Initialize payload att message verfier in sync

Adds the processing of execution payload envelope
Corrects the protos for attestations and slashings in Electra versions
Adds generators of full blocks for Electra

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",
@@ -26,6 +27,7 @@ go_library(
         "receive_attestation.go",
         "receive_blob.go",
         "receive_block.go",
+        "receive_execution_payload_envelope.go",
         "service.go",
         "tracked_proposer.go",
         "weak_subjectivity_checks.go",
@@ -44,6 +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",
@@ -126,6 +129,7 @@ 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",
@@ -167,6 +171,7 @@ go_test(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/epbs:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//container/trie:go_default_library",

beacon-chain/blockchain/chain_info.go

@@ -530,6 +530,11 @@ func (s *Service) recoverStateSummary(ctx context.Context, blockRoot [32]byte) (
 	return nil, errBlockDoesNotExist
 }
 
+// PayloadBeingSynced returns whether the payload for the block with the given root is currently being synced
+func (s *Service) PayloadBeingSynced(root [32]byte) bool {
+	return s.payloadBeingSynced.isSyncing(root)
+}
+
 // BlockBeingSynced returns whether the block with the given root is currently being synced
 func (s *Service) BlockBeingSynced(root [32]byte) bool {
 	return s.blockBeingSynced.isSyncing(root)

beacon-chain/blockchain/currently_syncing_execution_payload_envelope.go

@@ -0,0 +1,27 @@
+package blockchain
+
+import "sync"
+
+type currentlySyncingPayload struct {
+	sync.Mutex
+	roots map[[32]byte]struct{}
+}
+
+func (b *currentlySyncingPayload) set(root [32]byte) {
+	b.Lock()
+	defer b.Unlock()
+	b.roots[root] = struct{}{}
+}
+
+func (b *currentlySyncingPayload) unset(root [32]byte) {
+	b.Lock()
+	defer b.Unlock()
+	delete(b.roots, root)
+}
+
+func (b *currentlySyncingPayload) isSyncing(root [32]byte) bool {
+	b.Lock()
+	defer b.Unlock()
+	_, ok := b.roots[root]
+	return ok
+}

beacon-chain/blockchain/execution_engine.go

@@ -2,7 +2,6 @@ package blockchain
 
 import (
 	"context"
-	"crypto/sha256"
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -28,8 +27,6 @@ import (
 	"go.opencensus.io/trace"
 )
 
-const blobCommitmentVersionKZG uint8 = 0x01
-
 var defaultLatestValidHash = bytesutil.PadTo([]byte{0xff}, 32)
 
 // notifyForkchoiceUpdate signals execution engine the fork choice updates. Execution engine should:
@@ -402,13 +399,7 @@ func kzgCommitmentsToVersionedHashes(body interfaces.ReadOnlyBeaconBlockBody) ([
 
 	versionedHashes := make([]common.Hash, len(commitments))
 	for i, commitment := range commitments {
-		versionedHashes[i] = ConvertKzgCommitmentToVersionedHash(commitment)
+		versionedHashes[i] = primitives.ConvertKzgCommitmentToVersionedHash(commitment)
 	}
 	return versionedHashes, nil
 }
-
-func ConvertKzgCommitmentToVersionedHash(commitment []byte) common.Hash {
-	versionedHash := sha256.Sum256(commitment)
-	versionedHash[0] = blobCommitmentVersionKZG
-	return versionedHash
-}

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

@@ -69,6 +69,14 @@ 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
+	}
+}
+
 // 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/receive_attestation.go

@@ -176,7 +176,7 @@ 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_execution_payload_envelope.go

@@ -0,0 +1,166 @@
+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, err := envelope.BeaconBlockRoot()
+	if err != nil {
+		return errors.Wrap(err, "could not get beacon block root")
+	}
+	s.payloadBeingSynced.set(root)
+	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
+	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")
+	}
+
+	var lastValidHash []byte
+	var versionedHashes []common.Hash
+	versionedHashes, err = envelope.VersionedHashes()
+	if err != nil {
+		return false, errors.Wrap(err, "could not get versioned hashes to feed the engine")
+	}
+	root, err := envelope.BeaconBlockRoot()
+	if err != nil {
+		return false, errors.Wrap(err, "could not get beacon block root")
+	}
+	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, rootErr := e.BeaconBlockRoot()
+	if rootErr != nil {
+		return false, errors.Wrap(rootErr, "could not get beacon block root")
+	}
+	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, err := e.BeaconBlockRoot()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get beacon block root")
+	}
+	// 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 +1,104 @@
+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/epbs"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+)
+
+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 := &enginev1.ExecutionPayloadEnvelope{
+		Payload:         &enginev1.ExecutionPayloadElectra{},
+		BeaconBlockRoot: service.originBlockRoot[:],
+	}
+	e, err := epbs.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 := &enginev1.ExecutionPayloadEnvelope{
+		Payload:         &enginev1.ExecutionPayloadElectra{},
+		BeaconBlockRoot: service.originBlockRoot[:],
+	}
+	e, err := epbs.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 := &enginev1.ExecutionPayloadEnvelope{
+		Payload:         &enginev1.ExecutionPayloadElectra{},
+		BeaconBlockRoot: service.originBlockRoot[:],
+	}
+	e, err := epbs.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 := epbs.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/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 +76,7 @@ type config struct {
 	ChainStartFetcher       execution.ChainStartFetcher
 	BeaconDB                db.HeadAccessDatabase
 	DepositCache            cache.DepositCache
+	PayloadAttestationCache *cache.PayloadAttestationCache
 	PayloadIDCache          *cache.PayloadIDCache
 	TrackedValidatorsCache  *cache.TrackedValidatorsCache
 	AttPool                 attestations.Pool
@@ -179,6 +181,7 @@ 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]struct{})},
 	}
 	for _, opt := range opts {
 		if err := opt(srv); err != nil {
@@ -544,7 +547,7 @@ 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/cache/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
         "doc.go",
         "error.go",
         "interfaces.go",
+        "payload_attestation.go",
         "payload_id.go",
         "proposer_indices.go",
         "proposer_indices_disabled.go",  # keep
@@ -42,6 +43,7 @@ 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",
@@ -70,6 +72,7 @@ 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",
@@ -88,6 +91,7 @@ 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/prysm/v1alpha1:go_default_library",
         "//testing/assert:go_default_library",

beacon-chain/cache/payload_attestation.go

@@ -0,0 +1,116 @@
+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
+}
+
+// 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 +1,95 @@
+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)
+}

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"
 )
@@ -217,6 +218,42 @@ 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

@@ -287,12 +287,45 @@ func ProcessPayloadHeader(st state.BeaconState, header interfaces.ExecutionData)
 // 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
+		}
+		if header.Message == nil {
+			return payloadHash, errors.New("nil execution header")
+		}
+		return [32]byte(header.Message.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
+		}
+		if header.Message == nil {
+			return parentHash, errors.New("nil execution header")
+		}
+		return [32]byte(header.Message.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/epbs/BUILD.bazel

@@ -0,0 +1,37 @@
+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/epbs: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",
+    ],
+)

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 +1,138 @@
+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 {
+	payload, err := envelope.Execution()
+	if err != nil {
+		return err
+	}
+	exe, ok := payload.(interfaces.ExecutionDataElectra)
+	if !ok {
+		return errors.New("could not cast execution data to electra execution data")
+	}
+	preState, err = electra.ProcessDepositRequests(ctx, preState, exe.DepositRequests())
+	if err != nil {
+		return errors.Wrap(err, "could not process deposit receipts")
+	}
+	preState, err = electra.ProcessWithdrawalRequests(ctx, preState, exe.WithdrawalRequests())
+	if err != nil {
+		return errors.Wrap(err, "could not process execution layer withdrawal requests")
+	}
+	if err := electra.ProcessConsolidationRequests(ctx, preState, exe.ConsolidationRequests()); err != nil {
+		return errors.Wrap(err, "could not process consolidation requests")
+	}
+	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, err := envelope.BeaconBlockRoot()
+	if err != nil {
+		return err
+	}
+	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, err := envelope.BuilderIndex()
+	if err != nil {
+		return err
+	}
+	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, err := envelope.StateRoot()
+	if err != nil {
+		return err
+	}
+	if stateRoot != envelopeStateRoot {
+		return errors.New("state root mismatch")
+	}
+	return nil
+}

beacon-chain/core/epbs/execution_payload_envelope_test.go

@@ -0,0 +1,105 @@
+package epbs
+
+import (
+	"context"
+	"testing"
+
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	consensus_epbs "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util"
+)
+
+func TestProcessPayloadStateTransition(t *testing.T) {
+	bh := [32]byte{'h'}
+	payload := &enginev1.ExecutionPayloadElectra{BlockHash: bh[:]}
+	p := &enginev1.ExecutionPayloadEnvelope{Payload: payload}
+	e, err := consensus_epbs.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	stpb := &ethpb.BeaconStateEPBS{Slot: 3}
+	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 := &enginev1.ExecutionPayloadEnvelope{Payload: payload}
+	e, err := consensus_epbs.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)
+	require.ErrorContains(t, "attempted to wrap nil object", validateAgainstHeader(ctx, prest, e))
+
+	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 := &enginev1.ExecutionPayloadEnvelope{Payload: payload, BuilderIndex: 1}
+	e, err := consensus_epbs.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
+	require.ErrorContains(t, "attempted to wrap nil object", validateAgainstCommittedBid(h, e))
+	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 := &enginev1.ExecutionPayloadEnvelope{Payload: payload, BuilderIndex: 1}
+	e, err := consensus_epbs.WrappedROExecutionPayloadEnvelope(p)
+	require.NoError(t, err)
+	ctx := context.Background()
+	st, _ := util.DeterministicGenesisStateEpbs(t, 64)
+	require.ErrorContains(t, "attempted to wrap nil object", checkPostStateRoot(ctx, st, e))
+	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/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"
@@ -717,15 +719,26 @@ 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),
 	})
@@ -749,6 +762,31 @@ 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/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

@@ -53,6 +53,7 @@ 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)
@@ -87,6 +88,7 @@ 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

@@ -6,6 +6,7 @@ go_library(
         "archived_point.go",
         "backfill.go",
         "backup.go",
+        "blind_payload_envelope.go",
         "blocks.go",
         "checkpoint.go",
         "deposit_contract.go",
@@ -78,6 +79,7 @@ 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",
@@ -119,6 +121,7 @@ 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/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

@@ -118,6 +118,9 @@ 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")
 
 	// Deprecated: This bucket was migrated in PR 6461. Do not use, except for migrations.
 	slotsHasObjectBucket = []byte("slots-has-objects")
@@ -50,6 +51,7 @@ 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"
 )
 
@@ -159,6 +161,16 @@ 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)
@@ -1113,6 +1125,26 @@ 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/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",
@@ -47,6 +48,7 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "epbs_test.go",
         "ffg_update_test.go",
         "forkchoice_test.go",
         "last_root_test.go",

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

@@ -0,0 +1,9 @@
+package doublylinkedtree
+
+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{}
+}

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

@@ -0,0 +1,79 @@
+package doublylinkedtree
+
+import (
+	"context"
+	"testing"
+
+	"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)
+}

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 +115,27 @@ 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 {
+		slot, err := state.LatestFullSlot()
+		if err != nil {
+			return err
+		}
+		if slot == state.Slot() {
+			latestHeader, err := state.LatestExecutionPayloadHeaderEPBS()
+			if err != nil {
+				return err
+			}
+			copy(payloadHash[:], latestHeader.BlockHash)
+			copy(parentHash[:], latestHeader.ParentBlockHash)
+		} else {
+			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 +154,7 @@ 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
 	}
@@ -490,8 +509,12 @@ 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
 		}

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

@@ -22,7 +22,8 @@ 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,

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())

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")
@@ -327,7 +327,7 @@ 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)
@@ -337,7 +337,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 
 	// 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()
@@ -348,7 +348,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 
 	// 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()
@@ -359,7 +359,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 
 	// 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()
@@ -370,7 +370,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 	// 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()
@@ -382,7 +382,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 	//       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()
@@ -395,7 +395,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 	//              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()
@@ -408,7 +408,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 	//              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()
@@ -421,7 +421,7 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 	//              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()

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

@@ -67,5 +67,5 @@ type Node struct {
 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

@@ -47,7 +47,7 @@ type BlockProcessor interface {
 
 // 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.

beacon-chain/node/node.go

@@ -102,6 +102,7 @@ type BeaconNode struct {
 	blsToExecPool           blstoexec.PoolManager
 	depositCache            cache.DepositCache
 	trackedValidatorsCache  *cache.TrackedValidatorsCache
+	payloadAttestationCache *cache.PayloadAttestationCache
 	payloadIDCache          *cache.PayloadIDCache
 	stateFeed               *event.Feed
 	blockFeed               *event.Feed
@@ -152,6 +153,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		syncCommitteePool:       synccommittee.NewPool(),
 		blsToExecPool:           blstoexec.NewPool(),
 		trackedValidatorsCache:  cache.NewTrackedValidatorsCache(),
+		payloadAttestationCache: &cache.PayloadAttestationCache{},
 		payloadIDCache:          cache.NewPayloadIDCache(),
 		slasherBlockHeadersFeed: new(event.Feed),
 		slasherAttestationsFeed: new(event.Feed),
@@ -775,6 +777,7 @@ 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.WithPayloadIDCache(b.payloadIDCache),
 		blockchain.WithSyncChecker(b.syncChecker),
 	)
@@ -852,6 +855,7 @@ 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.WithPayloadReconstructor(web3Service),
 		regularsync.WithClockWaiter(b.clockWaiter),
 		regularsync.WithInitialSyncComplete(initialSyncComplete),

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",
     ],
@@ -68,6 +69,7 @@ go_library(
         "//monitoring/tracing: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",
@@ -186,9 +190,11 @@ 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/eth/config/handlers_test.go

@@ -20,6 +20,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/testing/require"
 )
 
+// Variables defined in the placeholderFields will not be tested in `TestGetSpec`.
+// These are variables that we don't use in Prysm. (i.e. future hardfork, light client... etc)
+var placeholderFields = []string{"DOMAIN_BEACON_BUILDER", "DOMAIN_PTC_ATTESTER"}
+
 func TestGetDepositContract(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig().Copy()
@@ -192,7 +196,7 @@ func TestGetSpec(t *testing.T) {
 	data, ok := resp.Data.(map[string]interface{})
 	require.Equal(t, true, ok)
 
-	assert.Equal(t, 155, len(data))
+	assert.Equal(t, 157, len(data))
 	for k, v := range data {
 		t.Run(k, func(t *testing.T) {
 			switch k {
@@ -530,6 +534,12 @@ func TestGetSpec(t *testing.T) {
 			case "MAX_DEPOSIT_REQUESTS_PER_PAYLOAD":
 				assert.Equal(t, "93", v)
 			default:
+				for _, pf := range placeholderFields {
+					if k == pf {
+						t.Logf("Skipping placeholder field: %s", k)
+						return
+					}
+				}
 				t.Errorf("Incorrect key: %s", k)
 			}
 		})

beacon-chain/rpc/eth/events/BUILD.bazel

@@ -20,6 +20,7 @@ go_library(
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/primitives:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/eth/v2:go_default_library",

beacon-chain/rpc/eth/events/events.go

@@ -11,7 +11,6 @@ import (
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v5/api"
 	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/operation"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
@@ -19,6 +18,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v5/network/httputil"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/eth/v1"
 	ethpbv2 "github.com/prysmaticlabs/prysm/v5/proto/eth/v2"
@@ -217,7 +217,7 @@ func handleBlockOperationEvents(w http.ResponseWriter, flusher http.Flusher, req
 		if !ok {
 			return write(w, flusher, topicDataMismatch, event.Data, BlobSidecarTopic)
 		}
-		versionedHash := blockchain.ConvertKzgCommitmentToVersionedHash(blobData.Blob.KzgCommitment)
+		versionedHash := primitives.ConvertKzgCommitmentToVersionedHash(blobData.Blob.KzgCommitment)
 		blobEvent := &structs.BlobSidecarEvent{
 			BlockRoot:     hexutil.Encode(blobData.Blob.BlockRootSlice()),
 			Index:         fmt.Sprintf("%d", blobData.Blob.Index),

beacon-chain/rpc/prysm/v1alpha1/validator/BUILD.bazel

@@ -25,6 +25,7 @@ go_library(
         "proposer_exits.go",
         "proposer_slashings.go",
         "proposer_sync_aggregate.go",
+        "ptc_attester.go",
         "server.go",
         "status.go",
         "sync_committee.go",

beacon-chain/rpc/prysm/v1alpha1/validator/duties.go

@@ -108,6 +108,7 @@ func (vs *Server) duties(ctx context.Context, req *ethpb.DutiesRequest) (*ethpb.
 				assignment.Committee = ca.Committee
 				assignment.AttesterSlot = ca.AttesterSlot
 				assignment.CommitteeIndex = ca.CommitteeIndex
+				assignment.PtcSlot = ca.PtcSlot
 			}
 			// Save the next epoch assignments.
 			ca, ok = nextEpochAssignments[idx]
@@ -115,6 +116,7 @@ func (vs *Server) duties(ctx context.Context, req *ethpb.DutiesRequest) (*ethpb.
 				nextAssignment.Committee = ca.Committee
 				nextAssignment.AttesterSlot = ca.AttesterSlot
 				nextAssignment.CommitteeIndex = ca.CommitteeIndex
+				nextAssignment.PtcSlot = ca.PtcSlot
 			}
 		} else {
 			// If the validator isn't in the beacon state, try finding their deposit to determine their status.

beacon-chain/rpc/prysm/v1alpha1/validator/ptc_attester.go

@@ -0,0 +1,17 @@
+package validator
+
+import (
+	"context"
+
+	"github.com/golang/protobuf/ptypes/empty"
+	"github.com/pkg/errors"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+func (vs *Server) GetPayloadAttestationData(ctx context.Context, req *ethpb.GetPayloadAttestationDataRequest) (*ethpb.PayloadAttestationData, error) {
+	return nil, errors.New("not implemented")
+}
+
+func (vs *Server) SubmitPayloadAttestation(ctx context.Context, in *ethpb.PayloadAttestationMessage) (*empty.Empty, error) {
+	return nil, errors.New("not implemented")
+}

beacon-chain/state/BUILD.bazel

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "error.go",
         "interfaces.go",
+        "interfaces_epbs.go",
         "prometheus.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/state",

beacon-chain/state/interfaces.go

@@ -60,6 +60,7 @@ type ReadOnlyBeaconState interface {
 	ReadOnlySyncCommittee
 	ReadOnlyDeposits
 	ReadOnlyConsolidations
+	ReadOnlyEpbsFields
 	ToProtoUnsafe() interface{}
 	ToProto() interface{}
 	GenesisTime() uint64
@@ -94,6 +95,7 @@ type WriteOnlyBeaconState interface {
 	WriteOnlyConsolidations
 	WriteOnlyWithdrawals
 	WriteOnlyDeposits
+	WriteOnlyEpbsFields
 	SetGenesisTime(val uint64) error
 	SetGenesisValidatorsRoot(val []byte) error
 	SetSlot(val primitives.Slot) error

beacon-chain/state/interfaces_epbs.go

@@ -0,0 +1,21 @@
+package state
+
+import (
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+)
+
+type ReadOnlyEpbsFields interface {
+	IsParentBlockFull() (bool, error)
+	LatestExecutionPayloadHeaderEPBS() (*enginev1.ExecutionPayloadHeaderEPBS, error)
+	LatestBlockHash() ([]byte, error)
+	LatestFullSlot() (primitives.Slot, error)
+	LastWithdrawalsRoot() ([]byte, error)
+}
+
+type WriteOnlyEpbsFields interface {
+	SetLatestExecutionPayloadHeaderEPBS(val *enginev1.ExecutionPayloadHeaderEPBS) error
+	SetLatestBlockHash(val []byte) error
+	SetLatestFullSlot(val primitives.Slot) error
+	SetLastWithdrawalsRoot(val []byte) error
+}

beacon-chain/state/state-native/BUILD.bazel

@@ -13,11 +13,13 @@ go_library(
         "getters_checkpoint.go",
         "getters_consolidation.go",
         "getters_deposit_requests.go",
+        "getters_epbs.go",
         "getters_eth1.go",
         "getters_exit.go",
         "getters_misc.go",
         "getters_participation.go",
         "getters_payload_header.go",
+        "getters_payload_header_epbs.go",
         "getters_randao.go",
         "getters_state.go",
         "getters_sync_committee.go",
@@ -34,6 +36,7 @@ go_library(
         "setters_churn.go",
         "setters_consolidation.go",
         "setters_deposit_requests.go",
+        "setters_epbs.go",
         "setters_eth1.go",
         "setters_misc.go",
         "setters_participation.go",
@@ -46,6 +49,7 @@ go_library(
         "spec_parameters.go",
         "ssz.go",
         "state_trie.go",
+        "state_trie_epbs.go",
         "types.go",
         "validator_index_cache.go",
     ],
@@ -98,6 +102,7 @@ go_test(
         "getters_deposit_requests_test.go",
         "getters_exit_test.go",
         "getters_participation_test.go",
+        "getters_setters_epbs_test.go",
         "getters_test.go",
         "getters_validator_test.go",
         "getters_withdrawal_test.go",
@@ -119,6 +124,7 @@ go_test(
         "setters_withdrawal_test.go",
         "state_fuzz_test.go",
         "state_test.go",
+        "state_trie_epbs_test.go",
         "state_trie_test.go",
         "types_test.go",
         "validator_index_cache_test.go",
@@ -152,6 +158,7 @@ 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_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_golang_snappy//:go_default_library",

beacon-chain/state/state-native/beacon_state_mainnet.go

@@ -60,6 +60,11 @@ type BeaconState struct {
 	latestExecutionPayloadHeaderElectra *enginev1.ExecutionPayloadHeaderElectra
 	nextWithdrawalIndex                 uint64
 	nextWithdrawalValidatorIndex        primitives.ValidatorIndex
+	// ePBS fields
+	latestBlockHash                  [32]byte
+	latestFullSlot                   primitives.Slot
+	latestExecutionPayloadHeaderEPBS *enginev1.ExecutionPayloadHeaderEPBS
+	lastWithdrawalsRoot              [32]byte
 
 	// Electra fields
 	depositRequestsStartIndex     uint64

beacon-chain/state/state-native/beacon_state_minimal.go

@@ -60,6 +60,11 @@ type BeaconState struct {
 	latestExecutionPayloadHeaderElectra *enginev1.ExecutionPayloadHeaderElectra
 	nextWithdrawalIndex                 uint64
 	nextWithdrawalValidatorIndex        primitives.ValidatorIndex
+	// ePBS fields
+	latestBlockHash                  [32]byte
+	latestFullSlot                   primitives.Slot
+	latestExecutionPayloadHeaderEPBS *enginev1.ExecutionPayloadHeaderEPBS
+	lastWithdrawalsRoot              [32]byte
 
 	// Electra fields
 	depositRequestsStartIndex     uint64

beacon-chain/state/state-native/getters_epbs.go

@@ -0,0 +1,75 @@
+package state_native
+
+import (
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+)
+
+// LatestExecutionPayloadHeaderEPBS retrieves a copy of the execution payload header from epbs state.
+// It returns an error if the operation is not supported for the beacon state's version.
+func (b *BeaconState) LatestExecutionPayloadHeaderEPBS() (*enginev1.ExecutionPayloadHeaderEPBS, error) {
+	if b.version < version.EPBS {
+		return nil, errNotSupported("LatestExecutionPayloadHeaderEPBS", b.version)
+	}
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	return b.executionPayloadHeaderVal(), nil
+}
+
+// IsParentBlockFull checks if the last committed payload header was fulfilled.
+// Returns true if both the beacon block and payload were present.
+// Call this function on a beacon state before processing the execution payload header.
+// It returns an error if the operation is not supported for the beacon state's version.
+func (b *BeaconState) IsParentBlockFull() (bool, error) {
+	if b.version < version.EPBS {
+		return false, errNotSupported("IsParentBlockFull", b.version)
+	}
+
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	headerBlockHash := bytesutil.ToBytes32(b.latestExecutionPayloadHeaderEPBS.BlockHash)
+	return headerBlockHash == b.latestBlockHash, nil
+}
+
+// LatestBlockHash returns the latest block hash.
+// It returns an error if the operation is not supported for the beacon state's version.
+func (b *BeaconState) LatestBlockHash() ([]byte, error) {
+	if b.version < version.EPBS {
+		return nil, errNotSupported("LatestBlockHash", b.version)
+	}
+
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	return b.latestBlockHash[:], nil
+}
+
+// LatestFullSlot returns the slot of the latest full block.
+// It returns an error if the operation is not supported for the beacon state's version.
+func (b *BeaconState) LatestFullSlot() (primitives.Slot, error) {
+	if b.version < version.EPBS {
+		return 0, errNotSupported("LatestFullSlot", b.version)
+	}
+
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	return b.latestFullSlot, nil
+}
+
+// LastWithdrawalsRoot returns the latest withdrawal root.
+// It returns an error if the operation is not supported for the beacon state's version.
+func (b *BeaconState) LastWithdrawalsRoot() ([]byte, error) {
+	if b.version < version.EPBS {
+		return nil, errNotSupported("LastWithdrawalsRoot", b.version)
+	}
+
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	return b.lastWithdrawalsRoot[:], nil
+}

beacon-chain/state/state-native/getters_payload_header_epbs.go

@@ -0,0 +1,10 @@
+package state_native
+
+import (
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+)
+
+func (b *BeaconState) executionPayloadHeaderVal() *enginev1.ExecutionPayloadHeaderEPBS {
+	return eth.CopyExecutionPayloadHeaderEPBS(b.latestExecutionPayloadHeaderEPBS)
+}

beacon-chain/state/state-native/getters_setters_epbs_test.go

@@ -0,0 +1,90 @@
+package state_native
+
+import (
+	"crypto/rand"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native/types"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func Test_LatestExecutionPayloadHeaderEPBS(t *testing.T) {
+	s := &BeaconState{version: version.EPBS}
+	_, err := s.LatestExecutionPayloadHeader()
+	require.ErrorContains(t, "unsupported version (epbs) for latest execution payload header", err)
+}
+
+func Test_SetLatestExecutionPayloadHeader(t *testing.T) {
+	s := &BeaconState{version: version.EPBS}
+	require.ErrorContains(t, "SetLatestExecutionPayloadHeader is not supported for epbs", s.SetLatestExecutionPayloadHeader(nil))
+}
+
+func Test_SetLatestExecutionPayloadHeaderEPBS(t *testing.T) {
+	s := &BeaconState{version: version.EPBS, dirtyFields: make(map[types.FieldIndex]bool)}
+	header := random.ExecutionPayloadHeader(t)
+	require.NoError(t, s.SetLatestExecutionPayloadHeaderEPBS(header))
+	require.Equal(t, true, s.dirtyFields[types.ExecutionPayloadHeader])
+
+	got, err := s.LatestExecutionPayloadHeaderEPBS()
+	require.NoError(t, err)
+	require.DeepEqual(t, got, header)
+}
+
+func Test_SetLatestBlockHash(t *testing.T) {
+	s := &BeaconState{version: version.EPBS, dirtyFields: make(map[types.FieldIndex]bool)}
+	b := make([]byte, fieldparams.RootLength)
+	_, err := rand.Read(b)
+	require.NoError(t, err)
+	require.NoError(t, s.SetLatestBlockHash(b))
+	require.Equal(t, true, s.dirtyFields[types.LatestBlockHash])
+
+	got, err := s.LatestBlockHash()
+	require.NoError(t, err)
+	require.DeepEqual(t, got, b)
+}
+
+func Test_SetLatestFullSlot(t *testing.T) {
+	s := &BeaconState{version: version.EPBS, dirtyFields: make(map[types.FieldIndex]bool)}
+	require.NoError(t, s.SetLatestFullSlot(primitives.Slot(3)))
+	require.Equal(t, true, s.dirtyFields[types.LatestFullSlot])
+
+	got, err := s.LatestFullSlot()
+	require.NoError(t, err)
+	require.Equal(t, primitives.Slot(3), got)
+}
+
+func Test_SetLastWithdrawalsRoot(t *testing.T) {
+	s := &BeaconState{version: version.EPBS, dirtyFields: make(map[types.FieldIndex]bool)}
+	b := make([]byte, fieldparams.RootLength)
+	_, err := rand.Read(b)
+	require.NoError(t, err)
+	require.NoError(t, s.SetLastWithdrawalsRoot(b))
+	require.Equal(t, true, s.dirtyFields[types.LastWithdrawalsRoot])
+
+	got, err := s.LastWithdrawalsRoot()
+	require.NoError(t, err)
+	require.DeepEqual(t, got, b)
+}
+
+func Test_UnsupportedStateVersionEpbs(t *testing.T) {
+	s := &BeaconState{version: version.Electra}
+	_, err := s.IsParentBlockFull()
+	require.ErrorContains(t, "IsParentBlockFull is not supported for electra", err)
+	_, err = s.LatestBlockHash()
+	require.ErrorContains(t, "LatestBlockHash is not supported for electra", err)
+	_, err = s.LatestFullSlot()
+	require.ErrorContains(t, "LatestFullSlot is not supported for electra", err)
+	_, err = s.LastWithdrawalsRoot()
+	require.ErrorContains(t, "LastWithdrawalsRoot is not supported for electra", err)
+	_, err = s.LatestExecutionPayloadHeaderEPBS()
+	require.ErrorContains(t, "LatestExecutionPayloadHeaderEPBS is not supported for electra", err)
+
+	require.ErrorContains(t, "LastWithdrawalsRoot is not supported for electra", s.SetLastWithdrawalsRoot(nil))
+	require.ErrorContains(t, "SetLatestBlockHash is not supported for electra", s.SetLatestBlockHash(nil))
+	require.ErrorContains(t, "SetLatestFullSlot is not supported for electra", s.SetLatestFullSlot(0))
+	require.ErrorContains(t, "SetLatestExecutionPayloadHeaderEPBS is not supported for electra", s.SetLatestExecutionPayloadHeaderEPBS(nil))
+}

beacon-chain/state/state-native/getters_state.go

@@ -212,6 +212,49 @@ func (b *BeaconState) ToProtoUnsafe() interface{} {
 			PendingPartialWithdrawals:     b.pendingPartialWithdrawals,
 			PendingConsolidations:         b.pendingConsolidations,
 		}
+	case version.EPBS:
+		return &ethpb.BeaconStateEPBS{
+			GenesisTime:                   b.genesisTime,
+			GenesisValidatorsRoot:         gvrCopy[:],
+			Slot:                          b.slot,
+			Fork:                          b.fork,
+			LatestBlockHeader:             b.latestBlockHeader,
+			BlockRoots:                    br,
+			StateRoots:                    sr,
+			HistoricalRoots:               b.historicalRoots.Slice(),
+			Eth1Data:                      b.eth1Data,
+			Eth1DataVotes:                 b.eth1DataVotes,
+			Eth1DepositIndex:              b.eth1DepositIndex,
+			Validators:                    vals,
+			Balances:                      bals,
+			RandaoMixes:                   rm,
+			Slashings:                     b.slashings,
+			PreviousEpochParticipation:    b.previousEpochParticipation,
+			CurrentEpochParticipation:     b.currentEpochParticipation,
+			JustificationBits:             b.justificationBits,
+			PreviousJustifiedCheckpoint:   b.previousJustifiedCheckpoint,
+			CurrentJustifiedCheckpoint:    b.currentJustifiedCheckpoint,
+			FinalizedCheckpoint:           b.finalizedCheckpoint,
+			InactivityScores:              b.inactivityScoresVal(),
+			CurrentSyncCommittee:          b.currentSyncCommittee,
+			NextSyncCommittee:             b.nextSyncCommittee,
+			NextWithdrawalIndex:           b.nextWithdrawalIndex,
+			NextWithdrawalValidatorIndex:  b.nextWithdrawalValidatorIndex,
+			HistoricalSummaries:           b.historicalSummaries,
+			DepositRequestsStartIndex:     b.depositRequestsStartIndex,
+			DepositBalanceToConsume:       b.depositBalanceToConsume,
+			ExitBalanceToConsume:          b.exitBalanceToConsume,
+			EarliestExitEpoch:             b.earliestExitEpoch,
+			ConsolidationBalanceToConsume: b.consolidationBalanceToConsume,
+			EarliestConsolidationEpoch:    b.earliestConsolidationEpoch,
+			PendingBalanceDeposits:        b.pendingBalanceDeposits,
+			PendingPartialWithdrawals:     b.pendingPartialWithdrawals,
+			PendingConsolidations:         b.pendingConsolidations,
+			LatestBlockHash:               b.latestBlockHash[:],
+			LatestFullSlot:                b.latestFullSlot,
+			LatestExecutionPayloadHeader:  b.latestExecutionPayloadHeaderEPBS,
+			LastWithdrawalsRoot:           b.lastWithdrawalsRoot[:],
+		}
 	default:
 		return nil
 	}
@@ -236,6 +279,9 @@ func (b *BeaconState) ToProto() interface{} {
 		inactivityScores = b.inactivityScoresVal()
 	}
 
+	LatestBlockHashCopy := b.latestBlockHash
+	lastWithdrawalsRootCopy := b.lastWithdrawalsRoot
+
 	switch b.version {
 	case version.Phase0:
 		return &ethpb.BeaconState{
@@ -418,6 +464,49 @@ func (b *BeaconState) ToProto() interface{} {
 			PendingPartialWithdrawals:     b.pendingPartialWithdrawalsVal(),
 			PendingConsolidations:         b.pendingConsolidationsVal(),
 		}
+	case version.EPBS:
+		return &ethpb.BeaconStateEPBS{
+			GenesisTime:                   b.genesisTime,
+			GenesisValidatorsRoot:         gvrCopy[:],
+			Slot:                          b.slot,
+			Fork:                          b.forkVal(),
+			LatestBlockHeader:             b.latestBlockHeaderVal(),
+			BlockRoots:                    br,
+			StateRoots:                    sr,
+			HistoricalRoots:               b.historicalRoots.Slice(),
+			Eth1Data:                      b.eth1DataVal(),
+			Eth1DataVotes:                 b.eth1DataVotesVal(),
+			Eth1DepositIndex:              b.eth1DepositIndex,
+			Validators:                    b.validatorsVal(),
+			Balances:                      b.balancesVal(),
+			RandaoMixes:                   rm,
+			Slashings:                     b.slashingsVal(),
+			PreviousEpochParticipation:    b.previousEpochParticipationVal(),
+			CurrentEpochParticipation:     b.currentEpochParticipationVal(),
+			JustificationBits:             b.justificationBitsVal(),
+			PreviousJustifiedCheckpoint:   b.previousJustifiedCheckpointVal(),
+			CurrentJustifiedCheckpoint:    b.currentJustifiedCheckpointVal(),
+			FinalizedCheckpoint:           b.finalizedCheckpointVal(),
+			InactivityScores:              b.inactivityScoresVal(),
+			CurrentSyncCommittee:          b.currentSyncCommitteeVal(),
+			NextSyncCommittee:             b.nextSyncCommitteeVal(),
+			NextWithdrawalIndex:           b.nextWithdrawalIndex,
+			NextWithdrawalValidatorIndex:  b.nextWithdrawalValidatorIndex,
+			HistoricalSummaries:           b.historicalSummariesVal(),
+			DepositRequestsStartIndex:     b.depositRequestsStartIndex,
+			DepositBalanceToConsume:       b.depositBalanceToConsume,
+			ExitBalanceToConsume:          b.exitBalanceToConsume,
+			EarliestExitEpoch:             b.earliestExitEpoch,
+			ConsolidationBalanceToConsume: b.consolidationBalanceToConsume,
+			EarliestConsolidationEpoch:    b.earliestConsolidationEpoch,
+			PendingBalanceDeposits:        b.pendingBalanceDepositsVal(),
+			PendingPartialWithdrawals:     b.pendingPartialWithdrawalsVal(),
+			PendingConsolidations:         b.pendingConsolidationsVal(),
+			LatestBlockHash:               LatestBlockHashCopy[:],
+			LatestFullSlot:                b.latestFullSlot,
+			LatestExecutionPayloadHeader:  b.executionPayloadHeaderVal(),
+			LastWithdrawalsRoot:           lastWithdrawalsRootCopy[:],
+		}
 	default:
 		return nil
 	}

beacon-chain/state/state-native/hasher.go

@@ -41,6 +41,8 @@ func ComputeFieldRootsWithHasher(ctx context.Context, state *BeaconState) ([][]b
 		fieldRoots = make([][]byte, params.BeaconConfig().BeaconStateDenebFieldCount)
 	case version.Electra:
 		fieldRoots = make([][]byte, params.BeaconConfig().BeaconStateElectraFieldCount)
+	case version.EPBS:
+		fieldRoots = make([][]byte, params.BeaconConfig().BeaconStateEpbsFieldCount)
 	default:
 		return nil, fmt.Errorf("unknown state version %s", version.String(state.version))
 	}
@@ -260,6 +262,14 @@ func ComputeFieldRootsWithHasher(ctx context.Context, state *BeaconState) ([][]b
 		}
 		fieldRoots[types.LatestExecutionPayloadHeaderElectra.RealPosition()] = executionPayloadRoot[:]
 	}
+	if state.version == version.EPBS {
+		// Execution payload header root.
+		executionPayloadRoot, err := state.latestExecutionPayloadHeaderEPBS.HashTreeRoot()
+		if err != nil {
+			return nil, err
+		}
+		fieldRoots[types.ExecutionPayloadHeader.RealPosition()] = executionPayloadRoot[:]
+	}
 
 	if state.version >= version.Capella {
 		// Next withdrawal index root.
@@ -327,5 +337,19 @@ func ComputeFieldRootsWithHasher(ctx context.Context, state *BeaconState) ([][]b
 		fieldRoots[types.PendingConsolidations.RealPosition()] = pcRoot[:]
 	}
 
+	if state.version >= version.EPBS {
+		// Latest block hash root.
+		latestBlockHashRoot := state.latestBlockHash[:]
+		fieldRoots[types.LatestBlockHash.RealPosition()] = latestBlockHashRoot
+
+		// Latest full slot root.
+		latestFullSlotRoot := ssz.Uint64Root(uint64(state.latestFullSlot))
+		fieldRoots[types.LatestFullSlot.RealPosition()] = latestFullSlotRoot[:]
+
+		// Last withdrawals root.
+		lastWithdrawalsRoot := state.lastWithdrawalsRoot[:]
+		fieldRoots[types.LastWithdrawalsRoot.RealPosition()] = lastWithdrawalsRoot
+	}
+
 	return fieldRoots, nil
 }

beacon-chain/state/state-native/setters_epbs.go

@@ -0,0 +1,69 @@
+package state_native
+
+import (
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native/types"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v5/proto/engine/v1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+)
+
+// SetLatestExecutionPayloadHeaderEPBS sets the latest execution payload header for the epbs beacon state.
+func (b *BeaconState) SetLatestExecutionPayloadHeaderEPBS(h *enginev1.ExecutionPayloadHeaderEPBS) error {
+	if b.version < version.EPBS {
+		return errNotSupported("SetLatestExecutionPayloadHeaderEPBS", b.version)
+	}
+
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	b.latestExecutionPayloadHeaderEPBS = h
+	b.markFieldAsDirty(types.ExecutionPayloadHeader)
+
+	return nil
+}
+
+// SetLatestBlockHash sets the latest block hash for the beacon state.
+func (b *BeaconState) SetLatestBlockHash(h []byte) error {
+	if b.version < version.EPBS {
+		return errNotSupported("SetLatestBlockHash", b.version)
+	}
+
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	b.latestBlockHash = bytesutil.ToBytes32(h)
+	b.markFieldAsDirty(types.LatestBlockHash)
+
+	return nil
+}
+
+// SetLatestFullSlot sets the latest full slot for the beacon state.
+func (b *BeaconState) SetLatestFullSlot(s primitives.Slot) error {
+	if b.version < version.EPBS {
+		return errNotSupported("SetLatestFullSlot", b.version)
+	}
+
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	b.latestFullSlot = s
+	b.markFieldAsDirty(types.LatestFullSlot)
+
+	return nil
+}
+
+// SetLastWithdrawalsRoot sets the latest withdrawals root for the beacon state.
+func (b *BeaconState) SetLastWithdrawalsRoot(r []byte) error {
+	if b.version < version.EPBS {
+		return errNotSupported("SetLastWithdrawalsRoot", b.version)
+	}
+
+	b.lock.Lock()
+	defer b.lock.Unlock()
+
+	b.lastWithdrawalsRoot = bytesutil.ToBytes32(r)
+	b.markFieldAsDirty(types.LastWithdrawalsRoot)
+
+	return nil
+}

beacon-chain/state/state-native/setters_payload_header.go

@@ -17,7 +17,7 @@ func (b *BeaconState) SetLatestExecutionPayloadHeader(val interfaces.ExecutionDa
 	b.lock.Lock()
 	defer b.lock.Unlock()
 
-	if b.version < version.Bellatrix {
+	if b.version < version.Bellatrix || b.version >= version.EPBS {
 		return errNotSupported("SetLatestExecutionPayloadHeader", b.version)
 	}
 

beacon-chain/state/state-native/spec_parameters.go

@@ -7,7 +7,7 @@ import (
 
 func (b *BeaconState) ProportionalSlashingMultiplier() (uint64, error) {
 	switch b.version {
-	case version.Bellatrix, version.Capella, version.Deneb, version.Electra:
+	case version.Bellatrix, version.Capella, version.Deneb, version.Electra, version.EPBS:
 		return params.BeaconConfig().ProportionalSlashingMultiplierBellatrix, nil
 	case version.Altair:
 		return params.BeaconConfig().ProportionalSlashingMultiplierAltair, nil
@@ -19,7 +19,7 @@ func (b *BeaconState) ProportionalSlashingMultiplier() (uint64, error) {
 
 func (b *BeaconState) InactivityPenaltyQuotient() (uint64, error) {
 	switch b.version {
-	case version.Bellatrix, version.Capella, version.Deneb, version.Electra:
+	case version.Bellatrix, version.Capella, version.Deneb, version.Electra, version.EPBS:
 		return params.BeaconConfig().InactivityPenaltyQuotientBellatrix, nil
 	case version.Altair:
 		return params.BeaconConfig().InactivityPenaltyQuotientAltair, nil

beacon-chain/state/state-native/state_trie.go

@@ -111,6 +111,27 @@ var electraFields = append(
 	types.PendingConsolidations,
 )
 
+var epbsFields = append(
+	altairFields,
+	types.NextWithdrawalIndex,
+	types.NextWithdrawalValidatorIndex,
+	types.HistoricalSummaries,
+	types.ExecutionPayloadHeader,    // new in ePBS
+	types.DepositRequestsStartIndex, // electra fields start here
+	types.DepositBalanceToConsume,
+	types.ExitBalanceToConsume,
+	types.EarliestExitEpoch,
+	types.ConsolidationBalanceToConsume,
+	types.EarliestConsolidationEpoch,
+	types.PendingBalanceDeposits,
+	types.PendingPartialWithdrawals,
+	types.PendingConsolidations,
+	types.LatestBlockHash, // ePBS fields start here
+	types.LatestFullSlot,
+	types.ExecutionPayloadHeader,
+	types.LastWithdrawalsRoot,
+)
+
 const (
 	phase0SharedFieldRefCount                     = 10
 	altairSharedFieldRefCount                     = 11
@@ -118,12 +139,14 @@ const (
 	capellaSharedFieldRefCount                    = 13
 	denebSharedFieldRefCount                      = 13
 	electraSharedFieldRefCount                    = 16
+	epbsSharedFieldRefCount                       = 16
 	experimentalStatePhase0SharedFieldRefCount    = 5
 	experimentalStateAltairSharedFieldRefCount    = 5
 	experimentalStateBellatrixSharedFieldRefCount = 6
 	experimentalStateCapellaSharedFieldRefCount   = 7
 	experimentalStateDenebSharedFieldRefCount     = 7
 	experimentalStateElectraSharedFieldRefCount   = 10
+	experimentalStateEpbsSharedFieldRefCount      = 10
 )
 
 // InitializeFromProtoPhase0 the beacon state from a protobuf representation.
@@ -155,6 +178,11 @@ func InitializeFromProtoElectra(st *ethpb.BeaconStateElectra) (state.BeaconState
 	return InitializeFromProtoUnsafeElectra(proto.Clone(st).(*ethpb.BeaconStateElectra))
 }
 
+// InitializeFromProtoEpbs initializes the beacon state from its protobuf representation.
+func InitializeFromProtoEpbs(st *ethpb.BeaconStateEPBS) (state.BeaconState, error) {
+	return InitializeFromProtoUnsafeEpbs(proto.Clone(st).(*ethpb.BeaconStateEPBS))
+}
+
 // InitializeFromProtoUnsafePhase0 directly uses the beacon state protobuf fields
 // and sets them as fields of the BeaconState type.
 func InitializeFromProtoUnsafePhase0(st *ethpb.BeaconState) (state.BeaconState, error) {
@@ -857,6 +885,8 @@ func (b *BeaconState) Copy() state.BeaconState {
 		fieldCount = params.BeaconConfig().BeaconStateDenebFieldCount
 	case version.Electra:
 		fieldCount = params.BeaconConfig().BeaconStateElectraFieldCount
+	case version.EPBS:
+		fieldCount = params.BeaconConfig().BeaconStateEpbsFieldCount
 	}
 
 	dst := &BeaconState{
@@ -874,6 +904,9 @@ func (b *BeaconState) Copy() state.BeaconState {
 		earliestExitEpoch:             b.earliestExitEpoch,
 		consolidationBalanceToConsume: b.consolidationBalanceToConsume,
 		earliestConsolidationEpoch:    b.earliestConsolidationEpoch,
+		latestBlockHash:               b.latestBlockHash,
+		latestFullSlot:                b.latestFullSlot,
+		lastWithdrawalsRoot:           b.lastWithdrawalsRoot,
 
 		// Large arrays, infrequently changed, constant size.
 		blockRoots:                b.blockRoots,
@@ -917,6 +950,7 @@ func (b *BeaconState) Copy() state.BeaconState {
 		latestExecutionPayloadHeaderCapella: b.latestExecutionPayloadHeaderCapella.Copy(),
 		latestExecutionPayloadHeaderDeneb:   b.latestExecutionPayloadHeaderDeneb.Copy(),
 		latestExecutionPayloadHeaderElectra: b.latestExecutionPayloadHeaderElectra.Copy(),
+		latestExecutionPayloadHeaderEPBS:    b.executionPayloadHeaderVal(),
 
 		id: types.Enumerator.Inc(),
 
@@ -955,6 +989,8 @@ func (b *BeaconState) Copy() state.BeaconState {
 			dst.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, experimentalStateDenebSharedFieldRefCount)
 		case version.Electra:
 			dst.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, experimentalStateElectraSharedFieldRefCount)
+		case version.EPBS:
+			dst.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, experimentalStateEpbsSharedFieldRefCount)
 		}
 	} else {
 		switch b.version {
@@ -970,6 +1006,8 @@ func (b *BeaconState) Copy() state.BeaconState {
 			dst.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, denebSharedFieldRefCount)
 		case version.Electra:
 			dst.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, electraSharedFieldRefCount)
+		case version.EPBS:
+			dst.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, epbsSharedFieldRefCount)
 		}
 	}
 
@@ -1064,6 +1102,8 @@ func (b *BeaconState) initializeMerkleLayers(ctx context.Context) error {
 		b.dirtyFields = make(map[types.FieldIndex]bool, params.BeaconConfig().BeaconStateDenebFieldCount)
 	case version.Electra:
 		b.dirtyFields = make(map[types.FieldIndex]bool, params.BeaconConfig().BeaconStateElectraFieldCount)
+	case version.EPBS:
+		b.dirtyFields = make(map[types.FieldIndex]bool, params.BeaconConfig().BeaconStateEpbsFieldCount)
 	default:
 		return fmt.Errorf("unknown state version (%s) when computing dirty fields in merklization", version.String(b.version))
 	}
@@ -1310,6 +1350,14 @@ func (b *BeaconState) rootSelector(ctx context.Context, field types.FieldIndex)
 		return stateutil.PendingPartialWithdrawalsRoot(b.pendingPartialWithdrawals)
 	case types.PendingConsolidations:
 		return stateutil.PendingConsolidationsRoot(b.pendingConsolidations)
+	case types.LatestBlockHash:
+		return b.latestBlockHash, nil
+	case types.LatestFullSlot:
+		return ssz.Uint64Root(uint64(b.latestFullSlot)), nil
+	case types.ExecutionPayloadHeader:
+		return b.latestExecutionPayloadHeaderEPBS.HashTreeRoot()
+	case types.LastWithdrawalsRoot:
+		return b.lastWithdrawalsRoot, nil
 	}
 	return [32]byte{}, errors.New("invalid field index provided")
 }

beacon-chain/state/state-native/state_trie_epbs.go

@@ -0,0 +1,148 @@
+package state_native
+
+import (
+	"runtime"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/fieldtrie"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native/types"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state/stateutil"
+	"github.com/prysmaticlabs/prysm/v5/config/features"
+	fieldparams "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v5/runtime/version"
+)
+
+// InitializeFromProtoUnsafeEpbs constructs a BeaconState from its protobuf representation.
+func InitializeFromProtoUnsafeEpbs(st *ethpb.BeaconStateEPBS) (*BeaconState, error) {
+	if st == nil {
+		return nil, errors.New("received nil state")
+	}
+
+	// Process historical roots.
+	hRoots := make([][32]byte, len(st.HistoricalRoots))
+	for i, root := range st.HistoricalRoots {
+		hRoots[i] = bytesutil.ToBytes32(root)
+	}
+
+	// Define the number of fields to track changes.
+	fieldCount := params.BeaconConfig().BeaconStateEpbsFieldCount
+	b := &BeaconState{
+		version:                       version.EPBS,
+		genesisTime:                   st.GenesisTime,
+		genesisValidatorsRoot:         bytesutil.ToBytes32(st.GenesisValidatorsRoot),
+		slot:                          st.Slot,
+		fork:                          st.Fork,
+		latestBlockHeader:             st.LatestBlockHeader,
+		historicalRoots:               hRoots,
+		eth1Data:                      st.Eth1Data,
+		eth1DataVotes:                 st.Eth1DataVotes,
+		eth1DepositIndex:              st.Eth1DepositIndex,
+		slashings:                     st.Slashings,
+		previousEpochParticipation:    st.PreviousEpochParticipation,
+		currentEpochParticipation:     st.CurrentEpochParticipation,
+		justificationBits:             st.JustificationBits,
+		previousJustifiedCheckpoint:   st.PreviousJustifiedCheckpoint,
+		currentJustifiedCheckpoint:    st.CurrentJustifiedCheckpoint,
+		finalizedCheckpoint:           st.FinalizedCheckpoint,
+		currentSyncCommittee:          st.CurrentSyncCommittee,
+		nextSyncCommittee:             st.NextSyncCommittee,
+		nextWithdrawalIndex:           st.NextWithdrawalIndex,
+		nextWithdrawalValidatorIndex:  st.NextWithdrawalValidatorIndex,
+		historicalSummaries:           st.HistoricalSummaries,
+		depositRequestsStartIndex:     st.DepositRequestsStartIndex,
+		depositBalanceToConsume:       st.DepositBalanceToConsume,
+		exitBalanceToConsume:          st.ExitBalanceToConsume,
+		earliestExitEpoch:             st.EarliestExitEpoch,
+		consolidationBalanceToConsume: st.ConsolidationBalanceToConsume,
+		earliestConsolidationEpoch:    st.EarliestConsolidationEpoch,
+		pendingBalanceDeposits:        st.PendingBalanceDeposits,
+		pendingPartialWithdrawals:     st.PendingPartialWithdrawals,
+		pendingConsolidations:         st.PendingConsolidations,
+
+		// ePBS fields
+		latestBlockHash:                  bytesutil.ToBytes32(st.LatestBlockHash),
+		latestFullSlot:                   st.LatestFullSlot,
+		latestExecutionPayloadHeaderEPBS: st.LatestExecutionPayloadHeader,
+		lastWithdrawalsRoot:              bytesutil.ToBytes32(st.LastWithdrawalsRoot),
+
+		dirtyFields:         make(map[types.FieldIndex]bool, fieldCount),
+		dirtyIndices:        make(map[types.FieldIndex][]uint64, fieldCount),
+		stateFieldLeaves:    make(map[types.FieldIndex]*fieldtrie.FieldTrie, fieldCount),
+		rebuildTrie:         make(map[types.FieldIndex]bool, fieldCount),
+		valMapHandler:       stateutil.NewValMapHandler(st.Validators),
+		validatorIndexCache: newFinalizedValidatorIndexCache(), // only used in post-electra and only populates when finalizing, otherwise it falls back to processing the full validator set
+	}
+
+	if features.Get().EnableExperimentalState {
+		b.blockRootsMultiValue = NewMultiValueBlockRoots(st.BlockRoots)
+		b.stateRootsMultiValue = NewMultiValueStateRoots(st.StateRoots)
+		b.randaoMixesMultiValue = NewMultiValueRandaoMixes(st.RandaoMixes)
+		b.balancesMultiValue = NewMultiValueBalances(st.Balances)
+		b.validatorsMultiValue = NewMultiValueValidators(st.Validators)
+		b.inactivityScoresMultiValue = NewMultiValueInactivityScores(st.InactivityScores)
+		b.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, experimentalStateEpbsSharedFieldRefCount)
+	} else {
+		bRoots := make([][32]byte, fieldparams.BlockRootsLength)
+		for i, r := range st.BlockRoots {
+			bRoots[i] = bytesutil.ToBytes32(r)
+		}
+		b.blockRoots = bRoots
+
+		sRoots := make([][32]byte, fieldparams.StateRootsLength)
+		for i, r := range st.StateRoots {
+			sRoots[i] = bytesutil.ToBytes32(r)
+		}
+		b.stateRoots = sRoots
+
+		mixes := make([][32]byte, fieldparams.RandaoMixesLength)
+		for i, m := range st.RandaoMixes {
+			mixes[i] = bytesutil.ToBytes32(m)
+		}
+		b.randaoMixes = mixes
+
+		b.balances = st.Balances
+		b.validators = st.Validators
+		b.inactivityScores = st.InactivityScores
+
+		b.sharedFieldReferences = make(map[types.FieldIndex]*stateutil.Reference, epbsSharedFieldRefCount)
+	}
+
+	for _, f := range epbsFields {
+		b.dirtyFields[f] = true
+		b.rebuildTrie[f] = true
+		b.dirtyIndices[f] = []uint64{}
+		trie, err := fieldtrie.NewFieldTrie(f, types.BasicArray, nil, 0)
+		if err != nil {
+			return nil, err
+		}
+		b.stateFieldLeaves[f] = trie
+	}
+
+	// Initialize field reference tracking for shared data.
+	b.sharedFieldReferences[types.HistoricalRoots] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.Eth1DataVotes] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.Slashings] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.PreviousEpochParticipationBits] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.CurrentEpochParticipationBits] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.HistoricalSummaries] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.PendingBalanceDeposits] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.PendingPartialWithdrawals] = stateutil.NewRef(1)
+	b.sharedFieldReferences[types.PendingConsolidations] = stateutil.NewRef(1)
+	if !features.Get().EnableExperimentalState {
+		b.sharedFieldReferences[types.BlockRoots] = stateutil.NewRef(1)
+		b.sharedFieldReferences[types.StateRoots] = stateutil.NewRef(1)
+		b.sharedFieldReferences[types.RandaoMixes] = stateutil.NewRef(1)
+		b.sharedFieldReferences[types.Balances] = stateutil.NewRef(1)
+		b.sharedFieldReferences[types.Validators] = stateutil.NewRef(1)
+		b.sharedFieldReferences[types.InactivityScores] = stateutil.NewRef(1)
+	}
+
+	state.Count.Inc()
+	// Finalizer runs when dst is being destroyed in garbage collection.
+	runtime.SetFinalizer(b, finalizerCleanup)
+	return b, nil
+}

beacon-chain/state/state-native/state_trie_epbs_test.go

@@ -0,0 +1,70 @@
+package state_native
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func Test_InitializeFromProtoEpbs(t *testing.T) {
+	st := random.BeaconState(t)
+
+	// Cache initial values to check against after initialization.
+	latestBlockHash := st.LatestBlockHash
+	latestFullSlot := st.LatestFullSlot
+	header := st.LatestExecutionPayloadHeader
+	lastWithdrawalsRoot := st.LastWithdrawalsRoot
+
+	s, err := InitializeFromProtoEpbs(st)
+	require.NoError(t, err)
+
+	// Assert that initial values match those in the new state.
+	gotLatestBlockHash, err := s.LatestBlockHash()
+	require.NoError(t, err)
+	require.DeepEqual(t, latestBlockHash, gotLatestBlockHash)
+	gotLatestFullSlot, err := s.LatestFullSlot()
+	require.NoError(t, err)
+	require.Equal(t, latestFullSlot, gotLatestFullSlot)
+	gotHeader, err := s.LatestExecutionPayloadHeaderEPBS()
+	require.NoError(t, err)
+	require.DeepEqual(t, header, gotHeader)
+	gotLastWithdrawalsRoot, err := s.LastWithdrawalsRoot()
+	require.NoError(t, err)
+	require.DeepEqual(t, lastWithdrawalsRoot, gotLastWithdrawalsRoot)
+}
+
+func Test_CopyEpbs(t *testing.T) {
+	st := random.BeaconState(t)
+	s, err := InitializeFromProtoUnsafeEpbs(st)
+	require.NoError(t, err)
+
+	// Test shallow copy.
+	sNoCopy := s
+	require.DeepEqual(t, s.latestExecutionPayloadHeaderEPBS, sNoCopy.latestExecutionPayloadHeaderEPBS)
+
+	// Modify a field to check if it reflects in the shallow copy.
+	s.latestExecutionPayloadHeaderEPBS.Slot = 100
+	require.Equal(t, s.latestExecutionPayloadHeaderEPBS, sNoCopy.latestExecutionPayloadHeaderEPBS)
+
+	// Copy the state
+	sCopy := s.Copy()
+	require.NoError(t, err)
+	header, err := sCopy.LatestExecutionPayloadHeaderEPBS()
+	require.NoError(t, err)
+	require.DeepEqual(t, s.latestExecutionPayloadHeaderEPBS, header)
+
+	// Modify the original to check if the copied state is independent.
+	s.latestExecutionPayloadHeaderEPBS.Slot = 200
+	require.DeepNotEqual(t, s.latestExecutionPayloadHeaderEPBS, header)
+}
+
+func Test_HashTreeRootEpbs(t *testing.T) {
+	st := random.BeaconState(t)
+	s, err := InitializeFromProtoUnsafeEpbs(st)
+	require.NoError(t, err)
+
+	_, err = s.HashTreeRoot(context.Background())
+	require.NoError(t, err)
+}

beacon-chain/state/state-native/types/types.go

@@ -114,6 +114,14 @@ func (f FieldIndex) String() string {
 		return "pendingPartialWithdrawals"
 	case PendingConsolidations:
 		return "pendingConsolidations"
+	case LatestBlockHash: // ePBS fields start here
+		return "LatestBlockHash"
+	case LatestFullSlot:
+		return "LatestFullSlot"
+	case ExecutionPayloadHeader:
+		return "ExecutionPayloadHeader"
+	case LastWithdrawalsRoot:
+		return "LastWithdrawalsRoot"
 	default:
 		return fmt.Sprintf("unknown field index number: %d", f)
 	}
@@ -171,7 +179,8 @@ func (f FieldIndex) RealPosition() int {
 		return 22
 	case NextSyncCommittee:
 		return 23
-	case LatestExecutionPayloadHeader, LatestExecutionPayloadHeaderCapella, LatestExecutionPayloadHeaderDeneb, LatestExecutionPayloadHeaderElectra:
+		// ExecutionPayloadHeader is from ePBS.
+	case LatestExecutionPayloadHeader, LatestExecutionPayloadHeaderCapella, LatestExecutionPayloadHeaderDeneb, LatestExecutionPayloadHeaderElectra, ExecutionPayloadHeader:
 		return 24
 	case NextWithdrawalIndex:
 		return 25
@@ -197,6 +206,12 @@ func (f FieldIndex) RealPosition() int {
 		return 35
 	case PendingConsolidations:
 		return 36
+	case LatestBlockHash: // ePBS fields start here
+		return 41
+	case LatestFullSlot:
+		return 42
+	case LastWithdrawalsRoot:
+		return 43
 	default:
 		return -1
 	}
@@ -250,6 +265,7 @@ const (
 	LatestExecutionPayloadHeaderCapella
 	LatestExecutionPayloadHeaderDeneb
 	LatestExecutionPayloadHeaderElectra
+	ExecutionPayloadHeader
 	NextWithdrawalIndex
 	NextWithdrawalValidatorIndex
 	HistoricalSummaries
@@ -262,6 +278,9 @@ const (
 	PendingBalanceDeposits        // Electra: EIP-7251
 	PendingPartialWithdrawals     // Electra: EIP-7251
 	PendingConsolidations         // Electra: EIP-7251
+	LatestBlockHash               // ePBS fields start here
+	LatestFullSlot
+	LastWithdrawalsRoot
 )
 
 // Enumerator keeps track of the number of states created since the node's start.

beacon-chain/sync/BUILD.bazel

@@ -16,6 +16,7 @@ go_library(
         "log.go",
         "metrics.go",
         "options.go",
+        "payload_attestations.go",
         "pending_attestations_queue.go",
         "pending_blocks_queue.go",
         "rate_limiter.go",
@@ -101,6 +102,7 @@ go_library(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/epbs/payload-attestation:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
@@ -155,6 +157,7 @@ go_test(
         "decode_pubsub_test.go",
         "error_test.go",
         "fork_watcher_test.go",
+        "payload_attestations_test.go",
         "pending_attestations_queue_test.go",
         "pending_blocks_queue_test.go",
         "rate_limiter_test.go",
@@ -228,6 +231,7 @@ go_test(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/epbs/payload-attestation:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
@@ -246,6 +250,7 @@ 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_d4l3k_messagediff//:go_default_library",

beacon-chain/sync/options.go

@@ -2,6 +2,7 @@ package sync
 
 import (
 	"github.com/prysmaticlabs/prysm/v5/async/event"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	blockfeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/block"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/operation"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
@@ -127,6 +128,13 @@ func WithSlasherBlockHeadersFeed(slasherBlockHeadersFeed *event.Feed) Option {
 	}
 }
 
+func WithPayloadAttestationCache(r *cache.PayloadAttestationCache) Option {
+	return func(s *Service) error {
+		s.payloadAttestationCache = r
+		return nil
+	}
+}
+
 func WithPayloadReconstructor(r execution.PayloadReconstructor) Option {
 	return func(s *Service) error {
 		s.cfg.executionPayloadReconstructor = r

beacon-chain/sync/payload_attestations.go

@@ -0,0 +1,114 @@
+package sync
+
+import (
+	"context"
+	"slices"
+
+	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/monitoring/tracing"
+	eth "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
+	"go.opencensus.io/trace"
+	"google.golang.org/protobuf/proto"
+)
+
+var (
+	errAlreadySeenPayloadAttestation = errors.New("payload attestation already seen for validator index")
+)
+
+func (s *Service) validatePayloadAttestation(ctx context.Context, pid peer.ID, msg *pubsub.Message) (pubsub.ValidationResult, error) {
+	if pid == s.cfg.p2p.PeerID() {
+		return pubsub.ValidationAccept, nil
+	}
+	if s.cfg.initialSync.Syncing() {
+		return pubsub.ValidationIgnore, nil
+	}
+	ctx, span := trace.StartSpan(ctx, "sync.validatePayloadAttestation")
+	defer span.End()
+	if msg.Topic == nil {
+		return pubsub.ValidationReject, errInvalidTopic
+	}
+	m, err := s.decodePubsubMessage(msg)
+	if err != nil {
+		tracing.AnnotateError(span, err)
+		return pubsub.ValidationReject, err
+	}
+	att, ok := m.(*eth.PayloadAttestationMessage)
+	if !ok {
+		return pubsub.ValidationReject, errWrongMessage
+	}
+	pa, err := payloadattestation.NewReadOnly(att)
+	if err != nil {
+		log.WithError(err).Error("failed to create read only payload attestation")
+		return pubsub.ValidationIgnore, err
+	}
+	v := s.newPayloadAttestationVerifier(pa, verification.GossipPayloadAttestationMessageRequirements)
+
+	if err := v.VerifyCurrentSlot(); err != nil {
+		return pubsub.ValidationIgnore, err
+	}
+
+	if err := v.VerifyPayloadStatus(); err != nil {
+		return pubsub.ValidationReject, err
+	}
+
+	if err := v.VerifyBlockRootSeen(s.hasBadBlock); err != nil {
+		return pubsub.ValidationIgnore, err
+	}
+
+	if err := v.VerifyBlockRootValid(s.hasBadBlock); err != nil {
+		return pubsub.ValidationReject, err
+	}
+
+	st, err := s.cfg.chain.HeadState(ctx)
+	if err != nil {
+		return pubsub.ValidationIgnore, err
+	}
+
+	if err := v.VerifyValidatorInPTC(ctx, st); err != nil {
+		return pubsub.ValidationReject, err
+	}
+
+	if err := v.VerifySignature(st); err != nil {
+		return pubsub.ValidationReject, err
+	}
+
+	if s.payloadAttestationCache.Seen(pa.BeaconBlockRoot(), uint64(pa.ValidatorIndex())) {
+		return pubsub.ValidationIgnore, errAlreadySeenPayloadAttestation
+	}
+
+	return pubsub.ValidationAccept, nil
+}
+
+func (s *Service) payloadAttestationSubscriber(ctx context.Context, msg proto.Message) error {
+	a, ok := msg.(*eth.PayloadAttestationMessage)
+	if !ok {
+		return errWrongMessage
+	}
+	if err := helpers.ValidateNilPayloadAttestationMessage(a); err != nil {
+		return err
+	}
+	root := [32]byte(a.Data.BeaconBlockRoot)
+	st, err := s.cfg.chain.HeadState(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.payloadAttestationCache.Seen(root, uint64(primitives.ValidatorIndex(idx))) {
+		return nil
+	}
+
+	return s.payloadAttestationCache.Add(a, uint64(idx))
+}

beacon-chain/sync/payload_attestations_test.go

@@ -0,0 +1,162 @@
+package sync
+
+import (
+	"bytes"
+	"context"
+	"reflect"
+	"testing"
+	"time"
+
+	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	pb "github.com/libp2p/go-libp2p-pubsub/pb"
+	"github.com/pkg/errors"
+	mock "github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p"
+	p2ptest "github.com/prysmaticlabs/prysm/v5/beacon-chain/p2p/testing"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
+	mockSync "github.com/prysmaticlabs/prysm/v5/beacon-chain/sync/initial-sync/testing"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/verification"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
+	"github.com/prysmaticlabs/prysm/v5/testing/require"
+	"github.com/prysmaticlabs/prysm/v5/testing/util/random"
+)
+
+func TestValidatePayloadAttestationMessage_IncorrectTopic(t *testing.T) {
+	ctx := context.Background()
+	p := p2ptest.NewTestP2P(t)
+	chainService := &mock.ChainService{Genesis: time.Unix(time.Now().Unix()-int64(params.BeaconConfig().SecondsPerSlot), 0)}
+	s := &Service{
+		payloadAttestationCache: &cache.PayloadAttestationCache{},
+		cfg:                     &config{chain: chainService, p2p: p, initialSync: &mockSync.Sync{}, clock: startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot)}}
+
+	msg := random.PayloadAttestation(t) // Using payload attestation for message should fail.
+	buf := new(bytes.Buffer)
+	_, err := p.Encoding().EncodeGossip(buf, msg)
+	require.NoError(t, err)
+
+	topic := p2p.GossipTypeMapping[reflect.TypeOf(msg)]
+	digest, err := s.currentForkDigest()
+	require.NoError(t, err)
+	topic = s.addDigestToTopic(topic, digest)
+
+	result, err := s.validatePayloadAttestation(ctx, "", &pubsub.Message{
+		Message: &pb.Message{
+			Data:  buf.Bytes(),
+			Topic: &topic,
+		}})
+	require.ErrorContains(t, "extraction failed for topic", err)
+	require.Equal(t, result, pubsub.ValidationReject)
+}
+
+func TestValidatePayloadAttestationMessage_ErrorPathsWithMock(t *testing.T) {
+	tests := []struct {
+		error    error
+		verifier verification.NewPayloadAttestationMsgVerifier
+		result   pubsub.ValidationResult
+	}{
+		{
+			error: errors.New("incorrect slot"),
+			verifier: func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+				return &verification.MockPayloadAttestation{ErrIncorrectPayloadAttSlot: errors.New("incorrect slot")}
+			},
+			result: pubsub.ValidationIgnore,
+		},
+		{
+			error: errors.New("incorrect status"),
+			verifier: func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+				return &verification.MockPayloadAttestation{ErrIncorrectPayloadAttStatus: errors.New("incorrect status")}
+			},
+			result: pubsub.ValidationReject,
+		},
+		{
+			error: errors.New("block root seen"),
+			verifier: func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+				return &verification.MockPayloadAttestation{ErrPayloadAttBlockRootNotSeen: errors.New("block root seen")}
+			},
+			result: pubsub.ValidationIgnore,
+		},
+		{
+			error: errors.New("block root invalid"),
+			verifier: func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+				return &verification.MockPayloadAttestation{ErrPayloadAttBlockRootInvalid: errors.New("block root invalid")}
+			},
+			result: pubsub.ValidationReject,
+		},
+		{
+			error: errors.New("validator not in PTC"),
+			verifier: func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+				return &verification.MockPayloadAttestation{ErrIncorrectPayloadAttValidator: errors.New("validator not in PTC")}
+			},
+			result: pubsub.ValidationReject,
+		},
+		{
+			error: errors.New("incorrect signature"),
+			verifier: func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+				return &verification.MockPayloadAttestation{ErrInvalidMessageSignature: errors.New("incorrect signature")}
+			},
+			result: pubsub.ValidationReject,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.error.Error(), func(t *testing.T) {
+			ctx := context.Background()
+			p := p2ptest.NewTestP2P(t)
+			chainService := &mock.ChainService{Genesis: time.Unix(time.Now().Unix()-int64(params.BeaconConfig().SecondsPerSlot), 0)}
+			s := &Service{
+				payloadAttestationCache: &cache.PayloadAttestationCache{},
+				cfg:                     &config{chain: chainService, p2p: p, initialSync: &mockSync.Sync{}, clock: startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot)}}
+			s.newPayloadAttestationVerifier = tt.verifier
+
+			msg := random.PayloadAttestationMessage(t)
+			buf := new(bytes.Buffer)
+			_, err := p.Encoding().EncodeGossip(buf, msg)
+			require.NoError(t, err)
+
+			topic := p2p.GossipTypeMapping[reflect.TypeOf(msg)]
+			digest, err := s.currentForkDigest()
+			require.NoError(t, err)
+			topic = s.addDigestToTopic(topic, digest)
+
+			result, err := s.validatePayloadAttestation(ctx, "", &pubsub.Message{
+				Message: &pb.Message{
+					Data:  buf.Bytes(),
+					Topic: &topic,
+				}})
+
+			require.ErrorContains(t, tt.error.Error(), err)
+			require.Equal(t, result, tt.result)
+		})
+	}
+}
+
+func TestValidatePayloadAttestationMessage_Accept(t *testing.T) {
+	ctx := context.Background()
+	p := p2ptest.NewTestP2P(t)
+	chainService := &mock.ChainService{Genesis: time.Unix(time.Now().Unix()-int64(params.BeaconConfig().SecondsPerSlot), 0)}
+	s := &Service{
+		payloadAttestationCache: &cache.PayloadAttestationCache{},
+		cfg:                     &config{chain: chainService, p2p: p, initialSync: &mockSync.Sync{}, clock: startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot)}}
+	s.newPayloadAttestationVerifier = func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+		return &verification.MockPayloadAttestation{}
+	}
+
+	msg := random.PayloadAttestationMessage(t)
+	buf := new(bytes.Buffer)
+	_, err := p.Encoding().EncodeGossip(buf, msg)
+	require.NoError(t, err)
+
+	topic := p2p.GossipTypeMapping[reflect.TypeOf(msg)]
+	digest, err := s.currentForkDigest()
+	require.NoError(t, err)
+	topic = s.addDigestToTopic(topic, digest)
+
+	result, err := s.validatePayloadAttestation(ctx, "", &pubsub.Message{
+		Message: &pb.Message{
+			Data:  buf.Bytes(),
+			Topic: &topic,
+		}})
+	require.NoError(t, err)
+	require.Equal(t, result, pubsub.ValidationAccept)
+}

beacon-chain/sync/service.go

@@ -19,6 +19,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v5/async/abool"
 	"github.com/prysmaticlabs/prysm/v5/async/event"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/blockchain"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/cache"
 	blockfeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/block"
 	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/operation"
 	statefeed "github.com/prysmaticlabs/prysm/v5/beacon-chain/core/feed/state"
@@ -38,6 +39,7 @@ import (
 	lruwrpr "github.com/prysmaticlabs/prysm/v5/cache/lru"
 	"github.com/prysmaticlabs/prysm/v5/config/params"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
 	leakybucket "github.com/prysmaticlabs/prysm/v5/container/leaky-bucket"
 	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
@@ -124,6 +126,7 @@ type Service struct {
 	seenPendingBlocks                map[[32]byte]bool
 	blkRootToPendingAtts             map[[32]byte][]ethpb.SignedAggregateAttAndProof
 	subHandler                       *subTopicHandler
+	payloadAttestationCache          *cache.PayloadAttestationCache
 	pendingAttsLock                  sync.RWMutex
 	pendingQueueLock                 sync.RWMutex
 	chainStarted                     *abool.AtomicBool
@@ -156,6 +159,7 @@ type Service struct {
 	initialSyncComplete              chan struct{}
 	verifierWaiter                   *verification.InitializerWaiter
 	newBlobVerifier                  verification.NewBlobVerifier
+	newPayloadAttestationVerifier    verification.NewPayloadAttestationMsgVerifier
 	availableBlocker                 coverage.AvailableBlocker
 	ctxMap                           ContextByteVersions
 }
@@ -214,6 +218,12 @@ func newBlobVerifierFromInitializer(ini *verification.Initializer) verification.
 	}
 }
 
+func newPayloadAttestationMessageFromInitializer(ini *verification.Initializer) verification.NewPayloadAttestationMsgVerifier {
+	return func(pa payloadattestation.ROMessage, reqs []verification.Requirement) verification.PayloadAttestationMsgVerifier {
+		return ini.NewPayloadAttestationMsgVerifier(pa, reqs)
+	}
+}
+
 // Start the regular sync service.
 func (s *Service) Start() {
 	v, err := s.verifierWaiter.WaitForInitializer(s.ctx)
@@ -222,6 +232,7 @@ func (s *Service) Start() {
 		return
 	}
 	s.newBlobVerifier = newBlobVerifierFromInitializer(v)
+	s.newPayloadAttestationVerifier = newPayloadAttestationMessageFromInitializer(v)
 
 	go s.verifierRoutine()
 	go s.registerHandlers()

beacon-chain/sync/subscriber.go

@@ -145,6 +145,16 @@ func (s *Service) registerSubscribers(epoch primitives.Epoch, digest [4]byte) {
 			params.BeaconConfig().BlobsidecarSubnetCount,
 		)
 	}
+
+	// New Gossip Topic for ePBS
+	if epoch >= params.BeaconConfig().EPBSForkEpoch {
+		s.subscribe(
+			p2p.PayloadAttestationMessageTopicFormat,
+			s.validatePayloadAttestation,
+			s.payloadAttestationSubscriber,
+			digest,
+		)
+	}
 }
 
 // subscribe to a given topic with a given validator and subscription handler.

beacon-chain/verification/BUILD.bazel

@@ -9,9 +9,12 @@ go_library(
         "error.go",
         "fake.go",
         "initializer.go",
+        "initializer_epbs.go",
         "interface.go",
         "metrics.go",
         "mock.go",
+        "payload_attestation.go",
+        "payload_attestation_mock.go",
         "result.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/beacon-chain/verification",
@@ -28,6 +31,7 @@ go_library(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
+        "//consensus-types/epbs/payload-attestation:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",
@@ -50,18 +54,22 @@ go_test(
         "blob_test.go",
         "cache_test.go",
         "initializer_test.go",
+        "payload_attestation_test.go",
         "result_test.go",
     ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/startup: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/epbs/payload-attestation:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",

beacon-chain/verification/initializer_epbs.go

@@ -0,0 +1,15 @@
+package verification
+
+import (
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
+)
+
+// NewPayloadAttestationMsgVerifier creates a PayloadAttestationMsgVerifier for a single payload attestation message,
+// with the given set of requirements.
+func (ini *Initializer) NewPayloadAttestationMsgVerifier(pa payloadattestation.ROMessage, reqs []Requirement) *PayloadAttMsgVerifier {
+	return &PayloadAttMsgVerifier{
+		sharedResources: ini.shared,
+		results:         newResults(reqs...),
+		pa:              pa,
+	}
+}

beacon-chain/verification/interface.go

@@ -3,7 +3,9 @@ package verification
 import (
 	"context"
 
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
 )
 
 // BlobVerifier defines the methods implemented by the ROBlobVerifier.
@@ -26,6 +28,23 @@ type BlobVerifier interface {
 	SatisfyRequirement(Requirement)
 }
 
+// PayloadAttestationMsgVerifier defines the methods implemented by the ROPayloadAttestation.
+// It is similar to BlobVerifier, but for payload attestation messages.
+type PayloadAttestationMsgVerifier interface {
+	VerifyCurrentSlot() error
+	VerifyPayloadStatus() error
+	VerifyBlockRootSeen(func([32]byte) bool) error
+	VerifyBlockRootValid(func([32]byte) bool) error
+	VerifyValidatorInPTC(context.Context, state.BeaconState) error
+	VerifySignature(state.BeaconState) error
+	VerifiedPayloadAttestation() (payloadattestation.VerifiedROMessage, error)
+	SatisfyRequirement(Requirement)
+}
+
 // NewBlobVerifier is a function signature that can be used by code that needs to be
 // able to mock Initializer.NewBlobVerifier without complex setup.
 type NewBlobVerifier func(b blocks.ROBlob, reqs []Requirement) BlobVerifier
+
+// NewPayloadAttestationMsgVerifier is a function signature that can be used by code that needs to be
+// able to mock Initializer.NewPayloadAttestationMsgVerifier without complex setup.
+type NewPayloadAttestationMsgVerifier func(pa payloadattestation.ROMessage, reqs []Requirement) PayloadAttestationMsgVerifier

beacon-chain/verification/payload_attestation.go

@@ -0,0 +1,231 @@
+package verification
+
+import (
+	"context"
+	"fmt"
+	"slices"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/time/slots"
+	log "github.com/sirupsen/logrus"
+)
+
+// RequirementList defines a list of requirements.
+type RequirementList []Requirement
+
+const (
+	RequireCurrentSlot Requirement = iota
+	RequireMessageNotSeen
+	RequireKnownPayloadStatus
+	RequireValidatorInPTC
+	RequireBlockRootSeen
+	RequireBlockRootValid
+	RequireSignatureValid
+)
+
+// PayloadAttGossipRequirements defines the list of requirements for gossip payload attestation messages.
+var PayloadAttGossipRequirements = []Requirement{
+	RequireCurrentSlot,
+	RequireMessageNotSeen,
+	RequireKnownPayloadStatus,
+	RequireValidatorInPTC,
+	RequireBlockRootSeen,
+	RequireBlockRootValid,
+	RequireSignatureValid,
+}
+
+// GossipPayloadAttestationMessageRequirements is a requirement list for gossip payload attestation messages.
+var GossipPayloadAttestationMessageRequirements = RequirementList(PayloadAttGossipRequirements)
+
+var (
+	ErrIncorrectPayloadAttSlot      = errors.New("payload att slot does not match the current slot")
+	ErrIncorrectPayloadAttStatus    = errors.New("unknown payload att status")
+	ErrPayloadAttBlockRootNotSeen   = errors.New("block root not seen")
+	ErrPayloadAttBlockRootInvalid   = errors.New("block root invalid")
+	ErrIncorrectPayloadAttValidator = errors.New("validator not present in payload timeliness committee")
+	ErrInvalidPayloadAttMessage     = errors.New("invalid payload attestation message")
+)
+
+var _ PayloadAttestationMsgVerifier = &PayloadAttMsgVerifier{}
+
+// PayloadAttMsgVerifier is a read-only verifier for payload attestation messages.
+type PayloadAttMsgVerifier struct {
+	*sharedResources
+	results *results
+	pa      payloadattestation.ROMessage
+}
+
+// VerifyCurrentSlot verifies if the current slot matches the expected slot.
+// Represents the following spec verification:
+// [IGNORE] data.slot is the current slot.
+func (v *PayloadAttMsgVerifier) VerifyCurrentSlot() (err error) {
+	defer v.record(RequireCurrentSlot, &err)
+
+	if v.pa.Slot() != v.clock.CurrentSlot() {
+		log.WithFields(logFields(v.pa)).Errorf("does not match current slot %d", v.clock.CurrentSlot())
+		return ErrIncorrectPayloadAttSlot
+	}
+
+	return nil
+}
+
+// VerifyPayloadStatus verifies if the payload status is known.
+// Represents the following spec verification:
+// [REJECT] data.payload_status < PAYLOAD_INVALID_STATUS.
+func (v *PayloadAttMsgVerifier) VerifyPayloadStatus() (err error) {
+	defer v.record(RequireKnownPayloadStatus, &err)
+
+	if v.pa.PayloadStatus() >= primitives.PAYLOAD_INVALID_STATUS {
+		log.WithFields(logFields(v.pa)).Error(ErrIncorrectPayloadAttStatus.Error())
+		return ErrIncorrectPayloadAttStatus
+	}
+
+	return nil
+}
+
+// VerifyBlockRootSeen verifies if the block root has been seen before.
+// Represents the following spec verification:
+// [IGNORE] The attestation's data.beacon_block_root has been seen (via both gossip and non-gossip sources).
+func (v *PayloadAttMsgVerifier) VerifyBlockRootSeen(parentSeen func([32]byte) bool) (err error) {
+	defer v.record(RequireBlockRootSeen, &err)
+
+	if parentSeen != nil && parentSeen(v.pa.BeaconBlockRoot()) {
+		return nil
+	}
+
+	if v.fc.HasNode(v.pa.BeaconBlockRoot()) {
+		return nil
+	}
+
+	log.WithFields(logFields(v.pa)).Error(ErrPayloadAttBlockRootNotSeen.Error())
+	return ErrPayloadAttBlockRootNotSeen
+}
+
+// VerifyBlockRootValid verifies if the block root is valid.
+// Represents the following spec verification:
+// [REJECT] The beacon block with root data.beacon_block_root passes validation.
+func (v *PayloadAttMsgVerifier) VerifyBlockRootValid(badBlock func([32]byte) bool) (err error) {
+	defer v.record(RequireBlockRootValid, &err)
+
+	if badBlock != nil && badBlock(v.pa.BeaconBlockRoot()) {
+		log.WithFields(logFields(v.pa)).Error(ErrPayloadAttBlockRootInvalid.Error())
+		return ErrPayloadAttBlockRootInvalid
+	}
+
+	return nil
+}
+
+// VerifyValidatorInPTC verifies if the validator is present.
+// Represents the following spec verification:
+// [REJECT] The validator index is within the payload committee in get_ptc(state, data.slot). For the current's slot head state.
+func (v *PayloadAttMsgVerifier) VerifyValidatorInPTC(ctx context.Context, st state.BeaconState) (err error) {
+	defer v.record(RequireValidatorInPTC, &err)
+
+	ptc, err := helpers.GetPayloadTimelinessCommittee(ctx, st, v.pa.Slot())
+	if err != nil {
+		return err
+	}
+
+	idx := slices.Index(ptc, v.pa.ValidatorIndex())
+	if idx == -1 {
+		log.WithFields(logFields(v.pa)).Error(ErrIncorrectPayloadAttValidator.Error())
+		return ErrIncorrectPayloadAttValidator
+	}
+
+	return nil
+}
+
+// VerifySignature verifies the signature of the payload attestation message.
+// Represents the following spec verification:
+// [REJECT] The signature of payload_attestation_message.signature is valid with respect to the validator index.
+func (v *PayloadAttMsgVerifier) VerifySignature(st state.BeaconState) (err error) {
+	defer v.record(RequireSignatureValid, &err)
+
+	err = validatePayloadAttestationMessageSignature(st, v.pa)
+	if err != nil {
+		if errors.Is(err, signing.ErrSigFailedToVerify) {
+			log.WithFields(logFields(v.pa)).Error("signature failed to validate")
+		} else {
+			log.WithFields(logFields(v.pa)).WithError(err).Error("could not validate signature")
+		}
+		return err
+	}
+
+	return nil
+}
+
+// VerifiedPayloadAttestation returns a verified payload attestation message by checking all requirements.
+func (v *PayloadAttMsgVerifier) VerifiedPayloadAttestation() (payloadattestation.VerifiedROMessage, error) {
+	if v.results.allSatisfied() {
+		return payloadattestation.NewVerifiedROMessage(v.pa), nil
+	}
+	return payloadattestation.VerifiedROMessage{}, ErrInvalidPayloadAttMessage
+}
+
+// SatisfyRequirement allows the caller to manually mark a requirement as satisfied.
+func (v *PayloadAttMsgVerifier) SatisfyRequirement(req Requirement) {
+	v.record(req, nil)
+}
+
+// ValidatePayloadAttestationMessageSignature verifies the signature of a payload attestation message.
+func validatePayloadAttestationMessageSignature(st state.BeaconState, payloadAtt payloadattestation.ROMessage) error {
+	val, err := st.ValidatorAtIndex(payloadAtt.ValidatorIndex())
+	if err != nil {
+		return err
+	}
+
+	pub, err := bls.PublicKeyFromBytes(val.PublicKey)
+	if err != nil {
+		return err
+	}
+
+	s := payloadAtt.Signature()
+	sig, err := bls.SignatureFromBytes(s[:])
+	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 := payloadAtt.SigningRoot(domain)
+	if err != nil {
+		return err
+	}
+
+	if !sig.Verify(pub, root[:]) {
+		return signing.ErrSigFailedToVerify
+	}
+	return nil
+}
+
+// record records the result of a requirement verification.
+func (v *PayloadAttMsgVerifier) record(req Requirement, err *error) {
+	if err == nil || *err == nil {
+		v.results.record(req, nil)
+		return
+	}
+
+	v.results.record(req, *err)
+}
+
+// logFields returns log fields for a ROMessage instance.
+func logFields(payload payloadattestation.ROMessage) log.Fields {
+	return log.Fields{
+		"slot":            payload.Slot(),
+		"validatorIndex":  payload.ValidatorIndex(),
+		"signature":       fmt.Sprintf("%#x", payload.Signature()),
+		"beaconBlockRoot": fmt.Sprintf("%#x", payload.BeaconBlockRoot()),
+		"payloadStatus":   payload.PayloadStatus(),
+	}
+}

beacon-chain/verification/payload_attestation_mock.go

@@ -0,0 +1,51 @@
+package verification
+
+import (
+	"context"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
+)
+
+type MockPayloadAttestation struct {
+	ErrIncorrectPayloadAttSlot      error
+	ErrIncorrectPayloadAttStatus    error
+	ErrIncorrectPayloadAttValidator error
+	ErrPayloadAttBlockRootNotSeen   error
+	ErrPayloadAttBlockRootInvalid   error
+	ErrInvalidPayloadAttMessage     error
+	ErrInvalidMessageSignature      error
+	ErrUnsatisfiedRequirement       error
+}
+
+var _ PayloadAttestationMsgVerifier = &MockPayloadAttestation{}
+
+func (m *MockPayloadAttestation) VerifyCurrentSlot() error {
+	return m.ErrIncorrectPayloadAttSlot
+}
+
+func (m *MockPayloadAttestation) VerifyPayloadStatus() error {
+	return m.ErrIncorrectPayloadAttStatus
+}
+
+func (m *MockPayloadAttestation) VerifyValidatorInPTC(ctx context.Context, st state.BeaconState) error {
+	return m.ErrIncorrectPayloadAttValidator
+}
+
+func (m *MockPayloadAttestation) VerifyBlockRootSeen(func([32]byte) bool) error {
+	return m.ErrPayloadAttBlockRootNotSeen
+}
+
+func (m *MockPayloadAttestation) VerifyBlockRootValid(func([32]byte) bool) error {
+	return m.ErrPayloadAttBlockRootInvalid
+}
+
+func (m *MockPayloadAttestation) VerifySignature(st state.BeaconState) (err error) {
+	return m.ErrInvalidMessageSignature
+}
+
+func (m *MockPayloadAttestation) VerifiedPayloadAttestation() (payloadattestation.VerifiedROMessage, error) {
+	return payloadattestation.VerifiedROMessage{}, nil
+}
+
+func (m *MockPayloadAttestation) SatisfyRequirement(req Requirement) {}

beacon-chain/verification/payload_attestation_test.go

@@ -0,0 +1,321 @@
+package verification
+
+import (
+	"context"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/signing"
+	"github.com/prysmaticlabs/prysm/v5/beacon-chain/startup"
+	state_native "github.com/prysmaticlabs/prysm/v5/beacon-chain/state/state-native"
+	"github.com/prysmaticlabs/prysm/v5/config/params"
+	payloadattestation "github.com/prysmaticlabs/prysm/v5/consensus-types/epbs/payload-attestation"
+	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v5/crypto/bls"
+	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
+	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/time/slots"
+)
+
+func TestVerifyCurrentSlot(t *testing.T) {
+	now := time.Now()
+	// make genesis 1 slot in the past
+	genesis := now.Add(-1 * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second)
+	clock := startup.NewClock(genesis, [32]byte{}, startup.WithNower(func() time.Time { return now }))
+
+	init := Initializer{shared: &sharedResources{clock: clock}}
+
+	t.Run("incorrect slot", func(t *testing.T) {
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data:      &ethpb.PayloadAttestationData{},
+			Signature: make([]byte, 96),
+		}, init)
+		require.ErrorIs(t, pa.VerifyCurrentSlot(), ErrIncorrectPayloadAttSlot)
+		require.Equal(t, true, pa.results.executed(RequireCurrentSlot))
+		require.Equal(t, ErrIncorrectPayloadAttSlot, pa.results.result(RequireCurrentSlot))
+	})
+
+	t.Run("current slot", func(t *testing.T) {
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				Slot: 1,
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.NoError(t, pa.VerifyCurrentSlot())
+		require.Equal(t, true, pa.results.executed(RequireCurrentSlot))
+		require.NoError(t, pa.results.result(RequireCurrentSlot))
+	})
+}
+
+func TestVerifyKnownPayloadStatus(t *testing.T) {
+	init := Initializer{shared: &sharedResources{clock: &startup.Clock{}}}
+
+	t.Run("unknown status", func(t *testing.T) {
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				PayloadStatus: primitives.PAYLOAD_INVALID_STATUS,
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.ErrorIs(t, pa.VerifyPayloadStatus(), ErrIncorrectPayloadAttStatus)
+		require.Equal(t, true, pa.results.executed(RequireKnownPayloadStatus))
+		require.Equal(t, ErrIncorrectPayloadAttStatus, pa.results.result(RequireKnownPayloadStatus))
+	})
+
+	t.Run("known status", func(t *testing.T) {
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data:      &ethpb.PayloadAttestationData{},
+			Signature: make([]byte, 96),
+		}, init)
+		require.NoError(t, pa.VerifyPayloadStatus())
+		require.Equal(t, true, pa.results.executed(RequireKnownPayloadStatus))
+		require.NoError(t, pa.results.result(RequireKnownPayloadStatus))
+	})
+}
+
+func TestVerifyBlockRootSeen(t *testing.T) {
+	blockRoot := [32]byte{1}
+
+	fc := &mockForkchoicer{
+		HasNodeCB: func(parent [32]byte) bool {
+			return parent == blockRoot
+		},
+	}
+
+	t.Run("happy path", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{fc: fc}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				BeaconBlockRoot: blockRoot[:],
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.NoError(t, pa.VerifyBlockRootSeen(nil))
+		require.Equal(t, true, pa.results.executed(RequireBlockRootSeen))
+		require.NoError(t, pa.results.result(RequireBlockRootSeen))
+	})
+
+	t.Run("unknown block", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{fc: fc}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data:      &ethpb.PayloadAttestationData{},
+			Signature: make([]byte, 96),
+		}, init)
+		require.ErrorIs(t, pa.VerifyBlockRootSeen(nil), ErrPayloadAttBlockRootNotSeen)
+		require.Equal(t, true, pa.results.executed(RequireBlockRootSeen))
+		require.Equal(t, ErrPayloadAttBlockRootNotSeen, pa.results.result(RequireBlockRootSeen))
+	})
+
+	t.Run("bad parent true", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				BeaconBlockRoot: blockRoot[:],
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.NoError(t, pa.VerifyBlockRootSeen(badParentCb(t, blockRoot, true)))
+		require.Equal(t, true, pa.results.executed(RequireBlockRootSeen))
+		require.NoError(t, pa.results.result(RequireBlockRootSeen))
+	})
+
+	t.Run("bad parent false, unknown block", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{fc: fc}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				BeaconBlockRoot: []byte{2},
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.ErrorIs(t, pa.VerifyBlockRootSeen(badParentCb(t, [32]byte{2}, false)), ErrPayloadAttBlockRootNotSeen)
+		require.Equal(t, true, pa.results.executed(RequireBlockRootSeen))
+		require.Equal(t, ErrPayloadAttBlockRootNotSeen, pa.results.result(RequireBlockRootSeen))
+	})
+}
+
+func TestVerifyBlockRootValid(t *testing.T) {
+	blockRoot := [32]byte{1}
+
+	t.Run("good block", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				BeaconBlockRoot: blockRoot[:],
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.NoError(t, pa.VerifyBlockRootValid(badParentCb(t, blockRoot, false)))
+		require.Equal(t, true, pa.results.executed(RequireBlockRootValid))
+		require.NoError(t, pa.results.result(RequireBlockRootValid))
+	})
+
+	t.Run("bad block", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				BeaconBlockRoot: blockRoot[:],
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.ErrorIs(t, pa.VerifyBlockRootValid(badParentCb(t, blockRoot, true)), ErrPayloadAttBlockRootInvalid)
+		require.Equal(t, true, pa.results.executed(RequireBlockRootValid))
+		require.Equal(t, ErrPayloadAttBlockRootInvalid, pa.results.result(RequireBlockRootValid))
+	})
+}
+
+func TestGetPayloadTimelinessCommittee(t *testing.T) {
+	validators := make([]*ethpb.Validator, 4*params.BeaconConfig().TargetCommitteeSize*uint64(params.BeaconConfig().SlotsPerEpoch))
+	validatorIndices := make([]primitives.ValidatorIndex, len(validators))
+
+	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,
+		}
+		validatorIndices[i] = primitives.ValidatorIndex(i)
+	}
+
+	st, err := state_native.InitializeFromProtoEpbs(&ethpb.BeaconStateEPBS{
+		Validators:  validators,
+		RandaoMixes: make([][]byte, params.BeaconConfig().EpochsPerHistoricalVector),
+	})
+	require.NoError(t, err)
+
+	slot := primitives.Slot(1)
+	ctx := context.Background()
+	ptc, err := helpers.GetPayloadTimelinessCommittee(ctx, st, slot)
+	require.NoError(t, err)
+
+	t.Run("in committee", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			ValidatorIndex: ptc[0],
+			Data: &ethpb.PayloadAttestationData{
+				Slot: slot,
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.NoError(t, pa.VerifyValidatorInPTC(ctx, st))
+		require.Equal(t, true, pa.results.executed(RequireValidatorInPTC))
+		require.NoError(t, pa.results.result(RequireValidatorInPTC))
+	})
+
+	t.Run("not in committee", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data: &ethpb.PayloadAttestationData{
+				Slot: slot,
+			},
+			Signature: make([]byte, 96),
+		}, init)
+		require.ErrorIs(t, pa.VerifyValidatorInPTC(ctx, st), ErrIncorrectPayloadAttValidator)
+		require.Equal(t, true, pa.results.executed(RequireValidatorInPTC))
+		require.Equal(t, ErrIncorrectPayloadAttValidator, pa.results.result(RequireValidatorInPTC))
+	})
+}
+
+func TestPayloadAttestationVerifySignature(t *testing.T) {
+	_, secretKeys, err := util.DeterministicDepositsAndKeys(2)
+	require.NoError(t, err)
+
+	st, err := state_native.InitializeFromProtoEpbs(&ethpb.BeaconStateEPBS{
+		Validators: []*ethpb.Validator{{PublicKey: secretKeys[0].PublicKey().Marshal()},
+			{PublicKey: secretKeys[1].PublicKey().Marshal()}},
+		Fork: &ethpb.Fork{
+			CurrentVersion:  params.BeaconConfig().EPBSForkVersion,
+			PreviousVersion: params.BeaconConfig().ElectraForkVersion,
+		},
+	})
+	require.NoError(t, err)
+
+	t.Run("valid signature", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		d := &ethpb.PayloadAttestationData{
+			BeaconBlockRoot: bytesutil.PadTo([]byte{'a'}, 32),
+			Slot:            1,
+			PayloadStatus:   primitives.PAYLOAD_WITHHELD,
+		}
+		signedBytes, err := signing.ComputeDomainAndSign(
+			st,
+			slots.ToEpoch(d.Slot),
+			d,
+			params.BeaconConfig().DomainPTCAttester,
+			secretKeys[0],
+		)
+		require.NoError(t, err)
+		sig, err := bls.SignatureFromBytes(signedBytes)
+		require.NoError(t, err)
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			Data:      d,
+			Signature: sig.Marshal(),
+		}, init)
+		require.NoError(t, pa.VerifySignature(st))
+		require.Equal(t, true, pa.results.executed(RequireSignatureValid))
+		require.NoError(t, pa.results.result(RequireSignatureValid))
+	})
+
+	t.Run("invalid signature", func(t *testing.T) {
+		init := Initializer{shared: &sharedResources{}}
+		d := &ethpb.PayloadAttestationData{
+			BeaconBlockRoot: bytesutil.PadTo([]byte{'a'}, 32),
+			Slot:            1,
+			PayloadStatus:   primitives.PAYLOAD_WITHHELD,
+		}
+		signedBytes, err := signing.ComputeDomainAndSign(
+			st,
+			slots.ToEpoch(d.Slot),
+			d,
+			params.BeaconConfig().DomainPTCAttester,
+			secretKeys[0],
+		)
+		require.NoError(t, err)
+		sig, err := bls.SignatureFromBytes(signedBytes)
+		require.NoError(t, err)
+		pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+			ValidatorIndex: 1,
+			Data:           d,
+			Signature:      sig.Marshal(),
+		}, init)
+		require.ErrorIs(t, pa.VerifySignature(st), signing.ErrSigFailedToVerify)
+		require.Equal(t, true, pa.results.executed(RequireSignatureValid))
+		require.Equal(t, signing.ErrSigFailedToVerify, pa.results.result(RequireSignatureValid))
+	})
+}
+
+func TestVerifiedPayloadAttestation(t *testing.T) {
+	init := Initializer{shared: &sharedResources{}}
+	pa := newPayloadAttestation(t, &ethpb.PayloadAttestationMessage{
+		Data:      &ethpb.PayloadAttestationData{},
+		Signature: make([]byte, 96),
+	}, init)
+
+	t.Run("missing last requirement", func(t *testing.T) {
+		for _, requirement := range GossipPayloadAttestationMessageRequirements[:len(GossipPayloadAttestationMessageRequirements)-1] {
+			pa.SatisfyRequirement(requirement)
+		}
+		_, err := pa.VerifiedPayloadAttestation()
+		require.ErrorIs(t, err, ErrInvalidPayloadAttMessage)
+	})
+
+	t.Run("satisfy all the requirements", func(t *testing.T) {
+		for _, requirement := range GossipPayloadAttestationMessageRequirements {
+			pa.SatisfyRequirement(requirement)
+		}
+		_, err := pa.VerifiedPayloadAttestation()
+		require.NoError(t, err)
+	})
+}
+
+func newPayloadAttestation(t *testing.T, m *ethpb.PayloadAttestationMessage, init Initializer) *PayloadAttMsgVerifier {
+	ro, err := payloadattestation.NewReadOnly(m)
+	require.NoError(t, err)
+	return init.NewPayloadAttestationMsgVerifier(ro, GossipPayloadAttestationMessageRequirements)
+}

config/fieldparams/mainnet.go

@@ -14,6 +14,7 @@ const (
 	CurrentEpochAttestationsLength        = 4096          // MAX_ATTESTATIONS * SLOTS_PER_EPOCH
 	SlashingsLength                       = 8192          // EPOCHS_PER_SLASHINGS_VECTOR
 	SyncCommitteeLength                   = 512           // SYNC_COMMITTEE_SIZE
+	PTCSize                               = 512           // PTC_SIZE [New in ePBS]
 	RootLength                            = 32            // RootLength defines the byte length of a Merkle root.
 	BLSSignatureLength                    = 96            // BLSSignatureLength defines the byte length of a BLSSignature.
 	BLSPubkeyLength                       = 48            // BLSPubkeyLength defines the byte length of a BLSSignature.
@@ -28,6 +29,7 @@ const (
 	MaxWithdrawalsPerPayload              = 16            // MaxWithdrawalsPerPayloadLength defines the maximum number of withdrawals that can be included in a payload.
 	MaxBlobsPerBlock                      = 6             // MaxBlobsPerBlock defines the maximum number of blobs with respect to consensus rule can be included in a block.
 	MaxBlobCommitmentsPerBlock            = 4096          // MaxBlobCommitmentsPerBlock defines the theoretical limit of blobs can be included in a block.
+	MaxPayloadAttestationsPerBlock        = 4             // MAX_PAYLOAD_ATTESTATIONS [New in ePBS]
 	LogMaxBlobCommitments                 = 12            // Log_2 of MaxBlobCommitmentsPerBlock
 	BlobLength                            = 131072        // BlobLength defines the byte length of a blob.
 	BlobSize                              = 131072        // defined to match blob.size in bazel ssz codegen

config/fieldparams/minimal.go

@@ -14,6 +14,7 @@ const (
 	CurrentEpochAttestationsLength        = 1024          // MAX_ATTESTATIONS * SLOTS_PER_EPOCH
 	SlashingsLength                       = 64            // EPOCHS_PER_SLASHINGS_VECTOR
 	SyncCommitteeLength                   = 32            // SYNC_COMMITTEE_SIZE
+	PTCSize                               = 32            // PTC_SIZE [New in ePBS]
 	RootLength                            = 32            // RootLength defines the byte length of a Merkle root.
 	BLSSignatureLength                    = 96            // BLSSignatureLength defines the byte length of a BLSSignature.
 	BLSPubkeyLength                       = 48            // BLSPubkeyLength defines the byte length of a BLSSignature.
@@ -28,6 +29,7 @@ const (
 	MaxWithdrawalsPerPayload              = 4             // MaxWithdrawalsPerPayloadLength defines the maximum number of withdrawals that can be included in a payload.
 	MaxBlobsPerBlock                      = 6             // MaxBlobsPerBlock defines the maximum number of blobs with respect to consensus rule can be included in a block.
 	MaxBlobCommitmentsPerBlock            = 16            // MaxBlobCommitmentsPerBlock defines the theoretical limit of blobs can be included in a block.
+	MaxPayloadAttestationsPerBlock        = 4             // MAX_PAYLOAD_ATTESTATIONS [New in ePBS]
 	LogMaxBlobCommitments                 = 4             // Log_2 of MaxBlobCommitmentsPerBlock
 	BlobLength                            = 131072        // BlobLength defines the byte length of a blob.
 	BlobSize                              = 131072        // defined to match blob.size in bazel ssz codegen

config/params/config.go

@@ -126,6 +126,8 @@ type BeaconChainConfig struct {
 	DomainApplicationBuilder          [4]byte `yaml:"DOMAIN_APPLICATION_BUILDER" spec:"true"`            // DomainApplicationBuilder defines the BLS signature domain for application builder.
 	DomainBLSToExecutionChange        [4]byte `yaml:"DOMAIN_BLS_TO_EXECUTION_CHANGE" spec:"true"`        // DomainBLSToExecutionChange defines the BLS signature domain to change withdrawal addresses to ETH1 prefix
 	DomainConsolidation               [4]byte `yaml:"DOMAIN_CONSOLIDATION" spec:"true"`
+	DomainBeaconBuilder               [4]byte `yaml:"DOMAIN_BEACON_BUILDER" spec:"false"` // DomainBeaconBuilder defines the BLS signature domain used by builders [New in ePBS]
+	DomainPTCAttester                 [4]byte `yaml:"DOMAIN_PTC_ATTESTER" spec:"false"`   // DomainPTCAttester defines the BLS signature domain used by PTC members [New in ePBS]
 
 	// Prysm constants.
 	GweiPerEth                     uint64          // GweiPerEth is the amount of gwei corresponding to 1 eth.
@@ -146,6 +148,7 @@ type BeaconChainConfig struct {
 	BeaconStateCapellaFieldCount   int             // BeaconStateCapellaFieldCount defines how many fields are in beacon state post upgrade to Capella.
 	BeaconStateDenebFieldCount     int             // BeaconStateDenebFieldCount defines how many fields are in beacon state post upgrade to Deneb.
 	BeaconStateElectraFieldCount   int             // BeaconStateElectraFieldCount defines how many fields are in beacon state post upgrade to Electra.
+	BeaconStateEpbsFieldCount      int             // BeaconStateEpbsFieldCount defines how many fields are in beacon state post upgrade to ePBS.
 
 	// Slasher constants.
 	WeakSubjectivityPeriod    primitives.Epoch // WeakSubjectivityPeriod defines the time period expressed in number of epochs were proof of stake network should validate block headers and attestations for slashable events.
@@ -166,6 +169,8 @@ type BeaconChainConfig struct {
 	DenebForkEpoch       primitives.Epoch `yaml:"DENEB_FORK_EPOCH" spec:"true"`       // DenebForkEpoch is used to represent the assigned fork epoch for deneb.
 	ElectraForkVersion   []byte           `yaml:"ELECTRA_FORK_VERSION" spec:"true"`   // ElectraForkVersion is used to represent the fork version for deneb.
 	ElectraForkEpoch     primitives.Epoch `yaml:"ELECTRA_FORK_EPOCH" spec:"true"`     // ElectraForkEpoch is used to represent the assigned fork epoch for deneb.
+	EPBSForkVersion      []byte           // EPBSForkVersion is used to represent the fork version for ePBS.
+	EPBSForkEpoch        primitives.Epoch // EPBSForkEpoch is used to represent the assigned fork epoch for ePBS.
 
 	ForkVersionSchedule map[[fieldparams.VersionLength]byte]primitives.Epoch // Schedule of fork epochs by version.
 	ForkVersionNames    map[[fieldparams.VersionLength]byte]string           // Human-readable names of fork versions.
@@ -314,6 +319,7 @@ func ConfigForkVersions(b *BeaconChainConfig) map[[fieldparams.VersionLength]byt
 		bytesutil.ToBytes4(b.CapellaForkVersion):   version.Capella,
 		bytesutil.ToBytes4(b.DenebForkVersion):     version.Deneb,
 		bytesutil.ToBytes4(b.ElectraForkVersion):   version.Electra,
+		bytesutil.ToBytes4(b.EPBSForkVersion):      version.EPBS,
 	}
 }
 

config/params/mainnet_config.go

@@ -29,6 +29,8 @@ const (
 	mainnetDenebForkEpoch = 269568 // March 13, 2024, 13:55:35 UTC
 	// Electra Fork Epoch for mainnet config
 	mainnetElectraForkEpoch = math.MaxUint64 // Far future / to be defined
+	// ePBS Fork Epoch for mainnet config.
+	mainnetEPBSForkEpoch = math.MaxUint64
 )
 
 var mainnetNetworkConfig = &NetworkConfig{
@@ -194,6 +196,7 @@ var mainnetBeaconConfig = &BeaconChainConfig{
 	BeaconStateCapellaFieldCount:   28,
 	BeaconStateDenebFieldCount:     28,
 	BeaconStateElectraFieldCount:   37,
+	BeaconStateEpbsFieldCount:      44,
 
 	// Slasher related values.
 	WeakSubjectivityPeriod:          54000,
@@ -216,6 +219,8 @@ var mainnetBeaconConfig = &BeaconChainConfig{
 	DenebForkEpoch:       mainnetDenebForkEpoch,
 	ElectraForkVersion:   []byte{5, 0, 0, 0},
 	ElectraForkEpoch:     mainnetElectraForkEpoch,
+	EPBSForkVersion:      []byte{6, 0, 0, 0},
+	EPBSForkEpoch:        mainnetEPBSForkEpoch,
 
 	// New values introduced in Altair hard fork 1.
 	// Participation flag indices.
@@ -335,6 +340,7 @@ func FillTestVersions(c *BeaconChainConfig, b byte) {
 	c.CapellaForkVersion = make([]byte, fieldparams.VersionLength)
 	c.DenebForkVersion = make([]byte, fieldparams.VersionLength)
 	c.ElectraForkVersion = make([]byte, fieldparams.VersionLength)
+	c.EPBSForkVersion = make([]byte, fieldparams.VersionLength)
 
 	c.GenesisForkVersion[fieldparams.VersionLength-1] = b
 	c.AltairForkVersion[fieldparams.VersionLength-1] = b
@@ -342,6 +348,7 @@ func FillTestVersions(c *BeaconChainConfig, b byte) {
 	c.CapellaForkVersion[fieldparams.VersionLength-1] = b
 	c.DenebForkVersion[fieldparams.VersionLength-1] = b
 	c.ElectraForkVersion[fieldparams.VersionLength-1] = b
+	c.EPBSForkVersion[fieldparams.VersionLength-1] = b
 
 	c.GenesisForkVersion[0] = 0
 	c.AltairForkVersion[0] = 1
@@ -349,4 +356,5 @@ func FillTestVersions(c *BeaconChainConfig, b byte) {
 	c.CapellaForkVersion[0] = 3
 	c.DenebForkVersion[0] = 4
 	c.ElectraForkVersion[0] = 5
+	c.EPBSForkVersion[0] = 6
 }

consensus-types/blocks/BUILD.bazel

@@ -7,11 +7,13 @@ go_library(
         "factory.go",
         "get_payload.go",
         "getters.go",
+        "getters_epbs.go",
         "kzg.go",
         "proto.go",
         "roblob.go",
         "roblock.go",
         "setters.go",
+        "setters_epbs.go",
         "types.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks",
@@ -41,11 +43,14 @@ go_test(
     srcs = [
         "execution_test.go",
         "factory_test.go",
+        "getters_epbs_test.go",
         "getters_test.go",
         "kzg_test.go",
+        "proto_epbs_test.go",
         "proto_test.go",
         "roblob_test.go",
         "roblock_test.go",
+        "setters_test.go",
     ],
     embed = [":go_default_library"],
     deps = [