,6 +22,7 @@ type ForkChoicer interface {
 	Unlock()
 	HeadRetriever        // to compute head.
 	BlockProcessor       // to track new block for fork choice.
+	PayloadProcessor     // to track new execution payload envelopes for forkchoice
 	AttestationProcessor // to track new attestation for fork choice.
 	Getter               // to retrieve fork choice information.
 	Setter               // to set fork choice information.
@@ -45,9 +47,13 @@ type BlockProcessor interface {
 	InsertChain(context.Context, []*forkchoicetypes.BlockAndCheckpoints) error
 }
 
+type PayloadProcessor interface {
+	InsertPayloadEnvelope(interfaces.ROExecutionPayloadEnvelope) error
+}
+
 // AttestationProcessor processes the attestation that's used for accounting fork choice.
 type AttestationProcessor interface {
-	ProcessAttestation(context.Context, []uint64, [32]byte, primitives.Epoch)
+	ProcessAttestation(context.Context, []uint64, [32]byte, primitives.Slot)
 }
 
 // Getter returns fork choice related information.
@@ -63,7 +69,8 @@ type FastGetter interface {
 	FinalizedCheckpoint() *forkchoicetypes.Checkpoint
 	FinalizedPayloadBlockHash() [32]byte
 	HasNode([32]byte) bool
-	HighestReceivedBlockSlot() primitives.Slot
+	HasHash([32]byte) bool
+	HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte)
 	HighestReceivedBlockDelay() primitives.Slot
 	IsCanonical(root [32]byte) bool
 	IsOptimistic(root [32]byte) (bool, error)
@@ -81,6 +88,7 @@ type FastGetter interface {
 	UnrealizedJustifiedPayloadBlockHash() [32]byte
 	Weight(root [32]byte) (uint64, error)
 	ParentRoot(root [32]byte) ([32]byte, error)
+	GetPTCVote() primitives.PTCStatus
 }
 
 // Setter allows to set forkchoice information

beacon-chain/forkchoice/ro.go

@@ -37,6 +37,13 @@ func (ro *ROForkChoice) HasNode(root [32]byte) bool {
 	return ro.getter.HasNode(root)
 }
 
+// HasHash delegates to the underlying forkchoice call, under a lock.
+func (ro *ROForkChoice) HasHash(root [32]byte) bool {
+	ro.l.RLock()
+	defer ro.l.RUnlock()
+	return ro.getter.HasHash(root)
+}
+
 // ProposerBoost delegates to the underlying forkchoice call, under a lock.
 func (ro *ROForkChoice) ProposerBoost() [fieldparams.RootLength]byte {
 	ro.l.RLock()
@@ -107,11 +114,11 @@ func (ro *ROForkChoice) NodeCount() int {
 	return ro.getter.NodeCount()
 }
 
-// HighestReceivedBlockSlot delegates to the underlying forkchoice call, under a lock.
-func (ro *ROForkChoice) HighestReceivedBlockSlot() primitives.Slot {
+// HighestReceivedBlockSlotRoot delegates to the underlying forkchoice call, under a lock.
+func (ro *ROForkChoice) HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte) {
 	ro.l.RLock()
 	defer ro.l.RUnlock()
-	return ro.getter.HighestReceivedBlockSlot()
+	return ro.getter.HighestReceivedBlockSlotRoot()
 }
 
 // HighestReceivedBlockDelay delegates to the underlying forkchoice call, under a lock.
@@ -176,3 +183,10 @@ func (ro *ROForkChoice) ParentRoot(root [32]byte) ([32]byte, error) {
 	defer ro.l.RUnlock()
 	return ro.getter.ParentRoot(root)
 }
+
+// GetPTCVote delegates to the underlying forkchoice call, under a lock.
+func (ro *ROForkChoice) GetPTCVote() primitives.PTCStatus {
+	ro.l.RLock()
+	defer ro.l.RUnlock()
+	return ro.getter.GetPTCVote()
+}

beacon-chain/forkchoice/ro_test.go

@@ -18,6 +18,7 @@ const (
 	rlockCalled
 	runlockCalled
 	hasNodeCalled
+	hasHashCalled
 	proposerBoostCalled
 	isCanonicalCalled
 	finalizedCheckpointCalled
@@ -28,7 +29,7 @@ const (
 	justifiedPayloadBlockHashCalled
 	unrealizedJustifiedPayloadBlockHashCalled
 	nodeCountCalled
-	highestReceivedBlockSlotCalled
+	highestReceivedBlockSlotRootCalled
 	highestReceivedBlockDelayCalled
 	receivedBlocksLastEpochCalled
 	weightCalled
@@ -38,6 +39,7 @@ const (
 	lastRootCalled
 	targetRootForEpochCalled
 	parentRootCalled
+	getPTCVoteCalled
 )
 
 func _discard(t *testing.T, e error) {
@@ -111,9 +113,9 @@ func TestROLocking(t *testing.T) {
 			cb:   func(g FastGetter) { g.NodeCount() },
 		},
 		{
-			name: "highestReceivedBlockSlotCalled",
-			call: highestReceivedBlockSlotCalled,
-			cb:   func(g FastGetter) { g.HighestReceivedBlockSlot() },
+			name: "highestReceivedBlockSlotRootCalled",
+			call: highestReceivedBlockSlotRootCalled,
+			cb:   func(g FastGetter) { g.HighestReceivedBlockSlotRoot() },
 		},
 		{
 			name: "highestReceivedBlockDelayCalled",
@@ -197,6 +199,11 @@ func (ro *mockROForkchoice) HasNode(_ [32]byte) bool {
 	return false
 }
 
+func (ro *mockROForkchoice) HasHash(_ [32]byte) bool {
+	ro.calls = append(ro.calls, hasHashCalled)
+	return false
+}
+
 func (ro *mockROForkchoice) ProposerBoost() [fieldparams.RootLength]byte {
 	ro.calls = append(ro.calls, proposerBoostCalled)
 	return [fieldparams.RootLength]byte{}
@@ -247,9 +254,9 @@ func (ro *mockROForkchoice) NodeCount() int {
 	return 0
 }
 
-func (ro *mockROForkchoice) HighestReceivedBlockSlot() primitives.Slot {
-	ro.calls = append(ro.calls, highestReceivedBlockSlotCalled)
-	return 0
+func (ro *mockROForkchoice) HighestReceivedBlockSlotRoot() (primitives.Slot, [32]byte) {
+	ro.calls = append(ro.calls, highestReceivedBlockSlotRootCalled)
+	return 0, [32]byte{}
 }
 
 func (ro *mockROForkchoice) HighestReceivedBlockDelay() primitives.Slot {
@@ -297,3 +304,8 @@ func (ro *mockROForkchoice) ParentRoot(_ [32]byte) ([32]byte, error) {
 	ro.calls = append(ro.calls, parentRootCalled)
 	return [32]byte{}, nil
 }
+
+func (ro *mockROForkchoice) GetPTCVote() primitives.PTCStatus {
+	ro.calls = append(ro.calls, getPTCVoteCalled)
+	return primitives.PAYLOAD_ABSENT
+}

beacon-chain/node/node.go

@@ -101,6 +101,9 @@ type BeaconNode struct {
 	blsToExecPool           blstoexec.PoolManager
 	depositCache            cache.DepositCache
 	trackedValidatorsCache  *cache.TrackedValidatorsCache
+	payloadAttestationCache *cache.PayloadAttestationCache
+	payloadEnvelopeCache    *sync.Map
+	executionHeaderCache    *cache.ExecutionPayloadHeaders
 	payloadIDCache          *cache.PayloadIDCache
 	stateFeed               *event.Feed
 	blockFeed               *event.Feed
@@ -151,6 +154,9 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		syncCommitteePool:       synccommittee.NewPool(),
 		blsToExecPool:           blstoexec.NewPool(),
 		trackedValidatorsCache:  cache.NewTrackedValidatorsCache(),
+		payloadAttestationCache: &cache.PayloadAttestationCache{},
+		payloadEnvelopeCache:    &sync.Map{},
+		executionHeaderCache:    cache.NewExecutionPayloadHeaders(),
 		payloadIDCache:          cache.NewPayloadIDCache(),
 		slasherBlockHeadersFeed: new(event.Feed),
 		slasherAttestationsFeed: new(event.Feed),
@@ -398,7 +404,7 @@ func initSyncWaiter(ctx context.Context, complete chan struct{}) func() error {
 }
 
 // StateFeed implements statefeed.Notifier.
-func (b *BeaconNode) StateFeed() event.SubscriberSender {
+func (b *BeaconNode) StateFeed() *event.Feed {
 	return b.stateFeed
 }
 
@@ -408,7 +414,7 @@ func (b *BeaconNode) BlockFeed() *event.Feed {
 }
 
 // OperationFeed implements opfeed.Notifier.
-func (b *BeaconNode) OperationFeed() event.SubscriberSender {
+func (b *BeaconNode) OperationFeed() *event.Feed {
 	return b.opFeed
 }
 
@@ -761,6 +767,8 @@ func (b *BeaconNode) registerBlockchainService(fc forkchoice.ForkChoicer, gs *st
 		blockchain.WithSyncComplete(syncComplete),
 		blockchain.WithBlobStorage(b.BlobStorage),
 		blockchain.WithTrackedValidatorsCache(b.trackedValidatorsCache),
+		blockchain.WithPayloadAttestationCache(b.payloadAttestationCache),
+		blockchain.WithPayloadEnvelopeCache(b.payloadEnvelopeCache),
 		blockchain.WithPayloadIDCache(b.payloadIDCache),
 		blockchain.WithSyncChecker(b.syncChecker),
 	)
@@ -838,6 +846,9 @@ func (b *BeaconNode) registerSyncService(initialSyncComplete chan struct{}, bFil
 		regularsync.WithStateGen(b.stateGen),
 		regularsync.WithSlasherAttestationsFeed(b.slasherAttestationsFeed),
 		regularsync.WithSlasherBlockHeadersFeed(b.slasherBlockHeadersFeed),
+		regularsync.WithPayloadAttestationCache(b.payloadAttestationCache),
+		regularsync.WithExecutionPayloadHeaderCache(b.executionHeaderCache),
+		regularsync.WithPayloadEnvelopeCache(b.payloadEnvelopeCache),
 		regularsync.WithPayloadReconstructor(web3Service),
 		regularsync.WithClockWaiter(b.clockWaiter),
 		regularsync.WithInitialSyncComplete(initialSyncComplete),
@@ -974,6 +985,8 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		FinalizationFetcher:           chainService,
 		BlockReceiver:                 chainService,
 		BlobReceiver:                  chainService,
+		PayloadAttestationReceiver:    chainService,
+		ExecutionPayloadReceiver:      chainService,
 		AttestationReceiver:           chainService,
 		GenesisTimeFetcher:            chainService,
 		GenesisFetcher:                chainService,

beacon-chain/p2p/BUILD.bazel

@@ -30,6 +30,7 @@ go_library(
         "service.go",
         "subnets.go",
         "topics.go",
+        "topics_epbs.go",
         "utils.go",
         "watch_peers.go",
     ],
@@ -69,6 +70,7 @@ go_library(
         "//monitoring/tracing/trace:go_default_library",
         "//network:go_default_library",
         "//network/forks:go_default_library",
+        "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/metadata:go_default_library",
         "//runtime:go_default_library",
@@ -159,6 +161,7 @@ go_test(
         "//encoding/bytesutil:go_default_library",
         "//network:go_default_library",
         "//network/forks:go_default_library",
+        "//proto/engine/v1:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/testing:go_default_library",
@@ -166,6 +169,7 @@ go_test(
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//testing/util/random:go_default_library",
         "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//crypto:go_default_library",
@@ -184,9 +188,11 @@ go_test(
         "@com_github_libp2p_go_libp2p_pubsub//pb:go_default_library",
         "@com_github_multiformats_go_multiaddr//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
         "@org_golang_google_protobuf//proto:go_default_library",
+        "@org_golang_google_protobuf//reflect/protoreflect:go_default_library",
     ],
 )

beacon-chain/p2p/broadcaster_test.go

@@ -12,6 +12,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/host"
+	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/prysmaticlabs/go-bitfield"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/peers"
@@ -25,7 +26,9 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 	"github.com/prysmaticlabs/prysm/v5/testing/util"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
 	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
 )
 
 func TestService_Broadcast(t *testing.T) {
@@ -520,3 +523,80 @@ func TestService_BroadcastBlob(t *testing.T) {
 	require.NoError(t, p.BroadcastBlob(ctx, subnet, blobSidecar))
 	require.Equal(t, false, util.WaitTimeout(&wg, 1*time.Second), "Failed to receive pubsub within 1s")
 }
+
+func TestService_BroadcastExecutionPayloadHeader(t *testing.T) {
+	msg := random.SignedExecutionPayloadHeader(t)
+	testBroadcast(t, SignedExecutionPayloadHeaderTopicFormat, msg)
+}
+
+func TestService_BroadcastExecutionPayloadEnvelope(t *testing.T) {
+	msg := random.SignedExecutionPayloadEnvelope(t)
+	testBroadcast(t, SignedExecutionPayloadEnvelopeTopicFormat, msg)
+}
+
+func TestService_BroadcastPayloadAttestationMessage(t *testing.T) {
+	msg := random.PayloadAttestationMessage(t)
+	testBroadcast(t, PayloadAttestationMessageTopicFormat, msg)
+}
+
+func testBroadcast(t *testing.T, topicFormat string, msg interface{}) {
+	// Create two peers and let them connect.
+	p1 := p2ptest.NewTestP2P(t)
+	p2 := p2ptest.NewTestP2P(t)
+	p1.Connect(p2)
+
+	if len(p1.BHost.Network().Peers()) == 0 {
+		t.Fatal("No peers")
+	}
+
+	// Create a `Service` for the first peer.
+	s1 := &Service{
+		host:                  p1.BHost,
+		pubsub:                p1.PubSub(),
+		joinedTopics:          map[string]*pubsub.Topic{},
+		cfg:                   &Config{},
+		genesisTime:           time.Now(),
+		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		peers: peers.NewStatus(context.Background(), &peers.StatusConfig{
+			ScorerParams: &scorers.Config{},
+		}),
+	}
+
+	// The second peer subscribes to the topic.
+	digest, err := s1.currentForkDigest()
+	require.NoError(t, err)
+	topic := fmt.Sprintf(topicFormat, digest) + s1.Encoding().ProtocolSuffix()
+	subscription, err := p2.SubscribeToTopic(topic)
+	require.NoError(t, err)
+
+	time.Sleep(50 * time.Millisecond) // Wait for libp2p to be set up.
+
+	// Start a goroutine listening for a pubsub message.
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+		defer cancel()
+
+		incomingMessage, err := subscription.Next(ctx)
+		require.NoError(t, err)
+
+		result, ok := msg.(ssz.Unmarshaler)
+		require.Equal(t, true, ok)
+		require.NoError(t, s1.Encoding().DecodeGossip(incomingMessage.Data, result))
+		require.DeepEqual(t, result, msg)
+	}()
+
+	// An attempt to broadcast a message unmapped to a topic should fail.
+	ctx := context.Background()
+	require.ErrorContains(t, "message type is not mapped to a PubSub topic", s1.Broadcast(ctx, nil))
+
+	// The first peer broadcasts the message to the second peer.
+	require.NoError(t, s1.Broadcast(ctx, msg.(protoreflect.ProtoMessage)))
+
+	// Wait for one second for the message to be delivered and processed.
+	if util.WaitTimeout(&wg, 1*time.Second) {
+		t.Error("Failed to receive pubsub within 1s")
+	}
+}

beacon-chain/p2p/gossip_topic_mappings.go

@@ -5,6 +5,7 @@ import (
 
 	"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"
 	"google.golang.org/protobuf/proto"
 )
@@ -22,6 +23,9 @@ var gossipTopicMappings = map[string]func() proto.Message{
 	SyncCommitteeSubnetTopicFormat:            func() proto.Message { return &ethpb.SyncCommitteeMessage{} },
 	BlsToExecutionChangeSubnetTopicFormat:     func() proto.Message { return &ethpb.SignedBLSToExecutionChange{} },
 	BlobSubnetTopicFormat:                     func() proto.Message { return &ethpb.BlobSidecar{} },
+	SignedExecutionPayloadHeaderTopicFormat:   func() proto.Message { return &enginev1.SignedExecutionPayloadHeader{} },
+	SignedExecutionPayloadEnvelopeTopicFormat: func() proto.Message { return &enginev1.SignedExecutionPayloadEnvelope{} },
+	PayloadAttestationMessageTopicFormat:      func() proto.Message { return &ethpb.PayloadAttestationMessage{} },
 }
 
 // GossipTopicMappings is a function to return the assigned data type
@@ -104,4 +108,8 @@ func init() {
 	GossipTypeMapping[reflect.TypeOf(&ethpb.AttestationElectra{})] = AttestationSubnetTopicFormat
 	GossipTypeMapping[reflect.TypeOf(&ethpb.AttesterSlashingElectra{})] = AttesterSlashingSubnetTopicFormat
 	GossipTypeMapping[reflect.TypeOf(&ethpb.SignedAggregateAttestationAndProofElectra{})] = AggregateAndProofSubnetTopicFormat
+	// Handle ePBS objects.
+	GossipTypeMapping[reflect.TypeOf(&enginev1.SignedExecutionPayloadHeader{})] = SignedExecutionPayloadHeaderTopicFormat
+	GossipTypeMapping[reflect.TypeOf(&enginev1.SignedExecutionPayloadEnvelope{})] = SignedExecutionPayloadEnvelopeTopicFormat
+	GossipTypeMapping[reflect.TypeOf(&ethpb.PayloadAttestationMessage{})] = PayloadAttestationMessageTopicFormat
 }

beacon-chain/p2p/gossip_topic_mappings_test.go

@@ -7,8 +7,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v5/testing/assert"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
 
 func TestMappingHasNoDuplicates(t *testing.T) {
@@ -30,17 +32,20 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	capellaForkEpoch := primitives.Epoch(300)
 	denebForkEpoch := primitives.Epoch(400)
 	electraForkEpoch := primitives.Epoch(500)
+	epbsForkEpoch := primitives.Epoch(600)
 
 	bCfg.AltairForkEpoch = altairForkEpoch
 	bCfg.BellatrixForkEpoch = bellatrixForkEpoch
 	bCfg.CapellaForkEpoch = capellaForkEpoch
 	bCfg.DenebForkEpoch = denebForkEpoch
 	bCfg.ElectraForkEpoch = electraForkEpoch
+	bCfg.EPBSForkEpoch = epbsForkEpoch
 	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.AltairForkVersion)] = primitives.Epoch(100)
 	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.BellatrixForkVersion)] = primitives.Epoch(200)
 	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.CapellaForkVersion)] = primitives.Epoch(300)
 	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.DenebForkVersion)] = primitives.Epoch(400)
 	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.ElectraForkVersion)] = primitives.Epoch(500)
+	bCfg.ForkVersionSchedule[bytesutil.ToBytes4(bCfg.EPBSForkVersion)] = primitives.Epoch(600)
 	params.OverrideBeaconConfig(bCfg)
 
 	// Phase 0
@@ -126,4 +131,15 @@ func TestGossipTopicMappings_CorrectType(t *testing.T) {
 	pMessage = GossipTopicMappings(AggregateAndProofSubnetTopicFormat, electraForkEpoch)
 	_, ok = pMessage.(*ethpb.SignedAggregateAttestationAndProofElectra)
 	assert.Equal(t, true, ok)
+
+	// Epbs fork
+	pMessage = GossipTopicMappings(SignedExecutionPayloadHeaderTopicFormat, epbsForkEpoch)
+	_, ok = pMessage.(*enginev1.SignedExecutionPayloadHeader)
+	require.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(SignedExecutionPayloadEnvelopeTopicFormat, epbsForkEpoch)
+	_, ok = pMessage.(*enginev1.SignedExecutionPayloadEnvelope)
+	require.Equal(t, true, ok)
+	pMessage = GossipTopicMappings(PayloadAttestationMessageTopicFormat, epbsForkEpoch)
+	_, ok = pMessage.(*ethpb.PayloadAttestationMessage)
+	require.Equal(t, true, ok)
 }

beacon-chain/p2p/topics_epbs.go

@@ -0,0 +1,11 @@
+package p2p
+
+const (
+	GossipSignedExecutionPayloadHeader   = "signed_execution_payload_header"
+	GossipSignedExecutionPayloadEnvelope = "signed_execution_payload_envelope"
+	GossipPayloadAttestationMessage      = "payload_attestation_message"
+
+	SignedExecutionPayloadHeaderTopicFormat   = GossipProtocolAndDigest + GossipSignedExecutionPayloadHeader
+	SignedExecutionPayloadEnvelopeTopicFormat = GossipProtocolAndDigest + GossipSignedExecutionPayloadEnvelope
+	PayloadAttestationMessageTopicFormat      = GossipProtocolAndDigest + GossipPayloadAttestationMessage
+)

beacon-chain/rpc/BUILD.bazel

@@ -89,6 +89,5 @@ go_test(
         "//testing/require:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
-        "@org_golang_x_exp//maps:go_default_library",
     ],
 )