remove duplicate HTR in call path

* wip workspace update

* update ethspecify yml

* fixing ethspecify

* fixing ethspecify

* fixing loader test

* changelog and reverting something in configs

* adding bad hash

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,6 +1,6 @@
 name: 🐞 Bug report
 description: Report a bug or problem with running Prysm
-labels: ["Bug"]
+type: "Bug"
 body:
   - type: markdown
     attributes:

.github/workflows/check-specrefs.yml

@@ -0,0 +1,43 @@
+name: Check Spec References
+on: [push, pull_request]
+
+jobs:
+  check-specrefs:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Check version consistency
+      run: |
+        WORKSPACE_VERSION=$(grep 'consensus_spec_version = ' WORKSPACE | sed 's/.*"\(.*\)"/\1/')
+        ETHSPECIFY_VERSION=$(grep '^version:' specrefs/.ethspecify.yml | sed 's/version: //')
+        if [ "$WORKSPACE_VERSION" != "$ETHSPECIFY_VERSION" ]; then
+          echo "Version mismatch between WORKSPACE and ethspecify"
+          echo "  WORKSPACE: $WORKSPACE_VERSION"
+          echo "  specrefs/.ethspecify.yml: $ETHSPECIFY_VERSION"
+          exit 1
+        else
+          echo "Versions match: $WORKSPACE_VERSION"
+        fi
+
+    - name: Install ethspecify
+      run: python3 -mpip install ethspecify
+
+    - name: Update spec references
+      run: ethspecify process --path=specrefs
+
+    - name: Check for differences
+      run: |
+        if ! git diff --exit-code specrefs >/dev/null; then
+          echo "Spec references are out-of-date!"
+          echo ""
+          git --no-pager diff specrefs
+          exit 1
+        else
+          echo "Spec references are up-to-date!"
+        fi
+
+    - name: Check spec references
+      run: ethspecify check --path=specrefs

WORKSPACE

@@ -253,16 +253,16 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.6.0-alpha.1"
+consensus_spec_version = "v1.6.0-alpha.6"
 
 load("@prysm//tools:download_spectests.bzl", "consensus_spec_tests")
 
 consensus_spec_tests(
     name = "consensus_spec_tests",
     flavors = {
-        "general": "sha256-o4t9p3R+fQHF4KOykGmwlG3zDw5wUdVWprkzId8aIsk=",
-        "minimal": "sha256-sU7ToI8t3MR8x0vVjC8ERmAHZDWpEmnAC9FWIpHi5x4=",
-        "mainnet": "sha256-YKS4wngg0LgI9Upp4MYJ77aG+8+e/G4YeqEIlp06LZw=",
+        "general": "sha256-7wkWuahuCO37uVYnxq8Badvi+jY907pBj68ixL8XDOI=",
+        "minimal": "sha256-Qy/f27N0LffS/ej7VhIubwDejD6LMK0VdenKkqtZVt4=",
+        "mainnet": "sha256-3H7mu5yE+FGz2Wr/nc8Nd9aEu93YoEpsYtn0zBSoeDE=",
     },
     version = consensus_spec_version,
 )
@@ -278,7 +278,7 @@ filegroup(
     visibility = ["//visibility:public"],
 )
     """,
-    integrity = "sha256-Nv4TEuEJPQIM4E6T9J0FOITsmappmXZjGtlhe1HEXnU=",
+    integrity = "sha256-uvz3XfMTGfy3/BtQQoEp5XQOgrWgcH/5Zo/gR0iiP+k=",
     strip_prefix = "consensus-specs-" + consensus_spec_version[1:],
     url = "https://github.com/ethereum/consensus-specs/archive/refs/tags/%s.tar.gz" % consensus_spec_version,
 )

api/client/builder/client.go

@@ -102,6 +102,7 @@ type BuilderClient interface {
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubkey [48]byte) (SignedBid, error)
 	RegisterValidator(ctx context.Context, svr []*ethpb.SignedValidatorRegistrationV1) error
 	SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error
 	Status(ctx context.Context) error
 }
 
@@ -152,7 +153,8 @@ func (c *Client) NodeURL() string {
 type reqOption func(*http.Request)
 
 // do is a generic, opinionated request function to reduce boilerplate amongst the methods in this package api/client/builder.
-func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, opts ...reqOption) (res []byte, header http.Header, err error) {
+// It validates that the HTTP response status matches the expectedStatus parameter.
+func (c *Client) do(ctx context.Context, method string, path string, body io.Reader, expectedStatus int, opts ...reqOption) (res []byte, header http.Header, err error) {
 	ctx, span := trace.StartSpan(ctx, "builder.client.do")
 	defer func() {
 		tracing.AnnotateError(span, err)
@@ -187,8 +189,8 @@ func (c *Client) do(ctx context.Context, method string, path string, body io.Rea
 			log.WithError(closeErr).Error("Failed to close response body")
 		}
 	}()
-	if r.StatusCode != http.StatusOK {
-		err = non200Err(r)
+	if r.StatusCode != expectedStatus {
+		err = unexpectedStatusErr(r, expectedStatus)
 		return
 	}
 	res, err = io.ReadAll(io.LimitReader(r.Body, client.MaxBodySize))
@@ -236,7 +238,7 @@ func (c *Client) GetHeader(ctx context.Context, slot primitives.Slot, parentHash
 			r.Header.Set("Accept", api.JsonMediaType)
 		}
 	}
-	data, header, err := c.do(ctx, http.MethodGet, path, nil, getOpts)
+	data, header, err := c.do(ctx, http.MethodGet, path, nil, http.StatusOK, getOpts)
 	if err != nil {
 		return nil, errors.Wrap(err, "error getting header from builder server")
 	}
@@ -409,7 +411,7 @@ func (c *Client) RegisterValidator(ctx context.Context, svr []*ethpb.SignedValid
 		}
 	}
 
-	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), postOpts); err != nil {
+	if _, _, err = c.do(ctx, http.MethodPost, postRegisterValidatorPath, bytes.NewBuffer(body), http.StatusOK, postOpts); err != nil {
 		return errors.Wrap(err, "do")
 	}
 	log.WithField("registrationCount", len(svr)).Debug("Successfully registered validator(s) on builder")
@@ -471,7 +473,7 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 
 	// post the blinded block - the execution payload response should contain the unblinded payload, along with the
 	// blobs bundle if it is post deneb.
-	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), postOpts)
+	data, header, err := c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), http.StatusOK, postOpts)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "error posting the blinded block to the builder api")
 	}
@@ -501,6 +503,24 @@ func (c *Client) SubmitBlindedBlock(ctx context.Context, sb interfaces.ReadOnlyS
 	return ed, blobs, nil
 }
 
+// SubmitBlindedBlockPostFulu calls the builder API endpoint post-Fulu where relays only return status codes.
+// This method is used after the Fulu fork when MEV-boost relays no longer return execution payloads.
+func (c *Client) SubmitBlindedBlockPostFulu(ctx context.Context, sb interfaces.ReadOnlySignedBeaconBlock) error {
+	body, postOpts, err := c.buildBlindedBlockRequest(sb)
+	if err != nil {
+		return err
+	}
+
+	// Post the blinded block - the response should only contain a status code (no payload)
+	_, _, err = c.do(ctx, http.MethodPost, postBlindedBeaconBlockPath, bytes.NewBuffer(body), http.StatusAccepted, postOpts)
+	if err != nil {
+		return errors.Wrap(err, "error posting the blinded block to the builder api post-Fulu")
+	}
+
+	// Success is indicated by no error (status 202)
+	return nil
+}
+
 func (c *Client) checkBlockVersion(respBytes []byte, header http.Header) (int, error) {
 	var versionHeader string
 	if c.sszEnabled {
@@ -657,11 +677,11 @@ func (c *Client) Status(ctx context.Context) error {
 	getOpts := func(r *http.Request) {
 		r.Header.Set("Accept", api.JsonMediaType)
 	}
-	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, getOpts)
+	_, _, err := c.do(ctx, http.MethodGet, getStatus, nil, http.StatusOK, getOpts)
 	return err
 }
 
-func non200Err(response *http.Response) error {
+func unexpectedStatusErr(response *http.Response, expected int) error {
 	bodyBytes, err := io.ReadAll(io.LimitReader(response.Body, client.MaxErrBodySize))
 	var errMessage ErrorMessage
 	var body string
@@ -670,7 +690,7 @@ func non200Err(response *http.Response) error {
 	} else {
 		body = "response body:\n" + string(bodyBytes)
 	}
-	msg := fmt.Sprintf("code=%d, url=%s, body=%s", response.StatusCode, response.Request.URL, body)
+	msg := fmt.Sprintf("expected=%d, got=%d, url=%s, body=%s", expected, response.StatusCode, response.Request.URL, body)
 	switch response.StatusCode {
 	case http.StatusUnsupportedMediaType:
 		log.WithError(ErrUnsupportedMediaType).Debug(msg)

api/client/builder/client_test.go

@@ -1555,6 +1555,89 @@ func testSignedBlindedBeaconBlockElectra(t *testing.T) *eth.SignedBlindedBeaconB
 	}
 }
 
+func TestSubmitBlindedBlockPostFulu(t *testing.T) {
+	ctx := t.Context()
+
+	t.Run("success", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
+				require.Equal(t, api.JsonMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, api.JsonMediaType, r.Header.Get("Accept"))
+				// Post-Fulu: only return status code, no payload
+				return &http.Response{
+					StatusCode: http.StatusAccepted,
+					Body:       io.NopCloser(bytes.NewBufferString("")),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.NoError(t, err)
+	})
+
+	t.Run("success_ssz", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get(api.VersionHeader))
+				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Content-Type"))
+				require.Equal(t, api.OctetStreamMediaType, r.Header.Get("Accept"))
+				// Post-Fulu: only return status code, no payload
+				return &http.Response{
+					StatusCode: http.StatusAccepted,
+					Body:       io.NopCloser(bytes.NewBufferString("")),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:         hc,
+			baseURL:    &url.URL{Host: "localhost:3500", Scheme: "http"},
+			sszEnabled: true,
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.NoError(t, err)
+	})
+
+	t.Run("error_response", func(t *testing.T) {
+		hc := &http.Client{
+			Transport: roundtrip(func(r *http.Request) (*http.Response, error) {
+				require.Equal(t, postBlindedBeaconBlockPath, r.URL.Path)
+				require.Equal(t, "bellatrix", r.Header.Get("Eth-Consensus-Version"))
+				message := ErrorMessage{
+					Code:    400,
+					Message: "Bad Request",
+				}
+				resp, err := json.Marshal(message)
+				require.NoError(t, err)
+				return &http.Response{
+					StatusCode: http.StatusBadRequest,
+					Body:       io.NopCloser(bytes.NewBuffer(resp)),
+					Request:    r.Clone(ctx),
+				}, nil
+			}),
+		}
+		c := &Client{
+			hc:      hc,
+			baseURL: &url.URL{Host: "localhost:3500", Scheme: "http"},
+		}
+		sbbb, err := blocks.NewSignedBeaconBlock(testSignedBlindedBeaconBlockBellatrix(t))
+		require.NoError(t, err)
+		err = c.SubmitBlindedBlockPostFulu(ctx, sbbb)
+		require.ErrorIs(t, err, ErrNotOK)
+	})
+}
+
 func TestRequestLogger(t *testing.T) {
 	wo := WithObserver(&requestLogger{})
 	c, err := NewClient("localhost:3500", wo)

api/client/builder/testing/mock.go

@@ -45,6 +45,11 @@ func (MockClient) SubmitBlindedBlock(_ context.Context, _ interfaces.ReadOnlySig
 	return nil, nil, nil
 }
 
+// SubmitBlindedBlockPostFulu --
+func (MockClient) SubmitBlindedBlockPostFulu(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) error {
+	return nil
+}
+
 // Status --
 func (MockClient) Status(_ context.Context) error {
 	return nil

api/client/builder/types_test.go

@@ -1699,7 +1699,7 @@ func TestExecutionPayloadHeaderCapellaRoundtrip(t *testing.T) {
 	require.DeepEqual(t, string(expected[0:len(expected)-1]), string(m))
 }
 
-func TestErrorMessage_non200Err(t *testing.T) {
+func TestErrorMessage_unexpectedStatusErr(t *testing.T) {
 	mockRequest := &http.Request{
 		URL: &url.URL{Path: "example.com"},
 	}
@@ -1779,7 +1779,7 @@ func TestErrorMessage_non200Err(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			err := non200Err(tt.args)
+			err := unexpectedStatusErr(tt.args, http.StatusOK)
 			if err != nil && tt.wantMessage != "" {
 				require.ErrorContains(t, tt.wantMessage, err)
 			}

beacon-chain/blockchain/kzg/kzg.go

@@ -14,7 +14,10 @@ const BytesPerBlob = ckzg4844.BytesPerBlob
 type Blob [BytesPerBlob]byte
 
 // BytesPerCell is the number of bytes in a single cell.
-const BytesPerCell = ckzg4844.BytesPerCell
+const (
+	BytesPerCell  = ckzg4844.BytesPerCell
+	BytesPerProof = ckzg4844.BytesPerProof
+)
 
 // Cell represents a chunk of an encoded Blob.
 type Cell [BytesPerCell]byte
@@ -23,7 +26,7 @@ type Cell [BytesPerCell]byte
 type Commitment [48]byte
 
 // Proof represents a KZG proof that attests to the validity of a Blob or parts of it.
-type Proof [48]byte
+type Proof [BytesPerProof]byte
 
 // Bytes48 is a 48-byte array.
 type Bytes48 = ckzg4844.Bytes48
@@ -102,7 +105,6 @@ func VerifyCellKZGProofBatch(commitmentsBytes []Bytes48, cellIndices []uint64, c
 	for i := range cells {
 		ckzgCells[i] = ckzg4844.Cell(cells[i])
 	}
-
 	return ckzg4844.VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, ckzgCells, proofsBytes)
 }
 

beacon-chain/blockchain/kzg/validation.go

@@ -1,32 +1,14 @@
 package kzg
 
 import (
+	"fmt"
+
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
+	ckzg4844 "github.com/ethereum/c-kzg-4844/v2/bindings/go"
+	"github.com/pkg/errors"
 )
 
-// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
-func Verify(sidecars ...blocks.ROBlob) error {
-	if len(sidecars) == 0 {
-		return nil
-	}
-	if len(sidecars) == 1 {
-		return kzgContext.VerifyBlobKZGProof(
-			bytesToBlob(sidecars[0].Blob),
-			bytesToCommitment(sidecars[0].KzgCommitment),
-			bytesToKZGProof(sidecars[0].KzgProof))
-	}
-	blobs := make([]GoKZG.Blob, len(sidecars))
-	cmts := make([]GoKZG.KZGCommitment, len(sidecars))
-	proofs := make([]GoKZG.KZGProof, len(sidecars))
-	for i, sidecar := range sidecars {
-		blobs[i] = *bytesToBlob(sidecar.Blob)
-		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
-		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
-	}
-	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
-}
-
 func bytesToBlob(blob []byte) *GoKZG.Blob {
 	var ret GoKZG.Blob
 	copy(ret[:], blob)
@@ -42,3 +24,144 @@ func bytesToKZGProof(proof []byte) (ret GoKZG.KZGProof) {
 	copy(ret[:], proof)
 	return
 }
+
+// Verify performs single or batch verification of commitments depending on the number of given BlobSidecars.
+func Verify(blobSidecars ...blocks.ROBlob) error {
+	if len(blobSidecars) == 0 {
+		return nil
+	}
+	if len(blobSidecars) == 1 {
+		return kzgContext.VerifyBlobKZGProof(
+			bytesToBlob(blobSidecars[0].Blob),
+			bytesToCommitment(blobSidecars[0].KzgCommitment),
+			bytesToKZGProof(blobSidecars[0].KzgProof))
+	}
+	blobs := make([]GoKZG.Blob, len(blobSidecars))
+	cmts := make([]GoKZG.KZGCommitment, len(blobSidecars))
+	proofs := make([]GoKZG.KZGProof, len(blobSidecars))
+	for i, sidecar := range blobSidecars {
+		blobs[i] = *bytesToBlob(sidecar.Blob)
+		cmts[i] = bytesToCommitment(sidecar.KzgCommitment)
+		proofs[i] = bytesToKZGProof(sidecar.KzgProof)
+	}
+	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
+}
+
+// VerifyBlobKZGProofBatch verifies KZG proofs for multiple blobs using batch verification.
+// This is more efficient than verifying each blob individually when len(blobs) > 1.
+// For single blob verification, it uses the optimized single verification path.
+func VerifyBlobKZGProofBatch(blobs [][]byte, commitments [][]byte, proofs [][]byte) error {
+	if len(blobs) != len(commitments) || len(blobs) != len(proofs) {
+		return errors.Errorf("number of blobs (%d), commitments (%d), and proofs (%d) must match", len(blobs), len(commitments), len(proofs))
+	}
+
+	if len(blobs) == 0 {
+		return nil
+	}
+
+	// Optimize for single blob case - use single verification to avoid batch overhead
+	if len(blobs) == 1 {
+		return kzgContext.VerifyBlobKZGProof(
+			bytesToBlob(blobs[0]),
+			bytesToCommitment(commitments[0]),
+			bytesToKZGProof(proofs[0]))
+	}
+
+	// Use batch verification for multiple blobs
+	ckzgBlobs := make([]ckzg4844.Blob, len(blobs))
+	ckzgCommitments := make([]ckzg4844.Bytes48, len(commitments))
+	ckzgProofs := make([]ckzg4844.Bytes48, len(proofs))
+
+	for i := range blobs {
+		if len(blobs[i]) != len(ckzg4844.Blob{}) {
+			return fmt.Errorf("blobs len (%d) differs from expected (%d)", len(blobs[i]), len(ckzg4844.Blob{}))
+		}
+		if len(commitments[i]) != len(ckzg4844.Bytes48{}) {
+			return fmt.Errorf("commitments len (%d) differs from expected (%d)", len(commitments[i]), len(ckzg4844.Blob{}))
+		}
+		if len(proofs[i]) != len(ckzg4844.Bytes48{}) {
+			return fmt.Errorf("proofs len (%d) differs from expected (%d)", len(proofs[i]), len(ckzg4844.Blob{}))
+		}
+		ckzgBlobs[i] = ckzg4844.Blob(blobs[i])
+		ckzgCommitments[i] = ckzg4844.Bytes48(commitments[i])
+		ckzgProofs[i] = ckzg4844.Bytes48(proofs[i])
+	}
+
+	valid, err := ckzg4844.VerifyBlobKZGProofBatch(ckzgBlobs, ckzgCommitments, ckzgProofs)
+	if err != nil {
+		return errors.Wrap(err, "batch verification")
+	}
+	if !valid {
+		return errors.New("batch KZG proof verification failed")
+	}
+
+	return nil
+}
+
+// VerifyCellKZGProofBatchFromBlobData verifies cell KZG proofs in batch format directly from blob data.
+// This is more efficient than reconstructing data column sidecars when you have the raw blob data and cell proofs.
+// For PeerDAS/Fulu, the execution client provides cell proofs in flattened format via BlobsBundleV2.
+// For single blob verification, it optimizes by computing cells once and verifying efficiently.
+func VerifyCellKZGProofBatchFromBlobData(blobs [][]byte, commitments [][]byte, cellProofs [][]byte, numberOfColumns uint64) error {
+	blobCount := uint64(len(blobs))
+	expectedCellProofs := blobCount * numberOfColumns
+
+	if uint64(len(cellProofs)) != expectedCellProofs {
+		return errors.Errorf("expected %d cell proofs, got %d", expectedCellProofs, len(cellProofs))
+	}
+
+	if len(commitments) != len(blobs) {
+		return errors.Errorf("number of commitments (%d) must match number of blobs (%d)", len(commitments), len(blobs))
+	}
+
+	if blobCount == 0 {
+		return nil
+	}
+
+	// Handle multiple blobs - compute cells for all blobs
+	allCells := make([]Cell, 0, expectedCellProofs)
+	allCommitments := make([]Bytes48, 0, expectedCellProofs)
+	allIndices := make([]uint64, 0, expectedCellProofs)
+	allProofs := make([]Bytes48, 0, expectedCellProofs)
+
+	for blobIndex := range blobs {
+		if len(blobs[blobIndex]) != len(Blob{}) {
+			return fmt.Errorf("blobs len (%d) differs from expected (%d)", len(blobs[blobIndex]), len(Blob{}))
+		}
+		// Convert blob to kzg.Blob type
+		blob := Blob(blobs[blobIndex])
+
+		// Compute cells for this blob
+		cells, err := ComputeCells(&blob)
+		if err != nil {
+			return errors.Wrapf(err, "failed to compute cells for blob %d", blobIndex)
+		}
+
+		// Add cells and corresponding data for each column
+		for columnIndex := range numberOfColumns {
+			cellProofIndex := uint64(blobIndex)*numberOfColumns + columnIndex
+			if len(commitments[blobIndex]) != len(Bytes48{}) {
+				return fmt.Errorf("commitments len (%d) differs from expected (%d)", len(commitments[blobIndex]), len(Bytes48{}))
+			}
+			if len(cellProofs[cellProofIndex]) != len(Bytes48{}) {
+				return fmt.Errorf("proofs len (%d) differs from expected (%d)", len(cellProofs[cellProofIndex]), len(Bytes48{}))
+			}
+			allCells = append(allCells, cells[columnIndex])
+			allCommitments = append(allCommitments, Bytes48(commitments[blobIndex]))
+			allIndices = append(allIndices, columnIndex)
+
+			allProofs = append(allProofs, Bytes48(cellProofs[cellProofIndex]))
+		}
+	}
+
+	// Batch verify all cells
+	valid, err := VerifyCellKZGProofBatch(allCommitments, allIndices, allCells, allProofs)
+	if err != nil {
+		return errors.Wrap(err, "cell batch verification")
+	}
+	if !valid {
+		return errors.New("cell KZG proof batch verification failed")
+	}
+
+	return nil
+}

beacon-chain/blockchain/kzg/validation_test.go

@@ -22,8 +22,8 @@ func GenerateCommitmentAndProof(blob GoKZG.Blob) (GoKZG.KZGCommitment, GoKZG.KZG
 }
 
 func TestVerify(t *testing.T) {
-	sidecars := make([]blocks.ROBlob, 0)
-	require.NoError(t, Verify(sidecars...))
+	blobSidecars := make([]blocks.ROBlob, 0)
+	require.NoError(t, Verify(blobSidecars...))
 }
 
 func TestBytesToAny(t *testing.T) {
@@ -37,6 +37,7 @@ func TestBytesToAny(t *testing.T) {
 }
 
 func TestGenerateCommitmentAndProof(t *testing.T) {
+	require.NoError(t, Start())
 	blob := random.GetRandBlob(123)
 	commitment, proof, err := GenerateCommitmentAndProof(blob)
 	require.NoError(t, err)
@@ -45,3 +46,432 @@ func TestGenerateCommitmentAndProof(t *testing.T) {
 	require.Equal(t, expectedCommitment, commitment)
 	require.Equal(t, expectedProof, proof)
 }
+
+func TestVerifyBlobKZGProofBatch(t *testing.T) {
+	// Initialize KZG for testing
+	require.NoError(t, Start())
+
+	t.Run("valid single blob batch", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+		proofs := [][]byte{proof[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.NoError(t, err)
+	})
+
+	t.Run("valid multiple blob batch", func(t *testing.T) {
+		blobCount := 3
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		proofs := make([][]byte, blobCount)
+
+		for i := 0; i < blobCount; i++ {
+			blob := random.GetRandBlob(int64(i))
+			commitment, proof, err := GenerateCommitmentAndProof(blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+			proofs[i] = proof[:]
+		}
+
+		err := VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.NoError(t, err)
+	})
+
+	t.Run("empty inputs should pass", func(t *testing.T) {
+		err := VerifyBlobKZGProofBatch([][]byte{}, [][]byte{}, [][]byte{})
+		require.NoError(t, err)
+	})
+
+	t.Run("mismatched input lengths", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Test different mismatch scenarios
+		err = VerifyBlobKZGProofBatch(
+			[][]byte{blob[:]},
+			[][]byte{},
+			[][]byte{proof[:]},
+		)
+		require.ErrorContains(t, "number of blobs (1), commitments (0), and proofs (1) must match", err)
+
+		err = VerifyBlobKZGProofBatch(
+			[][]byte{blob[:], blob[:]},
+			[][]byte{commitment[:]},
+			[][]byte{proof[:], proof[:]},
+		)
+		require.ErrorContains(t, "number of blobs (2), commitments (1), and proofs (2) must match", err)
+	})
+
+	t.Run("invalid commitment should fail", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		_, proof, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Use a different blob's commitment (mismatch)
+		differentBlob := random.GetRandBlob(456)
+		wrongCommitment, _, err := GenerateCommitmentAndProof(differentBlob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{wrongCommitment[:]}
+		proofs := [][]byte{proof[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		// Single blob optimization uses different error message
+		require.ErrorContains(t, "can't verify opening proof", err)
+	})
+
+	t.Run("invalid proof should fail", func(t *testing.T) {
+		blob := random.GetRandBlob(123)
+		commitment, _, err := GenerateCommitmentAndProof(blob)
+		require.NoError(t, err)
+
+		// Use wrong proof
+		invalidProof := make([]byte, 48) // All zeros
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+		proofs := [][]byte{invalidProof}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "short buffer", err)
+	})
+
+	t.Run("mixed valid and invalid proofs should fail", func(t *testing.T) {
+		// First blob - valid
+		blob1 := random.GetRandBlob(123)
+		commitment1, proof1, err := GenerateCommitmentAndProof(blob1)
+		require.NoError(t, err)
+
+		// Second blob - invalid proof
+		blob2 := random.GetRandBlob(456)
+		commitment2, _, err := GenerateCommitmentAndProof(blob2)
+		require.NoError(t, err)
+		invalidProof := make([]byte, 48) // All zeros
+
+		blobs := [][]byte{blob1[:], blob2[:]}
+		commitments := [][]byte{commitment1[:], commitment2[:]}
+		proofs := [][]byte{proof1[:], invalidProof}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "batch verification", err)
+	})
+
+	t.Run("batch KZG proof verification failed", func(t *testing.T) {
+		// Create multiple blobs with mismatched commitments and proofs to trigger batch verification failure
+		blob1 := random.GetRandBlob(123)
+		blob2 := random.GetRandBlob(456)
+
+		// Generate valid proof for blob1
+		commitment1, proof1, err := GenerateCommitmentAndProof(blob1)
+		require.NoError(t, err)
+
+		// Generate valid proof for blob2 but use wrong commitment (from blob1)
+		_, proof2, err := GenerateCommitmentAndProof(blob2)
+		require.NoError(t, err)
+
+		// Use blob2 data with blob1's commitment and blob2's proof - this should cause batch verification to fail
+		blobs := [][]byte{blob1[:], blob2[:]}
+		commitments := [][]byte{commitment1[:], commitment1[:]} // Wrong commitment for blob2
+		proofs := [][]byte{proof1[:], proof2[:]}
+
+		err = VerifyBlobKZGProofBatch(blobs, commitments, proofs)
+		require.ErrorContains(t, "batch KZG proof verification failed", err)
+	})
+}
+
+func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
+	// Initialize KZG for testing
+	require.NoError(t, Start())
+
+	t.Run("valid single blob cell verification", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Generate blob and commitment
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		// Compute cells and proofs
+		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Create flattened cell proofs (like execution client format)
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.NoError(t, err)
+	})
+
+	t.Run("valid multiple blob cell verification", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		for i := range blobCount {
+			// Generate blob and commitment
+			randBlob := random.GetRandBlob(int64(i))
+			var blob Blob
+			copy(blob[:], randBlob[:])
+			commitment, err := BlobToKZGCommitment(&blob)
+			require.NoError(t, err)
+
+			// Compute cells and proofs
+			cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+			require.NoError(t, err)
+
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+
+			// Add cell proofs for this blob
+			for j := range numberOfColumns {
+				allCellProofs = append(allCellProofs, cellsAndProofs.Proofs[j][:])
+			}
+		}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.NoError(t, err)
+	})
+
+	t.Run("empty inputs should pass", func(t *testing.T) {
+		err := VerifyCellKZGProofBatchFromBlobData([][]byte{}, [][]byte{}, [][]byte{}, 128)
+		require.NoError(t, err)
+	})
+
+	t.Run("mismatched blob and commitment count", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		err := VerifyCellKZGProofBatchFromBlobData(
+			[][]byte{blob[:]},
+			[][]byte{}, // Empty commitments
+			[][]byte{},
+			128,
+		)
+		require.ErrorContains(t, "expected 128 cell proofs", err)
+	})
+
+	t.Run("wrong cell proof count", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		// Wrong number of cell proofs - should be 128 for 1 blob, but provide 10
+		wrongCellProofs := make([][]byte, 10)
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, wrongCellProofs, numberOfColumns)
+		require.ErrorContains(t, "expected 128 cell proofs, got 10", err)
+	})
+
+	t.Run("invalid cell proofs should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		// Create invalid cell proofs (all zeros)
+		invalidCellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			invalidCellProofs[i] = make([]byte, 48) // All zeros
+		}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, invalidCellProofs, numberOfColumns)
+		require.ErrorContains(t, "cell batch verification", err)
+	})
+
+	t.Run("mismatched commitment should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Generate blob and correct cell proofs
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Generate wrong commitment from different blob
+		randBlob2 := random.GetRandBlob(456)
+		var differentBlob Blob
+		copy(differentBlob[:], randBlob2[:])
+		wrongCommitment, err := BlobToKZGCommitment(&differentBlob)
+		require.NoError(t, err)
+
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{wrongCommitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.ErrorContains(t, "cell KZG proof batch verification failed", err)
+	})
+
+	t.Run("invalid blob data that should cause ComputeCells to fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		// Create invalid blob (not properly formatted)
+		invalidBlobData := make([]byte, 10) // Too short
+		commitment := make([]byte, 48)      // Dummy commitment
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = make([]byte, 48)
+		}
+
+		blobs := [][]byte{invalidBlobData}
+		commitments := [][]byte{commitment}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.NotNil(t, err)
+		require.ErrorContains(t, "blobs len (10) differs from expected (131072)", err)
+	})
+
+	t.Run("invalid commitment size should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		
+		// Create invalid commitment (wrong size)
+		invalidCommitment := make([]byte, 32) // Should be 48 bytes
+		cellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			cellProofs[i] = make([]byte, 48)
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{invalidCommitment}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, cellProofs, numberOfColumns)
+		require.ErrorContains(t, "commitments len (32) differs from expected (48)", err)
+	})
+
+	t.Run("invalid cell proof size should fail", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		// Create invalid cell proofs (wrong size)
+		invalidCellProofs := make([][]byte, numberOfColumns)
+		for i := range numberOfColumns {
+			if i == 0 {
+				invalidCellProofs[i] = make([]byte, 32) // Wrong size - should be 48
+			} else {
+				invalidCellProofs[i] = make([]byte, 48)
+			}
+		}
+
+		blobs := [][]byte{blob[:]}
+		commitments := [][]byte{commitment[:]}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, invalidCellProofs, numberOfColumns)
+		require.ErrorContains(t, "proofs len (32) differs from expected (48)", err)
+	})
+
+	t.Run("multiple blobs with mixed invalid commitments", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		// First blob - valid
+		randBlob1 := random.GetRandBlob(123)
+		var blob1 Blob
+		copy(blob1[:], randBlob1[:])
+		commitment1, err := BlobToKZGCommitment(&blob1)
+		require.NoError(t, err)
+		blobs[0] = blob1[:]
+		commitments[0] = commitment1[:]
+
+		// Second blob - use invalid commitment size
+		randBlob2 := random.GetRandBlob(456)
+		var blob2 Blob
+		copy(blob2[:], randBlob2[:])
+		blobs[1] = blob2[:]
+		commitments[1] = make([]byte, 32) // Wrong size
+
+		// Add cell proofs for both blobs
+		for i := 0; i < blobCount; i++ {
+			for j := uint64(0); j < numberOfColumns; j++ {
+				allCellProofs = append(allCellProofs, make([]byte, 48))
+			}
+		}
+
+		err = VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.ErrorContains(t, "commitments len (32) differs from expected (48)", err)
+	})
+
+	t.Run("multiple blobs with mixed invalid cell proof sizes", func(t *testing.T) {
+		numberOfColumns := uint64(128)
+		blobCount := 2
+
+		blobs := make([][]byte, blobCount)
+		commitments := make([][]byte, blobCount)
+		var allCellProofs [][]byte
+
+		for i := 0; i < blobCount; i++ {
+			randBlob := random.GetRandBlob(int64(i))
+			var blob Blob
+			copy(blob[:], randBlob[:])
+			commitment, err := BlobToKZGCommitment(&blob)
+			require.NoError(t, err)
+			
+			blobs[i] = blob[:]
+			commitments[i] = commitment[:]
+			
+			// Add cell proofs - make some invalid in the second blob
+			for j := uint64(0); j < numberOfColumns; j++ {
+				if i == 1 && j == 64 {
+					// Invalid proof size in middle of second blob's proofs
+					allCellProofs = append(allCellProofs, make([]byte, 20))
+				} else {
+					allCellProofs = append(allCellProofs, make([]byte, 48))
+				}
+			}
+		}
+
+		err := VerifyCellKZGProofBatchFromBlobData(blobs, commitments, allCellProofs, numberOfColumns)
+		require.ErrorContains(t, "proofs len (20) differs from expected (48)", err)
+	})
+}

beacon-chain/blockchain/process_block.go

@@ -159,7 +159,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	}
 
 	// Fill in missing blocks
-	if err := s.fillInForkChoiceMissingBlocks(ctx, blks[0], preState.CurrentJustifiedCheckpoint(), preState.FinalizedCheckpoint()); err != nil {
+	if err := s.fillInForkChoiceMissingBlocks(ctx, blks[0], preState.FinalizedCheckpoint(), preState.CurrentJustifiedCheckpoint()); err != nil {
 		return errors.Wrap(err, "could not fill in missing blocks to forkchoice")
 	}
 
@@ -240,9 +240,10 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 			}
 		}
 
-		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), b); err != nil {
-			return errors.Wrapf(err, "could not validate sidecar availability at slot %d", b.Block().Slot())
+		if err := s.areSidecarsAvailable(ctx, avs, b); err != nil {
+			return errors.Wrapf(err, "could not validate sidecar availability for block %#x at slot %d", b.Root(), b.Block().Slot())
 		}
+
 		args := &forkchoicetypes.BlockAndCheckpoints{Block: b,
 			JustifiedCheckpoint: jCheckpoints[i],
 			FinalizedCheckpoint: fCheckpoints[i]}
@@ -308,6 +309,30 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }
 
+func (s *Service) areSidecarsAvailable(ctx context.Context, avs das.AvailabilityStore, roBlock consensusblocks.ROBlock) error {
+	blockVersion := roBlock.Version()
+	block := roBlock.Block()
+	slot := block.Slot()
+
+	if blockVersion >= version.Fulu {
+		if err := s.areDataColumnsAvailable(ctx, roBlock.Root(), block); err != nil {
+			return errors.Wrapf(err, "are data columns available for block %#x with slot %d", roBlock.Root(), slot)
+		}
+
+		return nil
+	}
+
+	if blockVersion >= version.Deneb {
+		if err := avs.IsDataAvailable(ctx, s.CurrentSlot(), roBlock); err != nil {
+			return errors.Wrapf(err, "could not validate sidecar availability at slot %d", slot)
+		}
+
+		return nil
+	}
+
+	return nil
+}
+
 func (s *Service) updateEpochBoundaryCaches(ctx context.Context, st state.BeaconState) error {
 	e := coreTime.CurrentEpoch(st)
 	if err := helpers.UpdateCommitteeCache(ctx, st, e); err != nil {
@@ -584,7 +609,7 @@ func (s *Service) runLateBlockTasks() {
 // It returns a map where each key represents a missing BlobSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // BlobSidecars against the set of known missing sidecars.
-func missingBlobIndices(bs *filesystem.BlobStorage, root [fieldparams.RootLength]byte, expected [][]byte, slot primitives.Slot) (map[uint64]bool, error) {
+func missingBlobIndices(store *filesystem.BlobStorage, root [fieldparams.RootLength]byte, expected [][]byte, slot primitives.Slot) (map[uint64]bool, error) {
 	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(slot)
 	if len(expected) == 0 {
 		return nil, nil
@@ -592,7 +617,7 @@ func missingBlobIndices(bs *filesystem.BlobStorage, root [fieldparams.RootLength
 	if len(expected) > maxBlobsPerBlock {
 		return nil, errMaxBlobsExceeded
 	}
-	indices := bs.Summary(root)
+	indices := store.Summary(root)
 	missing := make(map[uint64]bool, len(expected))
 	for i := range expected {
 		if len(expected[i]) > 0 && !indices.HasIndex(uint64(i)) {
@@ -607,7 +632,7 @@ func missingBlobIndices(bs *filesystem.BlobStorage, root [fieldparams.RootLength
 // It returns a map where each key represents a missing DataColumnSidecar index.
 // An empty map means we have all indices; a non-empty map can be used to compare incoming
 // DataColumns against the set of known missing sidecars.
-func missingDataColumnIndices(bs *filesystem.DataColumnStorage, root [fieldparams.RootLength]byte, expected map[uint64]bool) (map[uint64]bool, error) {
+func missingDataColumnIndices(store *filesystem.DataColumnStorage, root [fieldparams.RootLength]byte, expected map[uint64]bool) (map[uint64]bool, error) {
 	if len(expected) == 0 {
 		return nil, nil
 	}
@@ -619,7 +644,7 @@ func missingDataColumnIndices(bs *filesystem.DataColumnStorage, root [fieldparam
 	}
 
 	// Get a summary of the data columns stored in the database.
-	summary := bs.Summary(root)
+	summary := store.Summary(root)
 
 	// Check all expected data columns against the summary.
 	missing := make(map[uint64]bool)
@@ -639,14 +664,14 @@ func missingDataColumnIndices(bs *filesystem.DataColumnStorage, root [fieldparam
 // closed, the context hits cancellation/timeout, or notifications have been received for all the missing sidecars.
 func (s *Service) isDataAvailable(
 	ctx context.Context,
-	root [fieldparams.RootLength]byte,
-	signedBlock interfaces.ReadOnlySignedBeaconBlock,
+	roBlock consensusblocks.ROBlock,
 ) error {
-	block := signedBlock.Block()
+	block := roBlock.Block()
 	if block == nil {
 		return errors.New("invalid nil beacon block")
 	}
 
+	root := roBlock.Root()
 	blockVersion := block.Version()
 	if blockVersion >= version.Fulu {
 		return s.areDataColumnsAvailable(ctx, root, block)
@@ -666,8 +691,6 @@ func (s *Service) areDataColumnsAvailable(
 	root [fieldparams.RootLength]byte,
 	block interfaces.ReadOnlyBeaconBlock,
 ) error {
-	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
-
 	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS
 	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
 	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
@@ -701,6 +724,7 @@ func (s *Service) areDataColumnsAvailable(
 
 	// Compute the sampling size.
 	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#custody-sampling
+	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
 	samplingSize := max(samplesPerSlot, custodyGroupCount)
 
 	// Get the peer info for the node.
@@ -717,7 +741,7 @@ func (s *Service) areDataColumnsAvailable(
 	summary := s.dataColumnStorage.Summary(root)
 	storedDataColumnsCount := summary.Count()
 
-	minimumColumnCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+	minimumColumnCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
 
 	// As soon as we have enough data column sidecars, we can reconstruct the missing ones.
 	// We don't need to wait for the rest of the data columns to declare the block as available.
@@ -820,7 +844,7 @@ func (s *Service) areDataColumnsAvailable(
 				missingIndices = uint64MapToSortedSlice(missingMap)
 			}
 
-			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing %v", block.Slot(), root, missingIndices)
+			return errors.Wrapf(ctx.Err(), "data column sidecars slot: %d, BlockRoot: %#x, missing: %v", block.Slot(), root, missingIndices)
 		}
 	}
 }

beacon-chain/blockchain/process_block_helpers.go

@@ -30,6 +30,10 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// ErrInvalidCheckpointArgs may be returned when the finalized checkpoint has an epoch greater than the justified checkpoint epoch.
+// If you are seeing this error, make sure you haven't mixed up the order of the arguments in the method you are calling.
+var ErrInvalidCheckpointArgs = errors.New("finalized checkpoint cannot be greater than justified checkpoint")
+
 // CurrentSlot returns the current slot based on time.
 func (s *Service) CurrentSlot() primitives.Slot {
 	return slots.CurrentSlot(s.genesisTime)
@@ -454,6 +458,9 @@ func (s *Service) ancestorByDB(ctx context.Context, r [32]byte, slot primitives.
 // This is useful for block tree visualizer and additional vote accounting.
 func (s *Service) fillInForkChoiceMissingBlocks(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
 	fCheckpoint, jCheckpoint *ethpb.Checkpoint) error {
+	if fCheckpoint.Epoch > jCheckpoint.Epoch {
+		return ErrInvalidCheckpointArgs
+	}
 	pendingNodes := make([]*forkchoicetypes.BlockAndCheckpoints, 0)
 
 	// Fork choice only matters from last finalized slot.

beacon-chain/blockchain/process_block_test.go

@@ -375,6 +375,81 @@ func TestFillForkChoiceMissingBlocks_FinalizedSibling(t *testing.T) {
 	require.Equal(t, ErrNotDescendantOfFinalized.Error(), err.Error())
 }
 
+func TestFillForkChoiceMissingBlocks_ErrorCases(t *testing.T) {
+	tests := []struct {
+		name           string
+		finalizedEpoch primitives.Epoch
+		justifiedEpoch primitives.Epoch
+		expectedError  error
+	}{
+		{
+			name:           "finalized epoch greater than justified epoch",
+			finalizedEpoch: 5,
+			justifiedEpoch: 3,
+			expectedError:  ErrInvalidCheckpointArgs,
+		},
+		{
+			name:           "valid case - finalized equal to justified",
+			finalizedEpoch: 3,
+			justifiedEpoch: 3,
+			expectedError:  nil,
+		},
+		{
+			name:           "valid case - finalized less than justified",
+			finalizedEpoch: 2,
+			justifiedEpoch: 3,
+			expectedError:  nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			service, tr := minimalTestService(t)
+			ctx, beaconDB := tr.ctx, tr.db
+
+			st, _ := util.DeterministicGenesisState(t, 64)
+			require.NoError(t, service.saveGenesisData(ctx, st))
+
+			// Create a simple block for testing
+			blk := util.NewBeaconBlock()
+			blk.Block.Slot = 10
+			blk.Block.ParentRoot = service.originBlockRoot[:]
+			wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
+			require.NoError(t, err)
+			util.SaveBlock(t, ctx, beaconDB, blk)
+
+			// Create checkpoints with test case epochs
+			finalizedCheckpoint := &ethpb.Checkpoint{
+				Epoch: tt.finalizedEpoch,
+				Root:  service.originBlockRoot[:],
+			}
+			justifiedCheckpoint := &ethpb.Checkpoint{
+				Epoch: tt.justifiedEpoch,
+				Root:  service.originBlockRoot[:],
+			}
+
+			// Set up forkchoice store to avoid other errors
+			fcp := &ethpb.Checkpoint{Epoch: 0, Root: service.originBlockRoot[:]}
+			state, blkRoot, err := prepareForkchoiceState(ctx, 0, service.originBlockRoot, service.originBlockRoot, [32]byte{}, fcp, fcp)
+			require.NoError(t, err)
+			require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, state, blkRoot))
+
+			err = service.fillInForkChoiceMissingBlocks(
+				t.Context(), wsb, finalizedCheckpoint, justifiedCheckpoint)
+
+			if tt.expectedError != nil {
+				require.ErrorIs(t, err, tt.expectedError)
+			} else {
+				// For valid cases, we might get other errors (like block not being descendant of finalized)
+				// but we shouldn't get the checkpoint validation error
+				if err != nil && errors.Is(err, tt.expectedError) {
+					t.Errorf("Unexpected checkpoint validation error: %v", err)
+				}
+			}
+		})
+	}
+}
+
 // blockTree1 constructs the following tree:
 //
 //	/- B1
@@ -2132,13 +2207,13 @@ func TestNoViableHead_Reboot(t *testing.T) {
 
 	// Forkchoice has the genesisRoot loaded at startup
 	require.Equal(t, genesisRoot, service.ensureRootNotZeros(service.cfg.ForkChoiceStore.CachedHeadRoot()))
-	// Service's store has the finalized state as headRoot
+	// Service's store has the justified checkpoint root as headRoot (verified below through justified checkpoint comparison)
 	headRoot, err := service.HeadRoot(ctx)
 	require.NoError(t, err)
-	require.Equal(t, genesisRoot, bytesutil.ToBytes32(headRoot))
+	require.NotEqual(t, bytesutil.ToBytes32(params.BeaconConfig().ZeroHash[:]), bytesutil.ToBytes32(headRoot)) // Ensure head is not zero
 	optimistic, err := service.IsOptimistic(ctx)
 	require.NoError(t, err)
-	require.Equal(t, false, optimistic)
+	require.Equal(t, true, optimistic) // Head is now optimistic when starting from justified checkpoint
 
 	// Check that the node's justified checkpoint does not agree with the
 	// last valid state's justified checkpoint
@@ -2877,19 +2952,23 @@ func TestIsDataAvailable(t *testing.T) {
 		params := testIsAvailableParams{options: []Option{WithGenesisTime(time.Unix(0, 0))}}
 		ctx, _, service, root, signed := testIsAvailableSetup(t, params)
 
-		err := service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NoError(t, err)
 	})
 
 	t.Run("Fulu - no commitment in blocks", func(t *testing.T) {
 		ctx, _, service, root, signed := testIsAvailableSetup(t, testIsAvailableParams{})
 
-		err := service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NoError(t, err)
 	})
 
 	t.Run("Fulu - more than half of the columns in custody", func(t *testing.T) {
-		minimumColumnsCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+		minimumColumnsCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
 		indices := make([]uint64, 0, minimumColumnsCountToReconstruct)
 		for i := range minimumColumnsCountToReconstruct {
 			indices = append(indices, i)
@@ -2902,7 +2981,9 @@ func TestIsDataAvailable(t *testing.T) {
 
 		ctx, _, service, root, signed := testIsAvailableSetup(t, params)
 
-		err := service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NoError(t, err)
 	})
 
@@ -2914,7 +2995,9 @@ func TestIsDataAvailable(t *testing.T) {
 
 		ctx, _, service, root, signed := testIsAvailableSetup(t, params)
 
-		err := service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NoError(t, err)
 	})
 
@@ -2962,7 +3045,9 @@ func TestIsDataAvailable(t *testing.T) {
 		ctx, cancel := context.WithTimeout(ctx, time.Second*2)
 		defer cancel()
 
-		err = service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NoError(t, err)
 	})
 
@@ -2974,7 +3059,7 @@ func TestIsDataAvailable(t *testing.T) {
 
 		startWaiting := make(chan bool)
 
-		minimumColumnsCountToReconstruct := peerdas.MinimumColumnsCountToReconstruct()
+		minimumColumnsCountToReconstruct := peerdas.MinimumColumnCountToReconstruct()
 		indices := make([]uint64, 0, minimumColumnsCountToReconstruct-missingColumns)
 
 		for i := range minimumColumnsCountToReconstruct - missingColumns {
@@ -3024,7 +3109,9 @@ func TestIsDataAvailable(t *testing.T) {
 		ctx, cancel := context.WithTimeout(ctx, time.Second*2)
 		defer cancel()
 
-		err = service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NoError(t, err)
 	})
 
@@ -3043,7 +3130,9 @@ func TestIsDataAvailable(t *testing.T) {
 			cancel()
 		}()
 
-		err := service.isDataAvailable(ctx, root, signed)
+		roBlock, err := consensusblocks.NewROBlockWithRoot(signed, root)
+		require.NoError(t, err)
+		err = service.isDataAvailable(ctx, roBlock)
 		require.NotNil(t, err)
 	})
 }

beacon-chain/blockchain/receive_block.go

@@ -16,7 +16,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/slasher/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/features"
-	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -112,7 +111,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 		return err
 	}
 
-	daWaitedTime, err := s.handleDA(ctx, blockCopy, blockRoot, avs)
+	daWaitedTime, err := s.handleDA(ctx, avs, roblock)
 	if err != nil {
 		return err
 	}
@@ -240,37 +239,19 @@ func (s *Service) validateExecutionAndConsensus(
 	return postState, isValidPayload, nil
 }
 
-func (s *Service) handleDA(
-	ctx context.Context,
-	block interfaces.SignedBeaconBlock,
-	blockRoot [fieldparams.RootLength]byte,
-	avs das.AvailabilityStore,
-) (elapsed time.Duration, err error) {
-	defer func(start time.Time) {
-		elapsed = time.Since(start)
-
-		if err == nil {
-			dataAvailWaitedTime.Observe(float64(elapsed.Milliseconds()))
-		}
-	}(time.Now())
-
-	if avs == nil {
-		if err = s.isDataAvailable(ctx, blockRoot, block); err != nil {
-			return
-		}
-
-		return
+func (s *Service) handleDA(ctx context.Context, avs das.AvailabilityStore, block blocks.ROBlock) (time.Duration, error) {
+	var err error
+	start := time.Now()
+	if avs != nil {
+		err = avs.IsDataAvailable(ctx, s.CurrentSlot(), block)
+	} else {
+		err = s.isDataAvailable(ctx, block)
 	}
-
-	var rob blocks.ROBlock
-	rob, err = blocks.NewROBlockWithRoot(block, blockRoot)
+	elapsed := time.Since(start)
 	if err != nil {
-		return
+		dataAvailWaitedTime.Observe(float64(elapsed.Milliseconds()))
 	}
-
-	err = avs.IsDataAvailable(ctx, s.CurrentSlot(), rob)
-
-	return
+	return elapsed, err
 }
 
 func (s *Service) reportPostBlockProcessing(

beacon-chain/blockchain/receive_block_test.go

@@ -192,7 +192,9 @@ func TestHandleDA(t *testing.T) {
 	require.NoError(t, err)
 
 	s, _ := minimalTestService(t)
-	elapsed, err := s.handleDA(t.Context(), signedBeaconBlock, [fieldparams.RootLength]byte{}, nil)
+	block, err := blocks.NewROBlockWithRoot(signedBeaconBlock, [32]byte{})
+	require.NoError(t, err)
+	elapsed, err := s.handleDA(t.Context(), nil, block)
 	require.NoError(t, err)
 	require.Equal(t, true, elapsed > 0, "Elapsed time should be greater than 0")
 }

beacon-chain/blockchain/receive_data_column.go

@@ -17,7 +17,7 @@ func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataC
 // ReceiveDataColumn receives a single data column.
 func (s *Service) ReceiveDataColumn(dataColumnSidecar blocks.VerifiedRODataColumn) error {
 	if err := s.dataColumnStorage.Save([]blocks.VerifiedRODataColumn{dataColumnSidecar}); err != nil {
-		return errors.Wrap(err, "save data column sidecars")
+		return errors.Wrap(err, "save data column sidecar")
 	}
 
 	return nil

beacon-chain/blockchain/setup_forchoice.go

@@ -20,7 +20,7 @@ func (s *Service) setupForkchoice(st state.BeaconState) error {
 		return errors.Wrap(err, "could not set up forkchoice checkpoints")
 	}
 	if err := s.setupForkchoiceTree(st); err != nil {
-		return errors.Wrap(err, "could not set up forkchoice root")
+		return errors.Wrap(err, "could not set up forkchoice tree")
 	}
 	if err := s.initializeHead(s.ctx, st); err != nil {
 		return errors.Wrap(err, "could not initialize head from db")
@@ -30,24 +30,24 @@ func (s *Service) setupForkchoice(st state.BeaconState) error {
 
 func (s *Service) startupHeadRoot() [32]byte {
 	headStr := features.Get().ForceHead
-	cp := s.FinalizedCheckpt()
-	fRoot := s.ensureRootNotZeros([32]byte(cp.Root))
+	jp := s.CurrentJustifiedCheckpt()
+	jRoot := s.ensureRootNotZeros([32]byte(jp.Root))
 	if headStr == "" {
-		return fRoot
+		return jRoot
 	}
 	if headStr == "head" {
 		root, err := s.cfg.BeaconDB.HeadBlockRoot()
 		if err != nil {
-			log.WithError(err).Error("Could not get head block root, starting with finalized block as head")
-			return fRoot
+			log.WithError(err).Error("Could not get head block root, starting with justified block as head")
+			return jRoot
 		}
 		log.Infof("Using Head root of %#x", root)
 		return root
 	}
 	root, err := bytesutil.DecodeHexWithLength(headStr, 32)
 	if err != nil {
-		log.WithError(err).Error("Could not parse head root, starting with finalized block as head")
-		return fRoot
+		log.WithError(err).Error("Could not parse head root, starting with justified block as head")
+		return jRoot
 	}
 	return [32]byte(root)
 }

beacon-chain/blockchain/setup_forkchoice_test.go

@@ -32,7 +32,7 @@ func Test_startupHeadRoot(t *testing.T) {
 		})
 		defer resetCfg()
 		require.Equal(t, service.startupHeadRoot(), gr)
-		require.LogsContain(t, hook, "Could not get head block root, starting with finalized block as head")
+		require.LogsContain(t, hook, "Could not get head block root, starting with justified block as head")
 	})
 
 	st, _ := util.DeterministicGenesisState(t, 64)

beacon-chain/blockchain/setup_test.go

@@ -24,8 +24,8 @@ import (
 	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
-	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -89,7 +89,7 @@ func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
-func (mb *mockBroadcaster) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+func (mb *mockBroadcaster) BroadcastDataColumnSidecar(_ uint64, _ blocks.VerifiedRODataColumn) error {
 	mb.broadcastCalled = true
 	return nil
 }

beacon-chain/builder/service.go

@@ -25,6 +25,7 @@ var ErrNoBuilder = errors.New("builder endpoint not configured")
 // BlockBuilder defines the interface for interacting with the block builder
 type BlockBuilder interface {
 	SubmitBlindedBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) (interfaces.ExecutionData, v1.BlobsBundler, error)
+	SubmitBlindedBlockPostFulu(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) error
 	GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error)
 	RegisterValidator(ctx context.Context, reg []*ethpb.SignedValidatorRegistrationV1) error
 	RegistrationByValidatorID(ctx context.Context, id primitives.ValidatorIndex) (*ethpb.ValidatorRegistrationV1, error)
@@ -101,6 +102,22 @@ func (s *Service) SubmitBlindedBlock(ctx context.Context, b interfaces.ReadOnlyS
 	return s.c.SubmitBlindedBlock(ctx, b)
 }
 
+// SubmitBlindedBlockPostFulu submits a blinded block to the builder relay network post-Fulu.
+// After Fulu, relays only return status codes (no payload).
+func (s *Service) SubmitBlindedBlockPostFulu(ctx context.Context, b interfaces.ReadOnlySignedBeaconBlock) error {
+	ctx, span := trace.StartSpan(ctx, "builder.SubmitBlindedBlockPostFulu")
+	defer span.End()
+	start := time.Now()
+	defer func() {
+		submitBlindedBlockLatency.Observe(float64(time.Since(start).Milliseconds()))
+	}()
+	if s.c == nil {
+		return ErrNoBuilder
+	}
+
+	return s.c.SubmitBlindedBlockPostFulu(ctx, b)
+}
+
 // GetHeader retrieves the header for a given slot and parent hash from the builder relay network.
 func (s *Service) GetHeader(ctx context.Context, slot primitives.Slot, parentHash [32]byte, pubKey [48]byte) (builder.SignedBid, error) {
 	ctx, span := trace.StartSpan(ctx, "builder.GetHeader")

beacon-chain/builder/testing/mock.go

@@ -24,21 +24,22 @@ type Config struct {
 
 // MockBuilderService to mock builder.
 type MockBuilderService struct {
-	HasConfigured         bool
-	Payload               *v1.ExecutionPayload
-	PayloadCapella        *v1.ExecutionPayloadCapella
-	PayloadDeneb          *v1.ExecutionPayloadDeneb
-	BlobBundle            *v1.BlobsBundle
-	BlobBundleV2          *v1.BlobsBundleV2
-	ErrSubmitBlindedBlock error
-	Bid                   *ethpb.SignedBuilderBid
-	BidCapella            *ethpb.SignedBuilderBidCapella
-	BidDeneb              *ethpb.SignedBuilderBidDeneb
-	BidElectra            *ethpb.SignedBuilderBidElectra
-	RegistrationCache     *cache.RegistrationCache
-	ErrGetHeader          error
-	ErrRegisterValidator  error
-	Cfg                   *Config
+	HasConfigured                 bool
+	Payload                       *v1.ExecutionPayload
+	PayloadCapella                *v1.ExecutionPayloadCapella
+	PayloadDeneb                  *v1.ExecutionPayloadDeneb
+	BlobBundle                    *v1.BlobsBundle
+	BlobBundleV2                  *v1.BlobsBundleV2
+	ErrSubmitBlindedBlock         error
+	ErrSubmitBlindedBlockPostFulu error
+	Bid                           *ethpb.SignedBuilderBid
+	BidCapella                    *ethpb.SignedBuilderBidCapella
+	BidDeneb                      *ethpb.SignedBuilderBidDeneb
+	BidElectra                    *ethpb.SignedBuilderBidElectra
+	RegistrationCache             *cache.RegistrationCache
+	ErrGetHeader                  error
+	ErrRegisterValidator          error
+	Cfg                           *Config
 }
 
 // Configured for mocking.
@@ -115,3 +116,8 @@ func (s *MockBuilderService) RegistrationByValidatorID(ctx context.Context, id p
 func (s *MockBuilderService) RegisterValidator(context.Context, []*ethpb.SignedValidatorRegistrationV1) error {
 	return s.ErrRegisterValidator
 }
+
+// SubmitBlindedBlockPostFulu for mocking.
+func (s *MockBuilderService) SubmitBlindedBlockPostFulu(_ context.Context, _ interfaces.ReadOnlySignedBeaconBlock) error {
+	return s.ErrSubmitBlindedBlockPostFulu
+}

beacon-chain/core/helpers/beacon_committee.go

@@ -317,23 +317,15 @@ func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch pri
 	}
 
 	proposerAssignments := make(map[primitives.ValidatorIndex][]primitives.Slot)
-
-	originalStateSlot := state.Slot()
-
 	for slot := startSlot; slot < startSlot+params.BeaconConfig().SlotsPerEpoch; slot++ {
 		// Skip proposer assignment for genesis slot.
 		if slot == 0 {
 			continue
 		}
-		// Set the state's current slot.
-		if err := state.SetSlot(slot); err != nil {
-			return nil, err
-		}
-
 		// Determine the proposer index for the current slot.
-		i, err := BeaconProposerIndex(ctx, state)
+		i, err := BeaconProposerIndexAtSlot(ctx, state, slot)
 		if err != nil {
-			return nil, errors.Wrapf(err, "could not check proposer at slot %d", state.Slot())
+			return nil, errors.Wrapf(err, "could not check proposer at slot %d", slot)
 		}
 
 		// Append the slot to the proposer's assignments.
@@ -342,12 +334,6 @@ func ProposerAssignments(ctx context.Context, state state.BeaconState, epoch pri
 		}
 		proposerAssignments[i] = append(proposerAssignments[i], slot)
 	}
-
-	// Reset state back to its original slot.
-	if err := state.SetSlot(originalStateSlot); err != nil {
-		return nil, err
-	}
-
 	return proposerAssignments, nil
 }
 

beacon-chain/core/helpers/sync_committee_test.go

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

beacon-chain/core/helpers/validators.go

@@ -309,23 +309,29 @@ func beaconProposerIndexAtSlotFulu(state state.ReadOnlyBeaconState, slot primiti
 	if err != nil {
 		return 0, errors.Wrap(err, "could not get proposer lookahead")
 	}
+	spe := params.BeaconConfig().SlotsPerEpoch
 	if e == stateEpoch {
-		return lookAhead[slot%params.BeaconConfig().SlotsPerEpoch], nil
+		return lookAhead[slot%spe], nil
 	}
 	// The caller is requesting the proposer for the next epoch
-	return lookAhead[slot%params.BeaconConfig().SlotsPerEpoch+params.BeaconConfig().SlotsPerEpoch], nil
+	return lookAhead[spe+slot%spe], nil
 }
 
 // BeaconProposerIndexAtSlot returns proposer index at the given slot from the
 // point of view of the given state as head state
 func BeaconProposerIndexAtSlot(ctx context.Context, state state.ReadOnlyBeaconState, slot primitives.Slot) (primitives.ValidatorIndex, error) {
-	if state.Version() >= version.Fulu {
-		return beaconProposerIndexAtSlotFulu(state, slot)
-	}
 	e := slots.ToEpoch(slot)
+	stateEpoch := slots.ToEpoch(state.Slot())
+	// Even if the state is post Fulu, we may request a past proposer index.
+	if state.Version() >= version.Fulu && e >= params.BeaconConfig().FuluForkEpoch {
+		// We can use the cached lookahead only for the current and the next epoch.
+		if e == stateEpoch || e == stateEpoch+1 {
+			return beaconProposerIndexAtSlotFulu(state, slot)
+		}
+	}
 	// The cache uses the state root of the previous epoch - minimum_seed_lookahead last slot as key. (e.g. Starting epoch 1, slot 32, the key would be block root at slot 31)
-	// For simplicity, the node will skip caching of genesis epoch.
-	if e > params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
+	// For simplicity, the node will skip caching of genesis epoch. If the passed state has not yet reached this slot then we do not check the cache.
+	if e <= stateEpoch && e > params.BeaconConfig().GenesisEpoch+params.BeaconConfig().MinSeedLookahead {
 		s, err := slots.EpochEnd(e - 1)
 		if err != nil {
 			return 0, err

beacon-chain/core/helpers/validators_test.go

@@ -1161,6 +1161,10 @@ func TestValidatorMaxEffectiveBalance(t *testing.T) {
 }
 
 func TestBeaconProposerIndexAtSlotFulu(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.FuluForkEpoch = 1
+	params.OverrideBeaconConfig(cfg)
 	lookahead := make([]uint64, 64)
 	lookahead[0] = 15
 	lookahead[1] = 16
@@ -1180,8 +1184,4 @@ func TestBeaconProposerIndexAtSlotFulu(t *testing.T) {
 	idx, err = helpers.BeaconProposerIndexAtSlot(t.Context(), st, 130)
 	require.NoError(t, err)
 	require.Equal(t, primitives.ValidatorIndex(42), idx)
-	_, err = helpers.BeaconProposerIndexAtSlot(t.Context(), st, 95)
-	require.ErrorContains(t, "slot 95 is not in the current epoch 3 or the next epoch", err)
-	_, err = helpers.BeaconProposerIndexAtSlot(t.Context(), st, 160)
-	require.ErrorContains(t, "slot 160 is not in the current epoch 3 or the next epoch", err)
 }

beacon-chain/core/peerdas/BUILD.bazel

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "das_core.go",
         "info.go",
+        "log.go",
         "metrics.go",
         "p2p_interface.go",
         "reconstruction.go",
@@ -19,7 +20,6 @@ go_library(
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
-        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//container/trie:go_default_library",
         "//crypto/hash:go_default_library",
@@ -33,6 +33,7 @@ go_library(
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
         "@org_golang_x_sync//errgroup:go_default_library",
     ],
 )

beacon-chain/core/peerdas/das_core.go

@@ -4,15 +4,10 @@ import (
 	"encoding/binary"
 	"math"
 	"slices"
-	"time"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/holiman/uint256"
 	"github.com/pkg/errors"
@@ -20,12 +15,9 @@ import (
 
 var (
 	// Custom errors
-	ErrCustodyGroupTooLarge               = errors.New("custody group too large")
-	ErrCustodyGroupCountTooLarge          = errors.New("custody group count too large")
-	ErrSizeMismatch                       = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
-	ErrNotEnoughDataColumnSidecars        = errors.New("not enough columns")
-	ErrDataColumnSidecarsNotSortedByIndex = errors.New("data column sidecars are not sorted by index")
-	errWrongComputedCustodyGroupCount     = errors.New("wrong computed custody group count, should never happen")
+	ErrCustodyGroupTooLarge           = errors.New("custody group too large")
+	ErrCustodyGroupCountTooLarge      = errors.New("custody group count too large")
+	errWrongComputedCustodyGroupCount = errors.New("wrong computed custody group count, should never happen")
 
 	// maxUint256 is the maximum value of an uint256.
 	maxUint256 = &uint256.Int{math.MaxUint64, math.MaxUint64, math.MaxUint64, math.MaxUint64}
@@ -117,44 +109,6 @@ func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 	return columns, nil
 }
 
-// DataColumnSidecars computes the data column sidecars from the signed block, cells and cell proofs.
-// The returned value contains pointers to function parameters.
-// (If the caller alterates `cellsAndProofs` afterwards, the returned value will be modified as well.)
-// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block
-func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
-	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
-		return nil, nil
-	}
-
-	block := signedBlock.Block()
-	blockBody := block.Body()
-	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
-	if err != nil {
-		return nil, errors.Wrap(err, "blob KZG commitments")
-	}
-
-	if len(blobKzgCommitments) != len(cellsAndProofs) {
-		return nil, ErrSizeMismatch
-	}
-
-	signedBlockHeader, err := signedBlock.Header()
-	if err != nil {
-		return nil, errors.Wrap(err, "signed block header")
-	}
-
-	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
-	if err != nil {
-		return nil, errors.Wrap(err, "merkle proof KZG commitments")
-	}
-
-	dataColumnSidecars, err := dataColumnsSidecars(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
-	if err != nil {
-		return nil, errors.Wrap(err, "data column sidecars")
-	}
-
-	return dataColumnSidecars, nil
-}
-
 // ComputeCustodyGroupForColumn computes the custody group for a given column.
 // It is the reciprocal function of ComputeColumnsForCustodyGroup.
 func ComputeCustodyGroupForColumn(columnIndex uint64) (uint64, error) {
@@ -194,64 +148,3 @@ func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
 
 	return columns, nil
 }
-
-// dataColumnsSidecars computes the data column sidecars from the signed block header, the blob KZG commiments,
-// the KZG commitment includion proofs and cells and cell proofs.
-// The returned value contains pointers to function parameters.
-// (If the caller alterates input parameters afterwards, the returned value will be modified as well.)
-// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars
-func dataColumnsSidecars(
-	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
-	blobKzgCommitments [][]byte,
-	kzgCommitmentsInclusionProof [][]byte,
-	cellsAndProofs []kzg.CellsAndProofs,
-) ([]*ethpb.DataColumnSidecar, error) {
-	start := time.Now()
-	if len(blobKzgCommitments) != len(cellsAndProofs) {
-		return nil, ErrSizeMismatch
-	}
-
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	blobsCount := len(cellsAndProofs)
-	sidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
-	for columnIndex := range numberOfColumns {
-		column := make([]kzg.Cell, 0, blobsCount)
-		kzgProofOfColumn := make([]kzg.Proof, 0, blobsCount)
-
-		for rowIndex := range blobsCount {
-			cellsForRow := cellsAndProofs[rowIndex].Cells
-			proofsForRow := cellsAndProofs[rowIndex].Proofs
-
-			cell := cellsForRow[columnIndex]
-			column = append(column, cell)
-
-			kzgProof := proofsForRow[columnIndex]
-			kzgProofOfColumn = append(kzgProofOfColumn, kzgProof)
-		}
-
-		columnBytes := make([][]byte, 0, blobsCount)
-		for i := range column {
-			columnBytes = append(columnBytes, column[i][:])
-		}
-
-		kzgProofOfColumnBytes := make([][]byte, 0, blobsCount)
-		for _, kzgProof := range kzgProofOfColumn {
-			kzgProofOfColumnBytes = append(kzgProofOfColumnBytes, kzgProof[:])
-		}
-
-		sidecar := &ethpb.DataColumnSidecar{
-			Index:                        columnIndex,
-			Column:                       columnBytes,
-			KzgCommitments:               blobKzgCommitments,
-			KzgProofs:                    kzgProofOfColumnBytes,
-			SignedBlockHeader:            signedBlockHeader,
-			KzgCommitmentsInclusionProof: kzgCommitmentsInclusionProof,
-		}
-
-		sidecars = append(sidecars, sidecar)
-	}
-
-	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
-	return sidecars, nil
-}

beacon-chain/core/peerdas/das_core_test.go

@@ -3,13 +3,9 @@ package peerdas_test
 import (
 	"testing"
 
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 )
 
@@ -31,44 +27,6 @@ func TestComputeColumnsForCustodyGroup(t *testing.T) {
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
 }
 
-func TestDataColumnSidecars(t *testing.T) {
-	t.Run("nil signed block", func(t *testing.T) {
-		var expected []*ethpb.DataColumnSidecar = nil
-		actual, err := peerdas.DataColumnSidecars(nil, []kzg.CellsAndProofs{})
-		require.NoError(t, err)
-
-		require.DeepSSZEqual(t, expected, actual)
-	})
-
-	t.Run("empty cells and proofs", func(t *testing.T) {
-		// Create a protobuf signed beacon block.
-		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
-
-		// Create a signed beacon block from the protobuf.
-		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
-		require.NoError(t, err)
-
-		actual, err := peerdas.DataColumnSidecars(signedBeaconBlock, []kzg.CellsAndProofs{})
-		require.NoError(t, err)
-		require.IsNil(t, actual)
-	})
-
-	t.Run("sizes mismatch", func(t *testing.T) {
-		// Create a protobuf signed beacon block.
-		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
-
-		// Create a signed beacon block from the protobuf.
-		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
-		require.NoError(t, err)
-
-		// Create cells and proofs.
-		cellsAndProofs := make([]kzg.CellsAndProofs, 1)
-
-		_, err = peerdas.DataColumnSidecars(signedBeaconBlock, cellsAndProofs)
-		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
-	})
-}
-
 func TestComputeCustodyGroupForColumn(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig()

beacon-chain/core/peerdas/p2p_interface_test.go

@@ -63,17 +63,14 @@ func TestVerifyDataColumnSidecarKZGProofs(t *testing.T) {
 	t.Run("invalid proof", func(t *testing.T) {
 		sidecars := generateRandomSidecars(t, seed, blobCount)
 		sidecars[0].Column[0][0]++ // It is OK to overflow
-		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
 
-		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
 		require.ErrorIs(t, err, peerdas.ErrInvalidKZGProof)
 	})
 
 	t.Run("nominal", func(t *testing.T) {
 		sidecars := generateRandomSidecars(t, seed, blobCount)
-		roDataColumnSidecars := generateRODataColumnSidecars(t, sidecars)
-
-		err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+		err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
 		require.NoError(t, err)
 	})
 }
@@ -256,9 +253,8 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_SameCommitments_NoBatch(b *testin
 	for i := range int64(b.N) {
 		// Generate new random sidecars to ensure the KZG backend does not cache anything.
 		sidecars := generateRandomSidecars(b, i, blobCount)
-		roDataColumnSidecars := generateRODataColumnSidecars(b, sidecars)
 
-		for _, sidecar := range roDataColumnSidecars {
+		for _, sidecar := range sidecars {
 			sidecars := []blocks.RODataColumn{sidecar}
 			b.StartTimer()
 			err := peerdas.VerifyDataColumnsSidecarKZGProofs(sidecars)
@@ -282,7 +278,7 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch(b *testing.
 			b.ResetTimer()
 
 			for j := range int64(b.N) {
-				allSidecars := make([]*ethpb.DataColumnSidecar, 0, numberOfColumns)
+				allSidecars := make([]blocks.RODataColumn, 0, numberOfColumns)
 				for k := int64(0); k < numberOfColumns; k += columnsCount {
 					// Use different seeds to generate different blobs/commitments
 					seed := int64(b.N*i) + numberOfColumns*j + blobCount*k
@@ -292,10 +288,8 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch(b *testing.
 					allSidecars = append(allSidecars, sidecars[k:k+columnsCount]...)
 				}
 
-				roDataColumnSidecars := generateRODataColumnSidecars(b, allSidecars)
-
 				b.StartTimer()
-				err := peerdas.VerifyDataColumnsSidecarKZGProofs(roDataColumnSidecars)
+				err := peerdas.VerifyDataColumnsSidecarKZGProofs(allSidecars)
 				b.StopTimer()
 				require.NoError(b, err)
 			}
@@ -323,8 +317,7 @@ func BenchmarkVerifyDataColumnSidecarKZGProofs_DiffCommitments_Batch4(b *testing
 		for j := range int64(batchCount) {
 			// Use different seeds to generate different blobs/commitments
 			sidecars := generateRandomSidecars(b, int64(batchCount)*i+j*blobCount, blobCount)
-			roDataColumnSidecars := generateRODataColumnSidecars(b, sidecars[:columnsCount])
-			allSidecars = append(allSidecars, roDataColumnSidecars)
+			allSidecars = append(allSidecars, sidecars)
 		}
 
 		for _, sidecars := range allSidecars {
@@ -358,7 +351,7 @@ func createTestSidecar(t *testing.T, index uint64, column, kzgCommitments, kzgPr
 	return roSidecar
 }
 
-func generateRandomSidecars(t testing.TB, seed, blobCount int64) []*ethpb.DataColumnSidecar {
+func generateRandomSidecars(t testing.TB, seed, blobCount int64) []blocks.RODataColumn {
 	dbBlock := util.NewBeaconBlockDeneb()
 
 	commitments := make([][]byte, 0, blobCount)
@@ -379,20 +372,10 @@ func generateRandomSidecars(t testing.TB, seed, blobCount int64) []*ethpb.DataCo
 	require.NoError(t, err)
 
 	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
-	sidecars, err := peerdas.DataColumnSidecars(sBlock, cellsAndProofs)
+	rob, err := blocks.NewROBlock(sBlock)
+	require.NoError(t, err)
+	sidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(rob))
 	require.NoError(t, err)
 
 	return sidecars
 }
-
-func generateRODataColumnSidecars(t testing.TB, sidecars []*ethpb.DataColumnSidecar) []blocks.RODataColumn {
-	roDataColumnSidecars := make([]blocks.RODataColumn, 0, len(sidecars))
-	for _, sidecar := range sidecars {
-		roCol, err := blocks.NewRODataColumn(sidecar)
-		require.NoError(t, err)
-
-		roDataColumnSidecars = append(roDataColumnSidecars, roCol)
-	}
-
-	return roDataColumnSidecars
-}

beacon-chain/core/peerdas/reconstruction.go

@@ -5,7 +5,6 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/pkg/errors"
 	"golang.org/x/sync/errgroup"
@@ -18,8 +17,8 @@ var (
 	ErrBlobsCellsProofsMismatch = errors.New("blobs and cells proofs mismatch")
 )
 
-// MinimumColumnsCountToReconstruct return the minimum number of columns needed to proceed to a reconstruction.
-func MinimumColumnsCountToReconstruct() uint64 {
+// MinimumColumnCountToReconstruct return the minimum number of columns needed to proceed to a reconstruction.
+func MinimumColumnCountToReconstruct() uint64 {
 	// If the number of columns is odd, then we need total / 2 + 1 columns to reconstruct.
 	// If the number of columns is even, then we need total / 2 columns to reconstruct.
 	return (params.BeaconConfig().NumberOfColumns + 1) / 2
@@ -58,16 +57,10 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 
 	// Check if there is enough sidecars to reconstruct the missing columns.
 	sidecarCount := len(sidecarByIndex)
-	if uint64(sidecarCount) < MinimumColumnsCountToReconstruct() {
+	if uint64(sidecarCount) < MinimumColumnCountToReconstruct() {
 		return nil, ErrNotEnoughDataColumnSidecars
 	}
 
-	// Sidecars are verified and are committed to the same block.
-	// All signed block headers, KZG commitments, and inclusion proofs are the same.
-	signedBlockHeader := referenceSidecar.SignedBlockHeader
-	kzgCommitments := referenceSidecar.KzgCommitments
-	kzgCommitmentsInclusionProof := referenceSidecar.KzgCommitmentsInclusionProof
-
 	// Recover cells and compute proofs in parallel.
 	var wg errgroup.Group
 	cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
@@ -100,7 +93,7 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 		return nil, errors.Wrap(err, "wait for RecoverCellsAndKZGProofs")
 	}
 
-	outSidecars, err := dataColumnsSidecars(signedBlockHeader, kzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
+	outSidecars, err := ConstructDataColumnSidecar(cellsAndProofs, PopulateFromSidecar(referenceSidecar.RODataColumn))
 	if err != nil {
 		return nil, errors.Wrap(err, "data column sidecars from items")
 	}
@@ -109,71 +102,13 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 	// As a consequence, reconstructed sidecars are also verified.
 	outVerifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(outSidecars))
 	for _, sidecar := range outSidecars {
-		roSidecar, err := blocks.NewRODataColumnWithRoot(sidecar, blockRoot)
-		if err != nil {
-			return nil, errors.Wrap(err, "new RO data column with root")
-		}
-
-		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(sidecar)
 		outVerifiedRoSidecars = append(outVerifiedRoSidecars, verifiedRoSidecar)
 	}
 
 	return outVerifiedRoSidecars, nil
 }
 
-// ConstructDataColumnSidecars constructs data column sidecars from a block, (un-extended) blobs and
-// cell proofs corresponding the extended blobs. The main purpose of this function is to
-// construct data column sidecars from data obtained from the execution client via:
-// - `engine_getBlobsV2` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getblobsv2, or
-// - `engine_getPayloadV5` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getpayloadv5
-// Note: In this function, to stick with the `BlobsBundleV2` format returned by the execution client in `engine_getPayloadV5`,
-// cell proofs are "flattened".
-func ConstructDataColumnSidecars(block interfaces.ReadOnlySignedBeaconBlock, blobs [][]byte, cellProofs [][]byte) ([]*ethpb.DataColumnSidecar, error) {
-	// Check if the cells count is equal to the cell proofs count.
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-	blobCount := uint64(len(blobs))
-	cellProofsCount := uint64(len(cellProofs))
-
-	cellsCount := blobCount * numberOfColumns
-	if cellsCount != cellProofsCount {
-		return nil, ErrBlobsCellsProofsMismatch
-	}
-
-	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
-	for i, blob := range blobs {
-		var kzgBlob kzg.Blob
-		if copy(kzgBlob[:], blob) != len(kzgBlob) {
-			return nil, errors.New("wrong blob size - should never happen")
-		}
-
-		// Compute the extended cells from the (non-extended) blob.
-		cells, err := kzg.ComputeCells(&kzgBlob)
-		if err != nil {
-			return nil, errors.Wrap(err, "compute cells")
-		}
-
-		var proofs []kzg.Proof
-		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
-			var kzgProof kzg.Proof
-			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
-				return nil, errors.New("wrong KZG proof size - should never happen")
-			}
-
-			proofs = append(proofs, kzgProof)
-		}
-
-		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
-		cellsAndProofs = append(cellsAndProofs, cellsProofs)
-	}
-
-	dataColumnSidecars, err := DataColumnSidecars(block, cellsAndProofs)
-	if err != nil {
-		return nil, errors.Wrap(err, "data column sidcars")
-	}
-
-	return dataColumnSidecars, nil
-}
-
 // ReconstructBlobs constructs verified read only blobs sidecars from verified read only blob sidecars.
 // The following constraints must be satisfied:
 //   - All `dataColumnSidecars` has to be committed to the same block, and
@@ -256,6 +191,47 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 	return blobSidecars, nil
 }
 
+// ComputeCellsAndProofs computes the cells and proofs from blobs and cell proofs.
+func ComputeCellsAndProofs(blobs [][]byte, cellProofs [][]byte) ([]kzg.CellsAndProofs, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	blobCount := uint64(len(blobs))
+	cellProofsCount := uint64(len(cellProofs))
+
+	cellsCount := blobCount * numberOfColumns
+	if cellsCount != cellProofsCount {
+		return nil, ErrBlobsCellsProofsMismatch
+	}
+
+	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
+	for i, blob := range blobs {
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob) != len(kzgBlob) {
+			return nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, errors.Wrap(err, "compute cells")
+		}
+
+		var proofs []kzg.Proof
+		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
+				return nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			proofs = append(proofs, kzgProof)
+		}
+
+		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
+		cellsAndProofs = append(cellsAndProofs, cellsProofs)
+	}
+
+	return cellsAndProofs, nil
+}
+
 // blobSidecarsFromDataColumnSidecars converts verified data column sidecars to verified blob sidecars.
 func blobSidecarsFromDataColumnSidecars(roBlock blocks.ROBlock, dataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
 	referenceSidecar := dataColumnSidecars[0]

beacon-chain/core/peerdas/reconstruction_test.go

@@ -9,7 +9,6 @@ import (
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/pkg/errors"
@@ -48,7 +47,7 @@ func TestMinimumColumnsCountToReconstruct(t *testing.T) {
 			params.OverrideBeaconConfig(cfg)
 
 			// Compute the minimum number of columns needed to reconstruct.
-			actual := peerdas.MinimumColumnsCountToReconstruct()
+			actual := peerdas.MinimumColumnCountToReconstruct()
 			require.Equal(t, tc.expected, actual)
 		})
 	}
@@ -100,7 +99,7 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 	t.Run("not enough columns to enable reconstruction", func(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
 
-		minimum := peerdas.MinimumColumnsCountToReconstruct()
+		minimum := peerdas.MinimumColumnCountToReconstruct()
 		_, err := peerdas.ReconstructDataColumnSidecars(verifiedRoSidecars[:minimum-1])
 		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
 	})
@@ -124,50 +123,6 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 	})
 }
 
-func TestConstructDataColumnSidecars(t *testing.T) {
-	const (
-		blobCount    = 3
-		cellsPerBlob = fieldparams.CellsPerBlob
-	)
-
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	// Start the trusted setup.
-	err := kzg.Start()
-	require.NoError(t, err)
-
-	roBlock, _, baseVerifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
-
-	// Extract blobs and proofs from the sidecars.
-	blobs := make([][]byte, 0, blobCount)
-	cellProofs := make([][]byte, 0, cellsPerBlob)
-	for blobIndex := range blobCount {
-		blob := make([]byte, 0, cellsPerBlob)
-		for columnIndex := range cellsPerBlob {
-			cell := baseVerifiedRoSidecars[columnIndex].Column[blobIndex]
-			blob = append(blob, cell...)
-		}
-
-		blobs = append(blobs, blob)
-
-		for columnIndex := range numberOfColumns {
-			cellProof := baseVerifiedRoSidecars[columnIndex].KzgProofs[blobIndex]
-			cellProofs = append(cellProofs, cellProof)
-		}
-	}
-
-	actual, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
-	require.NoError(t, err)
-
-	// Extract the base verified ro sidecars into sidecars.
-	expected := make([]*ethpb.DataColumnSidecar, 0, len(baseVerifiedRoSidecars))
-	for _, verifiedRoSidecar := range baseVerifiedRoSidecars {
-		expected = append(expected, verifiedRoSidecar.DataColumnSidecar)
-	}
-
-	require.DeepSSZEqual(t, expected, actual)
-}
-
 func TestReconstructBlobs(t *testing.T) {
 	// Start the trusted setup.
 	err := kzg.Start()
@@ -250,7 +205,7 @@ func TestReconstructBlobs(t *testing.T) {
 		// Compute cells and proofs from blob sidecars.
 		var wg errgroup.Group
 		blobs := make([][]byte, blobCount)
-		cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		inputCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
 		for i := range blobCount {
 			blob := roBlobSidecars[i].Blob
 			blobs[i] = blob
@@ -267,7 +222,7 @@ func TestReconstructBlobs(t *testing.T) {
 
 				// It is safe for multiple goroutines to concurrently write to the same slice,
 				// as long as they are writing to different indices, which is the case here.
-				cellsAndProofs[i] = cp
+				inputCellsAndProofs[i] = cp
 
 				return nil
 			})
@@ -278,25 +233,24 @@ func TestReconstructBlobs(t *testing.T) {
 
 		// Flatten proofs.
 		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
-		for _, cp := range cellsAndProofs {
+		for _, cp := range inputCellsAndProofs {
 			for _, proof := range cp.Proofs {
 				cellProofs = append(cellProofs, proof[:])
 			}
 		}
 
-		// Construct data column sidecars.
-		// It is OK to use the public function `ConstructDataColumnSidecars`, as long as
-		// `TestConstructDataColumnSidecars` tests pass.
-		dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(roBlock, blobs, cellProofs)
+		// Compute celles and proofs from the blobs and cell proofs.
+		cellsAndProofs, err := peerdas.ComputeCellsAndProofs(blobs, cellProofs)
+		require.NoError(t, err)
+
+		// Construct data column sidears from the signed block and cells and proofs.
+		roDataColumnSidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(roBlock))
 		require.NoError(t, err)
 
 		// Convert to verified data column sidecars.
-		verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
-		for _, dataColumnSidecar := range dataColumnSidecars {
-			roSidecar, err := blocks.NewRODataColumn(dataColumnSidecar)
-			require.NoError(t, err)
-
-			verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roSidecar)
+		verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))
+		for _, roDataColumnSidecar := range roDataColumnSidecars {
+			verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roDataColumnSidecar)
 			verifiedRoSidecars = append(verifiedRoSidecars, verifiedRoSidecar)
 		}
 
@@ -339,3 +293,86 @@ func TestReconstructBlobs(t *testing.T) {
 	})
 
 }
+
+func TestComputeCellsAndProofs(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	t.Run("mismatched blob and proof counts", func(t *testing.T) {
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+		// Create one blob but proofs for two blobs
+		blobs := [][]byte{{}}
+
+		// Create proofs for 2 blobs worth of columns
+		cellProofs := make([][]byte, 2*numberOfColumns)
+
+		_, err := peerdas.ComputeCellsAndProofs(blobs, cellProofs)
+		require.ErrorIs(t, err, peerdas.ErrBlobsCellsProofsMismatch)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		const blobCount = 2
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+		// Generate test blobs
+		_, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, 42, blobCount)
+
+		// Extract blobs and compute expected cells and proofs
+		blobs := make([][]byte, blobCount)
+		expectedCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		var wg errgroup.Group
+
+		for i := range blobCount {
+			blob := roBlobSidecars[i].Blob
+			blobs[i] = blob
+
+			wg.Go(func() error {
+				var kzgBlob kzg.Blob
+				count := copy(kzgBlob[:], blob)
+				require.Equal(t, len(kzgBlob), count)
+
+				cp, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				if err != nil {
+					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
+				}
+
+				expectedCellsAndProofs[i] = cp
+				return nil
+			})
+		}
+
+		err := wg.Wait()
+		require.NoError(t, err)
+
+		// Flatten proofs
+		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
+		for _, cp := range expectedCellsAndProofs {
+			for _, proof := range cp.Proofs {
+				cellProofs = append(cellProofs, proof[:])
+			}
+		}
+
+		// Test ComputeCellsAndProofs
+		actualCellsAndProofs, err := peerdas.ComputeCellsAndProofs(blobs, cellProofs)
+		require.NoError(t, err)
+		require.Equal(t, blobCount, len(actualCellsAndProofs))
+
+		// Verify the results match expected
+		for i := range blobCount {
+			require.Equal(t, len(expectedCellsAndProofs[i].Cells), len(actualCellsAndProofs[i].Cells))
+			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), len(actualCellsAndProofs[i].Proofs))
+
+			// Compare cells
+			for j, expectedCell := range expectedCellsAndProofs[i].Cells {
+				require.Equal(t, expectedCell, actualCellsAndProofs[i].Cells[j])
+			}
+
+			// Compare proofs
+			for j, expectedProof := range expectedCellsAndProofs[i].Proofs {
+				require.Equal(t, expectedProof, actualCellsAndProofs[i].Proofs[j])
+			}
+		}
+	})
+}

beacon-chain/core/peerdas/validator.go

@@ -1,12 +1,24 @@
 package peerdas
 
 import (
+	"time"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	beaconState "github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/pkg/errors"
 )
 
+var (
+	ErrNilSignedBlockOrEmptyCellsAndProofs = errors.New("nil signed block or empty cells and proofs")
+	ErrSizeMismatch                        = errors.New("mismatch in the number of blob KZG commitments and cellsAndProofs")
+	ErrNotEnoughDataColumnSidecars         = errors.New("not enough columns")
+	ErrDataColumnSidecarsNotSortedByIndex  = errors.New("data column sidecars are not sorted by index")
+)
+
 // ValidatorsCustodyRequirement returns the number of custody groups regarding the validator indices attached to the beacon node.
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#validator-custody
 func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validatorsIndex map[primitives.ValidatorIndex]bool) (uint64, error) {
@@ -28,3 +40,154 @@ func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validat
 	count := totalNodeBalance / balancePerAdditionalCustodyGroup
 	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroups), nil
 }
+
+// ConstructDataColumnSidecar, given ConstructionPopulator and the cells/proofs associated with each blob in the
+// block, assembles sidecars which can be distributed to peers.
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block
+func ConstructDataColumnSidecar(rows []kzg.CellsAndProofs, src ConstructionPopulator) ([]blocks.RODataColumn, error) {
+	if len(rows) == 0 {
+		return nil, nil
+	}
+	start := time.Now()
+	cells, proofs, err := rotateRowsToCols(rows, params.BeaconConfig().NumberOfColumns)
+	if err != nil {
+		return nil, errors.Wrap(err, "rotate cells and proofs")
+	}
+
+	maxIdx := params.BeaconConfig().NumberOfColumns
+	roSidecars := make([]blocks.RODataColumn, 0, maxIdx)
+	for idx := range maxIdx {
+		sidecar := &ethpb.DataColumnSidecar{
+			Index:     idx,
+			Column:    cells[idx],
+			KzgProofs: proofs[idx],
+		}
+		if err := src.Populate(sidecar); err != nil {
+			return nil, errors.Wrap(err, "column field setter set")
+		}
+		if len(sidecar.KzgCommitments) != len(sidecar.Column) || len(sidecar.KzgCommitments) != len(sidecar.KzgProofs) {
+			return nil, ErrSizeMismatch
+		}
+
+		roSidecar, err := blocks.NewRODataColumnWithRoot(sidecar, src.Root())
+		if err != nil {
+			return nil, errors.Wrap(err, "new ro data column")
+		}
+		roSidecars = append(roSidecars, roSidecar)
+	}
+
+	dataColumnComputationTime.Observe(float64(time.Since(start).Milliseconds()))
+	return roSidecars, nil
+}
+
+// rotateRowsToCols takes a 2D slice of cells and proofs, where the x is rows (blobs) and y is columns,
+// and returns a 2D slice where x is columns and y is rows.
+func rotateRowsToCols(rows []kzg.CellsAndProofs, numCols uint64) ([][][]byte, [][][]byte, error) {
+	if len(rows) == 0 {
+		return nil, nil, nil
+	}
+	cellCols := make([][][]byte, numCols)
+	proofCols := make([][][]byte, numCols)
+	for i, cp := range rows {
+		if uint64(len(cp.Cells)) != numCols {
+			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough cells")
+		}
+		if len(cp.Cells) != len(cp.Proofs) {
+			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough proofs")
+		}
+		for j := uint64(0); j < numCols; j++ {
+			if i == 0 {
+				cellCols[j] = make([][]byte, len(rows))
+				proofCols[j] = make([][]byte, len(rows))
+			}
+			cellCols[j][i] = cp.Cells[j][:]
+			proofCols[j][i] = cp.Proofs[j][:]
+		}
+	}
+	return cellCols, proofCols, nil
+}
+
+// ConstructionPopulator is an interface that can be satisfied by a type that can use data from a struct
+// like a DataColumnSidecar or a BeaconBlock to set the fields in a data column sidecar that cannot
+// be obtained from the engine api.
+type ConstructionPopulator interface {
+	Populate(*ethpb.DataColumnSidecar) error
+	Slot() primitives.Slot
+	Root() [32]byte
+	Commitments() [][]byte
+	Type() string
+}
+
+func PopulateFromSidecar(sidecar blocks.RODataColumn) *SidecarReconstructionSource {
+	return &SidecarReconstructionSource{RODataColumn: sidecar}
+}
+
+type SidecarReconstructionSource struct {
+	blocks.RODataColumn
+}
+
+func (s *SidecarReconstructionSource) Populate(dc *ethpb.DataColumnSidecar) error {
+	dc.SignedBlockHeader = s.SignedBlockHeader
+	dc.KzgCommitments = s.KzgCommitments
+	dc.KzgCommitmentsInclusionProof = s.KzgCommitmentsInclusionProof
+	return nil
+}
+
+func (s *SidecarReconstructionSource) Root() [32]byte {
+	return s.BlockRoot()
+}
+
+func (s *SidecarReconstructionSource) Commitments() [][]byte {
+	return s.KzgCommitments
+}
+
+func (s *SidecarReconstructionSource) Type() string {
+	return "DataColumnSidecar"
+}
+
+var _ ConstructionPopulator = (*SidecarReconstructionSource)(nil)
+
+func PopulateFromBlock(block blocks.ROBlock) *BlockReconstructionSource {
+	return &BlockReconstructionSource{ROBlock: block}
+}
+
+type BlockReconstructionSource struct {
+	blocks.ROBlock
+}
+
+func (b *BlockReconstructionSource) Populate(dc *ethpb.DataColumnSidecar) error {
+	block := b.Block()
+	blockBody := block.Body()
+	blobKzgCommitments, err := blockBody.BlobKzgCommitments()
+	if err != nil {
+		return errors.Wrap(err, "blob KZG commitments")
+	}
+	dc.KzgCommitments = blobKzgCommitments
+	dc.SignedBlockHeader, err = b.Header()
+	if err != nil {
+		return errors.Wrap(err, "signed block header")
+	}
+	dc.KzgCommitmentsInclusionProof, err = blocks.MerkleProofKZGCommitments(blockBody)
+	if err != nil {
+		return errors.Wrap(err, "merkle proof KZG commitments")
+	}
+	return nil
+}
+
+func (s *BlockReconstructionSource) Slot() primitives.Slot {
+	return s.Block().Slot()
+}
+
+func (s *BlockReconstructionSource) Commitments() [][]byte {
+	c, err := s.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		log.WithField("root", s.Root()).Trace("Unable to get kzg commitments from block")
+	}
+	return c
+}
+
+func (s *BlockReconstructionSource) Type() string {
+	return "BeaconBlock"
+}
+
+var _ ConstructionPopulator = (*BlockReconstructionSource)(nil)

beacon-chain/core/peerdas/validator_test.go

@@ -3,11 +3,15 @@ package peerdas_test
 import (
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
 )
 
 func TestValidatorsCustodyRequirement(t *testing.T) {
@@ -53,3 +57,248 @@ func TestValidatorsCustodyRequirement(t *testing.T) {
 		})
 	}
 }
+
+func TestDataColumnSidecarsFromBlock(t *testing.T) {
+	t.Run("sizes mismatch", func(t *testing.T) {
+		// Create a protobuf signed beacon block.
+		signedBeaconBlockPb := util.NewBeaconBlockDeneb()
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs.
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, params.BeaconConfig().NumberOfColumns),
+				Proofs: make([]kzg.Proof, params.BeaconConfig().NumberOfColumns),
+			},
+		}
+
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		_, err = peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
+	})
+
+	t.Run("cells array too short for column index", func(t *testing.T) {
+		// Create a Fulu block with a blob commitment.
+		signedBeaconBlockPb := util.NewBeaconBlockFulu()
+		signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{make([]byte, 48)}
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs with insufficient cells for the number of columns.
+		// This simulates a scenario where cellsAndProofs has fewer cells than expected columns.
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, 10),  // Only 10 cells
+				Proofs: make([]kzg.Proof, 10), // Only 10 proofs
+			},
+		}
+
+		// This should fail because the function will try to access columns up to NumberOfColumns
+		// but we only have 10 cells/proofs.
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		_, err = peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("proofs array too short for column index", func(t *testing.T) {
+		// Create a Fulu block with a blob commitment.
+		signedBeaconBlockPb := util.NewBeaconBlockFulu()
+		signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{make([]byte, 48)}
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs with sufficient cells but insufficient proofs.
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, numberOfColumns),
+				Proofs: make([]kzg.Proof, 5), // Only 5 proofs, less than columns
+			},
+		}
+
+		// This should fail when trying to access proof beyond index 4.
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		_, err = peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+		require.ErrorContains(t, "not enough proofs", err)
+	})
+
+	t.Run("nominal", func(t *testing.T) {
+		// Create a Fulu block with blob commitments.
+		signedBeaconBlockPb := util.NewBeaconBlockFulu()
+		commitment1 := make([]byte, 48)
+		commitment2 := make([]byte, 48)
+
+		// Set different values to distinguish commitments
+		commitment1[0] = 0x01
+		commitment2[0] = 0x02
+		signedBeaconBlockPb.Block.Body.BlobKzgCommitments = [][]byte{commitment1, commitment2}
+
+		// Create a signed beacon block from the protobuf.
+		signedBeaconBlock, err := blocks.NewSignedBeaconBlock(signedBeaconBlockPb)
+		require.NoError(t, err)
+
+		// Create cells and proofs with correct dimensions.
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+		cellsAndProofs := []kzg.CellsAndProofs{
+			{
+				Cells:  make([]kzg.Cell, numberOfColumns),
+				Proofs: make([]kzg.Proof, numberOfColumns),
+			},
+			{
+				Cells:  make([]kzg.Cell, numberOfColumns),
+				Proofs: make([]kzg.Proof, numberOfColumns),
+			},
+		}
+
+		// Set distinct values in cells and proofs for testing
+		for i := range numberOfColumns {
+			cellsAndProofs[0].Cells[i][0] = byte(i)
+			cellsAndProofs[0].Proofs[i][0] = byte(i)
+			cellsAndProofs[1].Cells[i][0] = byte(i + 128)
+			cellsAndProofs[1].Proofs[i][0] = byte(i + 128)
+		}
+
+		rob, err := blocks.NewROBlock(signedBeaconBlock)
+		require.NoError(t, err)
+		sidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		require.NoError(t, err)
+		require.NotNil(t, sidecars)
+		require.Equal(t, int(numberOfColumns), len(sidecars))
+
+		// Verify each sidecar has the expected structure
+		for i, sidecar := range sidecars {
+			require.Equal(t, uint64(i), sidecar.Index)
+			require.Equal(t, 2, len(sidecar.Column))
+			require.Equal(t, 2, len(sidecar.KzgCommitments))
+			require.Equal(t, 2, len(sidecar.KzgProofs))
+
+			// Verify commitments match what we set
+			require.DeepEqual(t, commitment1, sidecar.KzgCommitments[0])
+			require.DeepEqual(t, commitment2, sidecar.KzgCommitments[1])
+
+			// Verify column data comes from the correct cells
+			require.Equal(t, byte(i), sidecar.Column[0][0])
+			require.Equal(t, byte(i+128), sidecar.Column[1][0])
+
+			// Verify proofs come from the correct proofs
+			require.Equal(t, byte(i), sidecar.KzgProofs[0][0])
+			require.Equal(t, byte(i+128), sidecar.KzgProofs[1][0])
+		}
+	})
+}
+
+func TestDataColumnSidecarsFromColumnSidecar(t *testing.T) {
+	// Create KZG commitments for 2 blobs
+	commitment1 := make([]byte, 48)
+	commitment2 := make([]byte, 48)
+	commitment1[0] = 0x01
+	commitment2[0] = 0x02
+	kzgCommitments := [][]byte{commitment1, commitment2}
+
+	// Create column data for 2 blobs
+	columnData := make([][]byte, 2)
+	columnData[0] = make([]byte, kzg.BytesPerCell)
+	columnData[1] = make([]byte, kzg.BytesPerCell)
+	columnData[0][0] = 0x11 // Distinct values
+	columnData[1][0] = 0x22
+
+	// Create KZG proofs for 2 blobs
+	kzgProofs := make([][]byte, 2)
+	kzgProofs[0] = make([]byte, 48)
+	kzgProofs[1] = make([]byte, 48)
+	kzgProofs[0][0] = 0x33
+	kzgProofs[1][0] = 0x44
+
+	// Create inclusion proof
+	inclusionProof := make([][]byte, 4)
+	for i := range inclusionProof {
+		inclusionProof[i] = make([]byte, 32)
+		inclusionProof[i][0] = byte(i + 0x50)
+	}
+
+	// Create the input VerifiedRODataColumn sidecar using test utility
+	_, verifiedSidecars := util.CreateTestVerifiedRoDataColumnSidecars(t, []util.DataColumnParam{
+		{
+			Index:                        5, // Column index 5
+			Column:                       columnData,
+			KzgCommitments:               kzgCommitments,
+			KzgProofs:                    kzgProofs,
+			KzgCommitmentsInclusionProof: inclusionProof,
+			Slot:                         42,
+			ProposerIndex:                7,
+			ParentRoot:                   make([]byte, 32),
+			StateRoot:                    make([]byte, 32),
+			BodyRoot:                     make([]byte, 32),
+		},
+	})
+	require.Equal(t, 1, len(verifiedSidecars))
+	verifiedInputSidecar := verifiedSidecars[0]
+
+	// Create cells and proofs with correct dimensions for 2 blobs
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	cellsAndProofs := []kzg.CellsAndProofs{
+		{
+			Cells:  make([]kzg.Cell, numberOfColumns),
+			Proofs: make([]kzg.Proof, numberOfColumns),
+		},
+		{
+			Cells:  make([]kzg.Cell, numberOfColumns),
+			Proofs: make([]kzg.Proof, numberOfColumns),
+		},
+	}
+
+	// Set distinct values in cells and proofs for testing
+	for i := range numberOfColumns {
+		cellsAndProofs[0].Cells[i][0] = byte(i)
+		cellsAndProofs[0].Proofs[i][0] = byte(i + 10)
+		cellsAndProofs[1].Cells[i][0] = byte(i + 128)
+		cellsAndProofs[1].Proofs[i][0] = byte(i + 138)
+	}
+
+	// Call the function
+	sidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromSidecar(verifiedInputSidecar.RODataColumn))
+	require.NoError(t, err)
+	require.NotNil(t, sidecars)
+	require.Equal(t, int(numberOfColumns), len(sidecars))
+
+	// Verify each sidecar has the expected structure
+	for i, sidecar := range sidecars {
+		require.Equal(t, uint64(i), sidecar.Index)
+		require.Equal(t, 2, len(sidecar.Column))
+		require.Equal(t, 2, len(sidecar.KzgCommitments))
+		require.Equal(t, 2, len(sidecar.KzgProofs))
+
+		// Verify commitments match input
+		require.DeepEqual(t, commitment1, sidecar.KzgCommitments[0])
+		require.DeepEqual(t, commitment2, sidecar.KzgCommitments[1])
+
+		// Verify column data comes from the correct cells
+		require.Equal(t, byte(i), sidecar.Column[0][0])
+		require.Equal(t, byte(i+128), sidecar.Column[1][0])
+
+		// Verify proofs come from the correct proofs
+		require.Equal(t, byte(i+10), sidecar.KzgProofs[0][0])
+		require.Equal(t, byte(i+138), sidecar.KzgProofs[1][0])
+
+		// Verify inclusion proof is preserved
+		require.Equal(t, len(inclusionProof), len(sidecar.KzgCommitmentsInclusionProof))
+		for j, proof := range sidecar.KzgCommitmentsInclusionProof {
+			require.Equal(t, byte(j+0x50), proof[0])
+		}
+
+		// Verify signed block header is preserved
+		require.Equal(t, primitives.Slot(42), sidecar.SignedBlockHeader.Header.Slot)
+		require.Equal(t, primitives.ValidatorIndex(7), sidecar.SignedBlockHeader.Header.ProposerIndex)
+	}
+}

beacon-chain/das/BUILD.bazel

@@ -4,7 +4,6 @@ go_library(
     name = "go_default_library",
     srcs = [
         "availability_blobs.go",
-        "availability_columns.go",
         "blob_cache.go",
         "data_column_cache.go",
         "iface.go",
@@ -13,7 +12,6 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/das",
     visibility = ["//visibility:public"],
     deps = [
-        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/verification:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -23,7 +21,6 @@ go_library(
         "//runtime/logging:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -33,7 +30,6 @@ go_test(
     name = "go_default_test",
     srcs = [
         "availability_blobs_test.go",
-        "availability_columns_test.go",
         "blob_cache_test.go",
         "data_column_cache_test.go",
     ],
@@ -49,7 +45,6 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_ethereum_go_ethereum//p2p/enode:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/das/availability_blobs.go

@@ -53,30 +53,25 @@ func NewLazilyPersistentStore(store *filesystem.BlobStorage, verifier BlobBatchV
 // Persist adds blobs to the working blob cache. Blobs stored in this cache will be persisted
 // for at least as long as the node is running. Once IsDataAvailable succeeds, all blobs referenced
 // by the given block are guaranteed to be persisted for the remainder of the retention period.
-func (s *LazilyPersistentStoreBlob) Persist(current primitives.Slot, sidecars ...blocks.ROSidecar) error {
+func (s *LazilyPersistentStoreBlob) Persist(current primitives.Slot, sidecars ...blocks.ROBlob) error {
 	if len(sidecars) == 0 {
 		return nil
 	}
 
-	blobSidecars, err := blocks.BlobSidecarsFromSidecars(sidecars)
-	if err != nil {
-		return errors.Wrap(err, "blob sidecars from sidecars")
-	}
-
-	if len(blobSidecars) > 1 {
-		firstRoot := blobSidecars[0].BlockRoot()
-		for _, sidecar := range blobSidecars[1:] {
+	if len(sidecars) > 1 {
+		firstRoot := sidecars[0].BlockRoot()
+		for _, sidecar := range sidecars[1:] {
 			if sidecar.BlockRoot() != firstRoot {
 				return errMixedRoots
 			}
 		}
 	}
-	if !params.WithinDAPeriod(slots.ToEpoch(blobSidecars[0].Slot()), slots.ToEpoch(current)) {
+	if !params.WithinDAPeriod(slots.ToEpoch(sidecars[0].Slot()), slots.ToEpoch(current)) {
 		return nil
 	}
-	key := keyFromSidecar(blobSidecars[0])
+	key := keyFromSidecar(sidecars[0])
 	entry := s.cache.ensure(key)
-	for _, blobSidecar := range blobSidecars {
+	for _, blobSidecar := range sidecars {
 		if err := entry.stash(&blobSidecar); err != nil {
 			return err
 		}

beacon-chain/das/availability_blobs_test.go

@@ -118,23 +118,21 @@ func TestLazilyPersistent_Missing(t *testing.T) {
 
 	blk, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 3)
 
-	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
-
 	mbv := &mockBlobBatchVerifier{t: t, scs: blobSidecars}
 	as := NewLazilyPersistentStore(store, mbv)
 
 	// Only one commitment persisted, should return error with other indices
-	require.NoError(t, as.Persist(1, scs[2]))
+	require.NoError(t, as.Persist(1, blobSidecars[2]))
 	err := as.IsDataAvailable(ctx, 1, blk)
 	require.ErrorIs(t, err, errMissingSidecar)
 
 	// All but one persisted, return missing idx
-	require.NoError(t, as.Persist(1, scs[0]))
+	require.NoError(t, as.Persist(1, blobSidecars[0]))
 	err = as.IsDataAvailable(ctx, 1, blk)
 	require.ErrorIs(t, err, errMissingSidecar)
 
 	// All persisted, return nil
-	require.NoError(t, as.Persist(1, scs...))
+	require.NoError(t, as.Persist(1, blobSidecars...))
 
 	require.NoError(t, as.IsDataAvailable(ctx, 1, blk))
 }
@@ -149,10 +147,8 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 	blobSidecars[0].KzgCommitment = bytesutil.PadTo([]byte("nope"), 48)
 	as := NewLazilyPersistentStore(store, mbv)
 
-	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
-
 	// Only one commitment persisted, should return error with other indices
-	require.NoError(t, as.Persist(1, scs[0]))
+	require.NoError(t, as.Persist(1, blobSidecars[0]))
 	err := as.IsDataAvailable(ctx, 1, blk)
 	require.NotNil(t, err)
 	require.ErrorIs(t, err, errCommitmentMismatch)
@@ -161,29 +157,25 @@ func TestLazilyPersistent_Mismatch(t *testing.T) {
 func TestLazyPersistOnceCommitted(t *testing.T) {
 	_, blobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 6)
 
-	scs := blocks.NewSidecarsFromBlobSidecars(blobSidecars)
-
 	as := NewLazilyPersistentStore(filesystem.NewEphemeralBlobStorage(t), &mockBlobBatchVerifier{})
 	// stashes as expected
-	require.NoError(t, as.Persist(1, scs...))
+	require.NoError(t, as.Persist(1, blobSidecars...))
 	// ignores duplicates
-	require.ErrorIs(t, as.Persist(1, scs...), ErrDuplicateSidecar)
+	require.ErrorIs(t, as.Persist(1, blobSidecars...), ErrDuplicateSidecar)
 
 	// ignores index out of bound
 	blobSidecars[0].Index = 6
-	require.ErrorIs(t, as.Persist(1, blocks.NewSidecarFromBlobSidecar(blobSidecars[0])), errIndexOutOfBounds)
+	require.ErrorIs(t, as.Persist(1, blobSidecars[0]), errIndexOutOfBounds)
 
 	_, moreBlobSidecars := util.GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 1, 4)
 
-	more := blocks.NewSidecarsFromBlobSidecars(moreBlobSidecars)
-
 	// ignores sidecars before the retention period
 	slotOOB, err := slots.EpochStart(params.BeaconConfig().MinEpochsForBlobsSidecarsRequest)
 	require.NoError(t, err)
-	require.NoError(t, as.Persist(32+slotOOB, more[0]))
+	require.NoError(t, as.Persist(32+slotOOB, moreBlobSidecars[0]))
 
 	// doesn't ignore new sidecars with a different block root
-	require.NoError(t, as.Persist(1, more...))
+	require.NoError(t, as.Persist(1, moreBlobSidecars...))
 }
 
 type mockBlobBatchVerifier struct {

beacon-chain/das/availability_columns.go

@@ -1,213 +0,0 @@
-package das
-
-import (
-	"context"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
-	"github.com/OffchainLabs/prysm/v6/time/slots"
-	"github.com/ethereum/go-ethereum/p2p/enode"
-	errors "github.com/pkg/errors"
-)
-
-// LazilyPersistentStoreColumn is an implementation of AvailabilityStore to be used when batch syncing data columns.
-// This implementation will hold any data columns passed to Persist until the IsDataAvailable is called for their
-// block, at which time they will undergo full verification and be saved to the disk.
-type LazilyPersistentStoreColumn struct {
-	store                  *filesystem.DataColumnStorage
-	nodeID                 enode.ID
-	cache                  *dataColumnCache
-	newDataColumnsVerifier verification.NewDataColumnsVerifier
-	custodyGroupCount      uint64
-}
-
-var _ AvailabilityStore = &LazilyPersistentStoreColumn{}
-
-// DataColumnsVerifier enables LazilyPersistentStoreColumn to manage the verification process
-// going from RODataColumn->VerifiedRODataColumn, while avoiding the decision of which individual verifications
-// to run and in what order. Since LazilyPersistentStoreColumn always tries to verify and save data columns only when
-// they are all available, the interface takes a slice of data column sidecars.
-type DataColumnsVerifier interface {
-	VerifiedRODataColumns(ctx context.Context, blk blocks.ROBlock, scs []blocks.RODataColumn) ([]blocks.VerifiedRODataColumn, error)
-}
-
-// NewLazilyPersistentStoreColumn creates a new LazilyPersistentStoreColumn.
-// WARNING: The resulting LazilyPersistentStoreColumn is NOT thread-safe.
-func NewLazilyPersistentStoreColumn(
-	store *filesystem.DataColumnStorage,
-	nodeID enode.ID,
-	newDataColumnsVerifier verification.NewDataColumnsVerifier,
-	custodyGroupCount uint64,
-) *LazilyPersistentStoreColumn {
-	return &LazilyPersistentStoreColumn{
-		store:                  store,
-		nodeID:                 nodeID,
-		cache:                  newDataColumnCache(),
-		newDataColumnsVerifier: newDataColumnsVerifier,
-		custodyGroupCount:      custodyGroupCount,
-	}
-}
-
-// PersistColumns adds columns to the working column cache. Columns stored in this cache will be persisted
-// for at least as long as the node is running. Once IsDataAvailable succeeds, all columns referenced
-// by the given block are guaranteed to be persisted for the remainder of the retention period.
-func (s *LazilyPersistentStoreColumn) Persist(current primitives.Slot, sidecars ...blocks.ROSidecar) error {
-	if len(sidecars) == 0 {
-		return nil
-	}
-
-	dataColumnSidecars, err := blocks.DataColumnSidecarsFromSidecars(sidecars)
-	if err != nil {
-		return errors.Wrap(err, "blob sidecars from sidecars")
-	}
-
-	// It is safe to retrieve the first sidecar.
-	firstSidecar := dataColumnSidecars[0]
-
-	if len(sidecars) > 1 {
-		firstRoot := firstSidecar.BlockRoot()
-		for _, sidecar := range dataColumnSidecars[1:] {
-			if sidecar.BlockRoot() != firstRoot {
-				return errMixedRoots
-			}
-		}
-	}
-
-	firstSidecarEpoch, currentEpoch := slots.ToEpoch(firstSidecar.Slot()), slots.ToEpoch(current)
-	if !params.WithinDAPeriod(firstSidecarEpoch, currentEpoch) {
-		return nil
-	}
-
-	key := cacheKey{slot: firstSidecar.Slot(), root: firstSidecar.BlockRoot()}
-	entry := s.cache.ensure(key)
-
-	for _, sidecar := range dataColumnSidecars {
-		if err := entry.stash(&sidecar); err != nil {
-			return errors.Wrap(err, "stash DataColumnSidecar")
-		}
-	}
-
-	return nil
-}
-
-// IsDataAvailable returns nil if all the commitments in the given block are persisted to the db and have been verified.
-// DataColumnsSidecars already in the db are assumed to have been previously verified against the block.
-func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, currentSlot primitives.Slot, block blocks.ROBlock) error {
-	blockCommitments, err := s.fullCommitmentsToCheck(s.nodeID, block, currentSlot)
-	if err != nil {
-		return errors.Wrapf(err, "full commitments to check with block root `%#x` and current slot `%d`", block.Root(), currentSlot)
-	}
-
-	// Return early for blocks that do not have any commitments.
-	if blockCommitments.count() == 0 {
-		return nil
-	}
-
-	// Get the root of the block.
-	blockRoot := block.Root()
-
-	// Build the cache key for the block.
-	key := cacheKey{slot: block.Block().Slot(), root: blockRoot}
-
-	// Retrieve the cache entry for the block, or create an empty one if it doesn't exist.
-	entry := s.cache.ensure(key)
-
-	// Delete the cache entry for the block at the end.
-	defer s.cache.delete(key)
-
-	// Set the disk summary for the block in the cache entry.
-	entry.setDiskSummary(s.store.Summary(blockRoot))
-
-	// Verify we have all the expected sidecars, and fail fast if any are missing or inconsistent.
-	// We don't try to salvage problematic batches because this indicates a misbehaving peer and we'd rather
-	// ignore their response and decrease their peer score.
-	roDataColumns, err := entry.filter(blockRoot, blockCommitments)
-	if err != nil {
-		return errors.Wrap(err, "entry filter")
-	}
-
-	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
-	verifier := s.newDataColumnsVerifier(roDataColumns, verification.ByRangeRequestDataColumnSidecarRequirements)
-
-	if err := verifier.ValidFields(); err != nil {
-		return errors.Wrap(err, "valid fields")
-	}
-
-	if err := verifier.SidecarInclusionProven(); err != nil {
-		return errors.Wrap(err, "sidecar inclusion proven")
-	}
-
-	if err := verifier.SidecarKzgProofVerified(); err != nil {
-		return errors.Wrap(err, "sidecar KZG proof verified")
-	}
-
-	verifiedRoDataColumns, err := verifier.VerifiedRODataColumns()
-	if err != nil {
-		return errors.Wrap(err, "verified RO data columns - should never happen")
-	}
-
-	if err := s.store.Save(verifiedRoDataColumns); err != nil {
-		return errors.Wrap(err, "save data column sidecars")
-	}
-
-	return nil
-}
-
-// fullCommitmentsToCheck returns the commitments to check for a given block.
-func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, block blocks.ROBlock, currentSlot primitives.Slot) (*safeCommitmentsArray, error) {
-	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
-
-	// Return early for blocks that are pre-Fulu.
-	if block.Version() < version.Fulu {
-		return &safeCommitmentsArray{}, nil
-	}
-
-	// Compute the block epoch.
-	blockSlot := block.Block().Slot()
-	blockEpoch := slots.ToEpoch(blockSlot)
-
-	// Compute the current epoch.
-	currentEpoch := slots.ToEpoch(currentSlot)
-
-	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.
-	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
-		return &safeCommitmentsArray{}, nil
-	}
-
-	// Retrieve the KZG commitments for the block.
-	kzgCommitments, err := block.Block().Body().BlobKzgCommitments()
-	if err != nil {
-		return nil, errors.Wrap(err, "blob KZG commitments")
-	}
-
-	// Return early if there are no commitments in the block.
-	if len(kzgCommitments) == 0 {
-		return &safeCommitmentsArray{}, nil
-	}
-
-	// Retrieve peer info.
-	samplingSize := max(s.custodyGroupCount, samplesPerSlot)
-	peerInfo, _, err := peerdas.Info(nodeID, samplingSize)
-	if err != nil {
-		return nil, errors.Wrap(err, "peer info")
-	}
-
-	// Create a safe commitments array for the custody columns.
-	commitmentsArray := &safeCommitmentsArray{}
-	commitmentsArraySize := uint64(len(commitmentsArray))
-
-	for column := range peerInfo.CustodyColumns {
-		if column >= commitmentsArraySize {
-			return nil, errors.Errorf("custody column index %d too high (max allowed %d) - should never happen", column, commitmentsArraySize)
-		}
-
-		commitmentsArray[column] = kzgCommitments
-	}
-
-	return commitmentsArray, nil
-}

beacon-chain/das/availability_columns_test.go

@@ -1,313 +0,0 @@
-package das
-
-import (
-	"context"
-	"testing"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
-	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
-	"github.com/OffchainLabs/prysm/v6/time/slots"
-	"github.com/ethereum/go-ethereum/p2p/enode"
-)
-
-var commitments = [][]byte{
-	bytesutil.PadTo([]byte("a"), 48),
-	bytesutil.PadTo([]byte("b"), 48),
-	bytesutil.PadTo([]byte("c"), 48),
-	bytesutil.PadTo([]byte("d"), 48),
-}
-
-func TestPersist(t *testing.T) {
-	t.Run("no sidecars", func(t *testing.T) {
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
-		err := lazilyPersistentStoreColumns.Persist(0)
-		require.NoError(t, err)
-		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
-	})
-
-	t.Run("mixed roots", func(t *testing.T) {
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-
-		dataColumnParamsByBlockRoot := []util.DataColumnParam{
-			{Slot: 1, Index: 1},
-			{Slot: 2, Index: 2},
-		}
-
-		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
-
-		err := lazilyPersistentStoreColumns.Persist(0, roSidecars...)
-		require.ErrorIs(t, err, errMixedRoots)
-		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
-	})
-
-	t.Run("outside DA period", func(t *testing.T) {
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-
-		dataColumnParamsByBlockRoot := []util.DataColumnParam{
-			{Slot: 1, Index: 1},
-		}
-
-		roSidecars, _ := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
-
-		err := lazilyPersistentStoreColumns.Persist(1_000_000, roSidecars...)
-		require.NoError(t, err)
-		require.Equal(t, 0, len(lazilyPersistentStoreColumns.cache.entries))
-	})
-
-	t.Run("nominal", func(t *testing.T) {
-		const slot = 42
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-
-		dataColumnParamsByBlockRoot := []util.DataColumnParam{
-			{Slot: slot, Index: 1},
-			{Slot: slot, Index: 5},
-		}
-
-		roSidecars, roDataColumns := roSidecarsFromDataColumnParamsByBlockRoot(t, dataColumnParamsByBlockRoot)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, nil, 0)
-
-		err := lazilyPersistentStoreColumns.Persist(slot, roSidecars...)
-		require.NoError(t, err)
-		require.Equal(t, 1, len(lazilyPersistentStoreColumns.cache.entries))
-
-		key := cacheKey{slot: slot, root: roDataColumns[0].BlockRoot()}
-		entry, ok := lazilyPersistentStoreColumns.cache.entries[key]
-		require.Equal(t, true, ok)
-
-		// A call to Persist does NOT save the sidecars to disk.
-		require.Equal(t, uint64(0), entry.diskSummary.Count())
-
-		require.DeepSSZEqual(t, roDataColumns[0], *entry.scs[1])
-		require.DeepSSZEqual(t, roDataColumns[1], *entry.scs[5])
-
-		for i, roDataColumn := range entry.scs {
-			if map[int]bool{1: true, 5: true}[i] {
-				continue
-			}
-
-			require.IsNil(t, roDataColumn)
-		}
-	})
-}
-
-func TestIsDataAvailable(t *testing.T) {
-	newDataColumnsVerifier := func(dataColumnSidecars []blocks.RODataColumn, _ []verification.Requirement) verification.DataColumnsVerifier {
-		return &mockDataColumnsVerifier{t: t, dataColumnSidecars: dataColumnSidecars}
-	}
-
-	ctx := t.Context()
-
-	t.Run("without commitments", func(t *testing.T) {
-		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
-		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
-
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, 0)
-
-		err := lazilyPersistentStoreColumns.IsDataAvailable(ctx, 0 /*current slot*/, signedRoBlock)
-		require.NoError(t, err)
-	})
-
-	t.Run("with commitments", func(t *testing.T) {
-		signedBeaconBlockFulu := util.NewBeaconBlockFulu()
-		signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
-		signedRoBlock := newSignedRoBlock(t, signedBeaconBlockFulu)
-		block := signedRoBlock.Block()
-		slot := block.Slot()
-		proposerIndex := block.ProposerIndex()
-		parentRoot := block.ParentRoot()
-		stateRoot := block.StateRoot()
-		bodyRoot, err := block.Body().HashTreeRoot()
-		require.NoError(t, err)
-
-		root := signedRoBlock.Root()
-
-		dataColumnStorage := filesystem.NewEphemeralDataColumnStorage(t)
-		lazilyPersistentStoreColumns := NewLazilyPersistentStoreColumn(dataColumnStorage, enode.ID{}, newDataColumnsVerifier, 0)
-
-		indices := [...]uint64{1, 17, 19, 42, 75, 87, 102, 117}
-		dataColumnsParams := make([]util.DataColumnParam, 0, len(indices))
-		for _, index := range indices {
-			dataColumnParams := util.DataColumnParam{
-				Index:          index,
-				KzgCommitments: commitments,
-
-				Slot:          slot,
-				ProposerIndex: proposerIndex,
-				ParentRoot:    parentRoot[:],
-				StateRoot:     stateRoot[:],
-				BodyRoot:      bodyRoot[:],
-			}
-
-			dataColumnsParams = append(dataColumnsParams, dataColumnParams)
-		}
-
-		_, verifiedRoDataColumns := util.CreateTestVerifiedRoDataColumnSidecars(t, dataColumnsParams)
-
-		key := cacheKey{root: root}
-		entry := lazilyPersistentStoreColumns.cache.ensure(key)
-		defer lazilyPersistentStoreColumns.cache.delete(key)
-
-		for _, verifiedRoDataColumn := range verifiedRoDataColumns {
-			err := entry.stash(&verifiedRoDataColumn.RODataColumn)
-			require.NoError(t, err)
-		}
-
-		err = lazilyPersistentStoreColumns.IsDataAvailable(ctx, slot, signedRoBlock)
-		require.NoError(t, err)
-
-		actual, err := dataColumnStorage.Get(root, indices[:])
-		require.NoError(t, err)
-
-		summary := dataColumnStorage.Summary(root)
-		require.Equal(t, uint64(len(indices)), summary.Count())
-		require.DeepSSZEqual(t, verifiedRoDataColumns, actual)
-	})
-}
-
-func TestFullCommitmentsToCheck(t *testing.T) {
-	windowSlots, err := slots.EpochEnd(params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest)
-	require.NoError(t, err)
-
-	testCases := []struct {
-		name        string
-		commitments [][]byte
-		block       func(*testing.T) blocks.ROBlock
-		slot        primitives.Slot
-	}{
-		{
-			name: "Pre-Fulu block",
-			block: func(t *testing.T) blocks.ROBlock {
-				return newSignedRoBlock(t, util.NewBeaconBlockElectra())
-			},
-		},
-		{
-			name: "Commitments outside data availability window",
-			block: func(t *testing.T) blocks.ROBlock {
-				beaconBlockElectra := util.NewBeaconBlockElectra()
-
-				// Block is from slot 0, "current slot" is window size +1 (so outside the window)
-				beaconBlockElectra.Block.Body.BlobKzgCommitments = commitments
-
-				return newSignedRoBlock(t, beaconBlockElectra)
-			},
-			slot: windowSlots + 1,
-		},
-		{
-			name: "Commitments within data availability window",
-			block: func(t *testing.T) blocks.ROBlock {
-				signedBeaconBlockFulu := util.NewBeaconBlockFulu()
-				signedBeaconBlockFulu.Block.Body.BlobKzgCommitments = commitments
-				signedBeaconBlockFulu.Block.Slot = 100
-
-				return newSignedRoBlock(t, signedBeaconBlockFulu)
-			},
-			commitments: commitments,
-			slot:        100,
-		},
-	}
-
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-			b := tc.block(t)
-			s := NewLazilyPersistentStoreColumn(nil, enode.ID{}, nil, numberOfColumns)
-
-			commitmentsArray, err := s.fullCommitmentsToCheck(enode.ID{}, b, tc.slot)
-			require.NoError(t, err)
-
-			for _, commitments := range commitmentsArray {
-				require.DeepEqual(t, tc.commitments, commitments)
-			}
-		})
-	}
-}
-
-func roSidecarsFromDataColumnParamsByBlockRoot(t *testing.T, parameters []util.DataColumnParam) ([]blocks.ROSidecar, []blocks.RODataColumn) {
-	roDataColumns, _ := util.CreateTestVerifiedRoDataColumnSidecars(t, parameters)
-
-	roSidecars := make([]blocks.ROSidecar, 0, len(roDataColumns))
-	for _, roDataColumn := range roDataColumns {
-		roSidecars = append(roSidecars, blocks.NewSidecarFromDataColumnSidecar(roDataColumn))
-	}
-
-	return roSidecars, roDataColumns
-}
-
-func newSignedRoBlock(t *testing.T, signedBeaconBlock interface{}) blocks.ROBlock {
-	sb, err := blocks.NewSignedBeaconBlock(signedBeaconBlock)
-	require.NoError(t, err)
-
-	rb, err := blocks.NewROBlock(sb)
-	require.NoError(t, err)
-
-	return rb
-}
-
-type mockDataColumnsVerifier struct {
-	t                                                                        *testing.T
-	dataColumnSidecars                                                       []blocks.RODataColumn
-	validCalled, SidecarInclusionProvenCalled, SidecarKzgProofVerifiedCalled bool
-}
-
-var _ verification.DataColumnsVerifier = &mockDataColumnsVerifier{}
-
-func (m *mockDataColumnsVerifier) VerifiedRODataColumns() ([]blocks.VerifiedRODataColumn, error) {
-	require.Equal(m.t, true, m.validCalled && m.SidecarInclusionProvenCalled && m.SidecarKzgProofVerifiedCalled)
-
-	verifiedDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(m.dataColumnSidecars))
-	for _, dataColumnSidecar := range m.dataColumnSidecars {
-		verifiedDataColumnSidecar := blocks.NewVerifiedRODataColumn(dataColumnSidecar)
-		verifiedDataColumnSidecars = append(verifiedDataColumnSidecars, verifiedDataColumnSidecar)
-	}
-
-	return verifiedDataColumnSidecars, nil
-}
-
-func (m *mockDataColumnsVerifier) SatisfyRequirement(verification.Requirement) {}
-
-func (m *mockDataColumnsVerifier) ValidFields() error {
-	m.validCalled = true
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) CorrectSubnet(dataColumnSidecarSubTopic string, expectedTopics []string) error {
-	return nil
-}
-func (m *mockDataColumnsVerifier) NotFromFutureSlot() error                         { return nil }
-func (m *mockDataColumnsVerifier) SlotAboveFinalized() error                        { return nil }
-func (m *mockDataColumnsVerifier) ValidProposerSignature(ctx context.Context) error { return nil }
-
-func (m *mockDataColumnsVerifier) SidecarParentSeen(parentSeen func([fieldparams.RootLength]byte) bool) error {
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarParentValid(badParent func([fieldparams.RootLength]byte) bool) error {
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarParentSlotLower() error       { return nil }
-func (m *mockDataColumnsVerifier) SidecarDescendsFromFinalized() error { return nil }
-
-func (m *mockDataColumnsVerifier) SidecarInclusionProven() error {
-	m.SidecarInclusionProvenCalled = true
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarKzgProofVerified() error {
-	m.SidecarKzgProofVerifiedCalled = true
-	return nil
-}
-
-func (m *mockDataColumnsVerifier) SidecarProposerExpected(ctx context.Context) error { return nil }

beacon-chain/das/blob_cache.go

@@ -99,20 +99,26 @@ func (e *blobCacheEntry) filter(root [32]byte, kc [][]byte, slot primitives.Slot
 		if e.diskSummary.HasIndex(i) {
 			continue
 		}
+		// Check if e.scs has this index before accessing
+		var sidecar *blocks.ROBlob
+		if i < uint64(len(e.scs)) {
+			sidecar = e.scs[i]
+		}
+
 		if kc[i] == nil {
-			if e.scs[i] != nil {
-				return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, no block commitment", root, i, e.scs[i].KzgCommitment)
+			if sidecar != nil {
+				return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, no block commitment", root, i, sidecar.KzgCommitment)
 			}
 			continue
 		}
 
-		if e.scs[i] == nil {
+		if sidecar == nil {
 			return nil, errors.Wrapf(errMissingSidecar, "root=%#x, index=%#x", root, i)
 		}
-		if !bytes.Equal(kc[i], e.scs[i].KzgCommitment) {
-			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, e.scs[i].KzgCommitment, kc[i])
+		if !bytes.Equal(kc[i], sidecar.KzgCommitment) {
+			return nil, errors.Wrapf(errCommitmentMismatch, "root=%#x, index=%#x, commitment=%#x, block commitment=%#x", root, i, sidecar.KzgCommitment, kc[i])
 		}
-		scs = append(scs, *e.scs[i])
+		scs = append(scs, *sidecar)
 	}
 
 	return scs, nil

beacon-chain/das/blob_cache_test.go

@@ -155,6 +155,41 @@ func TestFilter(t *testing.T) {
 			},
 			err: errCommitmentMismatch,
 		},
+		{
+			name: "empty scs array with commitments",
+			setup: func(t *testing.T) (*blobCacheEntry, [][]byte, []blocks.ROBlob) {
+				// This reproduces the panic condition where entry.scs is empty or nil
+				// but we have commitments to check
+				entry := &blobCacheEntry{
+					scs: nil, // Empty/nil array that caused the panic
+				}
+				// Create a commitment that would trigger the check at index 0
+				commits := [][]byte{
+					bytesutil.PadTo([]byte("commitment1"), 48),
+				}
+				return entry, commits, nil
+			},
+			err: errMissingSidecar,
+		},
+		{
+			name: "scs array shorter than commitments",
+			setup: func(t *testing.T) (*blobCacheEntry, [][]byte, []blocks.ROBlob) {
+				// This reproduces the condition where entry.scs exists but is shorter
+				// than the number of commitments we're checking
+				entry := &blobCacheEntry{
+					scs: make([]*blocks.ROBlob, 2), // Only 2 slots
+				}
+				// Create 4 commitments, accessing index 2 and 3 would have panicked
+				commits := [][]byte{
+					nil,
+					nil,
+					bytesutil.PadTo([]byte("commitment3"), 48),
+					bytesutil.PadTo([]byte("commitment4"), 48),
+				}
+				return entry, commits, nil
+			},
+			err: errMissingSidecar,
+		},
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {

beacon-chain/das/iface.go

@@ -15,5 +15,5 @@ import (
 // durably persisted before returning a non-error value.
 type AvailabilityStore interface {
 	IsDataAvailable(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
-	Persist(current primitives.Slot, sc ...blocks.ROSidecar) error
+	Persist(current primitives.Slot, blobSidecar ...blocks.ROBlob) error
 }

beacon-chain/das/mock.go

@@ -5,13 +5,12 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	errors "github.com/pkg/errors"
 )
 
 // MockAvailabilityStore is an implementation of AvailabilityStore that can be used by other packages in tests.
 type MockAvailabilityStore struct {
 	VerifyAvailabilityCallback func(ctx context.Context, current primitives.Slot, b blocks.ROBlock) error
-	PersistBlobsCallback       func(current primitives.Slot, sc ...blocks.ROBlob) error
+	PersistBlobsCallback       func(current primitives.Slot, blobSidecar ...blocks.ROBlob) error
 }
 
 var _ AvailabilityStore = &MockAvailabilityStore{}
@@ -25,13 +24,9 @@ func (m *MockAvailabilityStore) IsDataAvailable(ctx context.Context, current pri
 }
 
 // Persist satisfies the corresponding method of the AvailabilityStore interface in a way that is useful for tests.
-func (m *MockAvailabilityStore) Persist(current primitives.Slot, sc ...blocks.ROSidecar) error {
-	blobSidecars, err := blocks.BlobSidecarsFromSidecars(sc)
-	if err != nil {
-		return errors.Wrap(err, "blob sidecars from sidecars")
-	}
+func (m *MockAvailabilityStore) Persist(current primitives.Slot, blobSidecar ...blocks.ROBlob) error {
 	if m.PersistBlobsCallback != nil {
-		return m.PersistBlobsCallback(current, blobSidecars...)
+		return m.PersistBlobsCallback(current, blobSidecar...)
 	}
 	return nil
 }

beacon-chain/db/filesystem/data_column.go

@@ -100,6 +100,14 @@ type (
 	}
 )
 
+// DataColumnStorageReader is an interface to read data column sidecars from the filesystem.
+type DataColumnStorageReader interface {
+	Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary
+	Get(root [fieldparams.RootLength]byte, indices []uint64) ([]blocks.VerifiedRODataColumn, error)
+}
+
+var _ DataColumnStorageReader = &DataColumnStorage{}
+
 // WithDataColumnBasePath is a required option that sets the base path of data column storage.
 func WithDataColumnBasePath(base string) DataColumnStorageOption {
 	return func(b *DataColumnStorage) error {

beacon-chain/db/filesystem/data_column_cache.go

@@ -84,12 +84,6 @@ func (s DataColumnStorageSummary) Stored() map[uint64]bool {
 	return stored
 }
 
-// DataColumnStorageSummarizer can be used to receive a summary of metadata about data columns on disk for a given root.
-// The DataColumnStorageSummary can be used to check which indices (if any) are available for a given block by root.
-type DataColumnStorageSummarizer interface {
-	Summary(root [fieldparams.RootLength]byte) DataColumnStorageSummary
-}
-
 type dataColumnStorageSummaryCache struct {
 	mu                 sync.RWMutex
 	dataColumnCount    float64
@@ -98,8 +92,6 @@ type dataColumnStorageSummaryCache struct {
 	cache              map[[fieldparams.RootLength]byte]DataColumnStorageSummary
 }
 
-var _ DataColumnStorageSummarizer = &dataColumnStorageSummaryCache{}
-
 func newDataColumnStorageSummaryCache() *dataColumnStorageSummaryCache {
 	return &dataColumnStorageSummaryCache{
 		cache:             make(map[[fieldparams.RootLength]byte]DataColumnStorageSummary),

beacon-chain/db/filesystem/mock.go

@@ -144,14 +144,3 @@ func NewEphemeralDataColumnStorageWithMocker(t testing.TB) (*DataColumnMocker, *
 	fs, dcs := NewEphemeralDataColumnStorageAndFs(t)
 	return &DataColumnMocker{fs: fs, dcs: dcs}, dcs
 }
-
-func NewMockDataColumnStorageSummarizer(t *testing.T, set map[[fieldparams.RootLength]byte][]uint64) DataColumnStorageSummarizer {
-	c := newDataColumnStorageSummaryCache()
-	for root, indices := range set {
-		if err := c.set(DataColumnsIdent{Root: root, Epoch: 0, Indices: indices}); err != nil {
-			t.Fatal(err)
-		}
-	}
-
-	return c
-}

beacon-chain/db/iface/interface.go

@@ -115,6 +115,17 @@ type NoHeadAccessDatabase interface {
 	CleanUpDirtyStates(ctx context.Context, slotsPerArchivedPoint primitives.Slot) error
 	DeleteHistoricalDataBeforeSlot(ctx context.Context, slot primitives.Slot, batchSize int) (int, error)
 
+	// Genesis operations.
+	LoadGenesis(ctx context.Context, stateBytes []byte) error
+	SaveGenesisData(ctx context.Context, state state.BeaconState) error
+	EnsureEmbeddedGenesis(ctx context.Context) error
+
+	// Support for checkpoint sync and backfill.
+	SaveOriginCheckpointBlockRoot(ctx context.Context, blockRoot [32]byte) error
+	SaveOrigin(ctx context.Context, serState, serBlock []byte) error
+	SaveBackfillStatus(context.Context, *dbval.BackfillStatus) error
+	BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error
+
 	// Custody operations.
 	UpdateSubscribedToAllDataSubnets(ctx context.Context, subscribed bool) (bool, error)
 	UpdateCustodyInfo(ctx context.Context, earliestAvailableSlot primitives.Slot, custodyGroupCount uint64) (primitives.Slot, uint64, error)
@@ -131,16 +142,6 @@ type HeadAccessDatabase interface {
 	HeadBlock(ctx context.Context) (interfaces.ReadOnlySignedBeaconBlock, error)
 	HeadBlockRoot() ([32]byte, error)
 	SaveHeadBlockRoot(ctx context.Context, blockRoot [32]byte) error
-
-	// Genesis operations.
-	LoadGenesis(ctx context.Context, stateBytes []byte) error
-	SaveGenesisData(ctx context.Context, state state.BeaconState) error
-	EnsureEmbeddedGenesis(ctx context.Context) error
-
-	// Support for checkpoint sync and backfill.
-	SaveOrigin(ctx context.Context, serState, serBlock []byte) error
-	SaveBackfillStatus(context.Context, *dbval.BackfillStatus) error
-	BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error
 }
 
 // SlasherDatabase interface for persisting data related to detecting slashable offenses on Ethereum.

beacon-chain/execution/BUILD.bazel

@@ -25,6 +25,7 @@ go_library(
         "//testing/spectest:__subpackages__",
     ],
     deps = [
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
@@ -103,6 +104,7 @@ go_test(
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",

beacon-chain/execution/engine_client.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/execution/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
@@ -123,7 +124,7 @@ type Reconstructor interface {
 		ctx context.Context, blindedBlocks []interfaces.ReadOnlySignedBeaconBlock,
 	) ([]interfaces.SignedBeaconBlock, error)
 	ReconstructBlobSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [fieldparams.RootLength]byte, hi func(uint64) bool) ([]blocks.VerifiedROBlob, error)
-	ReconstructDataColumnSidecars(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [fieldparams.RootLength]byte) ([]blocks.VerifiedRODataColumn, error)
+	ConstructDataColumnSidecars(ctx context.Context, populator peerdas.ConstructionPopulator) ([]blocks.VerifiedRODataColumn, error)
 }
 
 // EngineCaller defines a client that can interact with an Ethereum
@@ -651,22 +652,41 @@ func (s *Service) ReconstructBlobSidecars(ctx context.Context, block interfaces.
 	return verifiedBlobs, nil
 }
 
-// ReconstructDataColumnSidecars reconstructs the verified data column sidecars for a given beacon block.
-// It retrieves the KZG commitments from the block body, fetches the associated blobs and cell proofs from the EL,
-// and constructs the corresponding verified read-only data column sidecars.
-func (s *Service) ReconstructDataColumnSidecars(ctx context.Context, signedROBlock interfaces.ReadOnlySignedBeaconBlock, blockRoot [fieldparams.RootLength]byte) ([]blocks.VerifiedRODataColumn, error) {
-	block := signedROBlock.Block()
-
+func (s *Service) ConstructDataColumnSidecars(ctx context.Context, populator peerdas.ConstructionPopulator) ([]blocks.VerifiedRODataColumn, error) {
+	root := populator.Root()
 	log := log.WithFields(logrus.Fields{
-		"root": fmt.Sprintf("%#x", blockRoot),
-		"slot": block.Slot(),
+		"root": fmt.Sprintf("%#x", root),
+		"slot": populator.Slot(),
 	})
 
-	kzgCommitments, err := block.Body().BlobKzgCommitments()
+	// Fetch cells and proofs from the execution client using the KZG commitments from the sidecar.
+	cellsAndProofs, err := s.cellsAndProofsForCommitments(ctx, populator.Commitments())
 	if err != nil {
-		return nil, wrapWithBlockRoot(err, blockRoot, "blob KZG commitments")
+		return nil, wrapWithBlockRoot(err, root, "fetch cells and proofs from execution client")
 	}
 
+	// Return early if nothing is returned from the EL.
+	if len(cellsAndProofs) == 0 {
+		return nil, nil
+	}
+
+	// Construct data column sidears from the signed block and cells and proofs.
+	roSidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofs, populator)
+	if err != nil {
+		return nil, wrapWithBlockRoot(err, populator.Root(), "data column sidcars from column sidecar")
+	}
+
+	// Upgrade the sidecars to verified sidecars.
+	// We trust the execution layer we are connected to, so we can upgrade the sidecar into a verified one.
+	verifiedROSidecars := upgradeSidecarsToVerifiedSidecars(roSidecars)
+
+	log.WithField("sourceType", populator.Type()).Debug("Data columns sidecars constructed from the execution client")
+
+	return verifiedROSidecars, nil
+}
+
+// cellsAndProofsForCommitments fetches cells and proofs from the execution client (using engine_getBlobsV2 execution API method)
+func (s *Service) cellsAndProofsForCommitments(ctx context.Context, kzgCommitments [][]byte) ([]kzg.CellsAndProofs, error) {
 	// Collect KZG hashes for all blobs.
 	versionedHashes := make([]common.Hash, 0, len(kzgCommitments))
 	for _, commitment := range kzgCommitments {
@@ -677,12 +697,11 @@ func (s *Service) ReconstructDataColumnSidecars(ctx context.Context, signedROBlo
 	// Fetch all blobsAndCellsProofs from the execution client.
 	blobAndProofV2s, err := s.GetBlobsV2(ctx, versionedHashes)
 	if err != nil {
-		return nil, wrapWithBlockRoot(err, blockRoot, "get blobs V2")
+		return nil, errors.Wrapf(err, "get blobs V2")
 	}
 
 	// Return early if nothing is returned from the EL.
 	if len(blobAndProofV2s) == 0 {
-		log.Debug("No blobs returned from execution client")
 		return nil, nil
 	}
 
@@ -690,34 +709,31 @@ func (s *Service) ReconstructDataColumnSidecars(ctx context.Context, signedROBlo
 	blobs, cellProofs := make([][]byte, 0, len(blobAndProofV2s)), make([][]byte, 0, len(blobAndProofV2s))
 	for _, blobsAndProofs := range blobAndProofV2s {
 		if blobsAndProofs == nil {
-			return nil, wrapWithBlockRoot(errMissingBlobsAndProofsFromEL, blockRoot, "")
+			return nil, errMissingBlobsAndProofsFromEL
 		}
 
-		blobs, cellProofs = append(blobs, blobsAndProofs.Blob), append(cellProofs, blobsAndProofs.KzgProofs...)
+		blobs = append(blobs, blobsAndProofs.Blob)
+		cellProofs = append(cellProofs, blobsAndProofs.KzgProofs...)
 	}
 
-	// Construct the data column sidcars from the blobs and cell proofs provided by the execution client.
-	dataColumnSidecars, err := peerdas.ConstructDataColumnSidecars(signedROBlock, blobs, cellProofs)
+	// Compute cells and proofs from the blobs and cell proofs.
+	cellsAndProofs, err := peerdas.ComputeCellsAndProofs(blobs, cellProofs)
 	if err != nil {
-		return nil, wrapWithBlockRoot(err, blockRoot, "construct data column sidecars")
+		return nil, errors.Wrap(err, "compute cells and proofs")
 	}
 
-	// Finally, construct verified RO data column sidecars.
-	// We trust the execution layer we are connected to, so we can upgrade the read only data column sidecar into a verified one.
-	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecars))
-	for _, dataColumnSidecar := range dataColumnSidecars {
-		roDataColumn, err := blocks.NewRODataColumnWithRoot(dataColumnSidecar, blockRoot)
-		if err != nil {
-			return nil, wrapWithBlockRoot(err, blockRoot, "new read-only data column with root")
-		}
+	return cellsAndProofs, nil
+}
 
-		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+// upgradeSidecarsToVerifiedSidecars upgrades a list of data column sidecars into verified data column sidecars.
+func upgradeSidecarsToVerifiedSidecars(roSidecars []blocks.RODataColumn) []blocks.VerifiedRODataColumn {
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(roSidecars))
+	for _, roSidecar := range roSidecars {
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roSidecar)
 		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
 	}
 
-	log.Debug("Data columns successfully reconstructed from the execution client")
-
-	return verifiedRODataColumns, nil
+	return verifiedRODataColumns
 }
 
 func fullPayloadFromPayloadBody(
@@ -1009,6 +1025,6 @@ func toBlockNumArg(number *big.Int) string {
 }
 
 // wrapWithBlockRoot returns a new error with the given block root.
-func wrapWithBlockRoot(err error, blockRoot [32]byte, message string) error {
+func wrapWithBlockRoot(err error, blockRoot [fieldparams.RootLength]byte, message string) error {
 	return errors.Wrap(err, fmt.Sprintf("%s for block %#x", message, blockRoot))
 }

beacon-chain/execution/engine_client_test.go

@@ -14,6 +14,7 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	mocks "github.com/OffchainLabs/prysm/v6/beacon-chain/execution/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
@@ -2556,7 +2557,7 @@ func TestReconstructBlobSidecars(t *testing.T) {
 	})
 }
 
-func TestReconstructDataColumnSidecars(t *testing.T) {
+func TestConstructDataColumnSidecarsFromBlock(t *testing.T) {
 	// Start the trusted setup.
 	err := kzg.Start()
 	require.NoError(t, err)
@@ -2580,11 +2581,14 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 	sb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(t, err)
 
+	roBlock, err := blocks.NewROBlockWithRoot(sb, r)
+	require.NoError(t, err)
+
 	ctx := context.Background()
 
 	t.Run("GetBlobsV2 is not supported", func(t *testing.T) {
-		_, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
-		require.ErrorContains(t, "get blobs V2 for block", err)
+		_, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromBlock(roBlock))
+		require.ErrorContains(t, "engine_getBlobsV2 is not supported", err)
 	})
 
 	t.Run("nothing received", func(t *testing.T) {
@@ -2594,7 +2598,7 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
 		defer rpcClient.Close()
 
-		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		dataColumns, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromBlock(roBlock))
 		require.NoError(t, err)
 		require.Equal(t, 0, len(dataColumns))
 	})
@@ -2607,7 +2611,7 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
 		defer rpcClient.Close()
 
-		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		dataColumns, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromBlock(roBlock))
 		require.NoError(t, err)
 		require.Equal(t, 128, len(dataColumns))
 	})
@@ -2620,10 +2624,134 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
 		defer rpcClient.Close()
 
-		dataColumns, err := client.ReconstructDataColumnSidecars(ctx, sb, r)
+		_, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromBlock(roBlock))
 		require.ErrorContains(t, errMissingBlobsAndProofsFromEL.Error(), err)
+	})
+}
+
+func TestConstructDataColumnSidecarsFromSidecar(t *testing.T) {
+	// Start the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Setup right fork epoch
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.CapellaForkEpoch = 1
+	cfg.DenebForkEpoch = 2
+	cfg.ElectraForkEpoch = 3
+	cfg.FuluForkEpoch = 4
+	params.OverrideBeaconConfig(cfg)
+
+	client := &Service{capabilityCache: &capabilityCache{}}
+
+	// Create KZG commitments for the sidecar
+	kzgCommitments := createRandomKzgCommitments(t, 3)
+
+	// Create a test verified data column sidecar
+	columnData := make([][]byte, 3)
+	for i := range columnData {
+		columnData[i] = make([]byte, kzg.BytesPerCell)
+		columnData[i][0] = byte(i + 0x10)
+	}
+
+	kzgProofs := make([][]byte, 3)
+	for i := range kzgProofs {
+		kzgProofs[i] = make([]byte, 48)
+		kzgProofs[i][0] = byte(i + 0x20)
+	}
+
+	inclusionProof := make([][]byte, 4)
+	for i := range inclusionProof {
+		inclusionProof[i] = make([]byte, 32)
+		inclusionProof[i][0] = byte(i + 0x30)
+	}
+
+	// Create the input VerifiedRODataColumn sidecar using test utility
+	_, verifiedSidecars := util.CreateTestVerifiedRoDataColumnSidecars(t, []util.DataColumnParam{
+		{
+			Index:                        7, // Column index 7
+			Column:                       columnData,
+			KzgCommitments:               kzgCommitments,
+			KzgProofs:                    kzgProofs,
+			KzgCommitmentsInclusionProof: inclusionProof,
+			Slot:                         4 * params.BeaconConfig().SlotsPerEpoch, // Fulu epoch
+			ProposerIndex:                9,
+			ParentRoot:                   make([]byte, 32),
+			StateRoot:                    make([]byte, 32),
+			BodyRoot:                     make([]byte, 32),
+		},
+	})
+	require.Equal(t, 1, len(verifiedSidecars))
+	sidecar := verifiedSidecars[0]
+
+	ctx := context.Background()
+
+	t.Run("GetBlobsV2 is not supported", func(t *testing.T) {
+		_, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromSidecar(sidecar.RODataColumn))
+		require.NotNil(t, err)
+		require.ErrorContains(t, "engine_getBlobsV2 is not supported", err)
+	})
+
+	t.Run("nothing received", func(t *testing.T) {
+		srv := createBlobServerV2(t, 0, []bool{})
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromSidecar(sidecar.RODataColumn))
+		require.NoError(t, err)
 		require.Equal(t, 0, len(dataColumns))
 	})
+
+	t.Run("receiving all blobs", func(t *testing.T) {
+		blobMasks := []bool{true, true, true}
+		srv := createBlobServerV2(t, 3, blobMasks)
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		dataColumns, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromSidecar(sidecar.RODataColumn))
+		require.NoError(t, err)
+		require.Equal(t, 128, len(dataColumns)) // NumberOfColumns
+
+		// Verify each sidecar has expected structure
+		for i, sidecar := range dataColumns {
+			require.Equal(t, uint64(i), sidecar.Index)
+			require.Equal(t, 3, len(sidecar.Column))         // 3 blobs
+			require.Equal(t, 3, len(sidecar.KzgCommitments)) // 3 commitments
+			require.Equal(t, 3, len(sidecar.KzgProofs))      // 3 proofs per column
+
+			// Verify commitments are preserved
+			for j, commitment := range sidecar.KzgCommitments {
+				require.DeepEqual(t, kzgCommitments[j], commitment)
+			}
+
+			// Verify inclusion proof is preserved
+			require.Equal(t, len(inclusionProof), len(sidecar.KzgCommitmentsInclusionProof))
+			for j, proof := range sidecar.KzgCommitmentsInclusionProof {
+				require.Equal(t, byte(j+0x30), proof[0])
+			}
+
+			// Verify signed block header is preserved
+			require.Equal(t, primitives.Slot(4*params.BeaconConfig().SlotsPerEpoch), sidecar.SignedBlockHeader.Header.Slot)
+			require.Equal(t, primitives.ValidatorIndex(9), sidecar.SignedBlockHeader.Header.ProposerIndex)
+		}
+	})
+
+	t.Run("missing some blobs", func(t *testing.T) {
+		blobMasks := []bool{false, true, true}
+		srv := createBlobServerV2(t, 3, blobMasks)
+		defer srv.Close()
+
+		rpcClient, client := setupRpcClientV2(t, srv.URL, client)
+		defer rpcClient.Close()
+
+		_, err := client.ConstructDataColumnSidecars(ctx, peerdas.PopulateFromSidecar(sidecar.RODataColumn))
+		require.ErrorContains(t, errMissingBlobsAndProofsFromEL.Error(), err)
+	})
 }
 
 func createRandomKzgCommitments(t *testing.T, num int) [][]byte {

beacon-chain/execution/testing/BUILD.bazel

@@ -14,6 +14,7 @@ go_library(
     ],
     deps = [
         "//async/event:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/execution/types:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",

beacon-chain/execution/testing/mock_engine_client.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"math/big"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -116,7 +117,8 @@ func (e *EngineClient) ReconstructBlobSidecars(context.Context, interfaces.ReadO
 	return e.BlobSidecars, e.ErrorBlobSidecars
 }
 
-func (e *EngineClient) ReconstructDataColumnSidecars(context.Context, interfaces.ReadOnlySignedBeaconBlock, [fieldparams.RootLength]byte) ([]blocks.VerifiedRODataColumn, error) {
+// ConstructDataColumnSidecars is a mock implementation of the ConstructDataColumnSidecars method.
+func (e *EngineClient) ConstructDataColumnSidecars(context.Context, peerdas.ConstructionPopulator) ([]blocks.VerifiedRODataColumn, error) {
 	return e.DataColumnSidecars, e.ErrorDataColumnSidecars
 }
 

beacon-chain/node/node.go

@@ -318,6 +318,7 @@ func startBaseServices(cliCtx *cli.Context, beacon *BeaconNode, depositAddress s
 	}
 
 	beacon.BlobStorage.WarmCache()
+	beacon.DataColumnStorage.WarmCache()
 
 	log.Debugln("Starting Slashing DB")
 	if err := beacon.startSlasherDB(cliCtx, clearer); err != nil {
@@ -845,6 +846,7 @@ func (b *BeaconNode) registerInitialSyncService(complete chan struct{}) error {
 		ClockWaiter:         b.clockWaiter,
 		InitialSyncComplete: complete,
 		BlobStorage:         b.BlobStorage,
+		DataColumnStorage:   b.DataColumnStorage,
 	}, opts...)
 	return b.services.RegisterService(is)
 }
@@ -939,6 +941,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		FinalizationFetcher:       chainService,
 		BlockReceiver:             chainService,
 		BlobReceiver:              chainService,
+		DataColumnReceiver:        chainService,
 		AttestationReceiver:       chainService,
 		GenesisTimeFetcher:        chainService,
 		GenesisFetcher:            chainService,
@@ -966,6 +969,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		Router:                    router,
 		ClockWaiter:               b.clockWaiter,
 		BlobStorage:               b.BlobStorage,
+		DataColumnStorage:         b.DataColumnStorage,
 		TrackedValidatorsCache:    b.trackedValidatorsCache,
 		PayloadIDCache:            b.payloadIDCache,
 		LCStore:                   b.lcStore,

beacon-chain/p2p/BUILD.bazel

@@ -60,6 +60,7 @@ go_library(
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
@@ -195,7 +196,6 @@ go_test(
         "@com_github_multiformats_go_multiaddr//:go_default_library",
         "@com_github_pkg_errors//: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",
     ],

beacon-chain/p2p/broadcaster.go

@@ -11,6 +11,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/crypto/hash"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing"
@@ -305,22 +306,16 @@ func (s *Service) BroadcastLightClientFinalityUpdate(ctx context.Context, update
 	return nil
 }
 
-// BroadcastDataColumn broadcasts a data column to the p2p network, the message is assumed to be
+// BroadcastDataColumnSidecar broadcasts a data column to the p2p network, the message is assumed to be
 // broadcasted to the current fork and to the input column subnet.
-func (s *Service) BroadcastDataColumn(
-	root [fieldparams.RootLength]byte,
+func (s *Service) BroadcastDataColumnSidecar(
 	dataColumnSubnet uint64,
-	dataColumnSidecar *ethpb.DataColumnSidecar,
+	dataColumnSidecar blocks.VerifiedRODataColumn,
 ) error {
 	// Add tracing to the function.
-	ctx, span := trace.StartSpan(s.ctx, "p2p.BroadcastDataColumn")
+	ctx, span := trace.StartSpan(s.ctx, "p2p.BroadcastDataColumnSidecar")
 	defer span.End()
 
-	// Ensure the data column sidecar is not nil.
-	if dataColumnSidecar == nil {
-		return errors.Errorf("attempted to broadcast nil data column sidecar at subnet %d", dataColumnSubnet)
-	}
-
 	// Retrieve the current fork digest.
 	forkDigest, err := s.currentForkDigest()
 	if err != nil {
@@ -330,20 +325,19 @@ func (s *Service) BroadcastDataColumn(
 	}
 
 	// Non-blocking broadcast, with attempts to discover a column subnet peer if none available.
-	go s.internalBroadcastDataColumn(ctx, root, dataColumnSubnet, dataColumnSidecar, forkDigest)
+	go s.internalBroadcastDataColumnSidecar(ctx, dataColumnSubnet, dataColumnSidecar, forkDigest)
 
 	return nil
 }
 
-func (s *Service) internalBroadcastDataColumn(
+func (s *Service) internalBroadcastDataColumnSidecar(
 	ctx context.Context,
-	root [fieldparams.RootLength]byte,
 	columnSubnet uint64,
-	dataColumnSidecar *ethpb.DataColumnSidecar,
+	dataColumnSidecar blocks.VerifiedRODataColumn,
 	forkDigest [fieldparams.VersionLength]byte,
 ) {
 	// Add tracing to the function.
-	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastDataColumn")
+	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastDataColumnSidecar")
 	defer span.End()
 
 	// Increase the number of broadcast attempts.
@@ -385,7 +379,7 @@ func (s *Service) internalBroadcastDataColumn(
 	log.WithFields(logrus.Fields{
 		"slot":               slot,
 		"timeSinceSlotStart": time.Since(slotStartTime),
-		"root":               fmt.Sprintf("%#x", root),
+		"root":               fmt.Sprintf("%#x", dataColumnSidecar.BlockRoot()),
 		"columnSubnet":       columnSubnet,
 	}).Debug("Broadcasted data column sidecar")
 

beacon-chain/p2p/broadcaster_test.go

@@ -711,13 +711,8 @@ func TestService_BroadcastDataColumn(t *testing.T) {
 	subnet := peerdas.ComputeSubnetForDataColumnSidecar(columnIndex)
 	topic := fmt.Sprintf(topicFormat, digest, subnet) + service.Encoding().ProtocolSuffix()
 
-	roSidecars, _ := util.CreateTestVerifiedRoDataColumnSidecars(t, []util.DataColumnParam{{Index: columnIndex}})
-	sidecar := roSidecars[0].DataColumnSidecar
-
-	// Attempt to broadcast nil object should fail.
-	var emptyRoot [fieldparams.RootLength]byte
-	err = service.BroadcastDataColumn(emptyRoot, subnet, nil)
-	require.ErrorContains(t, "attempted to broadcast nil", err)
+	_, verifiedRoSidecars := util.CreateTestVerifiedRoDataColumnSidecars(t, []util.DataColumnParam{{Index: columnIndex}})
+	verifiedRoSidecar := verifiedRoSidecars[0]
 
 	// Subscribe to the topic.
 	sub, err := p2.SubscribeToTopic(topic)
@@ -727,7 +722,7 @@ func TestService_BroadcastDataColumn(t *testing.T) {
 	time.Sleep(50 * time.Millisecond)
 
 	// Broadcast to peers and wait.
-	err = service.BroadcastDataColumn(emptyRoot, subnet, sidecar)
+	err = service.BroadcastDataColumnSidecar(subnet, verifiedRoSidecar)
 	require.NoError(t, err)
 
 	// Receive the message.
@@ -739,5 +734,5 @@ func TestService_BroadcastDataColumn(t *testing.T) {
 
 	var result ethpb.DataColumnSidecar
 	require.NoError(t, service.Encoding().DecodeGossip(msg.Data, &result))
-	require.DeepEqual(t, &result, sidecar)
+	require.DeepEqual(t, &result, verifiedRoSidecar)
 }

beacon-chain/p2p/custody.go

@@ -155,6 +155,7 @@ func (s *Service) custodyGroupCountFromPeerENR(pid peer.ID) uint64 {
 	log := log.WithFields(logrus.Fields{
 		"peerID":       pid,
 		"defaultValue": custodyRequirement,
+		"agent":        agentString(pid, s.Host()),
 	})
 
 	// Retrieve the ENR of the peer.

beacon-chain/p2p/custody_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
+	testp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
@@ -269,6 +270,7 @@ func TestCustodyGroupCountFromPeer(t *testing.T) {
 			service := &Service{
 				peers:    peers,
 				metaData: tc.metadata,
+				host:     testp2p.NewTestP2P(t).Host(),
 			}
 
 			// Retrieve the custody count from the remote peer.
@@ -329,6 +331,7 @@ func TestCustodyGroupCountFromPeerENR(t *testing.T) {
 
 			service := &Service{
 				peers: peers,
+				host:  testp2p.NewTestP2P(t).Host(),
 			}
 
 			actual := service.custodyGroupCountFromPeerENR(pid)

beacon-chain/p2p/discovery.go

@@ -443,20 +443,27 @@ func (s *Service) findPeers(ctx context.Context, missingPeerCount uint) ([]*enod
 			return peersToDial, ctx.Err()
 		}
 
-		// Skip peer not matching the filter.
 		node := iterator.Node()
-		if !s.filterPeer(node) {
-			continue
-		}
 
 		// Remove duplicates, keeping the node with higher seq.
 		existing, ok := nodeByNodeID[node.ID()]
-		if ok && existing.Seq() > node.Seq() {
+		if ok && existing.Seq() >= node.Seq() {
+			continue // keep existing and skip.
+		}
+
+		// Treat nodes that exist in nodeByNodeID with higher seq numbers as new peers
+		// Skip peer not matching the filter.
+		if !s.filterPeer(node) {
+			if ok {
+				// this means the existing peer with the lower sequence number is no longer valid
+				delete(nodeByNodeID, existing.ID())
+				missingPeerCount++
+			}
 			continue
 		}
-		nodeByNodeID[node.ID()] = node
 
 		// We found a new peer. Decrease the missing peer count.
+		nodeByNodeID[node.ID()] = node
 		missingPeerCount--
 	}
 
@@ -677,7 +684,7 @@ func (s *Service) filterPeer(node *enode.Node) bool {
 
 	peerData, multiAddrs, err := convertToAddrInfo(node)
 	if err != nil {
-		log.WithError(err).Debug("Could not convert to peer data")
+		log.WithError(err).WithField("node", node.String()).Debug("Could not convert to peer data")
 		return false
 	}
 
@@ -844,7 +851,7 @@ func convertToMultiAddr(nodes []*enode.Node) []ma.Multiaddr {
 func convertToAddrInfo(node *enode.Node) (*peer.AddrInfo, []ma.Multiaddr, error) {
 	multiAddrs, err := retrieveMultiAddrsFromNode(node)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, errors.Wrap(err, "retrieve multiaddrs from node")
 	}
 
 	if len(multiAddrs) == 0 {

beacon-chain/p2p/discovery_test.go

@@ -1,9 +1,11 @@
 package p2p
 
 import (
+	"bytes"
 	"context"
 	"crypto/ecdsa"
 	"crypto/rand"
+	"crypto/sha256"
 	"fmt"
 	mathRand "math/rand"
 	"net"
@@ -58,6 +60,81 @@ func createAddrAndPrivKey(t *testing.T) (net.IP, *ecdsa.PrivateKey) {
 	return ipAddr, pkey
 }
 
+// createTestNodeWithID creates a LocalNode for testing with deterministic private key
+// This is needed for deduplication tests where we need the same node ID across different sequence numbers
+func createTestNodeWithID(t *testing.T, id string) *enode.LocalNode {
+	// Create a deterministic reader based on the ID for consistent key generation
+	h := sha256.New()
+	h.Write([]byte(id))
+	seedBytes := h.Sum(nil)
+
+	// Create a deterministic reader using the seed
+	deterministicReader := bytes.NewReader(seedBytes)
+
+	// Generate the private key using the same approach as the production code
+	privKey, _, err := crypto.GenerateSecp256k1Key(deterministicReader)
+	require.NoError(t, err)
+
+	// Convert to ECDSA private key for enode usage
+	ecdsaPrivKey, err := ecdsaprysm.ConvertFromInterfacePrivKey(privKey)
+	require.NoError(t, err)
+
+	db, err := enode.OpenDB("")
+	require.NoError(t, err)
+	t.Cleanup(func() { db.Close() })
+
+	localNode := enode.NewLocalNode(db, ecdsaPrivKey)
+
+	// Set basic properties
+	localNode.SetStaticIP(net.ParseIP("127.0.0.1"))
+	localNode.Set(enr.TCP(3000))
+	localNode.Set(enr.UDP(3000))
+	localNode.Set(enr.WithEntry(eth2EnrKey, make([]byte, 16)))
+
+	return localNode
+}
+
+// createTestNodeRandom creates a LocalNode for testing using the existing createAddrAndPrivKey function
+func createTestNodeRandom(t *testing.T) *enode.LocalNode {
+	_, privKey := createAddrAndPrivKey(t)
+
+	db, err := enode.OpenDB("")
+	require.NoError(t, err)
+	t.Cleanup(func() { db.Close() })
+
+	localNode := enode.NewLocalNode(db, privKey)
+
+	// Set basic properties
+	localNode.SetStaticIP(net.ParseIP("127.0.0.1"))
+	localNode.Set(enr.TCP(3000))
+	localNode.Set(enr.UDP(3000))
+	localNode.Set(enr.WithEntry(eth2EnrKey, make([]byte, 16)))
+
+	return localNode
+}
+
+// setNodeSeq updates a LocalNode to have the specified sequence number
+func setNodeSeq(localNode *enode.LocalNode, seq uint64) {
+	// Force set the sequence number - we need to update the record seq-1 times
+	// because it starts at 1
+	currentSeq := localNode.Node().Seq()
+	for currentSeq < seq {
+		localNode.Set(enr.WithEntry("dummy", currentSeq))
+		currentSeq++
+	}
+}
+
+// setNodeSubnets sets the attestation subnets for a LocalNode
+func setNodeSubnets(localNode *enode.LocalNode, attSubnets []uint64) {
+	if len(attSubnets) > 0 {
+		bitV := bitfield.NewBitvector64()
+		for _, subnet := range attSubnets {
+			bitV.SetBitAt(subnet, true)
+		}
+		localNode.Set(enr.WithEntry(attSubnetEnrKey, &bitV))
+	}
+}
+
 func TestCreateListener(t *testing.T) {
 	port := 1024
 	ipAddr, pkey := createAddrAndPrivKey(t)
@@ -241,7 +318,7 @@ func TestCreateLocalNode(t *testing.T) {
 
 			// Check fork is set.
 			fork := new([]byte)
-			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(eth2ENRKey, fork)))
+			require.NoError(t, localNode.Node().Record().Load(enr.WithEntry(eth2EnrKey, fork)))
 			require.NotEmpty(t, *fork)
 
 			// Check att subnets.
@@ -492,7 +569,7 @@ func TestMultipleDiscoveryAddresses(t *testing.T) {
 	node := enode.NewLocalNode(db, key)
 	node.Set(enr.IPv4{127, 0, 0, 1})
 	node.Set(enr.IPv6{0x20, 0x01, 0x48, 0x60, 0, 0, 0x20, 0x01, 0, 0, 0, 0, 0, 0, 0x00, 0x68})
-	s := &Service{dv5Listener: mockListener{localNode: node}}
+	s := &Service{dv5Listener: testp2p.NewMockListener(node, nil)}
 
 	multiAddresses, err := s.DiscoveryAddresses()
 	require.NoError(t, err)
@@ -517,7 +594,7 @@ func TestDiscoveryV5_SeqNumber(t *testing.T) {
 	node := enode.NewLocalNode(db, key)
 	node.Set(enr.IPv4{127, 0, 0, 1})
 	currentSeq := node.Seq()
-	s := &Service{dv5Listener: mockListener{localNode: node}}
+	s := &Service{dv5Listener: testp2p.NewMockListener(node, nil)}
 	_, err = s.DiscoveryAddresses()
 	require.NoError(t, err)
 	newSeq := node.Seq()
@@ -529,7 +606,7 @@ func TestDiscoveryV5_SeqNumber(t *testing.T) {
 	nodeTwo.Set(enr.IPv6{0x20, 0x01, 0x48, 0x60, 0, 0, 0x20, 0x01, 0, 0, 0, 0, 0, 0, 0x00, 0x68})
 	seqTwo := nodeTwo.Seq()
 	assert.NotEqual(t, seqTwo, newSeq)
-	sTwo := &Service{dv5Listener: mockListener{localNode: nodeTwo}}
+	sTwo := &Service{dv5Listener: testp2p.NewMockListener(nodeTwo, nil)}
 	_, err = sTwo.DiscoveryAddresses()
 	require.NoError(t, err)
 	assert.Equal(t, seqTwo+1, nodeTwo.Seq())
@@ -886,3 +963,289 @@ func TestRefreshPersistentSubnets(t *testing.T) {
 	// Reset the config.
 	params.OverrideBeaconConfig(defaultCfg)
 }
+
+func TestFindPeers_NodeDeduplication(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cache.SubnetIDs.EmptyAllCaches()
+	defer cache.SubnetIDs.EmptyAllCaches()
+
+	ctx := t.Context()
+
+	// Create LocalNodes and manipulate sequence numbers
+	localNode1 := createTestNodeWithID(t, "node1")
+	localNode2 := createTestNodeWithID(t, "node2")
+	localNode3 := createTestNodeWithID(t, "node3")
+
+	// Create different sequence versions of node1
+	setNodeSeq(localNode1, 1)
+	node1_seq1 := localNode1.Node()
+	setNodeSeq(localNode1, 2)
+	node1_seq2 := localNode1.Node() // Same ID, higher seq
+	setNodeSeq(localNode1, 3)
+	node1_seq3 := localNode1.Node() // Same ID, even higher seq
+
+	// Other nodes with seq 1
+	node2_seq1 := localNode2.Node()
+	node3_seq1 := localNode3.Node()
+
+	tests := []struct {
+		name          string
+		nodes         []*enode.Node
+		missingPeers  uint
+		expectedCount int
+		description   string
+		eval          func(t *testing.T, result []*enode.Node)
+	}{
+		{
+			name: "No duplicates - all unique nodes",
+			nodes: []*enode.Node{
+				node2_seq1,
+				node3_seq1,
+			},
+			missingPeers:  2,
+			expectedCount: 2,
+			description:   "Should return all unique nodes without deduplication",
+			eval:          nil, // No special validation needed
+		},
+		{
+			name: "Duplicate with lower seq comes first - should replace",
+			nodes: []*enode.Node{
+				node1_seq1,
+				node1_seq2, // Higher seq, should replace
+				node2_seq1, // Different node added after duplicates are processed
+			},
+			missingPeers:  2, // Need 2 peers so we process all nodes
+			expectedCount: 2, // Should get node1 (with higher seq) and node2
+			description:   "Should keep node with higher sequence number when duplicate found",
+			eval: func(t *testing.T, result []*enode.Node) {
+				// Should have node2 and node1 with higher seq (node1_seq2)
+				foundNode1WithHigherSeq := false
+				for _, node := range result {
+					if node.ID() == node1_seq2.ID() {
+						require.Equal(t, node1_seq2.Seq(), node.Seq(), "Node1 should have higher seq")
+						foundNode1WithHigherSeq = true
+					}
+				}
+				require.Equal(t, true, foundNode1WithHigherSeq, "Should have node1 with higher seq")
+			},
+		},
+		{
+			name: "Duplicate with higher seq comes first - should keep existing",
+			nodes: []*enode.Node{
+				node1_seq3, // Higher seq
+				node1_seq2, // Lower seq, should be skipped (continue branch)
+				node1_seq1, // Even lower seq, should also be skipped (continue branch)
+				node2_seq1, // Different node added after duplicates are processed
+			},
+			missingPeers:  2,
+			expectedCount: 2,
+			description:   "Should keep existing node when it has higher sequence number and skip all lower seq duplicates",
+			eval: func(t *testing.T, result []*enode.Node) {
+				// Should have kept the node with highest seq (node1_seq3)
+				foundNode1WithHigherSeq := false
+				for _, node := range result {
+					if node.ID() == node1_seq3.ID() {
+						require.Equal(t, node1_seq3.Seq(), node.Seq(), "Node1 should have highest seq")
+						foundNode1WithHigherSeq = true
+					}
+				}
+				require.Equal(t, true, foundNode1WithHigherSeq, "Should have node1 with highest seq")
+			},
+		},
+		{
+			name: "Multiple duplicates with increasing seq",
+			nodes: []*enode.Node{
+				node1_seq1,
+				node1_seq2, // Should replace seq1
+				node1_seq3, // Should replace seq2
+				node2_seq1, // Different node added after duplicates are processed
+			},
+			missingPeers:  2,
+			expectedCount: 2,
+			description:   "Should keep updating to highest sequence number",
+			eval: func(t *testing.T, result []*enode.Node) {
+				// Should have the node with highest seq (node1_seq3)
+				foundNode1WithHigherSeq := false
+				for _, node := range result {
+					if node.ID() == node1_seq3.ID() {
+						require.Equal(t, node1_seq3.Seq(), node.Seq(), "Node1 should have highest seq")
+						foundNode1WithHigherSeq = true
+					}
+				}
+				require.Equal(t, true, foundNode1WithHigherSeq, "Should have node1 with highest seq")
+			},
+		},
+		{
+			name: "Duplicate with equal seq comes after - should skip",
+			nodes: []*enode.Node{
+				node1_seq2, // First occurrence
+				node1_seq2, // Same exact node instance, should be skipped (continue branch for >= case)
+				node2_seq1, // Different node
+			},
+			missingPeers:  2,
+			expectedCount: 2,
+			description:   "Should skip duplicate with equal sequence number",
+			eval: func(t *testing.T, result []*enode.Node) {
+				// Should have exactly one instance of node1_seq2 and one instance of node2_seq1
+				foundNode1 := false
+				foundNode2 := false
+				for _, node := range result {
+					if node.ID() == node1_seq2.ID() {
+						require.Equal(t, node1_seq2.Seq(), node.Seq(), "Node1 should have the expected seq")
+						require.Equal(t, false, foundNode1, "Should have only one instance of node1") // Ensure no duplicates
+						foundNode1 = true
+					}
+					if node.ID() == node2_seq1.ID() {
+						foundNode2 = true
+					}
+				}
+				require.Equal(t, true, foundNode1, "Should have node1")
+				require.Equal(t, true, foundNode2, "Should have node2")
+			},
+		},
+		{
+			name: "Mix of unique and duplicate nodes",
+			nodes: []*enode.Node{
+				node1_seq1,
+				node2_seq1,
+				node1_seq2, // Should replace node1_seq1
+				node3_seq1,
+				node1_seq3, // Should replace node1_seq2
+			},
+			missingPeers:  3,
+			expectedCount: 3,
+			description:   "Should handle mix of unique nodes and duplicates correctly",
+			eval:          nil, // Basic count validation is sufficient
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fakePeer := testp2p.NewTestP2P(t)
+
+			s := &Service{
+				cfg: &Config{
+					MaxPeers: 30,
+				},
+				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+				peers: peers.NewStatus(ctx, &peers.StatusConfig{
+					PeerLimit:    30,
+					ScorerParams: &scorers.Config{},
+				}),
+				host: fakePeer.BHost,
+			}
+
+			localNode := createTestNodeRandom(t)
+			mockIter := testp2p.NewMockIterator(tt.nodes)
+			s.dv5Listener = testp2p.NewMockListener(localNode, mockIter)
+
+			ctxWithTimeout, cancel := context.WithTimeout(ctx, 1*time.Second)
+			defer cancel()
+
+			result, err := s.findPeers(ctxWithTimeout, tt.missingPeers)
+
+			require.NoError(t, err, tt.description)
+			require.Equal(t, tt.expectedCount, len(result), tt.description)
+
+			if tt.eval != nil {
+				tt.eval(t, result)
+			}
+		})
+	}
+}
+
+// callbackIterator allows us to execute callbacks at specific points during iteration
+type callbackIterator struct {
+	nodes     []*enode.Node
+	index     int
+	callbacks map[int]func() // map from index to callback function
+}
+
+func (c *callbackIterator) Next() bool {
+	// Execute callback before checking if we can continue (if one exists)
+	if callback, exists := c.callbacks[c.index]; exists {
+		callback()
+	}
+
+	return c.index < len(c.nodes)
+}
+
+func (c *callbackIterator) Node() *enode.Node {
+	if c.index >= len(c.nodes) {
+		return nil
+	}
+
+	node := c.nodes[c.index]
+	c.index++
+	return node
+}
+
+func (c *callbackIterator) Close() {
+	// Nothing to clean up for this simple implementation
+}
+
+func TestFindPeers_received_bad_existing_node(t *testing.T) {
+	// This test successfully triggers delete(nodeByNodeID, node.ID()) in subnets.go by:
+	// 1. Processing node1_seq1 first (passes filterPeer, gets added to map
+	// 2. Callback marks peer as bad before processing node1_seq2"
+	// 3. Processing node1_seq2 (fails filterPeer, triggers delete since ok=true
+	params.SetupTestConfigCleanup(t)
+	cache.SubnetIDs.EmptyAllCaches()
+	defer cache.SubnetIDs.EmptyAllCaches()
+
+	// Create LocalNode with same ID but different sequences
+	localNode1 := createTestNodeWithID(t, "testnode")
+	node1_seq1 := localNode1.Node() // Get current node
+	currentSeq := node1_seq1.Seq()
+	setNodeSeq(localNode1, currentSeq+1) // Increment sequence by 1
+	node1_seq2 := localNode1.Node()      // This should have higher seq
+
+	// Additional node to ensure we have enough peers to process
+	localNode2 := createTestNodeWithID(t, "othernode")
+	node2 := localNode2.Node()
+
+	fakePeer := testp2p.NewTestP2P(t)
+
+	service := &Service{
+		cfg: &Config{
+			MaxPeers: 30,
+		},
+		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		peers: peers.NewStatus(t.Context(), &peers.StatusConfig{
+			PeerLimit:    30,
+			ScorerParams: &scorers.Config{},
+		}),
+		host: fakePeer.BHost,
+	}
+
+	// Create iterator with callback that marks peer as bad before processing node1_seq2
+	iter := &callbackIterator{
+		nodes: []*enode.Node{node1_seq1, node1_seq2, node2},
+		index: 0,
+		callbacks: map[int]func(){
+			1: func() { // Before processing node1_seq2 (index 1)
+				// Mark peer as bad before processing node1_seq2
+				peerData, _, _ := convertToAddrInfo(node1_seq2)
+				if peerData != nil {
+					service.peers.Add(node1_seq2.Record(), peerData.ID, nil, network.DirUnknown)
+					// Mark as bad peer - need enough increments to exceed threshold (6)
+					for i := 0; i < 10; i++ {
+						service.peers.Scorers().BadResponsesScorer().Increment(peerData.ID)
+					}
+				}
+			},
+		},
+	}
+
+	localNode := createTestNodeRandom(t)
+	service.dv5Listener = testp2p.NewMockListener(localNode, iter)
+
+	// Run findPeers - node1_seq1 gets processed first, then callback marks peer bad, then node1_seq2 fails
+	ctxWithTimeout, cancel := context.WithTimeout(t.Context(), 1*time.Second)
+	defer cancel()
+
+	result, err := service.findPeers(ctxWithTimeout, 3)
+
+	require.NoError(t, err)
+	require.Equal(t, 1, len(result))
+}

beacon-chain/p2p/fork.go

@@ -13,10 +13,17 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-var errEth2ENRDigestMismatch = errors.New("fork digest of peer does not match local value")
+var (
+	errForkScheduleMismatch  = errors.New("peer fork schedule incompatible")
+	errCurrentDigestMismatch = errors.Wrap(errForkScheduleMismatch, "current_fork_digest mismatch")
+	errNextVersionMismatch   = errors.Wrap(errForkScheduleMismatch, "next_fork_version mismatch")
+	errNextDigestMismatch    = errors.Wrap(errForkScheduleMismatch, "nfd (next fork digest) mismatch")
+)
 
-// ENR key used for Ethereum consensus-related fork data.
-var eth2ENRKey = params.BeaconNetworkConfig().ETH2Key
+const (
+	eth2EnrKey = "eth2" // The `eth2` ENR entry advertizes the node's view of the fork schedule with an ssz-encoded ENRForkID value.
+	nfdEnrKey  = "nfd"  // The `nfd` ENR entry separately advertizes the "next fork digest" aspect of the fork schedule.
+)
 
 // ForkDigest returns the current fork digest of
 // the node according to the local clock.
@@ -33,44 +40,86 @@ func (s *Service) currentForkDigest() ([4]byte, error) {
 // Compares fork ENRs between an incoming peer's record and our node's
 // local record values for current and next fork version/epoch.
 func compareForkENR(self, peer *enr.Record) error {
-	peerForkENR, err := forkEntry(peer)
+	peerEntry, err := forkEntry(peer)
 	if err != nil {
 		return err
 	}
-	currentForkENR, err := forkEntry(self)
+	selfEntry, err := forkEntry(self)
 	if err != nil {
 		return err
 	}
-	enrString, err := SerializeENR(peer)
+	peerString, err := SerializeENR(peer)
 	if err != nil {
 		return err
 	}
 	// Clients SHOULD connect to peers with current_fork_digest, next_fork_version,
 	// and next_fork_epoch that match local values.
-	if !bytes.Equal(peerForkENR.CurrentForkDigest, currentForkENR.CurrentForkDigest) {
-		return errors.Wrapf(errEth2ENRDigestMismatch,
+	if !bytes.Equal(peerEntry.CurrentForkDigest, selfEntry.CurrentForkDigest) {
+		return errors.Wrapf(errCurrentDigestMismatch,
 			"fork digest of peer with ENR %s: %v, does not match local value: %v",
-			enrString,
-			peerForkENR.CurrentForkDigest,
-			currentForkENR.CurrentForkDigest,
+			peerString,
+			peerEntry.CurrentForkDigest,
+			selfEntry.CurrentForkDigest,
 		)
 	}
+
 	// Clients MAY connect to peers with the same current_fork_version but a
 	// different next_fork_version/next_fork_epoch. Unless ENRForkID is manually
 	// updated to matching prior to the earlier next_fork_epoch of the two clients,
 	// these type of connecting clients will be unable to successfully interact
 	// starting at the earlier next_fork_epoch.
-	if peerForkENR.NextForkEpoch != currentForkENR.NextForkEpoch {
+	if peerEntry.NextForkEpoch != selfEntry.NextForkEpoch {
 		log.WithFields(logrus.Fields{
-			"peerNextForkEpoch": peerForkENR.NextForkEpoch,
-			"peerENR":           enrString,
+			"peerNextForkEpoch":   peerEntry.NextForkEpoch,
+			"peerNextForkVersion": peerEntry.NextForkVersion,
+			"peerENR":             peerString,
 		}).Trace("Peer matches fork digest but has different next fork epoch")
+		// We allow the connection because we have a different view of the next fork epoch. This
+		// could be due to peers that have no upgraded ahead of a fork or BPO schedule change, so
+		// we allow the connection to continue until the fork boundary.
+		return nil
 	}
-	if !bytes.Equal(peerForkENR.NextForkVersion, currentForkENR.NextForkVersion) {
-		log.WithFields(logrus.Fields{
-			"peerNextForkVersion": peerForkENR.NextForkVersion,
-			"peerENR":             enrString,
-		}).Trace("Peer matches fork digest but has different next fork version")
+
+	// Since we agree on the next fork epoch, we require next fork version to also be in agreement.
+	if !bytes.Equal(peerEntry.NextForkVersion, selfEntry.NextForkVersion) {
+		return errors.Wrapf(errNextVersionMismatch,
+			"next fork version of peer with ENR %s: %#x, does not match local value: %#x",
+			peerString, peerEntry.NextForkVersion, selfEntry.NextForkVersion)
+	}
+
+	// Fulu adds the following to the spec:
+	// ---
+	// A new entry is added to the ENR under the key nfd, short for next fork digest. This entry
+	// communicates the digest of the next scheduled fork, regardless of whether it is a regular
+	// or a Blob-Parameters-Only fork. This new entry MUST be added once FULU_FORK_EPOCH is assigned
+	// any value other than FAR_FUTURE_EPOCH. Adding this entry prior to the Fulu fork will not
+	// impact peering as nodes will ignore unknown ENR entries and nfd mismatches do not cause
+	// disconnects.
+	// When discovering and interfacing with peers, nodes MUST evaluate nfd alongside their existing
+	// consideration of the ENRForkID::next_* fields under the eth2 key, to form a more accurate
+	// view of the peer's intended next fork for the purposes of sustained peering. If there is a
+	// mismatch, the node MUST NOT disconnect before the fork boundary, but it MAY disconnect
+	// at/after the fork boundary.
+
+	// Nodes unprepared to follow the Fulu fork will be unaware of nfd entries. However, their
+	// existing comparison of eth2 entries (concretely next_fork_epoch) is sufficient to detect
+	// upcoming divergence.
+	// ---
+
+	// Because this is a new in-bound connection, we lean into the pre-fulu point that clients
+	// MAY connect to peers with the same current_fork_version but a different
+	// next_fork_version/next_fork_epoch, which implies we can chose to not connect to them when these
+	// don't match.
+	//
+	// Given that the next_fork_epoch matches, we will require the next_fork_digest to match.
+	if !params.FuluEnabled() {
+		return nil
+	}
+	peerNFD, selfNFD := nfd(peer), nfd(self)
+	if peerNFD != selfNFD {
+		return errors.Wrapf(errNextDigestMismatch,
+			"next fork digest of peer with ENR %s: %v, does not match local value: %v",
+			peerString, peerNFD, selfNFD)
 	}
 	return nil
 }
@@ -81,16 +130,28 @@ func updateENR(node *enode.LocalNode, entry, next params.NetworkScheduleEntry) e
 		NextForkVersion:   next.ForkVersion[:],
 		NextForkEpoch:     next.Epoch,
 	}
-	log.
-		WithField("CurrentForkDigest", fmt.Sprintf("%#x", enrForkID.CurrentForkDigest)).
-		WithField("NextForkVersion", fmt.Sprintf("%#x", enrForkID.NextForkVersion)).
-		WithField("NextForkEpoch", fmt.Sprintf("%d", enrForkID.NextForkEpoch)).
-		Info("Updating ENR Fork ID")
+	if entry.Epoch == next.Epoch {
+		enrForkID.NextForkEpoch = params.BeaconConfig().FarFutureEpoch
+	}
+	logFields := logrus.Fields{
+		"CurrentForkDigest": fmt.Sprintf("%#x", enrForkID.CurrentForkDigest),
+		"NextForkVersion":   fmt.Sprintf("%#x", enrForkID.NextForkVersion),
+		"NextForkEpoch":     fmt.Sprintf("%d", enrForkID.NextForkEpoch),
+	}
+	if params.BeaconConfig().FuluForkEpoch != params.BeaconConfig().FarFutureEpoch {
+		if entry.ForkDigest == next.ForkDigest {
+			node.Set(enr.WithEntry(nfdEnrKey, make([]byte, len(next.ForkDigest))))
+		} else {
+			node.Set(enr.WithEntry(nfdEnrKey, next.ForkDigest[:]))
+		}
+		logFields["NextForkDigest"] = fmt.Sprintf("%#x", next.ForkDigest)
+	}
+	log.WithFields(logFields).Info("Updating ENR Fork ID")
 	enc, err := enrForkID.MarshalSSZ()
 	if err != nil {
 		return err
 	}
-	forkEntry := enr.WithEntry(eth2ENRKey, enc)
+	forkEntry := enr.WithEntry(eth2EnrKey, enc)
 	node.Set(forkEntry)
 	return nil
 }
@@ -99,7 +160,7 @@ func updateENR(node *enode.LocalNode, entry, next params.NetworkScheduleEntry) e
 // under the Ethereum consensus EnrKey
 func forkEntry(record *enr.Record) (*pb.ENRForkID, error) {
 	sszEncodedForkEntry := make([]byte, 16)
-	entry := enr.WithEntry(eth2ENRKey, &sszEncodedForkEntry)
+	entry := enr.WithEntry(eth2EnrKey, &sszEncodedForkEntry)
 	err := record.Load(entry)
 	if err != nil {
 		return nil, err
@@ -110,3 +171,15 @@ func forkEntry(record *enr.Record) (*pb.ENRForkID, error) {
 	}
 	return forkEntry, nil
 }
+
+// nfd retrieves the value of the `nfd` ("next fork digest") key from an ENR record.
+func nfd(record *enr.Record) [4]byte {
+	digest := [4]byte{}
+	entry := enr.WithEntry(nfdEnrKey, &digest)
+	if err := record.Load(entry); err != nil {
+		// Treat a missing nfd entry as an empty digest.
+		// We do this to avoid errors when checking peers that have not upgraded for fulu.
+		return [4]byte{}
+	}
+	return digest
+}

beacon-chain/p2p/fork_test.go

@@ -16,14 +16,12 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
-	"github.com/sirupsen/logrus"
-	logTest "github.com/sirupsen/logrus/hooks/test"
 )
 
 func TestCompareForkENR(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
+	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().ElectraForkEpoch + 4096
 	params.BeaconConfig().InitializeForkSchedule()
-	logrus.SetLevel(logrus.TraceLevel)
 
 	db, err := enode.OpenDB("")
 	assert.NoError(t, err)
@@ -61,10 +59,10 @@ func TestCompareForkENR(t *testing.T) {
 				require.NoError(t, updateENR(peer, currentCopy, next))
 				return peer.Node()
 			},
-			expectErr: errEth2ENRDigestMismatch,
+			expectErr: errCurrentDigestMismatch,
 		},
 		{
-			name: "next fork version mismatch",
+			name: "next_fork_epoch match, next_fork_version mismatch",
 			node: func(t *testing.T) *enode.Node {
 				// Create a peer with the same current fork digest and next fork version/epoch.
 				peer := enode.NewLocalNode(db, k)
@@ -75,25 +73,44 @@ func TestCompareForkENR(t *testing.T) {
 				require.NoError(t, updateENR(peer, current, nextCopy))
 				return peer.Node()
 			},
-			expectLog: "Peer matches fork digest but has different next fork version",
+			expectErr: errNextVersionMismatch,
 		},
 		{
-			name: "next fork epoch mismatch",
+			name: "next fork epoch mismatch, next fork digest mismatch",
 			node: func(t *testing.T) *enode.Node {
 				// Create a peer with the same current fork digest and next fork version/epoch.
 				peer := enode.NewLocalNode(db, k)
 				nextCopy := next
+				// next epoch does not match, and neither does the next fork digest.
 				nextCopy.Epoch = nextCopy.Epoch + 1
+				nfd := [4]byte{0xFF, 0xFF, 0xFF, 0xFF}
+				require.NotEqual(t, next.ForkDigest, nfd)
+				//peer.Set(enr.WithEntry(nfdEnrKey, nfd[:]))
+				nextCopy.ForkDigest = nfd
 				require.NoError(t, updateENR(peer, current, nextCopy))
 				return peer.Node()
 			},
-			expectLog: "Peer matches fork digest but has different next fork epoch",
+			// no error because we allow a different next fork version / digest if the next fork epoch does not match
+		},
+		{
+			name: "next fork epoch -match-, next fork digest mismatch",
+			node: func(t *testing.T) *enode.Node {
+				peer := enode.NewLocalNode(db, k)
+				nextCopy := next
+				nfd := [4]byte{0xFF, 0xFF, 0xFF, 0xFF}
+				// next epoch *does match*, but the next fork digest doesn't - so we should get an error.
+				require.NotEqual(t, next.ForkDigest, nfd)
+				nextCopy.ForkDigest = nfd
+				//peer.Set(enr.WithEntry(nfdEnrKey, nfd[:]))
+				require.NoError(t, updateENR(peer, current, nextCopy))
+				return peer.Node()
+			},
+			expectErr: errNextDigestMismatch,
 		},
 	}
 
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
-			hook := logTest.NewGlobal()
 			peer := c.node(t)
 			err := compareForkENR(self.Node().Record(), peer.Record())
 			if c.expectErr != nil {
@@ -101,13 +118,27 @@ func TestCompareForkENR(t *testing.T) {
 			} else {
 				require.NoError(t, err, "Expected no error comparing fork ENRs")
 			}
-			if c.expectLog != "" {
-				require.LogsContain(t, hook, c.expectLog, "Expected log message not found")
-			}
 		})
 	}
 }
 
+func TestNfdSetAndLoad(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().ElectraForkEpoch + 4096
+	params.BeaconConfig().InitializeForkSchedule()
+	db, err := enode.OpenDB("")
+	assert.NoError(t, err)
+	_, k := createAddrAndPrivKey(t)
+	clock := startup.NewClock(time.Now(), params.BeaconConfig().GenesisValidatorsRoot)
+	current := params.GetNetworkScheduleEntry(clock.CurrentEpoch())
+	next := params.NextNetworkScheduleEntry(clock.CurrentEpoch())
+	next.ForkDigest = [4]byte{0xFF, 0xFF, 0xFF, 0xFF} // Ensure a unique digest for testing.
+	self := enode.NewLocalNode(db, k)
+	require.NoError(t, updateENR(self, current, next))
+	n := nfd(self.Node().Record())
+	assert.Equal(t, next.ForkDigest, n, "Expected nfd to match next fork digest")
+}
+
 func TestDiscv5_AddRetrieveForkEntryENR(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	params.BeaconConfig().InitializeForkSchedule()
@@ -122,7 +153,7 @@ func TestDiscv5_AddRetrieveForkEntryENR(t *testing.T) {
 	}
 	enc, err := enrForkID.MarshalSSZ()
 	require.NoError(t, err)
-	entry := enr.WithEntry(eth2ENRKey, enc)
+	entry := enr.WithEntry(eth2EnrKey, enc)
 	temp := t.TempDir()
 	randNum := rand.Int()
 	tempPath := path.Join(temp, strconv.Itoa(randNum))
@@ -177,3 +208,111 @@ func TestAddForkEntry_NextForkVersion(t *testing.T) {
 		"Wanted Next Fork Version to be equal to last entry in schedule")
 
 }
+
+func TestUpdateENR_FuluForkDigest(t *testing.T) {
+	setupTest := func(t *testing.T, fuluEnabled bool) (*enode.LocalNode, func()) {
+		params.SetupTestConfigCleanup(t)
+
+		cfg := params.BeaconConfig().Copy()
+		if fuluEnabled {
+			cfg.FuluForkEpoch = 100
+		} else {
+			cfg.FuluForkEpoch = cfg.FarFutureEpoch
+		}
+		cfg.FuluForkVersion = []byte{5, 0, 0, 0}
+		params.OverrideBeaconConfig(cfg)
+		cfg.InitializeForkSchedule()
+
+		pkey, err := privKey(&Config{DataDir: t.TempDir()})
+		require.NoError(t, err, "Could not get private key")
+		db, err := enode.OpenDB("")
+		require.NoError(t, err)
+
+		localNode := enode.NewLocalNode(db, pkey)
+		cleanup := func() {
+			db.Close()
+		}
+
+		return localNode, cleanup
+	}
+
+	tests := []struct {
+		name         string
+		fuluEnabled  bool
+		currentEntry params.NetworkScheduleEntry
+		nextEntry    params.NetworkScheduleEntry
+		validateNFD  func(t *testing.T, localNode *enode.LocalNode, nextEntry params.NetworkScheduleEntry)
+	}{
+		{
+			name:        "different digests sets nfd to next digest",
+			fuluEnabled: true,
+			currentEntry: params.NetworkScheduleEntry{
+				Epoch:       50,
+				ForkDigest:  [4]byte{1, 2, 3, 4},
+				ForkVersion: [4]byte{1, 0, 0, 0},
+			},
+			nextEntry: params.NetworkScheduleEntry{
+				Epoch:       100,
+				ForkDigest:  [4]byte{5, 6, 7, 8}, // Different from current
+				ForkVersion: [4]byte{2, 0, 0, 0},
+			},
+			validateNFD: func(t *testing.T, localNode *enode.LocalNode, nextEntry params.NetworkScheduleEntry) {
+				var nfdValue []byte
+				err := localNode.Node().Record().Load(enr.WithEntry(nfdEnrKey, &nfdValue))
+				require.NoError(t, err)
+				assert.DeepEqual(t, nextEntry.ForkDigest[:], nfdValue, "nfd entry should equal next fork digest")
+			},
+		},
+		{
+			name:        "same digests sets nfd to empty",
+			fuluEnabled: true,
+			currentEntry: params.NetworkScheduleEntry{
+				Epoch:       50,
+				ForkDigest:  [4]byte{1, 2, 3, 4},
+				ForkVersion: [4]byte{1, 0, 0, 0},
+			},
+			nextEntry: params.NetworkScheduleEntry{
+				Epoch:       100,
+				ForkDigest:  [4]byte{1, 2, 3, 4}, // Same as current
+				ForkVersion: [4]byte{2, 0, 0, 0},
+			},
+			validateNFD: func(t *testing.T, localNode *enode.LocalNode, nextEntry params.NetworkScheduleEntry) {
+				var nfdValue []byte
+				err := localNode.Node().Record().Load(enr.WithEntry(nfdEnrKey, &nfdValue))
+				require.NoError(t, err)
+				assert.DeepEqual(t, make([]byte, len(nextEntry.ForkDigest)), nfdValue, "nfd entry should be empty bytes when digests are same")
+			},
+		},
+		{
+			name:        "fulu disabled does not add nfd field",
+			fuluEnabled: false,
+			currentEntry: params.NetworkScheduleEntry{
+				Epoch:       50,
+				ForkDigest:  [4]byte{1, 2, 3, 4},
+				ForkVersion: [4]byte{1, 0, 0, 0},
+			},
+			nextEntry: params.NetworkScheduleEntry{
+				Epoch:       100,
+				ForkDigest:  [4]byte{5, 6, 7, 8}, // Different from current
+				ForkVersion: [4]byte{2, 0, 0, 0},
+			},
+			validateNFD: func(t *testing.T, localNode *enode.LocalNode, nextEntry params.NetworkScheduleEntry) {
+				var nfdValue []byte
+				err := localNode.Node().Record().Load(enr.WithEntry(nfdEnrKey, &nfdValue))
+				require.ErrorContains(t, "missing ENR key", err, "nfd field should not be present when Fulu fork is disabled")
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			localNode, cleanup := setupTest(t, tt.fuluEnabled)
+			defer cleanup()
+
+			currentEntry := tt.currentEntry
+			nextEntry := tt.nextEntry
+			require.NoError(t, updateENR(localNode, currentEntry, nextEntry))
+			tt.validateNFD(t, localNode, nextEntry)
+		})
+	}
+}

beacon-chain/p2p/interfaces.go

@@ -6,6 +6,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -51,7 +52,7 @@ type (
 		BroadcastBlob(ctx context.Context, subnet uint64, blob *ethpb.BlobSidecar) error
 		BroadcastLightClientOptimisticUpdate(ctx context.Context, update interfaces.LightClientOptimisticUpdate) error
 		BroadcastLightClientFinalityUpdate(ctx context.Context, update interfaces.LightClientFinalityUpdate) error
-		BroadcastDataColumn(root [fieldparams.RootLength]byte, columnSubnet uint64, dataColumnSidecar *ethpb.DataColumnSidecar) error
+		BroadcastDataColumnSidecar(columnSubnet uint64, dataColumnSidecar blocks.VerifiedRODataColumn) error
 	}
 
 	// SetStreamHandler configures p2p to handle streams of a certain topic ID.

beacon-chain/p2p/peers/scorers/gossip_scorer_test.go

@@ -42,7 +42,7 @@ func TestScorers_Gossip_Score(t *testing.T) {
 			},
 			check: func(scorer *scorers.GossipScorer) {
 				assert.Equal(t, 10.0, scorer.Score("peer1"), "Unexpected score")
-				assert.Equal(t, nil, scorer.IsBadPeer("peer1"), "Unexpected bad peer")
+				assert.NoError(t, scorer.IsBadPeer("peer1"), "Unexpected bad peer")
 				_, _, topicMap, err := scorer.GossipData("peer1")
 				assert.NoError(t, err)
 				assert.Equal(t, uint64(100), topicMap["a"].TimeInMesh, "incorrect time in mesh")

beacon-chain/p2p/pubsub_filter.go

@@ -10,6 +10,7 @@ import (
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	pubsubpb "github.com/libp2p/go-libp2p-pubsub/pb"
 	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
@@ -40,49 +41,68 @@ func (s *Service) setAllForkDigests() {
 	}
 }
 
+var (
+	errNotReadyToSubscribe         = fmt.Errorf("not ready to subscribe, service is not initialized")
+	errMissingLeadingSlash         = fmt.Errorf("topic is missing leading slash")
+	errTopicMissingProtocolVersion = fmt.Errorf("topic is missing protocol version (eth2)")
+	errTopicPathWrongPartCount     = fmt.Errorf("topic path has wrong part count")
+	errDigestInvalid               = fmt.Errorf("digest is invalid")
+	errDigestUnexpected            = fmt.Errorf("digest is unexpected")
+	errSnappySuffixMissing         = fmt.Errorf("snappy suffix is missing")
+	errTopicNotFound               = fmt.Errorf("topic not found in gossip topic mappings")
+)
+
 // CanSubscribe returns true if the topic is of interest and we could subscribe to it.
 func (s *Service) CanSubscribe(topic string) bool {
-	if !s.isInitialized() {
+	if err := s.checkSubscribable(topic); err != nil {
+		if !errors.Is(err, errNotReadyToSubscribe) {
+			logrus.WithError(err).WithField("topic", topic).Debug("CanSubscribe failed")
+		}
 		return false
 	}
+	return true
+}
+
+func (s *Service) checkSubscribable(topic string) error {
+	if !s.isInitialized() {
+		return errNotReadyToSubscribe
+	}
 	parts := strings.Split(topic, "/")
 	if len(parts) != 5 {
-		return false
+		return errTopicPathWrongPartCount
 	}
 	// The topic must start with a slash, which means the first part will be empty.
 	if parts[0] != "" {
-		return false
+		return errMissingLeadingSlash
 	}
-	if parts[1] != "eth2" {
-		return false
+	protocol, rawDigest, suffix := parts[1], parts[2], parts[4]
+	if protocol != "eth2" {
+		return errTopicMissingProtocolVersion
+	}
+	if suffix != encoder.ProtocolSuffixSSZSnappy {
+		return errSnappySuffixMissing
 	}
 
 	var digest [4]byte
-	dl, err := hex.Decode(digest[:], []byte(parts[2]))
-	if err == nil && dl != 4 {
-		err = fmt.Errorf("expected 4 bytes, got %d", dl)
-	}
+	dl, err := hex.Decode(digest[:], []byte(rawDigest))
 	if err != nil {
-		log.WithError(err).WithField("topic", topic).WithField("digest", parts[2]).Error("CanSubscribe failed to parse message")
-		return false
+		return errors.Wrapf(errDigestInvalid, "%v", err)
+	}
+	if dl != 4 {
+		return errors.Wrapf(errDigestInvalid, "wrong byte length")
 	}
 	if _, ok := s.allForkDigests[digest]; !ok {
-		log.WithField("topic", topic).WithField("digest", fmt.Sprintf("%#x", digest)).Error("CanSubscribe failed to find digest in allForkDigests")
-		return false
-	}
-
-	if parts[4] != encoder.ProtocolSuffixSSZSnappy {
-		return false
+		return errDigestUnexpected
 	}
 
 	// Check the incoming topic matches any topic mapping. This includes a check for part[3].
 	for gt := range gossipTopicMappings {
 		if _, err := scanfcheck(strings.Join(parts[0:4], "/"), gt); err == nil {
-			return true
+			return nil
 		}
 	}
 
-	return false
+	return errTopicNotFound
 }
 
 // FilterIncomingSubscriptions is invoked for all RPCs containing subscription notifications.
@@ -100,7 +120,22 @@ func (s *Service) FilterIncomingSubscriptions(peerID peer.ID, subs []*pubsubpb.R
 		return nil, pubsub.ErrTooManySubscriptions
 	}
 
-	return pubsub.FilterSubscriptions(subs, s.CanSubscribe), nil
+	return pubsub.FilterSubscriptions(subs, s.logCheckSubscribableError(peerID)), nil
+}
+
+func (s *Service) logCheckSubscribableError(pid peer.ID) func(string) bool {
+	return func(topic string) bool {
+		if err := s.checkSubscribable(topic); err != nil {
+			if !errors.Is(err, errNotReadyToSubscribe) {
+				log.WithError(err).WithFields(logrus.Fields{
+					"peerID": pid,
+					"topic":  topic,
+				}).Debug("Peer subscription rejected")
+			}
+			return false
+		}
+		return true
+	}
 }
 
 // scanfcheck uses fmt.Sscanf to check that a given string matches expected format. This method

beacon-chain/p2p/rpc_topic_mappings.go

@@ -169,7 +169,7 @@ var (
 		RPCDataColumnSidecarsByRangeTopicV1: new(pb.DataColumnSidecarsByRangeRequest),
 
 		// DataColumnSidecarsByRoot v1 Message
-		RPCDataColumnSidecarsByRootTopicV1: new(p2ptypes.DataColumnsByRootIdentifiers),
+		RPCDataColumnSidecarsByRootTopicV1: p2ptypes.DataColumnsByRootIdentifiers{},
 	}
 
 	// Maps all registered protocol prefixes.

beacon-chain/p2p/service_test.go

@@ -13,13 +13,13 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
+	testp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	prysmTime "github.com/OffchainLabs/prysm/v6/time"
-	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/libp2p/go-libp2p"
 	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/peer"
@@ -30,48 +30,6 @@ import (
 
 const testPingInterval = 100 * time.Millisecond
 
-type mockListener struct {
-	localNode *enode.LocalNode
-}
-
-func (m mockListener) Self() *enode.Node {
-	return m.localNode.Node()
-}
-
-func (mockListener) Close() {
-	// no-op
-}
-
-func (mockListener) Lookup(enode.ID) []*enode.Node {
-	panic("implement me")
-}
-
-func (mockListener) ReadRandomNodes(_ []*enode.Node) int {
-	panic("implement me")
-}
-
-func (mockListener) Resolve(*enode.Node) *enode.Node {
-	panic("implement me")
-}
-
-func (mockListener) Ping(*enode.Node) error {
-	panic("implement me")
-}
-
-func (mockListener) RequestENR(*enode.Node) (*enode.Node, error) {
-	panic("implement me")
-}
-
-func (mockListener) LocalNode() *enode.LocalNode {
-	panic("implement me")
-}
-
-func (mockListener) RandomNodes() enode.Iterator {
-	panic("implement me")
-}
-
-func (mockListener) RebootListener() error { panic("implement me") }
-
 func createHost(t *testing.T, port uint) (host.Host, *ecdsa.PrivateKey, net.IP) {
 	_, pkey := createAddrAndPrivKey(t)
 	ipAddr := net.ParseIP("127.0.0.1")
@@ -87,7 +45,7 @@ func TestService_Stop_SetsStartedToFalse(t *testing.T) {
 	s, err := NewService(t.Context(), &Config{StateNotifier: &mock.MockStateNotifier{}, DB: testDB.SetupDB(t)})
 	require.NoError(t, err)
 	s.started = true
-	s.dv5Listener = &mockListener{}
+	s.dv5Listener = testp2p.NewMockListener(nil, nil)
 	assert.NoError(t, s.Stop())
 	assert.Equal(t, false, s.started)
 }
@@ -113,7 +71,7 @@ func TestService_Start_OnlyStartsOnce(t *testing.T) {
 	}
 	s, err := NewService(t.Context(), cfg)
 	require.NoError(t, err)
-	s.dv5Listener = &mockListener{}
+	s.dv5Listener = testp2p.NewMockListener(nil, nil)
 	s.custodyInfo = &custodyInfo{}
 	exitRoutine := make(chan bool)
 	go func() {
@@ -133,14 +91,14 @@ func TestService_Start_OnlyStartsOnce(t *testing.T) {
 func TestService_Status_NotRunning(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	s := &Service{started: false}
-	s.dv5Listener = &mockListener{}
+	s.dv5Listener = testp2p.NewMockListener(nil, nil)
 	assert.ErrorContains(t, "not running", s.Status(), "Status returned wrong error")
 }
 
 func TestService_Status_NoGenesisTimeSet(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	s := &Service{started: true}
-	s.dv5Listener = &mockListener{}
+	s.dv5Listener = testp2p.NewMockListener(nil, nil)
 	assert.ErrorContains(t, "no genesis time set", s.Status(), "Status returned wrong error")
 
 	s.genesisTime = time.Now()

beacon-chain/p2p/subnets.go

@@ -134,6 +134,24 @@ func (s *Service) FindAndDialPeersWithSubnets(
 	return nil
 }
 
+// updateDefectiveSubnets updates the defective subnets map when a node with matching subnets is found.
+// It decrements the defective count for each subnet the node satisfies and removes subnets
+// that are fully satisfied (count reaches 0).
+func updateDefectiveSubnets(
+	nodeSubnets map[uint64]bool,
+	defectiveSubnets map[uint64]int,
+) {
+	for subnet := range defectiveSubnets {
+		if !nodeSubnets[subnet] {
+			continue
+		}
+		defectiveSubnets[subnet]--
+		if defectiveSubnets[subnet] == 0 {
+			delete(defectiveSubnets, subnet)
+		}
+	}
+}
+
 // findPeersWithSubnets finds peers subscribed to defective subnets in batches
 // until enough peers are found or the context is canceled.
 // It returns new peers found during the search.
@@ -169,6 +187,7 @@ func (s *Service) findPeersWithSubnets(
 
 	// Crawl the network for peers subscribed to the defective subnets.
 	nodeByNodeID := make(map[enode.ID]*enode.Node)
+
 	for len(defectiveSubnets) > 0 && iterator.Next() {
 		if err := ctx.Err(); err != nil {
 			// Convert the map to a slice.
@@ -180,14 +199,28 @@ func (s *Service) findPeersWithSubnets(
 			return peersToDial, err
 		}
 
-		// Get all needed subnets that the node is subscribed to.
-		// Skip nodes that are not subscribed to any of the defective subnets.
 		node := iterator.Node()
 
+		// Remove duplicates, keeping the node with higher seq.
+		existing, ok := nodeByNodeID[node.ID()]
+		if ok && existing.Seq() >= node.Seq() {
+			continue // keep existing and skip.
+		}
+
+		// Treat nodes that exist in nodeByNodeID with higher seq numbers as new peers
+		// Skip peer not matching the filter.
 		if !s.filterPeer(node) {
+			if ok {
+				// this means the existing peer with the lower sequence number is no longer valid
+				delete(nodeByNodeID, existing.ID())
+				// Note: We are choosing to not rollback changes to the defective subnets map in favor of calling s.defectiveSubnets once again after dialing peers.
+				// This is a case that should rarely happen and should be handled through a second iteration in FindAndDialPeersWithSubnets
+			}
 			continue
 		}
 
+		// Get all needed subnets that the node is subscribed to.
+		// Skip nodes that are not subscribed to any of the defective subnets.
 		nodeSubnets, err := filter(node)
 		if err != nil {
 			return nil, errors.Wrap(err, "filter node")
@@ -196,30 +229,14 @@ func (s *Service) findPeersWithSubnets(
 			continue
 		}
 
-		// Remove duplicates, keeping the node with higher seq.
-		existing, ok := nodeByNodeID[node.ID()]
-		if ok && existing.Seq() > node.Seq() {
-			continue
-		}
-		nodeByNodeID[node.ID()] = node
-
 		// We found a new peer. Modify the defective subnets map
 		// and the filter accordingly.
-		for subnet := range defectiveSubnets {
-			if !nodeSubnets[subnet] {
-				continue
-			}
+		nodeByNodeID[node.ID()] = node
 
-			defectiveSubnets[subnet]--
-
-			if defectiveSubnets[subnet] == 0 {
-				delete(defectiveSubnets, subnet)
-			}
-
-			filter, err = s.nodeFilter(topicFormat, defectiveSubnets)
-			if err != nil {
-				return nil, errors.Wrap(err, "node filter")
-			}
+		updateDefectiveSubnets(nodeSubnets, defectiveSubnets)
+		filter, err = s.nodeFilter(topicFormat, defectiveSubnets)
+		if err != nil {
+			return nil, errors.Wrap(err, "node filter")
 		}
 	}
 

beacon-chain/p2p/subnets_test.go

@@ -10,14 +10,19 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
+	testp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	ecdsaprysm "github.com/OffchainLabs/prysm/v6/crypto/ecdsa"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/prysmaticlabs/go-bitfield"
 )
 
@@ -541,3 +546,552 @@ func TestInitializePersistentSubnets(t *testing.T) {
 	assert.Equal(t, 2, len(subs))
 	assert.Equal(t, true, expTime.After(time.Now()))
 }
+
+func TestFindPeersWithSubnets_NodeDeduplication(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cache.SubnetIDs.EmptyAllCaches()
+	defer cache.SubnetIDs.EmptyAllCaches()
+
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+
+	localNode1 := createTestNodeWithID(t, "node1")
+	localNode2 := createTestNodeWithID(t, "node2")
+	localNode3 := createTestNodeWithID(t, "node3")
+
+	// Create different sequence versions of node1 with subnet 1
+	setNodeSubnets(localNode1, []uint64{1})
+	setNodeSeq(localNode1, 1)
+	node1_seq1_subnet1 := localNode1.Node()
+	setNodeSeq(localNode1, 2)
+	node1_seq2_subnet1 := localNode1.Node() // Same ID, higher seq
+	setNodeSeq(localNode1, 3)
+	node1_seq3_subnet1 := localNode1.Node() // Same ID, even higher seq
+
+	// Node2 with different sequences and subnets
+	setNodeSubnets(localNode2, []uint64{1})
+	node2_seq1_subnet1 := localNode2.Node()
+	setNodeSubnets(localNode2, []uint64{2}) // Different subnet
+	setNodeSeq(localNode2, 2)
+	node2_seq2_subnet2 := localNode2.Node()
+
+	// Node3 with multiple subnets
+	setNodeSubnets(localNode3, []uint64{1, 2})
+	node3_seq1_subnet1_2 := localNode3.Node()
+
+	tests := []struct {
+		name             string
+		nodes            []*enode.Node
+		defectiveSubnets map[uint64]int
+		expectedCount    int
+		description      string
+		eval             func(t *testing.T, result []*enode.Node) // Custom validation function
+	}{
+		{
+			name: "No duplicates - unique nodes with same subnet",
+			nodes: []*enode.Node{
+				node2_seq1_subnet1,
+				node3_seq1_subnet1_2,
+			},
+			defectiveSubnets: map[uint64]int{1: 2},
+			expectedCount:    2,
+			description:      "Should return all unique nodes subscribed to subnet",
+			eval:             nil, // No special validation needed
+		},
+		{
+			name: "Duplicate with lower seq first - should replace",
+			nodes: []*enode.Node{
+				node1_seq1_subnet1,
+				node1_seq2_subnet1, // Higher seq, should replace
+				node2_seq1_subnet1, // Different node to ensure we process enough nodes
+			},
+			defectiveSubnets: map[uint64]int{1: 2}, // Need 2 peers for subnet 1
+			expectedCount:    2,
+			description:      "Should replace with higher seq node for same subnet",
+			eval: func(t *testing.T, result []*enode.Node) {
+				found := false
+				for _, node := range result {
+					if node.ID() == node1_seq2_subnet1.ID() && node.Seq() == node1_seq2_subnet1.Seq() {
+						found = true
+						break
+					}
+				}
+				require.Equal(t, true, found, "Should have node with higher seq")
+			},
+		},
+		{
+			name: "Duplicate with higher seq first - should keep existing",
+			nodes: []*enode.Node{
+				node1_seq3_subnet1, // Higher seq
+				node1_seq2_subnet1, // Lower seq, should be skipped (continue branch)
+				node1_seq1_subnet1, // Even lower seq, should also be skipped (continue branch)
+				node2_seq1_subnet1, // Different node
+			},
+			defectiveSubnets: map[uint64]int{1: 2},
+			expectedCount:    2,
+			description:      "Should keep existing node with higher seq and skip lower seq duplicates",
+			eval: func(t *testing.T, result []*enode.Node) {
+				found := false
+				for _, node := range result {
+					if node.ID() == node1_seq3_subnet1.ID() && node.Seq() == node1_seq3_subnet1.Seq() {
+						found = true
+						break
+					}
+				}
+				require.Equal(t, true, found, "Should have node with highest seq")
+			},
+		},
+		{
+			name: "Multiple updates for same node",
+			nodes: []*enode.Node{
+				node1_seq1_subnet1,
+				node1_seq2_subnet1, // Should replace seq1
+				node1_seq3_subnet1, // Should replace seq2
+				node2_seq1_subnet1, // Different node
+			},
+			defectiveSubnets: map[uint64]int{1: 2},
+			expectedCount:    2,
+			description:      "Should keep updating to highest seq",
+			eval: func(t *testing.T, result []*enode.Node) {
+				found := false
+				for _, node := range result {
+					if node.ID() == node1_seq3_subnet1.ID() && node.Seq() == node1_seq3_subnet1.Seq() {
+						found = true
+						break
+					}
+				}
+				require.Equal(t, true, found, "Should have node with highest seq")
+			},
+		},
+		{
+			name: "Duplicate with equal seq in subnets - should skip",
+			nodes: []*enode.Node{
+				node1_seq2_subnet1, // First occurrence
+				node1_seq2_subnet1, // Same exact node instance, should be skipped (continue branch)
+				node2_seq1_subnet1, // Different node
+			},
+			defectiveSubnets: map[uint64]int{1: 2},
+			expectedCount:    2,
+			description:      "Should skip duplicate with equal sequence number in subnet search",
+			eval: func(t *testing.T, result []*enode.Node) {
+				foundNode1 := false
+				foundNode2 := false
+				node1Count := 0
+				for _, node := range result {
+					if node.ID() == node1_seq2_subnet1.ID() {
+						require.Equal(t, node1_seq2_subnet1.Seq(), node.Seq(), "Node1 should have expected seq")
+						foundNode1 = true
+						node1Count++
+					}
+					if node.ID() == node2_seq1_subnet1.ID() {
+						foundNode2 = true
+					}
+				}
+				require.Equal(t, true, foundNode1, "Should have node1")
+				require.Equal(t, true, foundNode2, "Should have node2")
+				require.Equal(t, 1, node1Count, "Should have exactly one instance of node1")
+			},
+		},
+		{
+			name: "Mix with different subnets",
+			nodes: []*enode.Node{
+				node2_seq1_subnet1,
+				node2_seq2_subnet2, // Higher seq but different subnet
+				node3_seq1_subnet1_2,
+			},
+			defectiveSubnets: map[uint64]int{1: 2, 2: 1},
+			expectedCount:    2, // node2 (latest) and node3
+			description:      "Should handle nodes with different subnet subscriptions",
+			eval:             nil, // Basic count validation is sufficient
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gFlags := new(flags.GlobalFlags)
+			gFlags.MinimumPeersPerSubnet = 1
+			flags.Init(gFlags)
+			defer flags.Init(new(flags.GlobalFlags))
+
+			fakePeer := testp2p.NewTestP2P(t)
+
+			s := &Service{
+				cfg: &Config{
+					MaxPeers: 30,
+					DB:       db,
+				},
+				genesisTime:           time.Now(),
+				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+				peers: peers.NewStatus(ctx, &peers.StatusConfig{
+					PeerLimit:    30,
+					ScorerParams: &scorers.Config{},
+				}),
+				host: fakePeer.BHost,
+			}
+
+			localNode := createTestNodeRandom(t)
+
+			mockIter := testp2p.NewMockIterator(tt.nodes)
+			s.dv5Listener = testp2p.NewMockListener(localNode, mockIter)
+
+			digest, err := s.currentForkDigest()
+			require.NoError(t, err)
+
+			ctxWithTimeout, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
+			defer cancel()
+
+			result, err := s.findPeersWithSubnets(
+				ctxWithTimeout,
+				AttestationSubnetTopicFormat,
+				digest,
+				1,
+				tt.defectiveSubnets,
+			)
+
+			require.NoError(t, err, tt.description)
+			require.Equal(t, tt.expectedCount, len(result), tt.description)
+
+			if tt.eval != nil {
+				tt.eval(t, result)
+			}
+		})
+	}
+}
+
+func TestFindPeersWithSubnets_FilterPeerRemoval(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cache.SubnetIDs.EmptyAllCaches()
+	defer cache.SubnetIDs.EmptyAllCaches()
+
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+
+	localNode1 := createTestNodeWithID(t, "node1")
+	localNode2 := createTestNodeWithID(t, "node2")
+	localNode3 := createTestNodeWithID(t, "node3")
+
+	// Create versions of node1 with subnet 1
+	setNodeSubnets(localNode1, []uint64{1})
+	setNodeSeq(localNode1, 1)
+	node1_seq1_valid_subnet1 := localNode1.Node()
+
+	// Create bad version (higher seq)
+	setNodeSeq(localNode1, 2)
+	node1_seq2_bad_subnet1 := localNode1.Node()
+
+	// Create another valid version
+	setNodeSeq(localNode1, 3)
+	node1_seq3_valid_subnet1 := localNode1.Node()
+
+	// Node2 with subnet 1
+	setNodeSubnets(localNode2, []uint64{1})
+	node2_seq1_valid_subnet1 := localNode2.Node()
+
+	// Node3 with subnet 1 and 2
+	setNodeSubnets(localNode3, []uint64{1, 2})
+	node3_seq1_valid_subnet1_2 := localNode3.Node()
+
+	tests := []struct {
+		name             string
+		nodes            []*enode.Node
+		defectiveSubnets map[uint64]int
+		expectedCount    int
+		description      string
+		eval             func(t *testing.T, result []*enode.Node)
+	}{
+		{
+			name: "Valid node in subnet followed by bad version - should remove",
+			nodes: []*enode.Node{
+				node1_seq1_valid_subnet1, // First add valid node with subnet 1
+				node1_seq2_bad_subnet1,   // Invalid version with higher seq - should delete
+				node2_seq1_valid_subnet1, // Different valid node with subnet 1
+			},
+			defectiveSubnets: map[uint64]int{1: 2}, // Need 2 peers for subnet 1
+			expectedCount:    1,                    // Only node2 should remain
+			description:      "Should remove node from map when bad version arrives, even if it has required subnet",
+			eval: func(t *testing.T, result []*enode.Node) {
+				foundNode1 := false
+				foundNode2 := false
+				for _, node := range result {
+					if node.ID() == node1_seq1_valid_subnet1.ID() {
+						foundNode1 = true
+					}
+					if node.ID() == node2_seq1_valid_subnet1.ID() {
+						foundNode2 = true
+					}
+				}
+				require.Equal(t, false, foundNode1, "Node1 should have been removed despite having subnet")
+				require.Equal(t, true, foundNode2, "Node2 should be present")
+			},
+		},
+		{
+			name: "Bad node with subnet stays bad even with higher seq",
+			nodes: []*enode.Node{
+				node1_seq2_bad_subnet1,   // First bad node - not added
+				node1_seq3_valid_subnet1, // Higher seq but same bad peer ID
+				node2_seq1_valid_subnet1, // Different valid node
+			},
+			defectiveSubnets: map[uint64]int{1: 2},
+			expectedCount:    1, // Only node2 (node1 remains bad)
+			description:      "Bad peer with subnet remains bad even with higher seq",
+			eval: func(t *testing.T, result []*enode.Node) {
+				foundNode1 := false
+				foundNode2 := false
+				for _, node := range result {
+					if node.ID() == node1_seq3_valid_subnet1.ID() {
+						foundNode1 = true
+					}
+					if node.ID() == node2_seq1_valid_subnet1.ID() {
+						foundNode2 = true
+					}
+				}
+				require.Equal(t, false, foundNode1, "Node1 should remain bad despite having subnet")
+				require.Equal(t, true, foundNode2, "Node2 should be present")
+			},
+		},
+		{
+			name: "Mixed valid and bad nodes with subnets",
+			nodes: []*enode.Node{
+				node1_seq1_valid_subnet1,   // Add valid node1 with subnet
+				node2_seq1_valid_subnet1,   // Add valid node2 with subnet
+				node1_seq2_bad_subnet1,     // Invalid update for node1 - should remove
+				node3_seq1_valid_subnet1_2, // Add valid node3 with multiple subnets
+			},
+			defectiveSubnets: map[uint64]int{1: 3}, // Need 3 peers for subnet 1
+			expectedCount:    2,                    // Only node2 and node3 should remain
+			description:      "Should handle removal of nodes with subnets when they become bad",
+			eval: func(t *testing.T, result []*enode.Node) {
+				foundNode1 := false
+				foundNode2 := false
+				foundNode3 := false
+				for _, node := range result {
+					if node.ID() == node1_seq1_valid_subnet1.ID() {
+						foundNode1 = true
+					}
+					if node.ID() == node2_seq1_valid_subnet1.ID() {
+						foundNode2 = true
+					}
+					if node.ID() == node3_seq1_valid_subnet1_2.ID() {
+						foundNode3 = true
+					}
+				}
+				require.Equal(t, false, foundNode1, "Node1 should have been removed")
+				require.Equal(t, true, foundNode2, "Node2 should be present")
+				require.Equal(t, true, foundNode3, "Node3 should be present")
+			},
+		},
+		{
+			name: "Node with subnet marked bad stays bad for all sequences",
+			nodes: []*enode.Node{
+				node1_seq1_valid_subnet1, // Add valid node1 with subnet
+				node1_seq2_bad_subnet1,   // Bad update - should remove and mark bad
+				node1_seq3_valid_subnet1, // Higher seq but still same bad peer ID
+				node2_seq1_valid_subnet1, // Different valid node
+			},
+			defectiveSubnets: map[uint64]int{1: 2},
+			expectedCount:    1, // Only node2 (node1 stays bad)
+			description:      "Once marked bad, subnet peer stays bad for all sequences",
+			eval: func(t *testing.T, result []*enode.Node) {
+				foundNode1 := false
+				foundNode2 := false
+				for _, node := range result {
+					if node.ID() == node1_seq3_valid_subnet1.ID() {
+						foundNode1 = true
+					}
+					if node.ID() == node2_seq1_valid_subnet1.ID() {
+						foundNode2 = true
+					}
+				}
+				require.Equal(t, false, foundNode1, "Node1 should stay bad")
+				require.Equal(t, true, foundNode2, "Node2 should be present")
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Initialize flags for subnet operations
+			gFlags := new(flags.GlobalFlags)
+			gFlags.MinimumPeersPerSubnet = 1
+			flags.Init(gFlags)
+			defer flags.Init(new(flags.GlobalFlags))
+
+			// Create test P2P instance
+			fakePeer := testp2p.NewTestP2P(t)
+
+			// Create mock service
+			s := &Service{
+				cfg: &Config{
+					MaxPeers: 30,
+					DB:       db,
+				},
+				genesisTime:           time.Now(),
+				genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+				peers: peers.NewStatus(ctx, &peers.StatusConfig{
+					PeerLimit:    30,
+					ScorerParams: &scorers.Config{},
+				}),
+				host: fakePeer.BHost,
+			}
+
+			// Mark specific node versions as "bad" to simulate filterPeer failures
+			for _, node := range tt.nodes {
+				if node == node1_seq2_bad_subnet1 {
+					// Get peer ID from the node to mark it as bad
+					peerData, _, _ := convertToAddrInfo(node)
+					if peerData != nil {
+						s.peers.Add(node.Record(), peerData.ID, nil, network.DirUnknown)
+						// Mark as bad peer - this will make filterPeer return false
+						s.peers.Scorers().BadResponsesScorer().Increment(peerData.ID)
+						s.peers.Scorers().BadResponsesScorer().Increment(peerData.ID)
+						s.peers.Scorers().BadResponsesScorer().Increment(peerData.ID)
+					}
+				}
+			}
+
+			localNode := createTestNodeRandom(t)
+
+			mockIter := testp2p.NewMockIterator(tt.nodes)
+			s.dv5Listener = testp2p.NewMockListener(localNode, mockIter)
+
+			digest, err := s.currentForkDigest()
+			require.NoError(t, err)
+
+			ctxWithTimeout, cancel := context.WithTimeout(ctx, 100*time.Millisecond)
+			defer cancel()
+
+			result, err := s.findPeersWithSubnets(
+				ctxWithTimeout,
+				AttestationSubnetTopicFormat,
+				digest,
+				1,
+				tt.defectiveSubnets,
+			)
+
+			require.NoError(t, err, tt.description)
+			require.Equal(t, tt.expectedCount, len(result), tt.description)
+
+			if tt.eval != nil {
+				tt.eval(t, result)
+			}
+		})
+	}
+}
+
+// callbackIterator allows us to execute callbacks at specific points during iteration
+type callbackIteratorForSubnets struct {
+	nodes     []*enode.Node
+	index     int
+	callbacks map[int]func() // map from index to callback function
+}
+
+func (c *callbackIteratorForSubnets) Next() bool {
+	// Execute callback before checking if we can continue (if one exists)
+	if callback, exists := c.callbacks[c.index]; exists {
+		callback()
+	}
+
+	return c.index < len(c.nodes)
+}
+
+func (c *callbackIteratorForSubnets) Node() *enode.Node {
+	if c.index >= len(c.nodes) {
+		return nil
+	}
+
+	node := c.nodes[c.index]
+	c.index++
+	return node
+}
+
+func (c *callbackIteratorForSubnets) Close() {
+	// Nothing to clean up for this simple implementation
+}
+
+func TestFindPeersWithSubnets_received_bad_existing_node(t *testing.T) {
+	// This test successfully triggers delete(nodeByNodeID, node.ID()) in subnets.go by:
+	// 1. Processing node1_seq1 first (passes filterPeer, gets added to map
+	// 2. Callback marks peer as bad before processing node1_seq2"
+	// 3. Processing node1_seq2 (fails filterPeer, triggers delete since ok=true
+	params.SetupTestConfigCleanup(t)
+	cache.SubnetIDs.EmptyAllCaches()
+	defer cache.SubnetIDs.EmptyAllCaches()
+
+	ctx := context.Background()
+	db := testDB.SetupDB(t)
+
+	// Create LocalNode with same ID but different sequences
+	localNode1 := createTestNodeWithID(t, "testnode")
+	setNodeSubnets(localNode1, []uint64{1})
+	node1_seq1 := localNode1.Node() // Get current node
+	currentSeq := node1_seq1.Seq()
+	setNodeSeq(localNode1, currentSeq+1) // Increment sequence by 1
+	node1_seq2 := localNode1.Node()      // This should have higher seq
+
+	// Additional node to ensure we have enough peers to process
+	localNode2 := createTestNodeWithID(t, "othernode")
+	setNodeSubnets(localNode2, []uint64{1})
+	node2 := localNode2.Node()
+
+	gFlags := new(flags.GlobalFlags)
+	gFlags.MinimumPeersPerSubnet = 1
+	flags.Init(gFlags)
+	defer flags.Init(new(flags.GlobalFlags))
+
+	fakePeer := testp2p.NewTestP2P(t)
+
+	service := &Service{
+		cfg: &Config{
+			MaxPeers: 30,
+			DB:       db,
+		},
+		genesisTime:           time.Now(),
+		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		peers: peers.NewStatus(ctx, &peers.StatusConfig{
+			PeerLimit:    30,
+			ScorerParams: &scorers.Config{},
+		}),
+		host: fakePeer.BHost,
+	}
+
+	// Create iterator with callback that marks peer as bad before processing node1_seq2
+	iter := &callbackIteratorForSubnets{
+		nodes: []*enode.Node{node1_seq1, node1_seq2, node2},
+		index: 0,
+		callbacks: map[int]func(){
+			1: func() { // Before processing node1_seq2 (index 1)
+				// Mark peer as bad before processing node1_seq2
+				peerData, _, _ := convertToAddrInfo(node1_seq2)
+				if peerData != nil {
+					service.peers.Add(node1_seq2.Record(), peerData.ID, nil, network.DirUnknown)
+					// Mark as bad peer - need enough increments to exceed threshold (6)
+					for i := 0; i < 10; i++ {
+						service.peers.Scorers().BadResponsesScorer().Increment(peerData.ID)
+					}
+				}
+			},
+		},
+	}
+
+	localNode := createTestNodeRandom(t)
+	service.dv5Listener = testp2p.NewMockListener(localNode, iter)
+
+	digest, err := service.currentForkDigest()
+	require.NoError(t, err)
+
+	// Run findPeersWithSubnets - node1_seq1 gets processed first, then callback marks peer bad, then node1_seq2 fails
+	ctxWithTimeout, cancel := context.WithTimeout(ctx, 1*time.Second)
+	defer cancel()
+
+	result, err := service.findPeersWithSubnets(
+		ctxWithTimeout,
+		AttestationSubnetTopicFormat,
+		digest,
+		1,
+		map[uint64]int{1: 2}, // Need 2 peers for subnet 1
+	)
+
+	require.NoError(t, err)
+	require.Equal(t, 1, len(result))
+	require.Equal(t, localNode2.Node().ID(), result[0].ID()) // only node2 should remain
+}

beacon-chain/p2p/testing/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "fuzz_p2p.go",
         "mock_broadcaster.go",
         "mock_host.go",
+        "mock_listener.go",
         "mock_metadataprovider.go",
         "mock_peermanager.go",
         "mock_peersprovider.go",
@@ -24,6 +25,7 @@ go_library(
         "//beacon-chain/p2p/peers/scorers:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",

beacon-chain/p2p/testing/fuzz_p2p.go

@@ -6,6 +6,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/encoder"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -167,8 +168,8 @@ func (*FakeP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfac
 	return nil
 }
 
-// BroadcastDataColumn -- fake.
-func (*FakeP2P) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
+// BroadcastDataColumnSidecar -- fake.
+func (*FakeP2P) BroadcastDataColumnSidecar(_ uint64, _ blocks.VerifiedRODataColumn) error {
 	return nil
 }
 

beacon-chain/p2p/testing/mock_broadcaster.go

@@ -5,7 +5,7 @@ import (
 	"sync"
 	"sync/atomic"
 
-	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"google.golang.org/protobuf/proto"
@@ -62,8 +62,8 @@ func (m *MockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
-// BroadcastDataColumn broadcasts a data column for mock.
-func (m *MockBroadcaster) BroadcastDataColumn([fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar) error {
+// BroadcastDataColumnSidecar broadcasts a data column for mock.
+func (m *MockBroadcaster) BroadcastDataColumnSidecar(uint64, blocks.VerifiedRODataColumn) error {
 	m.BroadcastCalled.Store(true)
 	return nil
 }

beacon-chain/p2p/testing/mock_listener.go

@@ -0,0 +1,128 @@
+package testing
+
+import (
+	"github.com/ethereum/go-ethereum/p2p/enode"
+)
+
+// MockListener is a mock implementation of the Listener and ListenerRebooter interfaces
+// that can be used in tests. It provides configurable behavior for all methods.
+type MockListener struct {
+	LocalNodeFunc   func() *enode.LocalNode
+	SelfFunc        func() *enode.Node
+	RandomNodesFunc func() enode.Iterator
+	LookupFunc      func(enode.ID) []*enode.Node
+	ResolveFunc     func(*enode.Node) *enode.Node
+	PingFunc        func(*enode.Node) error
+	RequestENRFunc  func(*enode.Node) (*enode.Node, error)
+	RebootFunc      func() error
+	CloseFunc       func()
+
+	// Default implementations
+	localNode *enode.LocalNode
+	iterator  enode.Iterator
+}
+
+// NewMockListener creates a new MockListener with default implementations
+func NewMockListener(localNode *enode.LocalNode, iterator enode.Iterator) *MockListener {
+	return &MockListener{
+		localNode: localNode,
+		iterator:  iterator,
+	}
+}
+
+func (m *MockListener) LocalNode() *enode.LocalNode {
+	if m.LocalNodeFunc != nil {
+		return m.LocalNodeFunc()
+	}
+	return m.localNode
+}
+
+func (m *MockListener) Self() *enode.Node {
+	if m.SelfFunc != nil {
+		return m.SelfFunc()
+	}
+	if m.localNode != nil {
+		return m.localNode.Node()
+	}
+	return nil
+}
+
+func (m *MockListener) RandomNodes() enode.Iterator {
+	if m.RandomNodesFunc != nil {
+		return m.RandomNodesFunc()
+	}
+	return m.iterator
+}
+
+func (m *MockListener) Lookup(id enode.ID) []*enode.Node {
+	if m.LookupFunc != nil {
+		return m.LookupFunc(id)
+	}
+	return nil
+}
+
+func (m *MockListener) Resolve(node *enode.Node) *enode.Node {
+	if m.ResolveFunc != nil {
+		return m.ResolveFunc(node)
+	}
+	return nil
+}
+
+func (m *MockListener) Ping(node *enode.Node) error {
+	if m.PingFunc != nil {
+		return m.PingFunc(node)
+	}
+	return nil
+}
+
+func (m *MockListener) RequestENR(node *enode.Node) (*enode.Node, error) {
+	if m.RequestENRFunc != nil {
+		return m.RequestENRFunc(node)
+	}
+	return nil, nil
+}
+
+func (m *MockListener) RebootListener() error {
+	if m.RebootFunc != nil {
+		return m.RebootFunc()
+	}
+	return nil
+}
+
+func (m *MockListener) Close() {
+	if m.CloseFunc != nil {
+		m.CloseFunc()
+	}
+}
+
+// MockIterator is a mock implementation of enode.Iterator for testing
+type MockIterator struct {
+	Nodes    []*enode.Node
+	Position int
+	Closed   bool
+}
+
+func NewMockIterator(nodes []*enode.Node) *MockIterator {
+	return &MockIterator{
+		Nodes: nodes,
+	}
+}
+
+func (m *MockIterator) Next() bool {
+	if m.Closed || m.Position >= len(m.Nodes) {
+		return false
+	}
+	m.Position++
+	return true
+}
+
+func (m *MockIterator) Node() *enode.Node {
+	if m.Position == 0 || m.Position > len(m.Nodes) {
+		return nil
+	}
+	return m.Nodes[m.Position-1]
+}
+
+func (m *MockIterator) Close() {
+	m.Closed = true
+}

beacon-chain/p2p/testing/p2p.go

@@ -17,6 +17,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
@@ -63,6 +64,7 @@ type TestP2P struct {
 	custodyInfoMut        sync.RWMutex // protects custodyGroupCount and earliestAvailableSlot
 	earliestAvailableSlot primitives.Slot
 	custodyGroupCount     uint64
+	enr                   *enr.Record
 }
 
 // NewTestP2P initializes a new p2p test service.
@@ -103,6 +105,7 @@ func NewTestP2P(t *testing.T, userOptions ...config.Option) *TestP2P {
 		pubsub:       ps,
 		joinedTopics: map[string]*pubsub.Topic{},
 		peers:        peerStatuses,
+		enr:          new(enr.Record),
 	}
 }
 
@@ -228,8 +231,8 @@ func (p *TestP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interf
 	return nil
 }
 
-// BroadcastDataColumn broadcasts a data column for mock.
-func (p *TestP2P) BroadcastDataColumn([fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar) error {
+// BroadcastDataColumnSidecar broadcasts a data column for mock.
+func (p *TestP2P) BroadcastDataColumnSidecar(uint64, blocks.VerifiedRODataColumn) error {
 	p.BroadcastCalled.Store(true)
 	return nil
 }
@@ -310,8 +313,8 @@ func (p *TestP2P) Host() host.Host {
 }
 
 // ENR returns the enr of the local peer.
-func (*TestP2P) ENR() *enr.Record {
-	return new(enr.Record)
+func (p *TestP2P) ENR() *enr.Record {
+	return p.enr
 }
 
 // NodeID returns the node id of the local peer.

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

@@ -18,6 +18,7 @@ go_library(
         "//api/server:go_default_library",
         "//api/server/structs:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/altair:go_default_library",
@@ -60,7 +61,6 @@ go_library(
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
-        "@com_github_ethereum_go_ethereum//crypto/kzg4844:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
@@ -72,6 +72,7 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "handlers_equivocation_test.go",
         "handlers_pool_test.go",
         "handlers_state_test.go",
         "handlers_test.go",
@@ -83,6 +84,7 @@ go_test(
         "//api:go_default_library",
         "//api/server:go_default_library",
         "//api/server/structs:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
@@ -123,7 +125,6 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "//time/slots:go_default_library",
-        "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",

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

@@ -13,6 +13,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/api"
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	corehelpers "github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
@@ -32,7 +33,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/ethereum/go-ethereum/crypto/kzg4844"
 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/sirupsen/logrus"
@@ -701,7 +701,7 @@ func (s *Server) publishBlockSSZ(ctx context.Context, w http.ResponseWriter, r *
 	// Validate and optionally broadcast sidecars on equivocation.
 	if err := s.validateBroadcast(ctx, r, genericBlock); err != nil {
 		if errors.Is(err, errEquivocatedBlock) {
-			b, err := blocks.NewSignedBeaconBlock(genericBlock)
+			b, err := blocks.NewSignedBeaconBlock(genericBlock.Block)
 			if err != nil {
 				httputil.HandleError(w, err.Error(), http.StatusBadRequest)
 				return
@@ -855,7 +855,7 @@ func (s *Server) publishBlock(ctx context.Context, w http.ResponseWriter, r *htt
 	// Validate and optionally broadcast sidecars on equivocation.
 	if err := s.validateBroadcast(ctx, r, genericBlock); err != nil {
 		if errors.Is(err, errEquivocatedBlock) {
-			b, err := blocks.NewSignedBeaconBlock(genericBlock)
+			b, err := blocks.NewSignedBeaconBlock(genericBlock.Block)
 			if err != nil {
 				httputil.HandleError(w, err.Error(), http.StatusBadRequest)
 				return
@@ -942,14 +942,13 @@ func decodePhase0JSON(body []byte) (*eth.GenericSignedBeaconBlock, error) {
 // broadcastSidecarsIfSupported broadcasts blob sidecars when an equivocated block occurs.
 func broadcastSidecarsIfSupported(ctx context.Context, s *Server, b interfaces.SignedBeaconBlock, gb *eth.GenericSignedBeaconBlock, versionHeader string) error {
 	switch versionHeader {
-	case version.String(version.Fulu):
-		return s.broadcastSeenBlockSidecars(ctx, b, gb.GetFulu().Blobs, gb.GetFulu().KzgProofs)
 	case version.String(version.Electra):
 		return s.broadcastSeenBlockSidecars(ctx, b, gb.GetElectra().Blobs, gb.GetElectra().KzgProofs)
 	case version.String(version.Deneb):
 		return s.broadcastSeenBlockSidecars(ctx, b, gb.GetDeneb().Blobs, gb.GetDeneb().KzgProofs)
 	default:
 		// other forks before Deneb do not support blob sidecars
+		// forks after fulu do not support blob sidecars, instead support data columns, no need to rebroadcast
 		return nil
 	}
 }
@@ -1053,7 +1052,7 @@ func (s *Server) validateConsensus(ctx context.Context, b *eth.GenericSignedBeac
 		return nil
 	}
 
-	if err := s.validateBlobSidecars(blk, blobs, proofs); err != nil {
+	if err := s.validateBlobs(blk, blobs, proofs); err != nil {
 		return err
 	}
 
@@ -1067,23 +1066,41 @@ func (s *Server) validateEquivocation(blk interfaces.ReadOnlyBeaconBlock) error
 	return nil
 }
 
-func (s *Server) validateBlobSidecars(blk interfaces.SignedBeaconBlock, blobs [][]byte, proofs [][]byte) error {
+func (s *Server) validateBlobs(blk interfaces.SignedBeaconBlock, blobs [][]byte, proofs [][]byte) error {
 	if blk.Version() < version.Deneb {
 		return nil
 	}
-	kzgs, err := blk.Block().Body().BlobKzgCommitments()
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	commitments, err := blk.Block().Body().BlobKzgCommitments()
 	if err != nil {
 		return errors.Wrap(err, "could not get blob kzg commitments")
 	}
-	if len(blobs) != len(proofs) || len(blobs) != len(kzgs) {
-		return errors.New("number of blobs, proofs, and commitments do not match")
+	maxBlobsPerBlock := params.BeaconConfig().MaxBlobsPerBlock(blk.Block().Slot())
+	if len(blobs) > maxBlobsPerBlock {
+		return fmt.Errorf("number of blobs over max, %d > %d", len(blobs), maxBlobsPerBlock)
 	}
-	for i, blob := range blobs {
-		b := kzg4844.Blob(blob)
-		if err := kzg4844.VerifyBlobProof(&b, kzg4844.Commitment(kzgs[i]), kzg4844.Proof(proofs[i])); err != nil {
-			return errors.Wrap(err, "could not verify blob proof")
+	if blk.Version() >= version.Fulu {
+		// For Fulu blocks, proofs are cell proofs (blobs * numberOfColumns)
+		expectedProofsCount := uint64(len(blobs)) * numberOfColumns
+		if uint64(len(proofs)) != expectedProofsCount || len(blobs) != len(commitments) {
+			return fmt.Errorf("number of blobs (%d), cell proofs (%d), and commitments (%d) do not match (expected %d cell proofs)", len(blobs), len(proofs), len(commitments), expectedProofsCount)
+		}
+		// For Fulu blocks, proofs are cell proofs from execution client's BlobsBundleV2
+		// Verify cell proofs directly without reconstructing data column sidecars
+		if err := kzg.VerifyCellKZGProofBatchFromBlobData(blobs, commitments, proofs, numberOfColumns); err != nil {
+			return errors.Wrap(err, "could not verify cell proofs")
+		}
+	} else {
+		// For pre-Fulu blocks, proofs are blob proofs (1:1 with blobs)
+		if len(blobs) != len(proofs) || len(blobs) != len(commitments) {
+			return errors.Errorf("number of blobs (%d), proofs (%d), and commitments (%d) do not match", len(blobs), len(proofs), len(commitments))
+		}
+		// Use batch verification for better performance
+		if err := kzg.VerifyBlobKZGProofBatch(blobs, commitments, proofs); err != nil {
+			return errors.Wrap(err, "could not verify blob proofs")
 		}
 	}
+
 	return nil
 }
 
@@ -1220,7 +1237,7 @@ func (s *Server) GetStateFork(w http.ResponseWriter, r *http.Request) {
 	fork := st.Fork()
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status"+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1331,7 +1348,7 @@ func (s *Server) GetCommittees(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 
@@ -1512,7 +1529,7 @@ func (s *Server) GetFinalityCheckpoints(w http.ResponseWriter, r *http.Request)
 	}
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1627,6 +1644,8 @@ func (s *Server) broadcastSeenBlockSidecars(
 	if err != nil {
 		return err
 	}
+
+	// Broadcast blob sidecars with forkchoice checking
 	for _, sc := range scs {
 		r, err := sc.SignedBlockHeader.Header.HashTreeRoot()
 		if err != nil {
@@ -1686,7 +1705,7 @@ func (s *Server) GetPendingConsolidations(w http.ResponseWriter, r *http.Request
 	} else {
 		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 		if err != nil {
-			httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1742,7 +1761,7 @@ func (s *Server) GetPendingDeposits(w http.ResponseWriter, r *http.Request) {
 	} else {
 		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 		if err != nil {
-			httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1798,7 +1817,7 @@ func (s *Server) GetPendingPartialWithdrawals(w http.ResponseWriter, r *http.Req
 	} else {
 		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 		if err != nil {
-			httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -1851,7 +1870,7 @@ func (s *Server) GetProposerLookahead(w http.ResponseWriter, r *http.Request) {
 	} else {
 		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 		if err != nil {
-			httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+			helpers.HandleIsOptimisticError(w, err)
 			return
 		}
 		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()

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

@@ -0,0 +1,35 @@
+package beacon
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/api/server/structs"
+	rpctesting "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared/testing"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+// TestBlocks_NewSignedBeaconBlock_EquivocationFix tests that blocks.NewSignedBeaconBlock
+// correctly handles the fixed case where genericBlock.Block is passed instead of genericBlock
+func TestBlocks_NewSignedBeaconBlock_EquivocationFix(t *testing.T) {
+	// Parse the Phase0 JSON block
+	var block structs.SignedBeaconBlock
+	err := json.Unmarshal([]byte(rpctesting.Phase0Block), &block)
+	require.NoError(t, err)
+	
+	// Convert to generic format
+	genericBlock, err := block.ToGeneric()
+	require.NoError(t, err)
+	
+	// Test the FIX: pass genericBlock.Block instead of genericBlock
+	// This is what our fix changed in handlers.go line 704 and 858
+	_, err = blocks.NewSignedBeaconBlock(genericBlock.Block)
+	require.NoError(t, err, "NewSignedBeaconBlock should work with genericBlock.Block")
+	
+	// Test the BROKEN version: pass genericBlock directly (this should fail)
+	_, err = blocks.NewSignedBeaconBlock(genericBlock)
+	if err == nil {
+		t.Errorf("NewSignedBeaconBlock should fail with whole genericBlock but succeeded")
+	}
+}

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

@@ -56,7 +56,7 @@ func (s *Server) GetStateRoot(w http.ResponseWriter, r *http.Request) {
 	}
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -125,7 +125,7 @@ func (s *Server) GetRandao(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 
@@ -227,7 +227,7 @@ func (s *Server) GetSyncCommittees(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 

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

@@ -14,6 +14,7 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/api"
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	chainMock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache/depositsnapshot"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
@@ -40,7 +41,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
-	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
@@ -4781,25 +4781,329 @@ func TestServer_broadcastBlobSidecars(t *testing.T) {
 	require.LogsContain(t, hook, "Broadcasted blob sidecar for already seen block")
 }
 
-func Test_validateBlobSidecars(t *testing.T) {
+func Test_validateBlobs(t *testing.T) {
+	require.NoError(t, kzg.Start())
+
 	blob := util.GetRandBlob(123)
-	commitment := GoKZG.KZGCommitment{180, 218, 156, 194, 59, 20, 10, 189, 186, 254, 132, 93, 7, 127, 104, 172, 238, 240, 237, 70, 83, 89, 1, 152, 99, 0, 165, 65, 143, 62, 20, 215, 230, 14, 205, 95, 28, 245, 54, 25, 160, 16, 178, 31, 232, 207, 38, 85}
-	proof := GoKZG.KZGProof{128, 110, 116, 170, 56, 111, 126, 87, 229, 234, 211, 42, 110, 150, 129, 206, 73, 142, 167, 243, 90, 149, 240, 240, 236, 204, 143, 182, 229, 249, 81, 27, 153, 171, 83, 70, 144, 250, 42, 1, 188, 215, 71, 235, 30, 7, 175, 86}
+	// Generate proper commitment and proof for the blob
+	var kzgBlob kzg.Blob
+	copy(kzgBlob[:], blob[:])
+	commitment, err := kzg.BlobToKZGCommitment(&kzgBlob)
+	require.NoError(t, err)
+	proof, err := kzg.ComputeBlobKZGProof(&kzgBlob, commitment)
+	require.NoError(t, err)
 	blk := util.NewBeaconBlockDeneb()
 	blk.Block.Body.BlobKzgCommitments = [][]byte{commitment[:]}
 	b, err := blocks.NewSignedBeaconBlock(blk)
 	require.NoError(t, err)
 	s := &Server{}
-	require.NoError(t, s.validateBlobSidecars(b, [][]byte{blob[:]}, [][]byte{proof[:]}))
+	require.NoError(t, s.validateBlobs(b, [][]byte{blob[:]}, [][]byte{proof[:]}))
 
-	require.ErrorContains(t, "number of blobs, proofs, and commitments do not match", s.validateBlobSidecars(b, [][]byte{blob[:]}, [][]byte{}))
+	require.ErrorContains(t, "number of blobs (1), proofs (0), and commitments (1) do not match", s.validateBlobs(b, [][]byte{blob[:]}, [][]byte{}))
 
 	sk, err := bls.RandKey()
 	require.NoError(t, err)
 	blk.Block.Body.BlobKzgCommitments = [][]byte{sk.PublicKey().Marshal()}
 	b, err = blocks.NewSignedBeaconBlock(blk)
 	require.NoError(t, err)
-	require.ErrorContains(t, "could not verify blob proof: can't verify opening proof", s.validateBlobSidecars(b, [][]byte{blob[:]}, [][]byte{proof[:]}))
+	require.ErrorContains(t, "could not verify blob proofs", s.validateBlobs(b, [][]byte{blob[:]}, [][]byte{proof[:]}))
+
+	blobs := [][]byte{}
+	commitments := [][]byte{}
+	proofs := [][]byte{}
+	for i := 0; i < 10; i++ {
+		blobs = append(blobs, blob[:])
+		commitments = append(commitments, commitment[:])
+		proofs = append(proofs, proof[:])
+	}
+	t.Run("pre-Deneb block should return early", func(t *testing.T) {
+		// Create a pre-Deneb block (e.g., Capella)
+		blk := util.NewBeaconBlockCapella()
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		s := &Server{}
+		// Should return nil for pre-Deneb blocks regardless of blobs
+		require.NoError(t, s.validateBlobs(b, [][]byte{}, [][]byte{}))
+		require.NoError(t, s.validateBlobs(b, blobs[:1], proofs[:1]))
+	})
+
+	t.Run("Deneb block with valid single blob", func(t *testing.T) {
+		blk := util.NewBeaconBlockDeneb()
+		blk.Block.Body.BlobKzgCommitments = [][]byte{commitment[:]}
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		s := &Server{}
+		require.NoError(t, s.validateBlobs(b, [][]byte{blob[:]}, [][]byte{proof[:]}))
+	})
+
+	t.Run("Deneb block with max blobs (6)", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 100
+		testCfg.DeprecatedMaxBlobsPerBlock = 6
+		params.OverrideBeaconConfig(testCfg)
+
+		blk := util.NewBeaconBlockDeneb()
+		blk.Block.Slot = 10 // Deneb slot
+		blk.Block.Body.BlobKzgCommitments = commitments[:6]
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		s := &Server{}
+		// Should pass with exactly 6 blobs
+		require.NoError(t, s.validateBlobs(b, blobs[:6], proofs[:6]))
+	})
+
+	t.Run("Deneb block exceeding max blobs", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 100
+		testCfg.DeprecatedMaxBlobsPerBlock = 6
+		params.OverrideBeaconConfig(testCfg)
+
+		blk := util.NewBeaconBlockDeneb()
+		blk.Block.Slot = 10 // Deneb slot
+		blk.Block.Body.BlobKzgCommitments = commitments[:7]
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		s := &Server{}
+		// Should fail with 7 blobs when max is 6
+		err = s.validateBlobs(b, blobs[:7], proofs[:7])
+		require.ErrorContains(t, "number of blobs over max, 7 > 6", err)
+	})
+
+	t.Run("Electra block with valid blobs", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		// Set up Electra config with max 9 blobs
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 5
+		testCfg.DeprecatedMaxBlobsPerBlock = 6
+		testCfg.DeprecatedMaxBlobsPerBlockElectra = 9
+		params.OverrideBeaconConfig(testCfg)
+
+		blk := util.NewBeaconBlockElectra()
+		blk.Block.Slot = 160 // Electra slot (epoch 5+)
+		blk.Block.Body.BlobKzgCommitments = commitments[:9]
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		s := &Server{}
+		// Should pass with 9 blobs in Electra
+		require.NoError(t, s.validateBlobs(b, blobs[:9], proofs[:9]))
+	})
+
+	t.Run("Electra block exceeding max blobs", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		// Set up Electra config with max 9 blobs
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 5
+		testCfg.DeprecatedMaxBlobsPerBlock = 6
+		testCfg.DeprecatedMaxBlobsPerBlockElectra = 9
+		params.OverrideBeaconConfig(testCfg)
+
+		blk := util.NewBeaconBlockElectra()
+		blk.Block.Slot = 160 // Electra slot
+		blk.Block.Body.BlobKzgCommitments = commitments[:10]
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+		s := &Server{}
+		// Should fail with 10 blobs when max is 9
+		err = s.validateBlobs(b, blobs[:10], proofs[:10])
+		require.ErrorContains(t, "number of blobs over max, 10 > 9", err)
+	})
+
+	t.Run("Fulu block with valid cell proofs", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 5
+		testCfg.FuluForkEpoch = 10
+		testCfg.DeprecatedMaxBlobsPerBlock = 6
+		testCfg.DeprecatedMaxBlobsPerBlockElectra = 9
+		testCfg.NumberOfColumns = 128 // Standard PeerDAS configuration
+		params.OverrideBeaconConfig(testCfg)
+
+		// Create Fulu block with proper cell proofs
+		blk := util.NewBeaconBlockFulu()
+		blk.Block.Slot = 320 // Epoch 10 (Fulu fork)
+
+		// Generate valid commitments and cell proofs for testing
+		blobCount := 2
+		commitments := make([][]byte, blobCount)
+		fuluBlobs := make([][]byte, blobCount)
+		var kzgBlobs []kzg.Blob
+
+		for i := 0; i < blobCount; i++ {
+			blob := util.GetRandBlob(int64(i))
+			fuluBlobs[i] = blob[:]
+			var kzgBlob kzg.Blob
+			copy(kzgBlob[:], blob[:])
+			kzgBlobs = append(kzgBlobs, kzgBlob)
+
+			// Generate commitment
+			commitment, err := kzg.BlobToKZGCommitment(&kzgBlob)
+			require.NoError(t, err)
+			commitments[i] = commitment[:]
+		}
+
+		blk.Block.Body.BlobKzgCommitments = commitments
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+
+		// Generate cell proofs for the blobs (flattened format like execution client)
+		numberOfColumns := params.BeaconConfig().NumberOfColumns
+		cellProofs := make([][]byte, uint64(blobCount)*numberOfColumns)
+		for blobIdx := 0; blobIdx < blobCount; blobIdx++ {
+			cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlobs[blobIdx])
+			require.NoError(t, err)
+
+			for colIdx := uint64(0); colIdx < numberOfColumns; colIdx++ {
+				cellProofIdx := uint64(blobIdx)*numberOfColumns + colIdx
+				cellProofs[cellProofIdx] = cellsAndProofs.Proofs[colIdx][:]
+			}
+		}
+
+		s := &Server{}
+		// Should use cell batch verification for Fulu blocks
+		require.NoError(t, s.validateBlobs(b, fuluBlobs, cellProofs))
+	})
+
+	t.Run("Fulu block with invalid cell proof count", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 5
+		testCfg.FuluForkEpoch = 10
+		testCfg.NumberOfColumns = 128
+		params.OverrideBeaconConfig(testCfg)
+
+		blk := util.NewBeaconBlockFulu()
+		blk.Block.Slot = 320 // Epoch 10 (Fulu fork)
+
+		// Create valid commitments but wrong number of cell proofs
+		blobCount := 2
+		commitments := make([][]byte, blobCount)
+		fuluBlobs := make([][]byte, blobCount)
+		for i := 0; i < blobCount; i++ {
+			blob := util.GetRandBlob(int64(i))
+			fuluBlobs[i] = blob[:]
+
+			var kzgBlob kzg.Blob
+			copy(kzgBlob[:], blob[:])
+			commitment, err := kzg.BlobToKZGCommitment(&kzgBlob)
+			require.NoError(t, err)
+			commitments[i] = commitment[:]
+		}
+
+		blk.Block.Body.BlobKzgCommitments = commitments
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+
+		// Wrong number of cell proofs (should be blobCount * numberOfColumns)
+		wrongCellProofs := make([][]byte, 10) // Too few proofs
+
+		s := &Server{}
+		err = s.validateBlobs(b, fuluBlobs, wrongCellProofs)
+		require.ErrorContains(t, "do not match", err)
+	})
+
+	t.Run("Deneb block with invalid blob proof", func(t *testing.T) {
+		blob := util.GetRandBlob(123)
+		invalidProof := make([]byte, 48) // All zeros - invalid proof
+
+		sk, err := bls.RandKey()
+		require.NoError(t, err)
+
+		blk := util.NewBeaconBlockDeneb()
+		blk.Block.Body.BlobKzgCommitments = [][]byte{sk.PublicKey().Marshal()}
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+
+		s := &Server{}
+		err = s.validateBlobs(b, [][]byte{blob[:]}, [][]byte{invalidProof})
+		require.ErrorContains(t, "could not verify blob proofs", err)
+	})
+
+	t.Run("empty blobs and proofs should pass", func(t *testing.T) {
+		blk := util.NewBeaconBlockDeneb()
+		blk.Block.Body.BlobKzgCommitments = [][]byte{}
+		b, err := blocks.NewSignedBeaconBlock(blk)
+		require.NoError(t, err)
+
+		s := &Server{}
+		require.NoError(t, s.validateBlobs(b, [][]byte{}, [][]byte{}))
+	})
+
+	t.Run("BlobSchedule with progressive increases (BPO)", func(t *testing.T) {
+		cfg := params.BeaconConfig().Copy()
+		defer params.OverrideBeaconConfig(cfg)
+
+		// Set up config with BlobSchedule (BPO - Blob Production Optimization)
+		testCfg := params.BeaconConfig().Copy()
+		testCfg.DenebForkEpoch = 0
+		testCfg.ElectraForkEpoch = 100
+		testCfg.FuluForkEpoch = 200
+		testCfg.DeprecatedMaxBlobsPerBlock = 6
+		testCfg.DeprecatedMaxBlobsPerBlockElectra = 9
+		// Define blob schedule with progressive increases
+		testCfg.BlobSchedule = []params.BlobScheduleEntry{
+			{Epoch: 0, MaxBlobsPerBlock: 3},  // Start with 3 blobs
+			{Epoch: 10, MaxBlobsPerBlock: 5}, // Increase to 5 at epoch 10
+			{Epoch: 20, MaxBlobsPerBlock: 7}, // Increase to 7 at epoch 20
+			{Epoch: 30, MaxBlobsPerBlock: 9}, // Increase to 9 at epoch 30
+		}
+		params.OverrideBeaconConfig(testCfg)
+
+		s := &Server{}
+
+		// Test epoch 0-9: max 3 blobs
+		t.Run("epoch 0-9: max 3 blobs", func(t *testing.T) {
+			blk := util.NewBeaconBlockDeneb()
+			blk.Block.Slot = 5 // Epoch 0
+			blk.Block.Body.BlobKzgCommitments = commitments[:3]
+			b, err := blocks.NewSignedBeaconBlock(blk)
+			require.NoError(t, err)
+			require.NoError(t, s.validateBlobs(b, blobs[:3], proofs[:3]))
+
+			// Should fail with 4 blobs
+			blk.Block.Body.BlobKzgCommitments = commitments[:4]
+			b, err = blocks.NewSignedBeaconBlock(blk)
+			require.NoError(t, err)
+			err = s.validateBlobs(b, blobs[:4], proofs[:4])
+			require.ErrorContains(t, "number of blobs over max, 4 > 3", err)
+		})
+
+		// Test epoch 30+: max 9 blobs
+		t.Run("epoch 30+: max 9 blobs", func(t *testing.T) {
+			blk := util.NewBeaconBlockDeneb()
+			blk.Block.Slot = 960 // Epoch 30
+			blk.Block.Body.BlobKzgCommitments = commitments[:9]
+			b, err := blocks.NewSignedBeaconBlock(blk)
+			require.NoError(t, err)
+			require.NoError(t, s.validateBlobs(b, blobs[:9], proofs[:9]))
+
+			// Should fail with 10 blobs
+			blk.Block.Body.BlobKzgCommitments = commitments[:10]
+			b, err = blocks.NewSignedBeaconBlock(blk)
+			require.NoError(t, err)
+			err = s.validateBlobs(b, blobs[:10], proofs[:10])
+			require.ErrorContains(t, "number of blobs over max, 10 > 9", err)
+		})
+	})
 }
 
 func TestGetPendingConsolidations(t *testing.T) {

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

@@ -44,7 +44,7 @@ func (s *Server) GetValidators(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -222,7 +222,7 @@ func (s *Server) GetValidator(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -258,7 +258,7 @@ func (s *Server) GetValidatorBalances(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
@@ -419,7 +419,7 @@ func (s *Server) getValidatorIdentitiesJSON(
 ) {
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()

beacon-chain/rpc/eth/debug/handlers.go

@@ -46,7 +46,7 @@ func (s *Server) getBeaconStateV2(ctx context.Context, w http.ResponseWriter, id
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, id, s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		httputil.HandleError(w, "Could not check if state is optimistic: "+err.Error(), http.StatusInternalServerError)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 	blockRoot, err := st.LatestBlockHeader().HashTreeRoot()

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

@@ -12,6 +12,7 @@ go_library(
     deps = [
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/db:go_default_library",
+        "//beacon-chain/rpc/eth/shared:go_default_library",
         "//beacon-chain/rpc/lookup:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
@@ -21,6 +22,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//network/httputil:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -40,6 +42,7 @@ go_test(
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
+        "//beacon-chain/rpc/lookup:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
@@ -57,5 +60,6 @@ go_test(
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
     ],
 )

beacon-chain/rpc/eth/helpers/error_handling.go

@@ -2,11 +2,14 @@ package helpers
 
 import (
 	"errors"
+	"net/http"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/lookup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
+	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -28,6 +31,22 @@ func PrepareStateFetchGRPCError(err error) error {
 	return status.Errorf(codes.Internal, "Invalid state ID: %v", err)
 }
 
+// HandleIsOptimisticError handles errors from IsOptimistic function calls and writes appropriate HTTP responses.
+func HandleIsOptimisticError(w http.ResponseWriter, err error) {
+	var fetchErr *lookup.FetchStateError
+	if errors.As(err, &fetchErr) {
+		shared.WriteStateFetchError(w, err)
+		return
+	}
+
+	var blockRootsNotFoundErr *lookup.BlockRootsNotFoundError
+	if errors.As(err, &blockRootsNotFoundErr) {
+		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusNotFound)
+		return
+	}
+	httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+}
+
 // IndexedVerificationFailure represents a collection of verification failures.
 type IndexedVerificationFailure struct {
 	Failures []*SingleIndexedVerificationFailure `json:"failures"`

beacon-chain/rpc/eth/helpers/sync.go

@@ -56,7 +56,8 @@ func IsOptimistic(
 		if bytesutil.IsHex(stateId) {
 			id, err := hexutil.Decode(stateIdString)
 			if err != nil {
-				return false, err
+				e := lookup.NewStateIdParseError(err)
+				return false, &e
 			}
 			return isStateRootOptimistic(ctx, id, optimisticModeFetcher, stateFetcher, chainInfo, database)
 		} else if len(stateId) == 32 {
@@ -127,7 +128,7 @@ func isStateRootOptimistic(
 ) (bool, error) {
 	st, err := stateFetcher.State(ctx, stateId)
 	if err != nil {
-		return true, errors.Wrap(err, "could not fetch state")
+		return true, lookup.NewFetchStateError(err)
 	}
 	if st.Slot() == chainInfo.HeadSlot() {
 		return optimisticModeFetcher.IsOptimistic(ctx)
@@ -137,7 +138,7 @@ func isStateRootOptimistic(
 		return true, errors.Wrapf(err, "could not get block roots for slot %d", st.Slot())
 	}
 	if !has {
-		return true, errors.New("no block roots returned from the database")
+		return true, lookup.NewBlockRootsNotFoundError()
 	}
 	for _, r := range roots {
 		b, err := database.Block(ctx, r)

beacon-chain/rpc/eth/helpers/sync_test.go

@@ -1,12 +1,15 @@
 package helpers
 
 import (
+	"net/http"
+	"net/http/httptest"
 	"strconv"
 	"testing"
 
 	chainmock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
 	doublylinkedtree "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/lookup"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/testutil"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
@@ -21,6 +24,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/pkg/errors"
 )
 
 func TestIsOptimistic(t *testing.T) {
@@ -226,7 +230,67 @@ func TestIsOptimistic(t *testing.T) {
 			require.NoError(t, err)
 			assert.Equal(t, true, o)
 		})
+		t.Run("State not found", func(t *testing.T) {
+			b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+			require.NoError(t, err)
+			b.SetStateRoot(bytesutil.PadTo([]byte("root"), 32))
+			db := dbtest.SetupDB(t)
+			require.NoError(t, db.SaveBlock(ctx, b))
+			chainSt, err := util.NewBeaconState()
+			require.NoError(t, err)
+			require.NoError(t, chainSt.SetSlot(fieldparams.SlotsPerEpoch))
+			bRoot, err := b.Block().HashTreeRoot()
+			require.NoError(t, err)
+			cs := &chainmock.ChainService{State: chainSt, OptimisticRoots: map[[32]byte]bool{bRoot: true}}
+			mf := &testutil.MockStater{
+				CustomError: lookup.NewFetchStateError(nil),
+			}
+			_, err = IsOptimistic(ctx, []byte(hexutil.Encode(bytesutil.PadTo([]byte("root"), 32))), cs, mf, cs, db)
+			var fetchErr *lookup.FetchStateError
+			require.Equal(t, true, errors.As(err, &fetchErr))
+		})
+
+		t.Run("stateId invalid", func(t *testing.T) {
+			b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+			require.NoError(t, err)
+			b.SetStateRoot(bytesutil.PadTo([]byte("root"), 32))
+			db := dbtest.SetupDB(t)
+			require.NoError(t, db.SaveBlock(ctx, b))
+			chainSt, err := util.NewBeaconState()
+			require.NoError(t, err)
+			require.NoError(t, chainSt.SetSlot(fieldparams.SlotsPerEpoch))
+			bRoot, err := b.Block().HashTreeRoot()
+			require.NoError(t, err)
+			cs := &chainmock.ChainService{State: chainSt, OptimisticRoots: map[[32]byte]bool{bRoot: true}}
+			mf := &testutil.MockStater{
+				CustomError: lookup.NewFetchStateError(nil),
+			}
+			_, err = IsOptimistic(ctx, []byte("0xabc"), cs, mf, cs, db)
+			var fetchErr *lookup.FetchStateError
+			require.Equal(t, false, errors.As(err, &fetchErr))
+		})
+		t.Run("block roots not found", func(t *testing.T) {
+			b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
+			require.NoError(t, err)
+			b.SetStateRoot(bytesutil.PadTo([]byte("root"), 32))
+			db := dbtest.SetupDB(t)
+			require.NoError(t, db.SaveBlock(ctx, b))
+			chainSt, err := util.NewBeaconState()
+			require.NoError(t, err)
+			require.NoError(t, chainSt.SetSlot(fieldparams.SlotsPerEpoch))
+			bRoot, err := b.Block().HashTreeRoot()
+			require.NoError(t, err)
+			cs := &chainmock.ChainService{State: chainSt, OptimisticRoots: map[[32]byte]bool{bRoot: true}}
+			st, err := util.NewBeaconState()
+			require.NoError(t, st.SetSlot(primitives.Slot(fieldparams.SlotsPerEpoch+1)))
+			require.NoError(t, err)
+			mf := &testutil.MockStater{BeaconState: st}
+			_, err = IsOptimistic(ctx, []byte(hexutil.Encode(bytesutil.PadTo([]byte("root"), 32))), cs, mf, cs, db)
+			var blockRootsNotFoundErr *lookup.BlockRootsNotFoundError
+			require.Equal(t, true, errors.As(err, &blockRootsNotFoundErr))
+		})
 	})
+
 	t.Run("slot", func(t *testing.T) {
 		t.Run("head is not optimistic", func(t *testing.T) {
 			cs := &chainmock.ChainService{Optimistic: false}
@@ -319,6 +383,36 @@ func TestIsOptimistic(t *testing.T) {
 	})
 }
 
+func TestHandleIsOptimisticError(t *testing.T) {
+	t.Run("fetch-state error handled as 404", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		notFoundErr := lookup.StateNotFoundError{}
+		fetchErr := lookup.NewFetchStateError(&notFoundErr)
+		HandleIsOptimisticError(rr, fetchErr)
+
+		require.Equal(t, http.StatusNotFound, rr.Code)
+		require.StringContains(t, notFoundErr.Error(), rr.Body.String())
+	})
+	t.Run("no block roots error handled as 404", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		blockRootsErr := lookup.NewBlockRootsNotFoundError()
+		HandleIsOptimisticError(rr, blockRootsErr)
+
+		require.Equal(t, http.StatusNotFound, rr.Code)
+		require.StringContains(t, blockRootsErr.Error(), rr.Body.String())
+	})
+
+	t.Run("generic error handled as 500", func(t *testing.T) {
+		rr := httptest.NewRecorder()
+		genericErr := errors.New("boom")
+
+		HandleIsOptimisticError(rr, genericErr)
+
+		require.Equal(t, http.StatusInternalServerError, rr.Code)
+		require.StringContains(t, "Could not check optimistic status: boom", rr.Body.String())
+	})
+}
+
 // prepareForkchoiceState prepares a beacon state with the given data to mock
 // insert into forkchoice
 func prepareForkchoiceState(

beacon-chain/rpc/eth/validator/handlers.go

@@ -1029,8 +1029,8 @@ func (s *Server) GetProposerDuties(w http.ResponseWriter, r *http.Request) {
 			httputil.HandleError(w, fmt.Sprintf("Could not get head state: %v ", err), http.StatusInternalServerError)
 			return
 		}
-		// Advance state with empty transitions up to the requested epoch start slot for pre fulu state only. Fulu state utilizes proposer look ahead field.
-		if st.Slot() < epochStartSlot && st.Version() != version.Fulu {
+		// Notice that even for Fulu requests for the next epoch, we are only advancing the state to the start of the current epoch.
+		if st.Slot() < epochStartSlot {
 			headRoot, err := s.HeadFetcher.HeadRoot(ctx)
 			if err != nil {
 				httputil.HandleError(w, fmt.Sprintf("Could not get head root: %v ", err), http.StatusInternalServerError)

beacon-chain/rpc/eth/validator/handlers_test.go

@@ -2645,78 +2645,6 @@ func TestGetProposerDuties(t *testing.T) {
 	})
 }
 
-func TestGetProposerDuties_FuluState(t *testing.T) {
-	helpers.ClearCache()
-
-	// Create a Fulu state with slot 0 (before epoch 1 start slot which is 32)
-	fuluState, err := util.NewBeaconStateFulu()
-	require.NoError(t, err)
-	require.NoError(t, fuluState.SetSlot(0)) // Set to slot 0
-
-	// Create some validators for the test
-	depChainStart := params.BeaconConfig().MinGenesisActiveValidatorCount
-	deposits, _, err := util.DeterministicDepositsAndKeys(depChainStart)
-	require.NoError(t, err)
-
-	validators := make([]*ethpbalpha.Validator, len(deposits))
-	for i, deposit := range deposits {
-		validators[i] = &ethpbalpha.Validator{
-			PublicKey:             deposit.Data.PublicKey,
-			ActivationEpoch:       0,
-			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
-			WithdrawalCredentials: make([]byte, 32),
-		}
-	}
-	require.NoError(t, fuluState.SetValidators(validators))
-
-	// Set up block roots
-	genesis := util.NewBeaconBlock()
-	genesisRoot, err := genesis.Block.HashTreeRoot()
-	require.NoError(t, err)
-	roots := make([][]byte, fieldparams.BlockRootsLength)
-	roots[0] = genesisRoot[:]
-	require.NoError(t, fuluState.SetBlockRoots(roots))
-
-	chainSlot := primitives.Slot(0)
-	chain := &mockChain.ChainService{
-		State: fuluState, Root: genesisRoot[:], Slot: &chainSlot,
-	}
-
-	db := dbutil.SetupDB(t)
-	require.NoError(t, db.SaveGenesisBlockRoot(t.Context(), genesisRoot))
-
-	s := &Server{
-		Stater:                 &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{0: fuluState}},
-		HeadFetcher:            chain,
-		TimeFetcher:            chain,
-		OptimisticModeFetcher:  chain,
-		SyncChecker:            &mockSync.Sync{IsSyncing: false},
-		PayloadIDCache:         cache.NewPayloadIDCache(),
-		TrackedValidatorsCache: cache.NewTrackedValidatorsCache(),
-		BeaconDB:               db,
-	}
-
-	// Request epoch 1 duties, which should require advancing from slot 0 to slot 32
-	// But for Fulu state, this advancement should be skipped
-	request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/proposer/{epoch}", nil)
-	request.SetPathValue("epoch", "1")
-	writer := httptest.NewRecorder()
-	writer.Body = &bytes.Buffer{}
-
-	s.GetProposerDuties(writer, request)
-	assert.Equal(t, http.StatusOK, writer.Code)
-
-	// Verify the state was not advanced - it should still be at slot 0
-	// This is the key assertion for the regression test
-	assert.Equal(t, primitives.Slot(0), fuluState.Slot(), "Fulu state should not have been advanced")
-
-	resp := &structs.GetProposerDutiesResponse{}
-	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
-
-	// Should still return proposer duties despite not advancing the state
-	assert.Equal(t, true, len(resp.Data) > 0, "Should return proposer duties even without state advancement")
-}
-
 func TestGetSyncCommitteeDuties(t *testing.T) {
 	helpers.ClearCache()
 	params.SetupTestConfigCleanup(t)

beacon-chain/rpc/lookup/blocker.go

@@ -23,6 +23,20 @@ import (
 	"github.com/pkg/errors"
 )
 
+type BlockRootsNotFoundError struct {
+	message string
+}
+
+func NewBlockRootsNotFoundError() *BlockRootsNotFoundError {
+	return &BlockRootsNotFoundError{
+		message: "no block roots returned from the database",
+	}
+}
+
+func (e BlockRootsNotFoundError) Error() string {
+	return e.message
+}
+
 // BlockIdParseError represents an error scenario where a block ID could not be parsed.
 type BlockIdParseError struct {
 	message string
@@ -341,7 +355,7 @@ func (p *BeaconDbBlocker) blobsFromStoredDataColumns(block blocks.ROBlock, indic
 	stored := summary.Stored()
 	count := uint64(len(stored))
 
-	if count < peerdas.MinimumColumnsCountToReconstruct() {
+	if count < peerdas.MinimumColumnCountToReconstruct() {
 		// There is no way to reconstruct the data columns.
 		return nil, &core.RpcError{
 			Err:    errors.Errorf("the node does not custody enough data columns to reconstruct blobs - please start the beacon node with the `--%s` flag to ensure this call to succeed, or retry later if it is already the case", flags.SubscribeAllDataSubnets.Name),

beacon-chain/rpc/lookup/blocker_test.go

@@ -220,16 +220,13 @@ func TestGetBlob(t *testing.T) {
 		cellsAndProofsList = append(cellsAndProofsList, cellsAndProogs)
 	}
 
-	dataColumnSidecarPb, err := peerdas.DataColumnSidecars(fuluBlock, cellsAndProofsList)
+	roDataColumnSidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofsList, peerdas.PopulateFromBlock(fuluBlock))
 	require.NoError(t, err)
 
-	verifiedRoDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecarPb))
-	for _, sidecarPb := range dataColumnSidecarPb {
-		roDataColumn, err := blocks.NewRODataColumnWithRoot(sidecarPb, fuluBlockRoot)
-		require.NoError(t, err)
-
-		verifiedRoDataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
-		verifiedRoDataColumnSidecars = append(verifiedRoDataColumnSidecars, verifiedRoDataColumn)
+	verifiedRoDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))
+	for _, roDataColumnSidecar := range roDataColumnSidecars {
+		verifiedRoDataColumnSidecar := blocks.NewVerifiedRODataColumn(roDataColumnSidecar)
+		verifiedRoDataColumnSidecars = append(verifiedRoDataColumnSidecars, verifiedRoDataColumnSidecar)
 	}
 
 	err = db.SaveBlock(t.Context(), fuluBlock)
@@ -443,7 +440,7 @@ func TestGetBlob(t *testing.T) {
 		setupFulu(t)
 
 		_, dataColumnStorage := filesystem.NewEphemeralDataColumnStorageAndFs(t)
-		err = dataColumnStorage.Save(verifiedRoDataColumnSidecars[1 : peerdas.MinimumColumnsCountToReconstruct()+1])
+		err = dataColumnStorage.Save(verifiedRoDataColumnSidecars[1 : peerdas.MinimumColumnCountToReconstruct()+1])
 		require.NoError(t, err)
 
 		blocker := &BeaconDbBlocker{

beacon-chain/rpc/lookup/stater.go

@@ -21,6 +21,27 @@ import (
 	"github.com/pkg/errors"
 )
 
+type FetchStateError struct {
+	message string
+	cause   error
+}
+
+func NewFetchStateError(cause error) *FetchStateError {
+	return &FetchStateError{
+		message: "could not fetch state",
+		cause:   cause,
+	}
+}
+
+func (e *FetchStateError) Error() string {
+	if e.cause != nil {
+		return e.message + ": " + e.cause.Error()
+	}
+	return e.message
+}
+
+func (e *FetchStateError) Unwrap() error { return e.cause }
+
 // StateIdParseError represents an error scenario where a state ID could not be parsed.
 type StateIdParseError struct {
 	message string

beacon-chain/rpc/prysm/beacon/validator_count.go

@@ -56,11 +56,7 @@ func (s *Server) GetValidatorCount(w http.ResponseWriter, r *http.Request) {
 
 	isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateID), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
 	if err != nil {
-		errJson := &httputil.DefaultJsonError{
-			Message: fmt.Sprintf("could not check if slot's block is optimistic: %v", err),
-			Code:    http.StatusInternalServerError,
-		}
-		httputil.WriteError(w, errJson)
+		helpers.HandleIsOptimisticError(w, err)
 		return
 	}
 

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

@@ -1,3 +1,5 @@
+# gazelle:ignore
+
 load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
@@ -37,6 +39,7 @@ go_library(
         "//api/client/builder:go_default_library",
         "//async/event:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
+        "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/builder:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositsnapshot:go_default_library",
@@ -47,6 +50,7 @@ go_library(
         "//beacon-chain/core/feed/operation:go_default_library",
         "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
@@ -63,8 +67,8 @@ go_library(
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/startup:go_default_library",
         "//beacon-chain/state:go_default_library",
-        "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
+        "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/sync:go_default_library",
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
@@ -81,7 +85,7 @@ go_library(
         "//crypto/rand:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
-	"//genesis:go_default_library",
+        "//genesis:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
@@ -181,7 +185,6 @@ common_deps = [
     "@org_golang_google_protobuf//types/known/emptypb:go_default_library",
 ]
 
-# gazelle:ignore
 go_test(
     name = "go_default_test",
     timeout = "moderate",

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

@@ -248,6 +248,8 @@ func (vs *Server) sendBlocks(stream ethpb.BeaconNodeValidator_StreamBlocksAltair
 		b.Block = &ethpb.StreamBlocksResponse_DenebBlock{DenebBlock: p}
 	case *ethpb.SignedBeaconBlockElectra:
 		b.Block = &ethpb.StreamBlocksResponse_ElectraBlock{ElectraBlock: p}
+	case *ethpb.SignedBeaconBlockFulu:
+		b.Block = &ethpb.StreamBlocksResponse_FuluBlock{FuluBlock: p}
 	default:
 		log.Errorf("Unknown block type %T", p)
 	}

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

@@ -381,3 +381,92 @@ func TestServer_StreamSlotsVerified_OnHeadUpdated(t *testing.T) {
 	}
 	<-exitRoutine
 }
+
+func TestServer_StreamBlocksVerified_FuluBlock(t *testing.T) {
+	db := dbTest.SetupDB(t)
+	ctx := t.Context()
+	beaconState, privs := util.DeterministicGenesisStateFulu(t, 32)
+	c, err := altair.NextSyncCommittee(ctx, beaconState)
+	require.NoError(t, err)
+	require.NoError(t, beaconState.SetCurrentSyncCommittee(c))
+
+	b, err := util.GenerateFullBlockFulu(beaconState, privs, util.DefaultBlockGenConfig(), 1)
+	require.NoError(t, err)
+	r, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	wrappedBlk := util.SaveBlock(t, ctx, db, b)
+	chainService := &chainMock.ChainService{State: beaconState}
+	server := &Server{
+		Ctx:           ctx,
+		StateNotifier: chainService.StateNotifier(),
+		HeadFetcher:   chainService,
+	}
+	exitRoutine := make(chan bool)
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	mockStream := mock.NewMockBeaconNodeValidatorAltair_StreamBlocksServer(ctrl)
+	mockStream.EXPECT().Send(&ethpb.StreamBlocksResponse{Block: &ethpb.StreamBlocksResponse_FuluBlock{FuluBlock: b}}).Do(func(arg0 interface{}) {
+		exitRoutine <- true
+	})
+	mockStream.EXPECT().Context().Return(ctx).AnyTimes()
+
+	go func(tt *testing.T) {
+		err := server.StreamBlocksAltair(&ethpb.StreamBlocksRequest{VerifiedOnly: true}, mockStream)
+		if s, _ := status.FromError(err); s.Code() != codes.Canceled {
+			assert.NoError(tt, err)
+		}
+	}(t)
+	// Send in a loop to ensure it is delivered (busy wait for the service to subscribe to the state feed).
+	for sent := 0; sent == 0; {
+		sent = server.StateNotifier.StateFeed().Send(&feed.Event{
+			Type: statefeed.BlockProcessed,
+			Data: &statefeed.BlockProcessedData{Slot: b.Block.Slot, BlockRoot: r, SignedBlock: wrappedBlk},
+		})
+	}
+	<-exitRoutine
+}
+
+func TestServer_StreamBlocks_FuluBlock(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	params.OverrideBeaconConfig(params.BeaconConfig())
+	ctx := t.Context()
+	beaconState, privs := util.DeterministicGenesisStateFulu(t, 64)
+	c, err := altair.NextSyncCommittee(ctx, beaconState)
+	require.NoError(t, err)
+	require.NoError(t, beaconState.SetCurrentSyncCommittee(c))
+
+	b, err := util.GenerateFullBlockFulu(beaconState, privs, util.DefaultBlockGenConfig(), 1)
+	require.NoError(t, err)
+	chainService := &chainMock.ChainService{State: beaconState}
+	server := &Server{
+		Ctx:           ctx,
+		BlockNotifier: chainService.BlockNotifier(),
+		HeadFetcher:   chainService,
+	}
+	exitRoutine := make(chan bool)
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	mockStream := mock.NewMockBeaconNodeValidatorAltair_StreamBlocksServer(ctrl)
+
+	mockStream.EXPECT().Send(&ethpb.StreamBlocksResponse{Block: &ethpb.StreamBlocksResponse_FuluBlock{FuluBlock: b}}).Do(func(arg0 interface{}) {
+		exitRoutine <- true
+	})
+	mockStream.EXPECT().Context().Return(ctx).AnyTimes()
+
+	go func(tt *testing.T) {
+		err := server.StreamBlocksAltair(&ethpb.StreamBlocksRequest{}, mockStream)
+		if s, _ := status.FromError(err); s.Code() != codes.Canceled {
+			assert.NoError(tt, err)
+		}
+	}(t)
+	wrappedBlk, err := blocks.NewSignedBeaconBlock(b)
+	require.NoError(t, err)
+	// Send in a loop to ensure it is delivered (busy wait for the service to subscribe to the state feed).
+	for sent := 0; sent == 0; {
+		sent = server.BlockNotifier.BlockFeed().Send(&feed.Event{
+			Type: blockfeed.ReceivedBlock,
+			Data: &blockfeed.ReceivedBlockData{SignedBlock: wrappedBlk},
+		})
+	}
+	<-exitRoutine
+}

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

@@ -29,12 +29,19 @@ func TestConstructGenericBeaconBlock(t *testing.T) {
 		require.NoError(t, err)
 		r1, err := eb.Block.HashTreeRoot()
 		require.NoError(t, err)
-		result, err := vs.constructGenericBeaconBlock(b, nil, primitives.ZeroWei())
+		bundle := &enginev1.BlobsBundleV2{
+			KzgCommitments: [][]byte{{1, 2, 3}},
+			Proofs:         [][]byte{{4, 5, 6}},
+			Blobs:          [][]byte{{7, 8, 9}},
+		}
+		result, err := vs.constructGenericBeaconBlock(b, bundle, primitives.ZeroWei())
 		require.NoError(t, err)
 		r2, err := result.GetFulu().Block.HashTreeRoot()
 		require.NoError(t, err)
 		require.Equal(t, r1, r2)
 		require.Equal(t, result.IsBlinded, false)
+		require.DeepEqual(t, bundle.Blobs, result.GetFulu().GetBlobs())
+		require.DeepEqual(t, bundle.Proofs, result.GetFulu().GetKzgProofs())
 	})
 
 	// Test for Electra version

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

@@ -15,9 +15,11 @@ import (
 	blockfeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/block"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/operation"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -58,28 +60,31 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 	if err != nil {
 		log.WithError(err).Error("Could not convert slot to time")
 	}
-	log.WithFields(logrus.Fields{
-		"slot":               req.Slot,
-		"sinceSlotStartTime": time.Since(t),
-	}).Info("Begin building block")
+
+	log := log.WithField("slot", req.Slot)
+	log.WithField("sinceSlotStartTime", time.Since(t)).Info("Begin building block")
 
 	// A syncing validator should not produce a block.
 	if vs.SyncChecker.Syncing() {
+		log.Error("Fail to build block: node is syncing")
 		return nil, status.Error(codes.Unavailable, "Syncing to latest head, not ready to respond")
 	}
 	// An optimistic validator MUST NOT produce a block (i.e., sign across the DOMAIN_BEACON_PROPOSER domain).
 	if slots.ToEpoch(req.Slot) >= params.BeaconConfig().BellatrixForkEpoch {
 		if err := vs.optimisticStatus(ctx); err != nil {
+			log.WithError(err).Error("Fail to build block: node is optimistic")
 			return nil, status.Errorf(codes.Unavailable, "Validator is not ready to propose: %v", err)
 		}
 	}
 
 	head, parentRoot, err := vs.getParentState(ctx, req.Slot)
 	if err != nil {
+		log.WithError(err).Error("Fail to build block: could not get parent state")
 		return nil, err
 	}
 	sBlk, err := getEmptyBlock(req.Slot)
 	if err != nil {
+		log.WithError(err).Error("Fail to build block: could not get empty block")
 		return nil, status.Errorf(codes.Internal, "Could not prepare block: %v", err)
 	}
 	// Set slot, graffiti, randao reveal, and parent root.
@@ -101,8 +106,7 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 	}
 
 	resp, err := vs.BuildBlockParallel(ctx, sBlk, head, req.SkipMevBoost, builderBoostFactor)
-	log := log.WithFields(logrus.Fields{
-		"slot":               req.Slot,
+	log = log.WithFields(logrus.Fields{
 		"sinceSlotStartTime": time.Since(t),
 		"validator":          sBlk.Block().ProposerIndex(),
 	})
@@ -275,6 +279,11 @@ func (vs *Server) BuildBlockParallel(ctx context.Context, sBlk interfaces.Signed
 //
 // ProposeBeaconBlock handles the proposal of beacon blocks.
 func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSignedBeaconBlock) (*ethpb.ProposeResponse, error) {
+	var (
+		blobSidecars       []*ethpb.BlobSidecar
+		dataColumnSidecars []blocks.RODataColumn
+	)
+
 	ctx, span := trace.StartSpan(ctx, "ProposerServer.ProposeBeaconBlock")
 	defer span.End()
 
@@ -286,22 +295,30 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 	if err != nil {
 		return nil, status.Errorf(codes.InvalidArgument, "%s: %v", "decode block failed", err)
 	}
-
-	var sidecars []*ethpb.BlobSidecar
-	if block.IsBlinded() {
-		block, sidecars, err = vs.handleBlindedBlock(ctx, block)
-	} else if block.Version() >= version.Deneb {
-		sidecars, err = vs.blobSidecarsFromUnblindedBlock(block, req)
-	}
-	if err != nil {
-		return nil, status.Errorf(codes.Internal, "%s: %v", "handle block failed", err)
-	}
-
 	root, err := block.Block().HashTreeRoot()
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not hash tree root: %v", err)
 	}
 
+	// For post-Fulu blinded blocks, submit to relay and return early
+	if block.IsBlinded() && slots.ToEpoch(block.Block().Slot()) >= params.BeaconConfig().FuluForkEpoch {
+		err := vs.BlockBuilder.SubmitBlindedBlockPostFulu(ctx, block)
+		if err != nil {
+			return nil, status.Errorf(codes.Internal, "Could not submit blinded block post-Fulu: %v", err)
+		}
+		return &ethpb.ProposeResponse{BlockRoot: root[:]}, nil
+	}
+
+	rob, err := blocks.NewROBlockWithRoot(block, root)
+	if block.IsBlinded() {
+		block, blobSidecars, err = vs.handleBlindedBlock(ctx, block)
+	} else if block.Version() >= version.Deneb {
+		blobSidecars, dataColumnSidecars, err = vs.handleUnblindedBlock(rob, req)
+	}
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "%s: %v", "handle block failed", err)
+	}
+
 	var wg sync.WaitGroup
 	errChan := make(chan error, 1)
 
@@ -315,10 +332,9 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 		errChan <- nil
 	}()
 
-	if err := vs.broadcastAndReceiveBlobs(ctx, sidecars, root); err != nil {
-		return nil, status.Errorf(codes.Internal, "Could not broadcast/receive blobs: %v", err)
+	if err := vs.broadcastAndReceiveSidecars(ctx, block, root, blobSidecars, dataColumnSidecars); err != nil {
+		return nil, status.Errorf(codes.Internal, "Could not broadcast/receive sidecars: %v", err)
 	}
-
 	wg.Wait()
 	if err := <-errChan; err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not broadcast/receive block: %v", err)
@@ -327,11 +343,35 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 	return &ethpb.ProposeResponse{BlockRoot: root[:]}, nil
 }
 
-// handleBlindedBlock processes blinded beacon blocks.
+// broadcastAndReceiveSidecars broadcasts and receives sidecars.
+func (vs *Server) broadcastAndReceiveSidecars(
+	ctx context.Context,
+	block interfaces.SignedBeaconBlock,
+	root [fieldparams.RootLength]byte,
+	blobSidecars []*ethpb.BlobSidecar,
+	dataColumnSidecars []blocks.RODataColumn,
+) error {
+	if block.Version() >= version.Fulu {
+		if err := vs.broadcastAndReceiveDataColumns(ctx, dataColumnSidecars, root); err != nil {
+			return errors.Wrap(err, "broadcast and receive data columns")
+		}
+		return nil
+	}
+
+	if err := vs.broadcastAndReceiveBlobs(ctx, blobSidecars, root); err != nil {
+		return errors.Wrap(err, "broadcast and receive blobs")
+	}
+
+	return nil
+}
+
+// handleBlindedBlock processes blinded beacon blocks (pre-Fulu only).
+// Post-Fulu blinded blocks are handled directly in ProposeBeaconBlock.
 func (vs *Server) handleBlindedBlock(ctx context.Context, block interfaces.SignedBeaconBlock) (interfaces.SignedBeaconBlock, []*ethpb.BlobSidecar, error) {
 	if block.Version() < version.Bellatrix {
 		return nil, nil, errors.New("pre-Bellatrix blinded block")
 	}
+
 	if vs.BlockBuilder == nil || !vs.BlockBuilder.Configured() {
 		return nil, nil, errors.New("unconfigured block builder")
 	}
@@ -358,16 +398,41 @@ func (vs *Server) handleBlindedBlock(ctx context.Context, block interfaces.Signe
 	return copiedBlock, sidecars, nil
 }
 
-func (vs *Server) blobSidecarsFromUnblindedBlock(block interfaces.SignedBeaconBlock, req *ethpb.GenericSignedBeaconBlock) ([]*ethpb.BlobSidecar, error) {
+func (vs *Server) handleUnblindedBlock(
+	block blocks.ROBlock,
+	req *ethpb.GenericSignedBeaconBlock,
+) ([]*ethpb.BlobSidecar, []blocks.RODataColumn, error) {
 	rawBlobs, proofs, err := blobsAndProofs(req)
 	if err != nil {
-		return nil, err
+		return nil, nil, err
 	}
-	return BuildBlobSidecars(block, rawBlobs, proofs)
+
+	if block.Version() >= version.Fulu {
+		// Compute cells and proofs from the blobs and cell proofs.
+		cellsAndProofs, err := peerdas.ComputeCellsAndProofs(rawBlobs, proofs)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "compute cells and proofs")
+		}
+
+		// Construct data column sidecars from the signed block and cells and proofs.
+		roDataColumnSidecars, err := peerdas.ConstructDataColumnSidecar(cellsAndProofs, peerdas.PopulateFromBlock(block))
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "data column sidcars")
+		}
+
+		return nil, roDataColumnSidecars, nil
+	}
+
+	blobSidecars, err := BuildBlobSidecars(block, rawBlobs, proofs)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "build blob sidecars")
+	}
+
+	return blobSidecars, nil, nil
 }
 
 // broadcastReceiveBlock broadcasts a block and handles its reception.
-func (vs *Server) broadcastReceiveBlock(ctx context.Context, block interfaces.SignedBeaconBlock, root [32]byte) error {
+func (vs *Server) broadcastReceiveBlock(ctx context.Context, block interfaces.SignedBeaconBlock, root [fieldparams.RootLength]byte) error {
 	protoBlock, err := block.Proto()
 	if err != nil {
 		return errors.Wrap(err, "protobuf conversion failed")
@@ -383,18 +448,14 @@ func (vs *Server) broadcastReceiveBlock(ctx context.Context, block interfaces.Si
 }
 
 // broadcastAndReceiveBlobs handles the broadcasting and reception of blob sidecars.
-func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethpb.BlobSidecar, root [32]byte) error {
+func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethpb.BlobSidecar, root [fieldparams.RootLength]byte) error {
 	eg, eCtx := errgroup.WithContext(ctx)
-	for i, sc := range sidecars {
-		// Copy the iteration instance to a local variable to give each go-routine its own copy to play with.
-		// See https://golang.org/doc/faq#closures_and_goroutines for more details.
-		subIdx := i
-		sCar := sc
+	for subIdx, sc := range sidecars {
 		eg.Go(func() error {
-			if err := vs.P2P.BroadcastBlob(eCtx, uint64(subIdx), sCar); err != nil {
+			if err := vs.P2P.BroadcastBlob(eCtx, uint64(subIdx), sc); err != nil {
 				return errors.Wrap(err, "broadcast blob failed")
 			}
-			readOnlySc, err := blocks.NewROBlobWithRoot(sCar, root)
+			readOnlySc, err := blocks.NewROBlobWithRoot(sc, root)
 			if err != nil {
 				return errors.Wrap(err, "ROBlob creation failed")
 			}
@@ -412,6 +473,48 @@ func (vs *Server) broadcastAndReceiveBlobs(ctx context.Context, sidecars []*ethp
 	return eg.Wait()
 }
 
+// broadcastAndReceiveDataColumns handles the broadcasting and reception of data columns sidecars.
+func (vs *Server) broadcastAndReceiveDataColumns(
+	ctx context.Context,
+	roSidecars []blocks.RODataColumn,
+	root [fieldparams.RootLength]byte,
+) error {
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(roSidecars))
+	eg, _ := errgroup.WithContext(ctx)
+	for _, roSidecar := range roSidecars {
+		// We build this block ourselves, so we can upgrade the read only data column sidecar into a verified one.
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roSidecar)
+		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
+
+		eg.Go(func() error {
+			// Compute the subnet index based on the column index.
+			subnet := peerdas.ComputeSubnetForDataColumnSidecar(roSidecar.Index)
+
+			if err := vs.P2P.BroadcastDataColumnSidecar(subnet, verifiedRODataColumn); err != nil {
+				return errors.Wrap(err, "broadcast data column")
+			}
+
+			return nil
+		})
+	}
+
+	if err := eg.Wait(); err != nil {
+		return errors.Wrap(err, "wait for data columns to be broadcasted")
+	}
+
+	if err := vs.DataColumnReceiver.ReceiveDataColumns(verifiedRODataColumns); err != nil {
+		return errors.Wrap(err, "receive data column")
+	}
+
+	for _, verifiedRODataColumn := range verifiedRODataColumns {
+		vs.OperationNotifier.OperationFeed().Send(&feed.Event{
+			Type: operation.DataColumnSidecarReceived,
+			Data: &operation.DataColumnSidecarReceivedData{DataColumn: &verifiedRODataColumn}, // #nosec G601
+		})
+	}
+	return nil
+}
+
 // Deprecated: The gRPC API will remain the default and fully supported through v8 (expected in 2026) but will be eventually removed in favor of REST API.
 //
 // PrepareBeaconProposer caches and updates the fee recipient for the given proposer.

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

@@ -10,7 +10,7 @@ import (
 )
 
 // BuildBlobSidecars given a block, builds the blob sidecars for the block.
-func BuildBlobSidecars(blk interfaces.SignedBeaconBlock, blobs [][]byte, kzgProofs [][]byte) ([]*ethpb.BlobSidecar, error) {
+func BuildBlobSidecars(blk interfaces.ReadOnlySignedBeaconBlock, blobs [][]byte, kzgProofs [][]byte) ([]*ethpb.BlobSidecar, error) {
 	if blk.Version() < version.Deneb {
 		return nil, nil // No blobs before deneb.
 	}

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

@@ -6,6 +6,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	mock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/builder"
 	builderTest "github.com/OffchainLabs/prysm/v6/beacon-chain/builder/testing"
@@ -894,6 +895,9 @@ func injectSlashings(t *testing.T, st state.BeaconState, keys []bls.SecretKey, s
 }
 
 func TestProposer_ProposeBlock_OK(t *testing.T) {
+	// Initialize KZG for Fulu blocks
+	require.NoError(t, kzg.Start())
+
 	tests := []struct {
 		name       string
 		block      func([32]byte) *ethpb.GenericSignedBeaconBlock
@@ -1098,6 +1102,131 @@ func TestProposer_ProposeBlock_OK(t *testing.T) {
 			},
 			err: "blob KZG commitments don't match number of blobs or KZG proofs",
 		},
+		{
+			name: "fulu block no blob",
+			block: func(parent [32]byte) *ethpb.GenericSignedBeaconBlock {
+				sb := &ethpb.SignedBeaconBlockContentsFulu{
+					Block: &ethpb.SignedBeaconBlockFulu{
+						Block: &ethpb.BeaconBlockElectra{Slot: 5, ParentRoot: parent[:], Body: util.HydrateBeaconBlockBodyElectra(&ethpb.BeaconBlockBodyElectra{})},
+					},
+				}
+				blk := &ethpb.GenericSignedBeaconBlock_Fulu{Fulu: sb}
+				return &ethpb.GenericSignedBeaconBlock{Block: blk, IsBlinded: false}
+			},
+		},
+		{
+			name: "fulu block with single blob and cell proofs",
+			block: func(parent [32]byte) *ethpb.GenericSignedBeaconBlock {
+				numberOfColumns := uint64(128)
+				// For Fulu, we have cell proofs (blobs * numberOfColumns)
+				cellProofs := make([][]byte, numberOfColumns)
+				for i := uint64(0); i < numberOfColumns; i++ {
+					cellProofs[i] = bytesutil.PadTo([]byte{byte(i)}, 48)
+				}
+				// Blob must be exactly 131072 bytes
+				blob := make([]byte, 131072)
+				blob[0] = 0x01
+				sb := &ethpb.SignedBeaconBlockContentsFulu{
+					Block: &ethpb.SignedBeaconBlockFulu{
+						Block: &ethpb.BeaconBlockElectra{
+							Slot: 5, ParentRoot: parent[:],
+							Body: util.HydrateBeaconBlockBodyElectra(&ethpb.BeaconBlockBodyElectra{
+								BlobKzgCommitments: [][]byte{bytesutil.PadTo([]byte("kc"), 48)},
+							}),
+						},
+					},
+					KzgProofs: cellProofs,
+					Blobs:     [][]byte{blob},
+				}
+				blk := &ethpb.GenericSignedBeaconBlock_Fulu{Fulu: sb}
+				return &ethpb.GenericSignedBeaconBlock{Block: blk, IsBlinded: false}
+			},
+		},
+		{
+			name: "fulu block with multiple blobs and cell proofs",
+			block: func(parent [32]byte) *ethpb.GenericSignedBeaconBlock {
+				numberOfColumns := uint64(128)
+				blobCount := 3
+				// For Fulu, we have cell proofs (blobs * numberOfColumns)
+				cellProofs := make([][]byte, uint64(blobCount)*numberOfColumns)
+				for i := range cellProofs {
+					cellProofs[i] = bytesutil.PadTo([]byte{byte(i % 256)}, 48)
+				}
+				// Create properly sized blobs (131072 bytes each)
+				blobs := make([][]byte, blobCount)
+				for i := 0; i < blobCount; i++ {
+					blob := make([]byte, 131072)
+					blob[0] = byte(i + 1)
+					blobs[i] = blob
+				}
+				sb := &ethpb.SignedBeaconBlockContentsFulu{
+					Block: &ethpb.SignedBeaconBlockFulu{
+						Block: &ethpb.BeaconBlockElectra{
+							Slot: 5, ParentRoot: parent[:],
+							Body: util.HydrateBeaconBlockBodyElectra(&ethpb.BeaconBlockBodyElectra{
+								BlobKzgCommitments: [][]byte{
+									bytesutil.PadTo([]byte("kc"), 48),
+									bytesutil.PadTo([]byte("kc1"), 48),
+									bytesutil.PadTo([]byte("kc2"), 48),
+								},
+							}),
+						},
+					},
+					KzgProofs: cellProofs,
+					Blobs:     blobs,
+				}
+				blk := &ethpb.GenericSignedBeaconBlock_Fulu{Fulu: sb}
+				return &ethpb.GenericSignedBeaconBlock{Block: blk, IsBlinded: false}
+			},
+		},
+		{
+			name: "fulu block wrong cell proof count (should be blobs * 128)",
+			block: func(parent [32]byte) *ethpb.GenericSignedBeaconBlock {
+				// Wrong number of cell proofs - should be 2 * 128 = 256, but providing only 2
+				// Create properly sized blobs
+				blob1 := make([]byte, 131072)
+				blob1[0] = 0x01
+				blob2 := make([]byte, 131072)
+				blob2[0] = 0x02
+				sb := &ethpb.SignedBeaconBlockContentsFulu{
+					Block: &ethpb.SignedBeaconBlockFulu{
+						Block: &ethpb.BeaconBlockElectra{
+							Slot: 5, ParentRoot: parent[:],
+							Body: util.HydrateBeaconBlockBodyElectra(&ethpb.BeaconBlockBodyElectra{
+								BlobKzgCommitments: [][]byte{
+									bytesutil.PadTo([]byte("kc"), 48),
+									bytesutil.PadTo([]byte("kc1"), 48),
+								},
+							}),
+						},
+					},
+					KzgProofs: [][]byte{{0x01}, {0x02}}, // Wrong: should be 256 cell proofs
+					Blobs:     [][]byte{blob1, blob2},
+				}
+				blk := &ethpb.GenericSignedBeaconBlock_Fulu{Fulu: sb}
+				return &ethpb.GenericSignedBeaconBlock{Block: blk, IsBlinded: false}
+			},
+			err: "blobs and cells proofs mismatch",
+		},
+		{
+			name: "blind fulu block with blob commitments",
+			block: func(parent [32]byte) *ethpb.GenericSignedBeaconBlock {
+				blockToPropose := util.NewBlindedBeaconBlockFulu()
+				blockToPropose.Message.Slot = 5
+				blockToPropose.Message.ParentRoot = parent[:]
+				txRoot, err := ssz.TransactionsRoot([][]byte{})
+				require.NoError(t, err)
+				withdrawalsRoot, err := ssz.WithdrawalSliceRoot([]*enginev1.Withdrawal{}, fieldparams.MaxWithdrawalsPerPayload)
+				require.NoError(t, err)
+				blockToPropose.Message.Body.ExecutionPayloadHeader.TransactionsRoot = txRoot[:]
+				blockToPropose.Message.Body.ExecutionPayloadHeader.WithdrawalsRoot = withdrawalsRoot[:]
+				blockToPropose.Message.Body.BlobKzgCommitments = [][]byte{bytesutil.PadTo([]byte{0x01}, 48)}
+				blk := &ethpb.GenericSignedBeaconBlock_BlindedFulu{BlindedFulu: blockToPropose}
+				return &ethpb.GenericSignedBeaconBlock{Block: blk}
+			},
+			useBuilder: true,
+			err:        "commitment value doesn't match block", // Known issue with mock builder cell proof mismatch
+		},
 	}
 
 	for _, tt := range tests {
@@ -1111,15 +1240,29 @@ func TestProposer_ProposeBlock_OK(t *testing.T) {
 
 			c := &mock.ChainService{Root: bsRoot[:], State: beaconState}
 			db := dbutil.SetupDB(t)
+			// Create cell proofs for Fulu blocks (128 proofs per blob)
+			numberOfColumns := uint64(128)
+			cellProofs := make([][]byte, numberOfColumns)
+			for i := uint64(0); i < numberOfColumns; i++ {
+				cellProofs[i] = bytesutil.PadTo([]byte{byte(i)}, 48)
+			}
+			// Create properly sized blob for mock builder
+			mockBlob := make([]byte, 131072)
+			mockBlob[0] = 0x03
+			// Use the same commitment as in the blind block test
+			mockCommitment := bytesutil.PadTo([]byte{0x01}, 48)
+
 			proposerServer := &Server{
 				BlockReceiver: c,
 				BlockNotifier: c.BlockNotifier(),
 				P2P:           mockp2p.NewTestP2P(t),
 				BlockBuilder: &builderTest.MockBuilderService{HasConfigured: tt.useBuilder, PayloadCapella: emptyPayloadCapella(), PayloadDeneb: emptyPayloadDeneb(),
-					BlobBundle: &enginev1.BlobsBundle{KzgCommitments: [][]byte{bytesutil.PadTo([]byte{0x01}, 48)}, Proofs: [][]byte{{0x02}}, Blobs: [][]byte{{0x03}}}},
-				BeaconDB:          db,
-				BlobReceiver:      c,
-				OperationNotifier: c.OperationNotifier(),
+					BlobBundle:   &enginev1.BlobsBundle{KzgCommitments: [][]byte{mockCommitment}, Proofs: [][]byte{{0x02}}, Blobs: [][]byte{{0x03}}},
+					BlobBundleV2: &enginev1.BlobsBundleV2{KzgCommitments: [][]byte{mockCommitment}, Proofs: cellProofs, Blobs: [][]byte{mockBlob}}},
+				BeaconDB:           db,
+				BlobReceiver:       c,
+				DataColumnReceiver: c, // Add DataColumnReceiver for Fulu blocks
+				OperationNotifier:  c.OperationNotifier(),
 			}
 			blockToPropose := tt.block(bsRoot)
 			res, err := proposerServer.ProposeBeaconBlock(t.Context(), blockToPropose)
@@ -3286,3 +3429,252 @@ func TestProposer_ElectraBlobsAndProofs(t *testing.T) {
 	require.Equal(t, 10, len(blobs))
 	require.Equal(t, 10, len(proofs))
 }
+
+func TestServer_ProposeBeaconBlock_PostFuluBlindedBlock(t *testing.T) {
+	db := dbutil.SetupDB(t)
+	ctx := t.Context()
+
+	beaconState, parentRoot, _ := util.DeterministicGenesisStateWithGenesisBlock(t, ctx, db, 100)
+	require.NoError(t, beaconState.SetSlot(1))
+
+	t.Run("post-Fulu blinded block - early return success", func(t *testing.T) {
+		// Set up config with Fulu fork at epoch 5
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.FuluForkEpoch = 5
+		params.OverrideBeaconConfig(cfg)
+
+		mockBuilder := &builderTest.MockBuilderService{
+			HasConfigured:                 true,
+			Cfg:                           &builderTest.Config{BeaconDB: db},
+			ErrSubmitBlindedBlockPostFulu: nil, // Success case
+		}
+
+		c := &mock.ChainService{State: beaconState, Root: parentRoot[:]}
+		proposerServer := &Server{
+			ChainStartFetcher: &mockExecution.Chain{},
+			Eth1InfoFetcher:   &mockExecution.Chain{},
+			Eth1BlockFetcher:  &mockExecution.Chain{},
+			BlockReceiver:     c,
+			BlobReceiver:      c,
+			HeadFetcher:       c,
+			BlockNotifier:     c.BlockNotifier(),
+			OperationNotifier: c.OperationNotifier(),
+			StateGen:          stategen.New(db, doublylinkedtree.New()),
+			TimeFetcher:       c,
+			SyncChecker:       &mockSync.Sync{IsSyncing: false},
+			BeaconDB:          db,
+			BlockBuilder:      mockBuilder,
+			P2P:               &mockp2p.MockBroadcaster{},
+		}
+
+		// Create a blinded block at slot 160 (epoch 5, which is >= FuluForkEpoch)
+		blindedBlock := util.NewBlindedBeaconBlockDeneb()
+		blindedBlock.Message.Slot = 160 // This puts us at epoch 5 (160/32 = 5)
+		blindedBlock.Message.ProposerIndex = 0
+		blindedBlock.Message.ParentRoot = parentRoot[:]
+		blindedBlock.Message.StateRoot = make([]byte, 32)
+
+		req := &ethpb.GenericSignedBeaconBlock{
+			Block: &ethpb.GenericSignedBeaconBlock_BlindedDeneb{BlindedDeneb: blindedBlock},
+		}
+
+		// This should trigger the post-Fulu early return path
+		res, err := proposerServer.ProposeBeaconBlock(ctx, req)
+		require.NoError(t, err)
+		require.NotNil(t, res)
+		require.NotEmpty(t, res.BlockRoot)
+	})
+
+	t.Run("post-Fulu blinded block - builder submission error", func(t *testing.T) {
+		// Set up config with Fulu fork at epoch 5
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.FuluForkEpoch = 5
+		params.OverrideBeaconConfig(cfg)
+
+		mockBuilder := &builderTest.MockBuilderService{
+			HasConfigured:                 true,
+			Cfg:                           &builderTest.Config{BeaconDB: db},
+			ErrSubmitBlindedBlockPostFulu: errors.New("post-Fulu builder submission failed"),
+		}
+
+		c := &mock.ChainService{State: beaconState, Root: parentRoot[:]}
+		proposerServer := &Server{
+			ChainStartFetcher: &mockExecution.Chain{},
+			Eth1InfoFetcher:   &mockExecution.Chain{},
+			Eth1BlockFetcher:  &mockExecution.Chain{},
+			BlockReceiver:     c,
+			BlobReceiver:      c,
+			HeadFetcher:       c,
+			BlockNotifier:     c.BlockNotifier(),
+			OperationNotifier: c.OperationNotifier(),
+			StateGen:          stategen.New(db, doublylinkedtree.New()),
+			TimeFetcher:       c,
+			SyncChecker:       &mockSync.Sync{IsSyncing: false},
+			BeaconDB:          db,
+			BlockBuilder:      mockBuilder,
+			P2P:               &mockp2p.MockBroadcaster{},
+		}
+
+		// Create a blinded block at slot 160 (epoch 5)
+		blindedBlock := util.NewBlindedBeaconBlockDeneb()
+		blindedBlock.Message.Slot = 160
+		blindedBlock.Message.ProposerIndex = 0
+		blindedBlock.Message.ParentRoot = parentRoot[:]
+		blindedBlock.Message.StateRoot = make([]byte, 32)
+
+		req := &ethpb.GenericSignedBeaconBlock{
+			Block: &ethpb.GenericSignedBeaconBlock_BlindedDeneb{BlindedDeneb: blindedBlock},
+		}
+
+		_, err := proposerServer.ProposeBeaconBlock(ctx, req)
+		require.ErrorContains(t, "Could not submit blinded block post-Fulu", err)
+		require.ErrorContains(t, "post-Fulu builder submission failed", err)
+	})
+
+	t.Run("pre-Fulu blinded block - uses regular handleBlindedBlock path", func(t *testing.T) {
+		// Set up config with Fulu fork at epoch 10 (future)
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.FuluForkEpoch = 10
+		params.OverrideBeaconConfig(cfg)
+
+		mockBuilder := &builderTest.MockBuilderService{
+			HasConfigured: true,
+			Cfg:           &builderTest.Config{BeaconDB: db},
+			PayloadDeneb:  &enginev1.ExecutionPayloadDeneb{},
+			BlobBundle:    &enginev1.BlobsBundle{},
+		}
+
+		c := &mock.ChainService{State: beaconState, Root: parentRoot[:]}
+		proposerServer := &Server{
+			ChainStartFetcher: &mockExecution.Chain{},
+			Eth1InfoFetcher:   &mockExecution.Chain{},
+			Eth1BlockFetcher:  &mockExecution.Chain{},
+			BlockReceiver:     c,
+			BlobReceiver:      c,
+			HeadFetcher:       c,
+			BlockNotifier:     c.BlockNotifier(),
+			OperationNotifier: c.OperationNotifier(),
+			StateGen:          stategen.New(db, doublylinkedtree.New()),
+			TimeFetcher:       c,
+			SyncChecker:       &mockSync.Sync{IsSyncing: false},
+			BeaconDB:          db,
+			BlockBuilder:      mockBuilder,
+			P2P:               &mockp2p.MockBroadcaster{},
+		}
+
+		// Create a blinded block at slot 160 (epoch 5, which is < FuluForkEpoch=10)
+		blindedBlock := util.NewBlindedBeaconBlockDeneb()
+		blindedBlock.Message.Slot = 160
+		blindedBlock.Message.ProposerIndex = 0
+		blindedBlock.Message.ParentRoot = parentRoot[:]
+		blindedBlock.Message.StateRoot = make([]byte, 32)
+
+		req := &ethpb.GenericSignedBeaconBlock{
+			Block: &ethpb.GenericSignedBeaconBlock_BlindedDeneb{BlindedDeneb: blindedBlock},
+		}
+
+		// This should NOT trigger the post-Fulu early return path, but use handleBlindedBlock instead
+		res, err := proposerServer.ProposeBeaconBlock(ctx, req)
+		require.NoError(t, err)
+		require.NotNil(t, res)
+		require.NotEmpty(t, res.BlockRoot)
+	})
+
+	t.Run("boundary test - exactly at Fulu fork epoch", func(t *testing.T) {
+		// Set up config with Fulu fork at epoch 5
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.FuluForkEpoch = 5
+		params.OverrideBeaconConfig(cfg)
+
+		mockBuilder := &builderTest.MockBuilderService{
+			HasConfigured:                 true,
+			Cfg:                           &builderTest.Config{BeaconDB: db},
+			ErrSubmitBlindedBlockPostFulu: nil,
+		}
+
+		c := &mock.ChainService{State: beaconState, Root: parentRoot[:]}
+		proposerServer := &Server{
+			ChainStartFetcher: &mockExecution.Chain{},
+			Eth1InfoFetcher:   &mockExecution.Chain{},
+			Eth1BlockFetcher:  &mockExecution.Chain{},
+			BlockReceiver:     c,
+			BlobReceiver:      c,
+			HeadFetcher:       c,
+			BlockNotifier:     c.BlockNotifier(),
+			OperationNotifier: c.OperationNotifier(),
+			StateGen:          stategen.New(db, doublylinkedtree.New()),
+			TimeFetcher:       c,
+			SyncChecker:       &mockSync.Sync{IsSyncing: false},
+			BeaconDB:          db,
+			BlockBuilder:      mockBuilder,
+			P2P:               &mockp2p.MockBroadcaster{},
+		}
+
+		// Create a blinded block at slot 160 (exactly epoch 5)
+		blindedBlock := util.NewBlindedBeaconBlockDeneb()
+		blindedBlock.Message.Slot = 160 // 160/32 = 5 (exactly at FuluForkEpoch)
+		blindedBlock.Message.ProposerIndex = 0
+		blindedBlock.Message.ParentRoot = parentRoot[:]
+		blindedBlock.Message.StateRoot = make([]byte, 32)
+
+		req := &ethpb.GenericSignedBeaconBlock{
+			Block: &ethpb.GenericSignedBeaconBlock_BlindedDeneb{BlindedDeneb: blindedBlock},
+		}
+
+		// Should trigger post-Fulu path since epoch 5 >= FuluForkEpoch (5)
+		res, err := proposerServer.ProposeBeaconBlock(ctx, req)
+		require.NoError(t, err)
+		require.NotNil(t, res)
+		require.NotEmpty(t, res.BlockRoot)
+	})
+
+	t.Run("unblinded block - not affected by post-Fulu condition", func(t *testing.T) {
+		// Set up config with Fulu fork at epoch 5
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig().Copy()
+		cfg.FuluForkEpoch = 5
+		params.OverrideBeaconConfig(cfg)
+
+		c := &mock.ChainService{State: beaconState, Root: parentRoot[:]}
+		proposerServer := &Server{
+			ChainStartFetcher: &mockExecution.Chain{},
+			Eth1InfoFetcher:   &mockExecution.Chain{},
+			Eth1BlockFetcher:  &mockExecution.Chain{},
+			BlockReceiver:     c,
+			BlobReceiver:      c,
+			HeadFetcher:       c,
+			BlockNotifier:     c.BlockNotifier(),
+			OperationNotifier: c.OperationNotifier(),
+			StateGen:          stategen.New(db, doublylinkedtree.New()),
+			TimeFetcher:       c,
+			SyncChecker:       &mockSync.Sync{IsSyncing: false},
+			BeaconDB:          db,
+			P2P:               &mockp2p.MockBroadcaster{},
+		}
+
+		// Create an unblinded block at slot 160 (epoch 5)
+		unblindeBlock := util.NewBeaconBlockDeneb()
+		unblindeBlock.Block.Slot = 160
+		unblindeBlock.Block.ProposerIndex = 0
+		unblindeBlock.Block.ParentRoot = parentRoot[:]
+		unblindeBlock.Block.StateRoot = make([]byte, 32)
+
+		req := &ethpb.GenericSignedBeaconBlock{
+			Block: &ethpb.GenericSignedBeaconBlock_Deneb{
+				Deneb: &ethpb.SignedBeaconBlockContentsDeneb{
+					Block: unblindeBlock,
+				},
+			},
+		}
+
+		// Unblinded blocks should not trigger post-Fulu condition, even at epoch >= FuluForkEpoch
+		res, err := proposerServer.ProposeBeaconBlock(ctx, req)
+		require.NoError(t, err)
+		require.NotNil(t, res)
+		require.NotEmpty(t, res.BlockRoot)
+	})
+}

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

@@ -69,6 +69,7 @@ type Server struct {
 	SyncCommitteePool       synccommittee.Pool
 	BlockReceiver           blockchain.BlockReceiver
 	BlobReceiver            blockchain.BlobReceiver
+	DataColumnReceiver      blockchain.DataColumnReceiver
 	MockEth1Votes           bool
 	Eth1BlockFetcher        execution.POWBlockFetcher
 	PendingDepositsFetcher  depositsnapshot.PendingDepositsFetcher

beacon-chain/rpc/service.go

@@ -89,6 +89,7 @@ type Config struct {
 	AttestationReceiver       blockchain.AttestationReceiver
 	BlockReceiver             blockchain.BlockReceiver
 	BlobReceiver              blockchain.BlobReceiver
+	DataColumnReceiver        blockchain.DataColumnReceiver
 	ExecutionChainService     execution.Chain
 	ChainStartFetcher         execution.ChainStartFetcher
 	ExecutionChainInfoFetcher execution.ChainInfoFetcher
@@ -120,6 +121,7 @@ type Config struct {
 	Router                    *http.ServeMux
 	ClockWaiter               startup.ClockWaiter
 	BlobStorage               *filesystem.BlobStorage
+	DataColumnStorage         *filesystem.DataColumnStorage
 	TrackedValidatorsCache    *cache.TrackedValidatorsCache
 	PayloadIDCache            *cache.PayloadIDCache
 	LCStore                   *lightClient.Store
@@ -196,6 +198,7 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 		ChainInfoFetcher:   s.cfg.ChainInfoFetcher,
 		GenesisTimeFetcher: s.cfg.GenesisTimeFetcher,
 		BlobStorage:        s.cfg.BlobStorage,
+		DataColumnStorage:  s.cfg.DataColumnStorage,
 	}
 	rewardFetcher := &rewards.BlockRewardService{Replayer: ch, DB: s.cfg.BeaconDB}
 	coreService := &core.Service{
@@ -236,6 +239,7 @@ func NewService(ctx context.Context, cfg *Config) *Service {
 		P2P:                     s.cfg.Broadcaster,
 		BlockReceiver:           s.cfg.BlockReceiver,
 		BlobReceiver:            s.cfg.BlobReceiver,
+		DataColumnReceiver:      s.cfg.DataColumnReceiver,
 		MockEth1Votes:           s.cfg.MockEth1Votes,
 		Eth1BlockFetcher:        s.cfg.ExecutionChainService,
 		PendingDepositsFetcher:  s.cfg.PendingDepositFetcher,

beacon-chain/rpc/testutil/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "mock_blocker.go",
         "mock_exec_chain_info_fetcher.go",
         "mock_genesis_timefetcher.go",
+        "mock_sidecars.go",
         "mock_stater.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/testutil",