Changelog fragment

* adding in check for post fulu support

* gaz

* fixing unit tests and typo

* gaz

* manu feedback

* addressing manu's suggestion

* fixing tests

CHANGELOG.md

@@ -2993,7 +2993,7 @@ There are two known issues with this release:
 
 ### Added
 
-- Web3Signer support. See the [documentation](https://docs.prylabs.network/docs/next/wallet/web3signer) for more
+- Web3Signer support. See the [documentation](https://prysm.offchainlabs.com/docs/manage-wallet/web3signer/) for more
   details.
 - Bellatrix support. See [kiln testnet instructions](https://hackmd.io/OqIoTiQvS9KOIataIFksBQ?view)
 - Weak subjectivity sync / checkpoint sync. This is an experimental feature and may have unintended side effects for

DEPENDENCIES.md

@@ -2,7 +2,7 @@
 
 Prysm is go project with many complicated dependencies, including some c++ based libraries. There
 are two parts to Prysm's dependency management. Go modules and bazel managed dependencies. Be sure 
-to read [Why Bazel?](https://github.com/OffchainLabs/documentation/issues/138) to fully
+to read [Why Bazel?](https://prysm.offchainlabs.com/docs/install-prysm/install-with-bazel/#why-bazel) to fully
 understand the reasoning behind an additional layer of build tooling via Bazel rather than a pure
 "go build" project.
 

WORKSPACE

@@ -253,16 +253,16 @@ filegroup(
     url = "https://github.com/ethereum/EIPs/archive/5480440fe51742ed23342b68cf106cefd427e39d.tar.gz",
 )
 
-consensus_spec_version = "v1.6.0-alpha.5"
+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-BXuEb1XbeSft0qzVFnoB8KC0YR1qM3ybT5lKUDbUWn8=",
-        "minimal": "sha256-EjwSHgBbWSoy5hm9V+A/bVMabyojaKsBNPrRtuPVq4k=",
-        "mainnet": "sha256-OGWMzarzaV1B9mVpy48/DCUbhjfX+b64pAxWwPLWhAs=",
+        "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-FQWR5EZuVcQGR0ol9vpd7eunnfGexJ/7J3xycrFEJbU=",
+    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/server/httprest/options.go

@@ -1,9 +1,8 @@
 package httprest
 
 import (
-	"time"
-
 	"net/http"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/api/server/middleware"
 )

async/every.go

@@ -29,3 +29,24 @@ func RunEvery(ctx context.Context, period time.Duration, f func()) {
 		}
 	}()
 }
+
+// RunEveryDynamic runs the provided command periodically with a dynamic interval.
+// The interval is determined by calling the intervalFunc before each execution.
+// It runs in a goroutine, and can be cancelled by finishing the supplied context.
+func RunEveryDynamic(ctx context.Context, intervalFunc func() time.Duration, f func()) {
+	go func() {
+		for {
+			// Get the next interval duration
+			interval := intervalFunc()
+			timer := time.NewTimer(interval)
+
+			select {
+			case <-timer.C:
+				f()
+			case <-ctx.Done():
+				timer.Stop()
+				return
+			}
+		}
+	}()
+}

async/every_test.go

@@ -38,3 +38,51 @@ func TestEveryRuns(t *testing.T) {
 		t.Error("Counter incremented after stop")
 	}
 }
+
+func TestEveryDynamicRuns(t *testing.T) {
+	ctx, cancel := context.WithCancel(t.Context())
+
+	i := int32(0)
+	intervalCount := int32(0)
+
+	// Start with 50ms intervals, then increase to 100ms after 2 calls
+	async.RunEveryDynamic(ctx, func() time.Duration {
+		count := atomic.LoadInt32(&intervalCount)
+		atomic.AddInt32(&intervalCount, 1)
+		if count < 2 {
+			return 50 * time.Millisecond
+		}
+		return 100 * time.Millisecond
+	}, func() {
+		atomic.AddInt32(&i, 1)
+	})
+
+	// After 150ms, should have run at least 2 times (at 50ms and 100ms)
+	time.Sleep(150 * time.Millisecond)
+	count1 := atomic.LoadInt32(&i)
+	if count1 < 2 {
+		t.Errorf("Expected at least 2 runs after 150ms, got %d", count1)
+	}
+
+	// After another 150ms (total 300ms), should have run at least 3 times
+	// (50ms, 100ms, 150ms, 250ms)
+	time.Sleep(150 * time.Millisecond)
+	count2 := atomic.LoadInt32(&i)
+	if count2 < 3 {
+		t.Errorf("Expected at least 3 runs after 300ms, got %d", count2)
+	}
+
+	cancel()
+
+	// Sleep for a bit to let the cancel take place.
+	time.Sleep(100 * time.Millisecond)
+
+	last := atomic.LoadInt32(&i)
+
+	// Sleep for a bit and ensure the value has not increased.
+	time.Sleep(200 * time.Millisecond)
+
+	if atomic.LoadInt32(&i) != last {
+		t.Error("Counter incremented after stop")
+	}
+}

beacon-chain/blockchain/kzg/kzg.go

@@ -102,7 +102,6 @@ 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

@@ -1,10 +1,30 @@
 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"
 )
 
+func bytesToBlob(blob []byte) *GoKZG.Blob {
+	var ret GoKZG.Blob
+	copy(ret[:], blob)
+	return &ret
+}
+
+func bytesToCommitment(commitment []byte) (ret GoKZG.KZGCommitment) {
+	copy(ret[:], commitment)
+	return
+}
+
+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 {
@@ -27,18 +47,121 @@ func Verify(blobSidecars ...blocks.ROBlob) error {
 	return kzgContext.VerifyBlobKZGProofBatch(blobs, cmts, proofs)
 }
 
-func bytesToBlob(blob []byte) *GoKZG.Blob {
-	var ret GoKZG.Blob
-	copy(ret[:], blob)
-	return &ret
+// 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
 }
 
-func bytesToCommitment(commitment []byte) (ret GoKZG.KZGCommitment) {
-	copy(ret[:], commitment)
-	return
-}
+// 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
 
-func bytesToKZGProof(proof []byte) (ret GoKZG.KZGProof) {
-	copy(ret[:], proof)
-	return
+	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

@@ -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")
 	}
 

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

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/cache/sync_committee.go

@@ -67,6 +67,30 @@ func (s *SyncCommitteeCache) Clear() {
 	s.cache = cache.NewFIFO(keyFn)
 }
 
+// CurrentPeriodPositions returns current period positions of validator indices with respect with
+// sync committee. If any input validator index has no assignment, an empty list will be returned
+// for that validator. If the input root does not exist in cache, `ErrNonExistingSyncCommitteeKey` is returned.
+// Manual checking of state for index position in state is recommended when `ErrNonExistingSyncCommitteeKey` is returned.
+func (s *SyncCommitteeCache) CurrentPeriodPositions(root [32]byte, indices []primitives.ValidatorIndex) ([][]primitives.CommitteeIndex, error) {
+	s.lock.RLock()
+	defer s.lock.RUnlock()
+
+	pos, err := s.positionsInCommittee(root, indices)
+	if err != nil {
+		return nil, err
+	}
+	result := make([][]primitives.CommitteeIndex, len(pos))
+	for i, p := range pos {
+		if p == nil {
+			result[i] = []primitives.CommitteeIndex{}
+		} else {
+			result[i] = p.currentPeriod
+		}
+	}
+
+	return result, nil
+}
+
 // CurrentPeriodIndexPosition returns current period index position of a validator index with respect with
 // sync committee. If the input validator index has no assignment, an empty list will be returned.
 // If the input root does not exist in cache, `ErrNonExistingSyncCommitteeKey` is returned.
@@ -104,11 +128,7 @@ func (s *SyncCommitteeCache) NextPeriodIndexPosition(root [32]byte, valIdx primi
 	return pos.nextPeriod, nil
 }
 
-// Helper function for `CurrentPeriodIndexPosition` and `NextPeriodIndexPosition` to return a mapping
-// of validator index to its index(s) position in the sync committee.
-func (s *SyncCommitteeCache) idxPositionInCommittee(
-	root [32]byte, valIdx primitives.ValidatorIndex,
-) (*positionInCommittee, error) {
+func (s *SyncCommitteeCache) positionsInCommittee(root [32]byte, indices []primitives.ValidatorIndex) ([]*positionInCommittee, error) {
 	obj, exists, err := s.cache.GetByKey(key(root))
 	if err != nil {
 		return nil, err
@@ -121,13 +141,33 @@ func (s *SyncCommitteeCache) idxPositionInCommittee(
 	if !ok {
 		return nil, errNotSyncCommitteeIndexPosition
 	}
-	idxInCommittee, ok := item.vIndexToPositionMap[valIdx]
-	if !ok {
-		SyncCommitteeCacheMiss.Inc()
+	result := make([]*positionInCommittee, len(indices))
+	for i, idx := range indices {
+		idxInCommittee, ok := item.vIndexToPositionMap[idx]
+		if ok {
+			SyncCommitteeCacheHit.Inc()
+			result[i] = idxInCommittee
+		} else {
+			SyncCommitteeCacheMiss.Inc()
+			result[i] = nil
+		}
+	}
+	return result, nil
+}
+
+// Helper function for `CurrentPeriodIndexPosition` and `NextPeriodIndexPosition` to return a mapping
+// of validator index to its index(s) position in the sync committee.
+func (s *SyncCommitteeCache) idxPositionInCommittee(
+	root [32]byte, valIdx primitives.ValidatorIndex,
+) (*positionInCommittee, error) {
+	positions, err := s.positionsInCommittee(root, []primitives.ValidatorIndex{valIdx})
+	if err != nil {
+		return nil, err
+	}
+	if len(positions) == 0 {
 		return nil, nil
 	}
-	SyncCommitteeCacheHit.Inc()
-	return idxInCommittee, nil
+	return positions[0], nil
 }
 
 // UpdatePositionsInCommittee updates caching of validators position in sync committee in respect to

beacon-chain/cache/sync_committee_disabled.go

@@ -16,6 +16,11 @@ func NewSyncCommittee() *FakeSyncCommitteeCache {
 	return &FakeSyncCommitteeCache{}
 }
 
+// CurrentPeriodPositions -- fake
+func (s *FakeSyncCommitteeCache) CurrentPeriodPositions(root [32]byte, indices []primitives.ValidatorIndex) ([][]primitives.CommitteeIndex, error) {
+	return nil, nil
+}
+
 // CurrentEpochIndexPosition -- fake.
 func (s *FakeSyncCommitteeCache) CurrentPeriodIndexPosition(root [32]byte, valIdx primitives.ValidatorIndex) ([]primitives.CommitteeIndex, error) {
 	return nil, nil

beacon-chain/core/blocks/attester_slashing.go

@@ -5,6 +5,7 @@ import (
 	"sort"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
@@ -39,11 +40,11 @@ func ProcessAttesterSlashings(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashings []ethpb.AttSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	var err error
 	for _, slashing := range slashings {
-		beaconState, err = ProcessAttesterSlashing(ctx, beaconState, slashing, slashFunc)
+		beaconState, err = ProcessAttesterSlashing(ctx, beaconState, slashing, exitInfo)
 		if err != nil {
 			return nil, err
 		}
@@ -56,7 +57,7 @@ func ProcessAttesterSlashing(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashing ethpb.AttSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	if err := VerifyAttesterSlashing(ctx, beaconState, slashing); err != nil {
 		return nil, errors.Wrap(err, "could not verify attester slashing")
@@ -75,10 +76,9 @@ func ProcessAttesterSlashing(
 			return nil, err
 		}
 		if helpers.IsSlashableValidator(val.ActivationEpoch(), val.WithdrawableEpoch(), val.Slashed(), currentEpoch) {
-			beaconState, err = slashFunc(ctx, beaconState, primitives.ValidatorIndex(validatorIndex))
+			beaconState, err = validators.SlashValidator(ctx, beaconState, primitives.ValidatorIndex(validatorIndex), exitInfo)
 			if err != nil {
-				return nil, errors.Wrapf(err, "could not slash validator index %d",
-					validatorIndex)
+				return nil, errors.Wrapf(err, "could not slash validator index %d", validatorIndex)
 			}
 			slashedAny = true
 		}

beacon-chain/core/blocks/attester_slashing_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
@@ -44,11 +45,10 @@ func TestProcessAttesterSlashings_DataNotSlashable(t *testing.T) {
 				Target: &ethpb.Checkpoint{Epoch: 1}},
 		})}}
 
-	var registry []*ethpb.Validator
 	currentSlot := primitives.Slot(0)
 
 	beaconState, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
-		Validators: registry,
+		Validators: []*ethpb.Validator{{}},
 		Slot:       currentSlot,
 	})
 	require.NoError(t, err)
@@ -62,16 +62,15 @@ func TestProcessAttesterSlashings_DataNotSlashable(t *testing.T) {
 	for i, s := range b.Block.Body.AttesterSlashings {
 		ss[i] = s
 	}
-	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.SlashValidator)
+	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, "attestations are not slashable", err)
 }
 
 func TestProcessAttesterSlashings_IndexedAttestationFailedToVerify(t *testing.T) {
-	var registry []*ethpb.Validator
 	currentSlot := primitives.Slot(0)
 
 	beaconState, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
-		Validators: registry,
+		Validators: []*ethpb.Validator{{}},
 		Slot:       currentSlot,
 	})
 	require.NoError(t, err)
@@ -101,7 +100,7 @@ func TestProcessAttesterSlashings_IndexedAttestationFailedToVerify(t *testing.T)
 	for i, s := range b.Block.Body.AttesterSlashings {
 		ss[i] = s
 	}
-	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.SlashValidator)
+	_, err = blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, "validator indices count exceeds MAX_VALIDATORS_PER_COMMITTEE", err)
 }
 
@@ -243,7 +242,7 @@ func TestProcessAttesterSlashings_AppliesCorrectStatus(t *testing.T) {
 			currentSlot := 2 * params.BeaconConfig().SlotsPerEpoch
 			require.NoError(t, tc.st.SetSlot(currentSlot))
 
-			newState, err := blocks.ProcessAttesterSlashings(t.Context(), tc.st, []ethpb.AttSlashing{tc.slashing}, v.SlashValidator)
+			newState, err := blocks.ProcessAttesterSlashings(t.Context(), tc.st, []ethpb.AttSlashing{tc.slashing}, v.ExitInformation(tc.st))
 			require.NoError(t, err)
 			newRegistry := newState.Validators()
 
@@ -265,3 +264,83 @@ func TestProcessAttesterSlashings_AppliesCorrectStatus(t *testing.T) {
 		})
 	}
 }
+
+func TestProcessAttesterSlashing_ExitEpochGetsUpdated(t *testing.T) {
+	st, keys := util.DeterministicGenesisStateElectra(t, 8)
+	bal, err := helpers.TotalActiveBalance(st)
+	require.NoError(t, err)
+	perEpochChurn := helpers.ActivationExitChurnLimit(primitives.Gwei(bal))
+	vals := st.Validators()
+
+	// We set the total effective balance of slashed validators
+	// higher than the churn limit for a single epoch.
+	vals[0].EffectiveBalance = uint64(perEpochChurn / 3)
+	vals[1].EffectiveBalance = uint64(perEpochChurn / 3)
+	vals[2].EffectiveBalance = uint64(perEpochChurn / 3)
+	vals[3].EffectiveBalance = uint64(perEpochChurn / 3)
+	require.NoError(t, st.SetValidators(vals))
+
+	sl1att1 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		Data: &ethpb.AttestationData{
+			Source: &ethpb.Checkpoint{Epoch: 1},
+		},
+		AttestingIndices: []uint64{0, 1},
+	})
+	sl1att2 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		AttestingIndices: []uint64{0, 1},
+	})
+	slashing1 := &ethpb.AttesterSlashingElectra{
+		Attestation_1: sl1att1,
+		Attestation_2: sl1att2,
+	}
+	sl2att1 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		Data: &ethpb.AttestationData{
+			Source: &ethpb.Checkpoint{Epoch: 1},
+		},
+		AttestingIndices: []uint64{2, 3},
+	})
+	sl2att2 := util.HydrateIndexedAttestationElectra(&ethpb.IndexedAttestationElectra{
+		AttestingIndices: []uint64{2, 3},
+	})
+	slashing2 := &ethpb.AttesterSlashingElectra{
+		Attestation_1: sl2att1,
+		Attestation_2: sl2att2,
+	}
+
+	domain, err := signing.Domain(st.Fork(), 0, params.BeaconConfig().DomainBeaconAttester, st.GenesisValidatorsRoot())
+	require.NoError(t, err)
+
+	signingRoot, err := signing.ComputeSigningRoot(sl1att1.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 := keys[0].Sign(signingRoot[:])
+	sig1 := keys[1].Sign(signingRoot[:])
+	aggregateSig := bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl1att1.Signature = aggregateSig.Marshal()
+
+	signingRoot, err = signing.ComputeSigningRoot(sl1att2.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = keys[0].Sign(signingRoot[:])
+	sig1 = keys[1].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl1att2.Signature = aggregateSig.Marshal()
+
+	signingRoot, err = signing.ComputeSigningRoot(sl2att1.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = keys[2].Sign(signingRoot[:])
+	sig1 = keys[3].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl2att1.Signature = aggregateSig.Marshal()
+
+	signingRoot, err = signing.ComputeSigningRoot(sl2att2.GetData(), domain)
+	assert.NoError(t, err, "Could not get signing root of beacon block header")
+	sig0 = keys[2].Sign(signingRoot[:])
+	sig1 = keys[3].Sign(signingRoot[:])
+	aggregateSig = bls.AggregateSignatures([]bls.Signature{sig0, sig1})
+	sl2att2.Signature = aggregateSig.Marshal()
+
+	exitInfo := v.ExitInformation(st)
+	assert.Equal(t, primitives.Epoch(0), exitInfo.HighestExitEpoch)
+	_, err = blocks.ProcessAttesterSlashings(t.Context(), st, []ethpb.AttSlashing{slashing1, slashing2}, exitInfo)
+	require.NoError(t, err)
+	assert.Equal(t, primitives.Epoch(6), exitInfo.HighestExitEpoch)
+}

beacon-chain/core/blocks/block_operations_fuzz_test.go

@@ -191,7 +191,7 @@ func TestFuzzProcessProposerSlashings_10000(t *testing.T) {
 		fuzzer.Fuzz(p)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessProposerSlashings(ctx, s, []*ethpb.ProposerSlashing{p}, v.SlashValidator)
+		r, err := ProcessProposerSlashings(ctx, s, []*ethpb.ProposerSlashing{p}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and slashing: %v", r, err, state, p)
 		}
@@ -224,7 +224,7 @@ func TestFuzzProcessAttesterSlashings_10000(t *testing.T) {
 		fuzzer.Fuzz(a)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessAttesterSlashings(ctx, s, []ethpb.AttSlashing{a}, v.SlashValidator)
+		r, err := ProcessAttesterSlashings(ctx, s, []ethpb.AttSlashing{a}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and slashing: %v", r, err, state, a)
 		}
@@ -334,7 +334,7 @@ func TestFuzzProcessVoluntaryExits_10000(t *testing.T) {
 		fuzzer.Fuzz(e)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessVoluntaryExits(ctx, s, []*ethpb.SignedVoluntaryExit{e})
+		r, err := ProcessVoluntaryExits(ctx, s, []*ethpb.SignedVoluntaryExit{e}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and exit: %v", r, err, state, e)
 		}
@@ -351,7 +351,7 @@ func TestFuzzProcessVoluntaryExitsNoVerify_10000(t *testing.T) {
 		fuzzer.Fuzz(e)
 		s, err := state_native.InitializeFromProtoUnsafePhase0(state)
 		require.NoError(t, err)
-		r, err := ProcessVoluntaryExits(t.Context(), s, []*ethpb.SignedVoluntaryExit{e})
+		r, err := ProcessVoluntaryExits(t.Context(), s, []*ethpb.SignedVoluntaryExit{e}, v.ExitInformation(s))
 		if err != nil && r != nil {
 			t.Fatalf("return value should be nil on err. found: %v on error: %v for state: %v and block: %v", r, err, state, e)
 		}

beacon-chain/core/blocks/block_regression_test.go

@@ -94,7 +94,7 @@ func TestProcessAttesterSlashings_RegressionSlashableIndices(t *testing.T) {
 	for i, s := range b.Block.Body.AttesterSlashings {
 		ss[i] = s
 	}
-	newState, err := blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.SlashValidator)
+	newState, err := blocks.ProcessAttesterSlashings(t.Context(), beaconState, ss, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 	newRegistry := newState.Validators()
 	if !newRegistry[expectedSlashedVal].Slashed {

beacon-chain/core/blocks/exit.go

@@ -9,7 +9,6 @@ import (
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -50,13 +49,12 @@ func ProcessVoluntaryExits(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	exits []*ethpb.SignedVoluntaryExit,
+	exitInfo *v.ExitInfo,
 ) (state.BeaconState, error) {
 	// Avoid calculating the epoch churn if no exits exist.
 	if len(exits) == 0 {
 		return beaconState, nil
 	}
-	maxExitEpoch, churn := v.MaxExitEpochAndChurn(beaconState)
-	var exitEpoch primitives.Epoch
 	for idx, exit := range exits {
 		if exit == nil || exit.Exit == nil {
 			return nil, errors.New("nil voluntary exit in block body")
@@ -68,15 +66,8 @@ func ProcessVoluntaryExits(
 		if err := VerifyExitAndSignature(val, beaconState, exit); err != nil {
 			return nil, errors.Wrapf(err, "could not verify exit %d", idx)
 		}
-		beaconState, exitEpoch, err = v.InitiateValidatorExit(ctx, beaconState, exit.Exit.ValidatorIndex, maxExitEpoch, churn)
-		if err == nil {
-			if exitEpoch > maxExitEpoch {
-				maxExitEpoch = exitEpoch
-				churn = 1
-			} else if exitEpoch == maxExitEpoch {
-				churn++
-			}
-		} else if !errors.Is(err, v.ErrValidatorAlreadyExited) {
+		beaconState, err = v.InitiateValidatorExit(ctx, beaconState, exit.Exit.ValidatorIndex, exitInfo)
+		if err != nil && !errors.Is(err, v.ErrValidatorAlreadyExited) {
 			return nil, err
 		}
 	}

beacon-chain/core/blocks/exit_test.go

@@ -7,6 +7,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	state_native "github.com/OffchainLabs/prysm/v6/beacon-chain/state/state-native"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -46,7 +47,7 @@ func TestProcessVoluntaryExits_NotActiveLongEnoughToExit(t *testing.T) {
 	}
 
 	want := "validator has not been active long enough to exit"
-	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits)
+	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits, validators.ExitInformation(state))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -76,7 +77,7 @@ func TestProcessVoluntaryExits_ExitAlreadySubmitted(t *testing.T) {
 	}
 
 	want := "validator with index 0 has already submitted an exit, which will take place at epoch: 10"
-	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits)
+	_, err = blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits, validators.ExitInformation(state))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -124,7 +125,7 @@ func TestProcessVoluntaryExits_AppliesCorrectStatus(t *testing.T) {
 		},
 	}
 
-	newState, err := blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits)
+	newState, err := blocks.ProcessVoluntaryExits(t.Context(), state, b.Block.Body.VoluntaryExits, validators.ExitInformation(state))
 	require.NoError(t, err, "Could not process exits")
 	newRegistry := newState.Validators()
 	if newRegistry[0].ExitEpoch != helpers.ActivationExitEpoch(primitives.Epoch(state.Slot()/params.BeaconConfig().SlotsPerEpoch)) {

beacon-chain/core/blocks/proposer_slashing.go

@@ -7,9 +7,9 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
@@ -19,11 +19,6 @@ import (
 // ErrCouldNotVerifyBlockHeader is returned when a block header's signature cannot be verified.
 var ErrCouldNotVerifyBlockHeader = errors.New("could not verify beacon block header")
 
-type slashValidatorFunc func(
-	ctx context.Context,
-	st state.BeaconState,
-	vid primitives.ValidatorIndex) (state.BeaconState, error)
-
 // ProcessProposerSlashings is one of the operations performed
 // on each processed beacon block to slash proposers based on
 // slashing conditions if any slashable events occurred.
@@ -54,11 +49,11 @@ func ProcessProposerSlashings(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashings []*ethpb.ProposerSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	var err error
 	for _, slashing := range slashings {
-		beaconState, err = ProcessProposerSlashing(ctx, beaconState, slashing, slashFunc)
+		beaconState, err = ProcessProposerSlashing(ctx, beaconState, slashing, exitInfo)
 		if err != nil {
 			return nil, err
 		}
@@ -71,7 +66,7 @@ func ProcessProposerSlashing(
 	ctx context.Context,
 	beaconState state.BeaconState,
 	slashing *ethpb.ProposerSlashing,
-	slashFunc slashValidatorFunc,
+	exitInfo *validators.ExitInfo,
 ) (state.BeaconState, error) {
 	var err error
 	if slashing == nil {
@@ -80,7 +75,7 @@ func ProcessProposerSlashing(
 	if err = VerifyProposerSlashing(beaconState, slashing); err != nil {
 		return nil, errors.Wrap(err, "could not verify proposer slashing")
 	}
-	beaconState, err = slashFunc(ctx, beaconState, slashing.Header_1.Header.ProposerIndex)
+	beaconState, err = validators.SlashValidator(ctx, beaconState, slashing.Header_1.Header.ProposerIndex, exitInfo)
 	if err != nil {
 		return nil, errors.Wrapf(err, "could not slash proposer index %d", slashing.Header_1.Header.ProposerIndex)
 	}

beacon-chain/core/blocks/proposer_slashing_test.go

@@ -50,7 +50,7 @@ func TestProcessProposerSlashings_UnmatchedHeaderSlots(t *testing.T) {
 		},
 	}
 	want := "mismatched header slots"
-	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.SlashValidator)
+	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -83,7 +83,7 @@ func TestProcessProposerSlashings_SameHeaders(t *testing.T) {
 		},
 	}
 	want := "expected slashing headers to differ"
-	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.SlashValidator)
+	_, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -133,7 +133,7 @@ func TestProcessProposerSlashings_ValidatorNotSlashable(t *testing.T) {
 		"validator with key %#x is not slashable",
 		bytesutil.ToBytes48(beaconState.Validators()[0].PublicKey),
 	)
-	_, err = blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.SlashValidator)
+	_, err = blocks.ProcessProposerSlashings(t.Context(), beaconState, b.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	assert.ErrorContains(t, want, err)
 }
 
@@ -172,7 +172,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatus(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()
@@ -220,7 +220,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusAltair(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()
@@ -268,7 +268,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusBellatrix(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()
@@ -316,7 +316,7 @@ func TestProcessProposerSlashings_AppliesCorrectStatusCapella(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Body.ProposerSlashings = slashings
 
-	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.SlashValidator)
+	newState, err := blocks.ProcessProposerSlashings(t.Context(), beaconState, block.Block.Body.ProposerSlashings, v.ExitInformation(beaconState))
 	require.NoError(t, err)
 
 	newStateVals := newState.Validators()

beacon-chain/core/electra/registry_updates.go

@@ -84,8 +84,8 @@ func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) error {
 	// Handle validator ejections.
 	for _, idx := range eligibleForEjection {
 		var err error
-		// exitQueueEpoch and churn arguments are not used in electra.
-		st, _, err = validators.InitiateValidatorExit(ctx, st, idx, 0 /*exitQueueEpoch*/, 0 /*churn*/)
+		// exit info is not used in electra
+		st, err = validators.InitiateValidatorExit(ctx, st, idx, &validators.ExitInfo{})
 		if err != nil && !errors.Is(err, validators.ErrValidatorAlreadyExited) {
 			return fmt.Errorf("failed to initiate validator exit at index %d: %w", idx, err)
 		}

beacon-chain/core/electra/transition_no_verify_sig.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
@@ -46,18 +47,21 @@ var (
 //      # [New in Electra:EIP7251]
 //      for_ops(body.execution_payload.consolidation_requests, process_consolidation_request)
 
-func ProcessOperations(
-	ctx context.Context,
-	st state.BeaconState,
-	block interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
+func ProcessOperations(ctx context.Context, st state.BeaconState, block interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
+	var err error
+
 	// 6110 validations are in VerifyOperationLengths
 	bb := block.Body()
 	// Electra extends the altair operations.
-	st, err := ProcessProposerSlashings(ctx, st, bb.ProposerSlashings(), v.SlashValidator)
+	exitInfo := v.ExitInformation(st)
+	if err := helpers.UpdateTotalActiveBalanceCache(st, exitInfo.TotalActiveBalance); err != nil {
+		return nil, errors.Wrap(err, "could not update total active balance cache")
+	}
+	st, err = ProcessProposerSlashings(ctx, st, bb.ProposerSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process altair proposer slashing")
 	}
-	st, err = ProcessAttesterSlashings(ctx, st, bb.AttesterSlashings(), v.SlashValidator)
+	st, err = ProcessAttesterSlashings(ctx, st, bb.AttesterSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process altair attester slashing")
 	}
@@ -68,7 +72,7 @@ func ProcessOperations(
 	if _, err := ProcessDeposits(ctx, st, bb.Deposits()); err != nil { // new in electra
 		return nil, errors.Wrap(err, "could not process altair deposit")
 	}
-	st, err = ProcessVoluntaryExits(ctx, st, bb.VoluntaryExits())
+	st, err = ProcessVoluntaryExits(ctx, st, bb.VoluntaryExits(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process voluntary exits")
 	}

beacon-chain/core/electra/withdrawals.go

@@ -147,9 +147,8 @@ func ProcessWithdrawalRequests(ctx context.Context, st state.BeaconState, wrs []
 		if isFullExitRequest {
 			// Only exit validator if it has no pending withdrawals in the queue
 			if pendingBalanceToWithdraw == 0 {
-				maxExitEpoch, churn := validators.MaxExitEpochAndChurn(st)
 				var err error
-				st, _, err = validators.InitiateValidatorExit(ctx, st, vIdx, maxExitEpoch, churn)
+				st, err = validators.InitiateValidatorExit(ctx, st, vIdx, validators.ExitInformation(st))
 				if err != nil {
 					return nil, err
 				}

beacon-chain/core/epoch/epoch_processing.go

@@ -99,8 +99,7 @@ func ProcessRegistryUpdates(ctx context.Context, st state.BeaconState) (state.Be
 	for _, idx := range eligibleForEjection {
 		// Here is fine to do a quadratic loop since this should
 		// barely happen
-		maxExitEpoch, churn := validators.MaxExitEpochAndChurn(st)
-		st, _, err = validators.InitiateValidatorExit(ctx, st, idx, maxExitEpoch, churn)
+		st, err = validators.InitiateValidatorExit(ctx, st, idx, validators.ExitInformation(st))
 		if err != nil && !errors.Is(err, validators.ErrValidatorAlreadyExited) {
 			return nil, errors.Wrapf(err, "could not initiate exit for validator %d", idx)
 		}

beacon-chain/core/fulu/transition.go

@@ -16,10 +16,10 @@ func ProcessEpoch(ctx context.Context, state state.BeaconState) error {
 	if err := electra.ProcessEpoch(ctx, state); err != nil {
 		return errors.Wrap(err, "could not process epoch in fulu transition")
 	}
-	return processProposerLookahead(ctx, state)
+	return ProcessProposerLookahead(ctx, state)
 }
 
-func processProposerLookahead(ctx context.Context, state state.BeaconState) error {
+func ProcessProposerLookahead(ctx context.Context, state state.BeaconState) error {
 	_, span := trace.StartSpan(ctx, "fulu.processProposerLookahead")
 	defer span.End()
 

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/rewards_penalties.go

@@ -87,6 +87,11 @@ func TotalActiveBalance(s state.ReadOnlyBeaconState) (uint64, error) {
 	return total, nil
 }
 
+// UpdateTotalActiveBalanceCache updates the cache with the given total active balance.
+func UpdateTotalActiveBalanceCache(s state.BeaconState, total uint64) error {
+	return balanceCache.AddTotalEffectiveBalance(s, total)
+}
+
 // IncreaseBalance increases validator with the given 'index' balance by 'delta' in Gwei.
 //
 // Spec pseudocode definition:

beacon-chain/core/helpers/rewards_penalties_test.go

@@ -297,3 +297,30 @@ func TestIncreaseBadBalance_NotOK(t *testing.T) {
 		require.ErrorContains(t, "addition overflows", helpers.IncreaseBalance(state, test.i, test.nb))
 	}
 }
+
+func TestUpdateTotalActiveBalanceCache(t *testing.T) {
+	helpers.ClearCache()
+
+	// Create a test state with some validators
+	validators := []*ethpb.Validator{
+		{EffectiveBalance: 32 * 1e9, ExitEpoch: params.BeaconConfig().FarFutureEpoch, ActivationEpoch: 0},
+		{EffectiveBalance: 32 * 1e9, ExitEpoch: params.BeaconConfig().FarFutureEpoch, ActivationEpoch: 0},
+		{EffectiveBalance: 31 * 1e9, ExitEpoch: params.BeaconConfig().FarFutureEpoch, ActivationEpoch: 0},
+	}
+	state, err := state_native.InitializeFromProtoPhase0(&ethpb.BeaconState{
+		Validators: validators,
+		Slot:       0,
+	})
+	require.NoError(t, err)
+
+	// Test updating cache with a specific total
+	testTotal := uint64(95 * 1e9) // 32 + 32 + 31 = 95
+	err = helpers.UpdateTotalActiveBalanceCache(state, testTotal)
+	require.NoError(t, err)
+
+	// Verify the cache was updated by retrieving the total active balance
+	// which should now return the cached value
+	cachedTotal, err := helpers.TotalActiveBalance(state)
+	require.NoError(t, err)
+	assert.Equal(t, testTotal, cachedTotal, "Cache should return the updated total")
+}

beacon-chain/core/helpers/sync_committee.go

@@ -21,6 +21,39 @@ var (
 	syncCommitteeCache = cache.NewSyncCommittee()
 )
 
+// CurrentPeriodPositions returns committee indices of the current period sync committee for input validators.
+func CurrentPeriodPositions(st state.BeaconState, indices []primitives.ValidatorIndex) ([][]primitives.CommitteeIndex, error) {
+	root, err := SyncPeriodBoundaryRoot(st)
+	if err != nil {
+		return nil, err
+	}
+	pos, err := syncCommitteeCache.CurrentPeriodPositions(root, indices)
+	if errors.Is(err, cache.ErrNonExistingSyncCommitteeKey) {
+		committee, err := st.CurrentSyncCommittee()
+		if err != nil {
+			return nil, err
+		}
+
+		// Fill in the cache on miss.
+		go func() {
+			if err := syncCommitteeCache.UpdatePositionsInCommittee(root, st); err != nil {
+				log.WithError(err).Error("Could not fill sync committee cache on miss")
+			}
+		}()
+
+		pos = make([][]primitives.CommitteeIndex, len(indices))
+		for i, idx := range indices {
+			pubkey := st.PubkeyAtIndex(idx)
+			pos[i] = findSubCommitteeIndices(pubkey[:], committee.Pubkeys)
+		}
+		return pos, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return pos, nil
+}
+
 // IsCurrentPeriodSyncCommittee returns true if the input validator index belongs in the current period sync committee
 // along with the sync committee root.
 // 1. Checks if the public key exists in the sync committee cache

beacon-chain/core/helpers/sync_committee_test.go

@@ -17,6 +17,38 @@ import (
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 )
 
+func TestCurrentPeriodPositions(t *testing.T) {
+	helpers.ClearCache()
+
+	validators := make([]*ethpb.Validator, params.BeaconConfig().SyncCommitteeSize)
+	syncCommittee := &ethpb.SyncCommittee{
+		Pubkeys: make([][]byte, params.BeaconConfig().SyncCommitteeSize),
+	}
+	for i := 0; i < len(validators); i++ {
+		k := make([]byte, 48)
+		copy(k, strconv.Itoa(i))
+		validators[i] = &ethpb.Validator{
+			PublicKey: k,
+		}
+		syncCommittee.Pubkeys[i] = bytesutil.PadTo(k, 48)
+	}
+	state, err := state_native.InitializeFromProtoAltair(&ethpb.BeaconStateAltair{
+		Validators: validators,
+	})
+	require.NoError(t, err)
+	require.NoError(t, state.SetCurrentSyncCommittee(syncCommittee))
+	require.NoError(t, state.SetNextSyncCommittee(syncCommittee))
+	require.NoError(t, err, helpers.SyncCommitteeCache().UpdatePositionsInCommittee([32]byte{}, state))
+
+	positions, err := helpers.CurrentPeriodPositions(state, []primitives.ValidatorIndex{0, 1})
+	require.NoError(t, err)
+	require.Equal(t, 2, len(positions))
+	require.Equal(t, 1, len(positions[0]))
+	assert.Equal(t, primitives.CommitteeIndex(0), positions[0][0])
+	require.Equal(t, 1, len(positions[1]))
+	assert.Equal(t, primitives.CommitteeIndex(1), positions[1][0])
+}
+
 func TestIsCurrentEpochSyncCommittee_UsingCache(t *testing.T) {
 	helpers.ClearCache()
 

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/transition/transition_no_verify_sig.go

@@ -8,6 +8,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/altair"
 	b "github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/electra"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition/interop"
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
@@ -374,15 +375,18 @@ func ProcessBlockForStateRoot(
 }
 
 // This calls altair block operations.
-func altairOperations(
-	ctx context.Context,
-	st state.BeaconState,
-	beaconBlock interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
-	st, err := b.ProcessProposerSlashings(ctx, st, beaconBlock.Body().ProposerSlashings(), v.SlashValidator)
+func altairOperations(ctx context.Context, st state.BeaconState, beaconBlock interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
+	var err error
+
+	exitInfo := v.ExitInformation(st)
+	if err := helpers.UpdateTotalActiveBalanceCache(st, exitInfo.TotalActiveBalance); err != nil {
+		return nil, errors.Wrap(err, "could not update total active balance cache")
+	}
+	st, err = b.ProcessProposerSlashings(ctx, st, beaconBlock.Body().ProposerSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process altair proposer slashing")
 	}
-	st, err = b.ProcessAttesterSlashings(ctx, st, beaconBlock.Body().AttesterSlashings(), v.SlashValidator)
+	st, err = b.ProcessAttesterSlashings(ctx, st, beaconBlock.Body().AttesterSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process altair attester slashing")
 	}
@@ -393,7 +397,7 @@ func altairOperations(
 	if _, err := altair.ProcessDeposits(ctx, st, beaconBlock.Body().Deposits()); err != nil {
 		return nil, errors.Wrap(err, "could not process altair deposit")
 	}
-	st, err = b.ProcessVoluntaryExits(ctx, st, beaconBlock.Body().VoluntaryExits())
+	st, err = b.ProcessVoluntaryExits(ctx, st, beaconBlock.Body().VoluntaryExits(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process voluntary exits")
 	}
@@ -401,15 +405,18 @@ func altairOperations(
 }
 
 // This calls phase 0 block operations.
-func phase0Operations(
-	ctx context.Context,
-	st state.BeaconState,
-	beaconBlock interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
-	st, err := b.ProcessProposerSlashings(ctx, st, beaconBlock.Body().ProposerSlashings(), v.SlashValidator)
+func phase0Operations(ctx context.Context, st state.BeaconState, beaconBlock interfaces.ReadOnlyBeaconBlock) (state.BeaconState, error) {
+	var err error
+
+	exitInfo := v.ExitInformation(st)
+	if err := helpers.UpdateTotalActiveBalanceCache(st, exitInfo.TotalActiveBalance); err != nil {
+		return nil, errors.Wrap(err, "could not update total active balance cache")
+	}
+	st, err = b.ProcessProposerSlashings(ctx, st, beaconBlock.Body().ProposerSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process block proposer slashings")
 	}
-	st, err = b.ProcessAttesterSlashings(ctx, st, beaconBlock.Body().AttesterSlashings(), v.SlashValidator)
+	st, err = b.ProcessAttesterSlashings(ctx, st, beaconBlock.Body().AttesterSlashings(), exitInfo)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not process block attester slashings")
 	}
@@ -420,5 +427,9 @@ func phase0Operations(
 	if _, err := altair.ProcessDeposits(ctx, st, beaconBlock.Body().Deposits()); err != nil {
 		return nil, errors.Wrap(err, "could not process deposits")
 	}
-	return b.ProcessVoluntaryExits(ctx, st, beaconBlock.Body().VoluntaryExits())
+	st, err = b.ProcessVoluntaryExits(ctx, st, beaconBlock.Body().VoluntaryExits(), exitInfo)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not process voluntary exits")
+	}
+	return st, nil
 }

beacon-chain/core/validators/validator.go

@@ -13,34 +13,55 @@ import (
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/math"
+	mathutil "github.com/OffchainLabs/prysm/v6/math"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
 )
 
+// ExitInfo provides information about validator exits in the state.
+type ExitInfo struct {
+	HighestExitEpoch   primitives.Epoch
+	Churn              uint64
+	TotalActiveBalance uint64
+}
+
 // ErrValidatorAlreadyExited is an error raised when trying to process an exit of
 // an already exited validator
 var ErrValidatorAlreadyExited = errors.New("validator already exited")
 
-// MaxExitEpochAndChurn returns the maximum non-FAR_FUTURE_EPOCH exit
-// epoch and the number of them
-func MaxExitEpochAndChurn(s state.BeaconState) (maxExitEpoch primitives.Epoch, churn uint64) {
+// ExitInformation returns information about validator exits.
+func ExitInformation(s state.BeaconState) *ExitInfo {
+	exitInfo := &ExitInfo{}
+
 	farFutureEpoch := params.BeaconConfig().FarFutureEpoch
+	currentEpoch := slots.ToEpoch(s.Slot())
+	totalActiveBalance := uint64(0)
+
 	err := s.ReadFromEveryValidator(func(idx int, val state.ReadOnlyValidator) error {
 		e := val.ExitEpoch()
 		if e != farFutureEpoch {
-			if e > maxExitEpoch {
-				maxExitEpoch = e
-				churn = 1
-			} else if e == maxExitEpoch {
-				churn++
+			if e > exitInfo.HighestExitEpoch {
+				exitInfo.HighestExitEpoch = e
+				exitInfo.Churn = 1
+			} else if e == exitInfo.HighestExitEpoch {
+				exitInfo.Churn++
 			}
 		}
+
+		// Calculate total active balance in the same loop
+		if helpers.IsActiveValidatorUsingTrie(val, currentEpoch) {
+			totalActiveBalance += val.EffectiveBalance()
+		}
+
 		return nil
 	})
 	_ = err
-	return
+
+	// Apply minimum balance as per spec
+	exitInfo.TotalActiveBalance = mathutil.Max(params.BeaconConfig().EffectiveBalanceIncrement, totalActiveBalance)
+	return exitInfo
 }
 
 // InitiateValidatorExit takes in validator index and updates
@@ -64,59 +85,117 @@ func MaxExitEpochAndChurn(s state.BeaconState) (maxExitEpoch primitives.Epoch, c
 //	    # Set validator exit epoch and withdrawable epoch
 //	    validator.exit_epoch = exit_queue_epoch
 //	    validator.withdrawable_epoch = Epoch(validator.exit_epoch + MIN_VALIDATOR_WITHDRAWABILITY_DELAY)
-func InitiateValidatorExit(ctx context.Context, s state.BeaconState, idx primitives.ValidatorIndex, exitQueueEpoch primitives.Epoch, churn uint64) (state.BeaconState, primitives.Epoch, error) {
+func InitiateValidatorExit(
+	ctx context.Context,
+	s state.BeaconState,
+	idx primitives.ValidatorIndex,
+	exitInfo *ExitInfo,
+) (state.BeaconState, error) {
 	validator, err := s.ValidatorAtIndex(idx)
 	if err != nil {
-		return nil, 0, err
+		return nil, err
 	}
 	if validator.ExitEpoch != params.BeaconConfig().FarFutureEpoch {
-		return s, validator.ExitEpoch, ErrValidatorAlreadyExited
+		return s, ErrValidatorAlreadyExited
 	}
 
 	// Compute exit queue epoch.
 	if s.Version() < version.Electra {
-		// Relevant spec code from phase0:
-		//
-		//	exit_epochs = [v.exit_epoch for v in state.validators if v.exit_epoch != FAR_FUTURE_EPOCH]
-		//	exit_queue_epoch = max(exit_epochs + [compute_activation_exit_epoch(get_current_epoch(state))])
-		//	exit_queue_churn = len([v for v in state.validators if v.exit_epoch == exit_queue_epoch])
-		//	if exit_queue_churn >= get_validator_churn_limit(state):
-		//	    exit_queue_epoch += Epoch(1)
-		exitableEpoch := helpers.ActivationExitEpoch(time.CurrentEpoch(s))
-		if exitableEpoch > exitQueueEpoch {
-			exitQueueEpoch = exitableEpoch
-			churn = 0
-		}
-		activeValidatorCount, err := helpers.ActiveValidatorCount(ctx, s, time.CurrentEpoch(s))
-		if err != nil {
-			return nil, 0, errors.Wrap(err, "could not get active validator count")
-		}
-		currentChurn := helpers.ValidatorExitChurnLimit(activeValidatorCount)
-
-		if churn >= currentChurn {
-			exitQueueEpoch, err = exitQueueEpoch.SafeAdd(1)
-			if err != nil {
-				return nil, 0, err
-			}
+		if err = initiateValidatorExitPreElectra(ctx, s, exitInfo); err != nil {
+			return nil, err
 		}
 	} else {
 		// [Modified in Electra:EIP7251]
 		// exit_queue_epoch = compute_exit_epoch_and_update_churn(state, validator.effective_balance)
 		var err error
-		exitQueueEpoch, err = s.ExitEpochAndUpdateChurn(primitives.Gwei(validator.EffectiveBalance))
+		exitInfo.HighestExitEpoch, err = s.ExitEpochAndUpdateChurn(primitives.Gwei(validator.EffectiveBalance))
 		if err != nil {
-			return nil, 0, err
+			return nil, err
 		}
 	}
-	validator.ExitEpoch = exitQueueEpoch
-	validator.WithdrawableEpoch, err = exitQueueEpoch.SafeAddEpoch(params.BeaconConfig().MinValidatorWithdrawabilityDelay)
+	validator.ExitEpoch = exitInfo.HighestExitEpoch
+	validator.WithdrawableEpoch, err = exitInfo.HighestExitEpoch.SafeAddEpoch(params.BeaconConfig().MinValidatorWithdrawabilityDelay)
 	if err != nil {
-		return nil, 0, err
+		return nil, err
 	}
 	if err := s.UpdateValidatorAtIndex(idx, validator); err != nil {
-		return nil, 0, err
+		return nil, err
 	}
-	return s, exitQueueEpoch, nil
+	return s, nil
+}
+
+// InitiateValidatorExitForTotalBal has the same functionality as InitiateValidatorExit,
+// the only difference being how total active balance is obtained. In InitiateValidatorExit
+// it is calculated inside the function and in InitiateValidatorExitForTotalBal it's a
+// function argument.
+func InitiateValidatorExitForTotalBal(
+	ctx context.Context,
+	s state.BeaconState,
+	idx primitives.ValidatorIndex,
+	exitInfo *ExitInfo,
+	totalActiveBalance primitives.Gwei,
+) (state.BeaconState, error) {
+	validator, err := s.ValidatorAtIndex(idx)
+	if err != nil {
+		return nil, err
+	}
+	if validator.ExitEpoch != params.BeaconConfig().FarFutureEpoch {
+		return s, ErrValidatorAlreadyExited
+	}
+
+	// Compute exit queue epoch.
+	if s.Version() < version.Electra {
+		if err = initiateValidatorExitPreElectra(ctx, s, exitInfo); err != nil {
+			return nil, err
+		}
+	} else {
+		// [Modified in Electra:EIP7251]
+		// exit_queue_epoch = compute_exit_epoch_and_update_churn(state, validator.effective_balance)
+		var err error
+		exitInfo.HighestExitEpoch, err = s.ExitEpochAndUpdateChurnForTotalBal(totalActiveBalance, primitives.Gwei(validator.EffectiveBalance))
+		if err != nil {
+			return nil, err
+		}
+	}
+	validator.ExitEpoch = exitInfo.HighestExitEpoch
+	validator.WithdrawableEpoch, err = exitInfo.HighestExitEpoch.SafeAddEpoch(params.BeaconConfig().MinValidatorWithdrawabilityDelay)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.UpdateValidatorAtIndex(idx, validator); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func initiateValidatorExitPreElectra(ctx context.Context, s state.BeaconState, exitInfo *ExitInfo) error {
+	// Relevant spec code from phase0:
+	//
+	//	exit_epochs = [v.exit_epoch for v in state.validators if v.exit_epoch != FAR_FUTURE_EPOCH]
+	//	exit_queue_epoch = max(exit_epochs + [compute_activation_exit_epoch(get_current_epoch(state))])
+	//	exit_queue_churn = len([v for v in state.validators if v.exit_epoch == exit_queue_epoch])
+	//	if exit_queue_churn >= get_validator_churn_limit(state):
+	//	    exit_queue_epoch += Epoch(1)
+	exitableEpoch := helpers.ActivationExitEpoch(time.CurrentEpoch(s))
+	if exitableEpoch > exitInfo.HighestExitEpoch {
+		exitInfo.HighestExitEpoch = exitableEpoch
+		exitInfo.Churn = 0
+	}
+	activeValidatorCount, err := helpers.ActiveValidatorCount(ctx, s, time.CurrentEpoch(s))
+	if err != nil {
+		return errors.Wrap(err, "could not get active validator count")
+	}
+	currentChurn := helpers.ValidatorExitChurnLimit(activeValidatorCount)
+	if exitInfo.Churn >= currentChurn {
+		exitInfo.HighestExitEpoch, err = exitInfo.HighestExitEpoch.SafeAdd(1)
+		if err != nil {
+			return err
+		}
+		exitInfo.Churn = 1
+	} else {
+		exitInfo.Churn = exitInfo.Churn + 1
+	}
+	return nil
 }
 
 // SlashValidator slashes the malicious validator's balance and awards
@@ -152,9 +231,12 @@ func InitiateValidatorExit(ctx context.Context, s state.BeaconState, idx primiti
 func SlashValidator(
 	ctx context.Context,
 	s state.BeaconState,
-	slashedIdx primitives.ValidatorIndex) (state.BeaconState, error) {
-	maxExitEpoch, churn := MaxExitEpochAndChurn(s)
-	s, _, err := InitiateValidatorExit(ctx, s, slashedIdx, maxExitEpoch, churn)
+	slashedIdx primitives.ValidatorIndex,
+	exitInfo *ExitInfo,
+) (state.BeaconState, error) {
+	var err error
+
+	s, err = InitiateValidatorExitForTotalBal(ctx, s, slashedIdx, exitInfo, primitives.Gwei(exitInfo.TotalActiveBalance))
 	if err != nil && !errors.Is(err, ErrValidatorAlreadyExited) {
 		return nil, errors.Wrapf(err, "could not initiate validator %d exit", slashedIdx)
 	}

beacon-chain/core/validators/validator_test.go

@@ -49,9 +49,11 @@ func TestInitiateValidatorExit_AlreadyExited(t *testing.T) {
 	}}
 	state, err := state_native.InitializeFromProtoPhase0(base)
 	require.NoError(t, err)
-	newState, epoch, err := validators.InitiateValidatorExit(t.Context(), state, 0, 199, 1)
+	exitInfo := &validators.ExitInfo{HighestExitEpoch: 199, Churn: 1}
+	newState, err := validators.InitiateValidatorExit(t.Context(), state, 0, exitInfo)
 	require.ErrorIs(t, err, validators.ErrValidatorAlreadyExited)
-	require.Equal(t, exitEpoch, epoch)
+	assert.Equal(t, primitives.Epoch(199), exitInfo.HighestExitEpoch)
+	assert.Equal(t, uint64(1), exitInfo.Churn)
 	v, err := newState.ValidatorAtIndex(0)
 	require.NoError(t, err)
 	assert.Equal(t, exitEpoch, v.ExitEpoch, "Already exited")
@@ -68,9 +70,11 @@ func TestInitiateValidatorExit_ProperExit(t *testing.T) {
 	}}
 	state, err := state_native.InitializeFromProtoPhase0(base)
 	require.NoError(t, err)
-	newState, epoch, err := validators.InitiateValidatorExit(t.Context(), state, idx, exitedEpoch+2, 1)
+	exitInfo := &validators.ExitInfo{HighestExitEpoch: exitedEpoch + 2, Churn: 1}
+	newState, err := validators.InitiateValidatorExit(t.Context(), state, idx, exitInfo)
 	require.NoError(t, err)
-	require.Equal(t, exitedEpoch+2, epoch)
+	assert.Equal(t, exitedEpoch+2, exitInfo.HighestExitEpoch)
+	assert.Equal(t, uint64(2), exitInfo.Churn)
 	v, err := newState.ValidatorAtIndex(idx)
 	require.NoError(t, err)
 	assert.Equal(t, exitedEpoch+2, v.ExitEpoch, "Exit epoch was not the highest")
@@ -88,9 +92,11 @@ func TestInitiateValidatorExit_ChurnOverflow(t *testing.T) {
 	}}
 	state, err := state_native.InitializeFromProtoPhase0(base)
 	require.NoError(t, err)
-	newState, epoch, err := validators.InitiateValidatorExit(t.Context(), state, idx, exitedEpoch+2, 4)
+	exitInfo := &validators.ExitInfo{HighestExitEpoch: exitedEpoch + 2, Churn: 4}
+	newState, err := validators.InitiateValidatorExit(t.Context(), state, idx, exitInfo)
 	require.NoError(t, err)
-	require.Equal(t, exitedEpoch+3, epoch)
+	assert.Equal(t, exitedEpoch+3, exitInfo.HighestExitEpoch)
+	assert.Equal(t, uint64(1), exitInfo.Churn)
 
 	// Because of exit queue overflow,
 	// validator who init exited has to wait one more epoch.
@@ -110,7 +116,8 @@ func TestInitiateValidatorExit_WithdrawalOverflows(t *testing.T) {
 	}}
 	state, err := state_native.InitializeFromProtoPhase0(base)
 	require.NoError(t, err)
-	_, _, err = validators.InitiateValidatorExit(t.Context(), state, 1, params.BeaconConfig().FarFutureEpoch-1, 1)
+	exitInfo := &validators.ExitInfo{HighestExitEpoch: params.BeaconConfig().FarFutureEpoch - 1, Churn: 1}
+	_, err = validators.InitiateValidatorExit(t.Context(), state, 1, exitInfo)
 	require.ErrorContains(t, "addition overflows", err)
 }
 
@@ -146,12 +153,11 @@ func TestInitiateValidatorExit_ProperExit_Electra(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, primitives.Gwei(0), ebtc)
 
-	newState, epoch, err := validators.InitiateValidatorExit(t.Context(), state, idx, 0, 0) // exitQueueEpoch and churn are not used in electra
+	newState, err := validators.InitiateValidatorExit(t.Context(), state, idx, &validators.ExitInfo{}) // exit info is not used in electra
 	require.NoError(t, err)
 
 	// Expect that the exit epoch is the next available epoch with max seed lookahead.
 	want := helpers.ActivationExitEpoch(exitedEpoch + 1)
-	require.Equal(t, want, epoch)
 	v, err := newState.ValidatorAtIndex(idx)
 	require.NoError(t, err)
 	assert.Equal(t, want, v.ExitEpoch, "Exit epoch was not the highest")
@@ -190,7 +196,7 @@ func TestSlashValidator_OK(t *testing.T) {
 	require.NoError(t, err, "Could not get proposer")
 	proposerBal, err := state.BalanceAtIndex(proposer)
 	require.NoError(t, err)
-	slashedState, err := validators.SlashValidator(t.Context(), state, slashedIdx)
+	slashedState, err := validators.SlashValidator(t.Context(), state, slashedIdx, validators.ExitInformation(state))
 	require.NoError(t, err, "Could not slash validator")
 	require.Equal(t, true, slashedState.Version() == version.Phase0)
 
@@ -244,7 +250,7 @@ func TestSlashValidator_Electra(t *testing.T) {
 	require.NoError(t, err, "Could not get proposer")
 	proposerBal, err := state.BalanceAtIndex(proposer)
 	require.NoError(t, err)
-	slashedState, err := validators.SlashValidator(t.Context(), state, slashedIdx)
+	slashedState, err := validators.SlashValidator(t.Context(), state, slashedIdx, validators.ExitInformation(state))
 	require.NoError(t, err, "Could not slash validator")
 	require.Equal(t, true, slashedState.Version() == version.Electra)
 
@@ -505,8 +511,8 @@ func TestValidatorMaxExitEpochAndChurn(t *testing.T) {
 	for _, tt := range tests {
 		s, err := state_native.InitializeFromProtoPhase0(tt.state)
 		require.NoError(t, err)
-		epoch, churn := validators.MaxExitEpochAndChurn(s)
-		require.Equal(t, tt.wantedEpoch, epoch)
-		require.Equal(t, tt.wantedChurn, churn)
+		exitInfo := validators.ExitInformation(s)
+		require.Equal(t, tt.wantedEpoch, exitInfo.HighestExitEpoch)
+		require.Equal(t, tt.wantedChurn, exitInfo.Churn)
 	}
 }

beacon-chain/db/filesystem/layout_by_epoch.go

@@ -116,19 +116,43 @@ func (l *periodicEpochLayout) pruneBefore(before primitives.Epoch) (*pruneSummar
 	}
 	// Roll up summaries and clean up per-epoch directories.
 	rollup := &pruneSummary{}
+
+	// Track which period directories might be empty after epoch removal
+	periodsToCheck := make(map[string]struct{})
+
 	for epoch, sum := range sums {
 		rollup.blobsPruned += sum.blobsPruned
 		rollup.failedRemovals = append(rollup.failedRemovals, sum.failedRemovals...)
 		rmdir := l.epochDir(epoch)
+		periodDir := l.periodDir(epoch)
+
 		if len(sum.failedRemovals) == 0 {
 			if err := l.fs.Remove(rmdir); err != nil {
 				log.WithField("dir", rmdir).WithError(err).Error("Failed to remove epoch directory while pruning")
+			} else {
+				periodsToCheck[periodDir] = struct{}{}
 			}
 		} else {
 			log.WithField("dir", rmdir).WithField("numFailed", len(sum.failedRemovals)).WithError(err).Error("Unable to remove epoch directory due to pruning failures")
 		}
 	}
 
+	//Clean up empty period directories
+	for periodDir := range periodsToCheck {
+		entries, err := afero.ReadDir(l.fs, periodDir)
+		if err != nil {
+			log.WithField("dir", periodDir).WithError(err).Debug("Failed to read period directory contents")
+			continue
+		}
+
+		// Only attempt to remove if directory is empty
+		if len(entries) == 0 {
+			if err := l.fs.Remove(periodDir); err != nil {
+				log.WithField("dir", periodDir).WithError(err).Error("Failed to remove empty period directory")
+			}
+		}
+	}
+
 	return rollup, nil
 }
 

beacon-chain/db/filesystem/pruner_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/config/params"
@@ -195,3 +196,48 @@ func TestLayoutPruneBefore(t *testing.T) {
 		})
 	}
 }
+
+func TestLayoutByEpochPruneBefore(t *testing.T) {
+	roots := testRoots(10)
+	cases := []struct {
+		name   string
+		pruned []testIdent
+		remain []testIdent
+		err    error
+		sum    pruneSummary
+	}{
+		{
+			name: "single epoch period cleanup",
+			pruned: []testIdent{
+				{offset: 0, blobIdent: blobIdent{root: roots[0], epoch: 367076, index: 0}},
+			},
+			remain: []testIdent{
+				{offset: 0, blobIdent: blobIdent{root: roots[1], epoch: 371176, index: 0}}, // Different period
+			},
+			sum: pruneSummary{blobsPruned: 1},
+		},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			fs, bs := NewEphemeralBlobStorageAndFs(t, WithLayout(LayoutNameByEpoch))
+			pruned := testSetupBlobIdentPaths(t, fs, bs, c.pruned)
+			remain := testSetupBlobIdentPaths(t, fs, bs, c.remain)
+
+			time.Sleep(1 * time.Second)
+			for _, id := range pruned {
+				_, err := fs.Stat(bs.layout.sszPath(id))
+				require.Equal(t, true, os.IsNotExist(err))
+
+				dirs := bs.layout.blockParentDirs(id)
+				for i := len(dirs) - 1; i > 0; i-- {
+					_, err = fs.Stat(dirs[i])
+					require.Equal(t, true, os.IsNotExist(err))
+				}
+			}
+			for _, id := range remain {
+				_, err := fs.Stat(bs.layout.sszPath(id))
+				require.NoError(t, err)
+			}
+		})
+	}
+}

beacon-chain/node/node.go

@@ -941,6 +941,7 @@ func (b *BeaconNode) registerRPCService(router *http.ServeMux) error {
 		FinalizationFetcher:       chainService,
 		BlockReceiver:             chainService,
 		BlobReceiver:              chainService,
+		DataColumnReceiver:        chainService,
 		AttestationReceiver:       chainService,
 		GenesisTimeFetcher:        chainService,
 		GenesisFetcher:            chainService,

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

@@ -684,7 +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
 	}
 
@@ -851,7 +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/monitoring.go

@@ -18,6 +18,7 @@ var (
 		"lodestar",
 		"js-libp2p",
 		"rust-libp2p",
+		"erigon/caplin",
 	}
 	p2pPeerCount = promauto.NewGaugeVec(prometheus.GaugeOpts{
 		Name: "p2p_peer_count",

beacon-chain/p2p/testing/p2p.go

@@ -50,6 +50,7 @@ const (
 
 // TestP2P represents a p2p implementation that can be used for testing.
 type TestP2P struct {
+	mu                    sync.Mutex
 	t                     *testing.T
 	BHost                 host.Host
 	EnodeID               enode.ID
@@ -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),
 	}
 }
 
@@ -241,6 +244,8 @@ func (p *TestP2P) SetStreamHandler(topic string, handler network.StreamHandler)
 
 // JoinTopic will join PubSub topic, if not already joined.
 func (p *TestP2P) JoinTopic(topic string, opts ...pubsub.TopicOpt) (*pubsub.Topic, error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
 	if _, ok := p.joinedTopics[topic]; !ok {
 		joinedTopic, err := p.pubsub.Join(topic, opts...)
 		if err != nil {
@@ -310,8 +315,8 @@ 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/endpoints.go

@@ -1230,6 +1230,7 @@ func (s *Service) prysmBeaconEndpoints(
 			methods: []string{http.MethodGet},
 		},
 		{
+			// Warning: no longer supported post Fulu fork
 			template: "/prysm/v1/beacon/blobs",
 			name:     namespace + ".PublishBlobs",
 			middleware: []middleware.Middleware{

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",
@@ -84,6 +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",
@@ -124,7 +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"
@@ -334,26 +334,26 @@ func (s *Server) GetBlockAttestationsV2(w http.ResponseWriter, r *http.Request)
 	consensusAtts := blk.Block().Body().Attestations()
 
 	v := blk.Block().Version()
-	var attStructs []interface{}
+	attStructs := make([]interface{}, len(consensusAtts))
 	if v >= version.Electra {
-		for _, att := range consensusAtts {
+		for index, att := range consensusAtts {
 			a, ok := att.(*eth.AttestationElectra)
 			if !ok {
 				httputil.HandleError(w, fmt.Sprintf("unable to convert consensus attestations electra of type %T", att), http.StatusInternalServerError)
 				return
 			}
 			attStruct := structs.AttElectraFromConsensus(a)
-			attStructs = append(attStructs, attStruct)
+			attStructs[index] = attStruct
 		}
 	} else {
-		for _, att := range consensusAtts {
+		for index, att := range consensusAtts {
 			a, ok := att.(*eth.Attestation)
 			if !ok {
 				httputil.HandleError(w, fmt.Sprintf("unable to convert consensus attestation of type %T", att), http.StatusInternalServerError)
 				return
 			}
 			attStruct := structs.AttFromConsensus(a)
-			attStructs = append(attStructs, attStruct)
+			attStructs[index] = attStruct
 		}
 	}
 
@@ -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
 }
 
@@ -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 {

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

@@ -17,19 +17,19 @@ func TestBlocks_NewSignedBeaconBlock_EquivocationFix(t *testing.T) {
 	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_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"
@@ -910,6 +910,100 @@ func TestGetBlockAttestations(t *testing.T) {
 			})
 		})
 	})
+
+	t.Run("empty-attestations", func(t *testing.T) {
+		t.Run("v1", func(t *testing.T) {
+			b := util.NewBeaconBlock()
+			b.Block.Body.Attestations = []*eth.Attestation{} // Explicitly set empty attestations
+			sb, err := blocks.NewSignedBeaconBlock(b)
+			require.NoError(t, err)
+
+			mockChainService := &chainMock.ChainService{
+				FinalizedRoots: map[[32]byte]bool{},
+			}
+
+			s := &Server{
+				OptimisticModeFetcher: mockChainService,
+				FinalizationFetcher:   mockChainService,
+				Blocker:               &testutil.MockBlocker{BlockToReturn: sb},
+			}
+
+			request := httptest.NewRequest(http.MethodGet, "http://foo.example/eth/v1/beacon/blocks/{block_id}/attestations", nil)
+			request.SetPathValue("block_id", "head")
+			writer := httptest.NewRecorder()
+			writer.Body = &bytes.Buffer{}
+
+			s.GetBlockAttestations(writer, request)
+			require.Equal(t, http.StatusOK, writer.Code)
+			resp := &structs.GetBlockAttestationsResponse{}
+			require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+
+			// Ensure data is empty array, not null
+			require.NotNil(t, resp.Data)
+			assert.Equal(t, 0, len(resp.Data))
+		})
+
+		t.Run("v2-pre-electra", func(t *testing.T) {
+			b := util.NewBeaconBlock()
+			b.Block.Body.Attestations = []*eth.Attestation{} // Explicitly set empty attestations
+			sb, err := blocks.NewSignedBeaconBlock(b)
+			require.NoError(t, err)
+			mockChainService := &chainMock.ChainService{
+				FinalizedRoots: map[[32]byte]bool{},
+			}
+
+			s := &Server{
+				OptimisticModeFetcher: mockChainService,
+				FinalizationFetcher:   mockChainService,
+				Blocker:               &testutil.MockBlocker{BlockToReturn: sb},
+			}
+
+			request := httptest.NewRequest(http.MethodGet, "http://foo.example/eth/v2/beacon/blocks/{block_id}/attestations", nil)
+			request.SetPathValue("block_id", "head")
+			writer := httptest.NewRecorder()
+			writer.Body = &bytes.Buffer{}
+
+			s.GetBlockAttestationsV2(writer, request)
+			require.Equal(t, http.StatusOK, writer.Code)
+			resp := &structs.GetBlockAttestationsV2Response{}
+			require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+			// Ensure data is "[]", not null
+			require.NotNil(t, resp.Data)
+			assert.Equal(t, string(json.RawMessage("[]")), string(resp.Data))
+		})
+
+		t.Run("v2-electra", func(t *testing.T) {
+			eb := util.NewBeaconBlockFulu()
+			eb.Block.Body.Attestations = []*eth.AttestationElectra{} // Explicitly set empty attestations
+			esb, err := blocks.NewSignedBeaconBlock(eb)
+			require.NoError(t, err)
+
+			mockChainService := &chainMock.ChainService{
+				FinalizedRoots: map[[32]byte]bool{},
+			}
+
+			s := &Server{
+				OptimisticModeFetcher: mockChainService,
+				FinalizationFetcher:   mockChainService,
+				Blocker:               &testutil.MockBlocker{BlockToReturn: esb},
+			}
+
+			request := httptest.NewRequest(http.MethodGet, "http://foo.example/eth/v2/beacon/blocks/{block_id}/attestations", nil)
+			request.SetPathValue("block_id", "head")
+			writer := httptest.NewRecorder()
+			writer.Body = &bytes.Buffer{}
+
+			s.GetBlockAttestationsV2(writer, request)
+			require.Equal(t, http.StatusOK, writer.Code)
+			resp := &structs.GetBlockAttestationsV2Response{}
+			require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+
+			// Ensure data is "[]", not null
+			require.NotNil(t, resp.Data)
+			assert.Equal(t, string(json.RawMessage("[]")), string(resp.Data))
+			assert.Equal(t, "fulu", resp.Version)
+		})
+	})
 }
 
 func TestGetBlindedBlock(t *testing.T) {
@@ -4781,25 +4875,329 @@ 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/rewards/service.go

@@ -68,7 +68,8 @@ func (rs *BlockRewardService) GetBlockRewardsData(ctx context.Context, blk inter
 			Code:    http.StatusInternalServerError,
 		}
 	}
-	st, err = coreblocks.ProcessAttesterSlashings(ctx, st, blk.Body().AttesterSlashings(), validators.SlashValidator)
+	exitInfo := validators.ExitInformation(st)
+	st, err = coreblocks.ProcessAttesterSlashings(ctx, st, blk.Body().AttesterSlashings(), exitInfo)
 	if err != nil {
 		return nil, &httputil.DefaultJsonError{
 			Message: "Could not get attester slashing rewards: " + err.Error(),
@@ -82,7 +83,7 @@ func (rs *BlockRewardService) GetBlockRewardsData(ctx context.Context, blk inter
 			Code:    http.StatusInternalServerError,
 		}
 	}
-	st, err = coreblocks.ProcessProposerSlashings(ctx, st, blk.Body().ProposerSlashings(), validators.SlashValidator)
+	st, err = coreblocks.ProcessProposerSlashings(ctx, st, blk.Body().ProposerSlashings(), exitInfo)
 	if err != nil {
 		return nil, &httputil.DefaultJsonError{
 			Message: "Could not get proposer slashing rewards: " + err.Error(),

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/prysm/beacon/handlers.go

@@ -186,6 +186,7 @@ func (s *Server) GetChainHead(w http.ResponseWriter, r *http.Request) {
 	httputil.WriteJson(w, response)
 }
 
+// Warning: no longer supported post Fulu blobs
 func (s *Server) PublishBlobs(w http.ResponseWriter, r *http.Request) {
 	ctx, span := trace.StartSpan(r.Context(), "beacon.PublishBlobs")
 	defer span.End()
@@ -215,6 +216,15 @@ func (s *Server) PublishBlobs(w http.ResponseWriter, r *http.Request) {
 			httputil.HandleError(w, "Could not decode blob sidecar: "+err.Error(), http.StatusBadRequest)
 			return
 		}
+		scEpoch := slots.ToEpoch(sc.SignedBlockHeader.Header.Slot)
+		if scEpoch < params.BeaconConfig().DenebForkEpoch {
+			httputil.HandleError(w, "Blob sidecars not supported for pre deneb", http.StatusBadRequest)
+			return
+		}
+		if scEpoch > params.BeaconConfig().FuluForkEpoch {
+			httputil.HandleError(w, "Blob sidecars not supported for post fulu blobs", http.StatusBadRequest)
+			return
+		}
 
 		readOnlySc, err := blocks.NewROBlobWithRoot(sc, bytesutil.ToBytes32(root))
 		if err != nil {

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

@@ -1017,6 +1017,11 @@ func TestPublishBlobs_BadBlockRoot(t *testing.T) {
 }
 
 func TestPublishBlobs(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.DenebForkEpoch = 0 // Set Deneb fork to epoch 0 so slot 0 is valid
+	params.OverrideBeaconConfig(cfg)
+
 	server := &Server{
 		BlobReceiver: &chainMock.ChainService{},
 		Broadcaster:  &mockp2p.MockBroadcaster{},
@@ -1032,3 +1037,94 @@ func TestPublishBlobs(t *testing.T) {
 	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 1)
 	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), true)
 }
+
+func TestPublishBlobs_PreDeneb(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.DenebForkEpoch = 10 // Set Deneb fork to epoch 10, so slot 0 is pre-Deneb
+	params.OverrideBeaconConfig(cfg)
+
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.PublishBlobsRequest)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Blob sidecars not supported for pre deneb", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}
+
+func TestPublishBlobs_PostFulu(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.DenebForkEpoch = 0
+	cfg.FuluForkEpoch = 0 // Set Fulu fork to epoch 0
+	params.OverrideBeaconConfig(cfg)
+
+	server := &Server{
+		BlobReceiver: &chainMock.ChainService{},
+		Broadcaster:  &mockp2p.MockBroadcaster{},
+		SyncChecker:  &mockSync.Sync{IsSyncing: false},
+	}
+
+	// Create a custom request with a slot in epoch 1 (which is > FuluForkEpoch of 0)
+	postFuluRequest := fmt.Sprintf(`{
+		"block_root" : "0x0000000000000000000000000000000000000000000000000000000000000000",
+		"blob_sidecars" : {
+		   "sidecars" : [
+			  {
+				 "blob" : "%s",
+				 "index" : "0",
+				 "kzg_commitment" : "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+				 "kzg_commitment_inclusion_proof" : [
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000",
+					"0x0000000000000000000000000000000000000000000000000000000000000000"
+				 ],
+				 "kzg_proof" : "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+				 "signed_block_header" : {
+					"message" : {
+					   "body_root" : "0x0000000000000000000000000000000000000000000000000000000000000000",
+					   "parent_root" : "0x0000000000000000000000000000000000000000000000000000000000000000",
+					   "proposer_index" : "0",
+					   "slot" : "33",
+					   "state_root" : "0x0000000000000000000000000000000000000000000000000000000000000000"
+					},
+					"signature" : "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
+				 }
+			  }
+		   ]
+		}
+	 }`, rpctesting.Blob)
+
+	request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(postFuluRequest)))
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+	server.PublishBlobs(writer, request)
+	assert.Equal(t, http.StatusBadRequest, writer.Code)
+	assert.StringContains(t, "Blob sidecars not supported for post fulu blobs", writer.Body.String())
+
+	assert.Equal(t, len(server.BlobReceiver.(*chainMock.ChainService).Blobs), 0)
+	assert.Equal(t, server.Broadcaster.(*mockp2p.MockBroadcaster).BroadcastCalled.Load(), false)
+}

beacon-chain/rpc/prysm/v1alpha1/beacon/config_test.go

@@ -19,7 +19,7 @@ func TestServer_GetBeaconConfig(t *testing.T) {
 	conf := params.BeaconConfig()
 	confType := reflect.TypeOf(conf).Elem()
 	numFields := confType.NumField()
-	
+
 	// Count only exported fields, as unexported fields are not included in the config
 	exportedFields := 0
 	for i := 0; i < numFields; i++ {

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

@@ -39,6 +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",
@@ -49,6 +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",

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 []*ethpb.DataColumnSidecar
+	)
+
 	ctx, span := trace.StartSpan(ctx, "ProposerServer.ProposeBeaconBlock")
 	defer span.End()
 
@@ -300,11 +309,10 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 		return &ethpb.ProposeResponse{BlockRoot: root[:]}, nil
 	}
 
-	var sidecars []*ethpb.BlobSidecar
 	if block.IsBlinded() {
-		block, sidecars, err = vs.handleBlindedBlock(ctx, block)
+		block, blobSidecars, err = vs.handleBlindedBlock(ctx, block)
 	} else if block.Version() >= version.Deneb {
-		sidecars, err = vs.blobSidecarsFromUnblindedBlock(block, req)
+		blobSidecars, dataColumnSidecars, err = vs.handleUnblindedBlock(block, req)
 	}
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "%s: %v", "handle block failed", err)
@@ -323,10 +331,9 @@ 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)
@@ -335,12 +342,35 @@ func (vs *Server) ProposeBeaconBlock(ctx context.Context, req *ethpb.GenericSign
 	return &ethpb.ProposeResponse{BlockRoot: root[:]}, nil
 }
 
+// broadcastAndReceiveSidecars broadcasts and receives sidecars.
+func (vs *Server) broadcastAndReceiveSidecars(
+	ctx context.Context,
+	block interfaces.SignedBeaconBlock,
+	root [fieldparams.RootLength]byte,
+	blobSidecars []*ethpb.BlobSidecar,
+	dataColumnSideCars []*ethpb.DataColumnSidecar,
+) 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")
 	}
@@ -367,16 +397,34 @@ 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 interfaces.SignedBeaconBlock,
+	req *ethpb.GenericSignedBeaconBlock,
+) ([]*ethpb.BlobSidecar, []*ethpb.DataColumnSidecar, 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 {
+		dataColumnSideCars, err := peerdas.ConstructDataColumnSidecars(block, rawBlobs, proofs)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "construct data column sidecars")
+		}
+
+		return nil, dataColumnSideCars, 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")
@@ -392,18 +440,14 @@ 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")
 			}
@@ -421,6 +465,53 @@ 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,
+	sidecars []*ethpb.DataColumnSidecar,
+	root [fieldparams.RootLength]byte,
+) error {
+	verifiedRODataColumns := make([]blocks.VerifiedRODataColumn, 0, len(sidecars))
+	eg, _ := errgroup.WithContext(ctx)
+	for _, sidecar := range sidecars {
+		roDataColumn, err := blocks.NewRODataColumnWithRoot(sidecar, root)
+		if err != nil {
+			return errors.Wrap(err, "new read-only data column with root")
+		}
+
+		// We build this block ourselves, so we can upgrade the read only data column sidecar into a verified one.
+		verifiedRODataColumn := blocks.NewVerifiedRODataColumn(roDataColumn)
+		verifiedRODataColumns = append(verifiedRODataColumns, verifiedRODataColumn)
+
+		eg.Go(func() error {
+			// Compute the subnet index based on the column index.
+			subnet := peerdas.ComputeSubnetForDataColumnSidecar(sidecar.Index)
+
+			if err := vs.P2P.BroadcastDataColumnSidecar(root, subnet, sidecar); 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_altair.go

@@ -1,8 +1,10 @@
 package validator
 
 import (
+	"bytes"
 	"context"
 
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
@@ -15,6 +17,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/go-bitfield"
 )
 
 func (vs *Server) setSyncAggregate(ctx context.Context, blk interfaces.SignedBeaconBlock) {
@@ -51,21 +54,28 @@ func (vs *Server) getSyncAggregate(ctx context.Context, slot primitives.Slot, ro
 	if vs.SyncCommitteePool == nil {
 		return nil, errors.New("sync committee pool is nil")
 	}
-	// Contributions have to match the input root
-	contributions, err := vs.SyncCommitteePool.SyncCommitteeContributions(slot)
+
+	poolContributions, err := vs.SyncCommitteePool.SyncCommitteeContributions(slot)
 	if err != nil {
 		return nil, err
 	}
-	proposerContributions := proposerSyncContributions(contributions).filterByBlockRoot(root)
+	// Contributions have to match the input root
+	proposerContributions := proposerSyncContributions(poolContributions).filterByBlockRoot(root)
 
-	// Each sync subcommittee is 128 bits and the sync committee is 512 bits for mainnet.
+	aggregatedContributions, err := vs.aggregatedSyncCommitteeMessages(ctx, slot, root, poolContributions)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get aggregated sync committee messages")
+	}
+	proposerContributions = append(proposerContributions, aggregatedContributions...)
+
+	subcommitteeCount := params.BeaconConfig().SyncCommitteeSubnetCount
 	var bitsHolder [][]byte
-	for i := uint64(0); i < params.BeaconConfig().SyncCommitteeSubnetCount; i++ {
+	for i := uint64(0); i < subcommitteeCount; i++ {
 		bitsHolder = append(bitsHolder, ethpb.NewSyncCommitteeAggregationBits())
 	}
-	sigsHolder := make([]bls.Signature, 0, params.BeaconConfig().SyncCommitteeSize/params.BeaconConfig().SyncCommitteeSubnetCount)
+	sigsHolder := make([]bls.Signature, 0, params.BeaconConfig().SyncCommitteeSize/subcommitteeCount)
 
-	for i := uint64(0); i < params.BeaconConfig().SyncCommitteeSubnetCount; i++ {
+	for i := uint64(0); i < subcommitteeCount; i++ {
 		cs := proposerContributions.filterBySubIndex(i)
 		aggregates, err := synccontribution.Aggregate(cs)
 		if err != nil {
@@ -107,3 +117,107 @@ func (vs *Server) getSyncAggregate(ctx context.Context, slot primitives.Slot, ro
 		SyncCommitteeSignature: syncSigBytes[:],
 	}, nil
 }
+
+func (vs *Server) aggregatedSyncCommitteeMessages(
+	ctx context.Context,
+	slot primitives.Slot,
+	root [32]byte,
+	poolContributions []*ethpb.SyncCommitteeContribution,
+) ([]*ethpb.SyncCommitteeContribution, error) {
+	subcommitteeCount := params.BeaconConfig().SyncCommitteeSubnetCount
+	subcommitteeSize := params.BeaconConfig().SyncCommitteeSize / subcommitteeCount
+	sigsPerSubcommittee := make([][][]byte, subcommitteeCount)
+	bitsPerSubcommittee := make([]bitfield.Bitfield, subcommitteeCount)
+	for i := uint64(0); i < subcommitteeCount; i++ {
+		sigsPerSubcommittee[i] = make([][]byte, 0, subcommitteeSize)
+		bitsPerSubcommittee[i] = ethpb.NewSyncCommitteeAggregationBits()
+	}
+
+	// Get committee position(s) for each message's validator index.
+	scMessages, err := vs.SyncCommitteePool.SyncCommitteeMessages(slot)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get sync committee messages")
+	}
+	messageIndices := make([]primitives.ValidatorIndex, 0, len(scMessages))
+	messageSigs := make([][]byte, 0, len(scMessages))
+	for _, msg := range scMessages {
+		if bytes.Equal(root[:], msg.BlockRoot) {
+			messageIndices = append(messageIndices, msg.ValidatorIndex)
+			messageSigs = append(messageSigs, msg.Signature)
+		}
+	}
+	st, err := vs.HeadFetcher.HeadState(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get head state")
+	}
+	positions, err := helpers.CurrentPeriodPositions(st, messageIndices)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get sync committee positions")
+	}
+
+	// Based on committee position(s), set the appropriate subcommittee bit and signature.
+	for i, ci := range positions {
+		for _, index := range ci {
+			k := uint64(index)
+			subnetIndex := k / subcommitteeSize
+			indexMod := k % subcommitteeSize
+
+			// Existing aggregated contributions from the pool intersecting with aggregates
+			// created from single sync committee messages can result in bit intersections
+			// that fail to produce the best possible final aggregate. Ignoring bits that are
+			// already set in pool contributions makes intersections impossible.
+			intersects := false
+			for _, poolContrib := range poolContributions {
+				if poolContrib.SubcommitteeIndex == subnetIndex && poolContrib.AggregationBits.BitAt(indexMod) {
+					intersects = true
+				}
+			}
+			if !intersects && !bitsPerSubcommittee[subnetIndex].BitAt(indexMod) {
+				bitsPerSubcommittee[subnetIndex].SetBitAt(indexMod, true)
+				sigsPerSubcommittee[subnetIndex] = append(sigsPerSubcommittee[subnetIndex], messageSigs[i])
+			}
+		}
+	}
+
+	// Aggregate.
+	result := make([]*ethpb.SyncCommitteeContribution, 0, subcommitteeCount)
+	for i := uint64(0); i < subcommitteeCount; i++ {
+		aggregatedSig := make([]byte, 96)
+		aggregatedSig[0] = 0xC0
+		if len(sigsPerSubcommittee[i]) != 0 {
+			contrib, err := aggregateSyncSubcommitteeMessages(slot, root, i, bitsPerSubcommittee[i], sigsPerSubcommittee[i])
+			if err != nil {
+				// Skip aggregating this subcommittee
+				log.WithError(err).Errorf("Could not aggregate sync messages for subcommittee %d", i)
+				continue
+			}
+			result = append(result, contrib)
+		}
+	}
+
+	return result, nil
+}
+
+func aggregateSyncSubcommitteeMessages(
+	slot primitives.Slot,
+	root [32]byte,
+	subcommitteeIndex uint64,
+	bits bitfield.Bitfield,
+	sigs [][]byte,
+) (*ethpb.SyncCommitteeContribution, error) {
+	var err error
+	uncompressedSigs := make([]bls.Signature, len(sigs))
+	for i, sig := range sigs {
+		uncompressedSigs[i], err = bls.SignatureFromBytesNoValidation(sig)
+		if err != nil {
+			return nil, errors.Wrap(err, "could not create signature from bytes")
+		}
+	}
+	return &ethpb.SyncCommitteeContribution{
+		Slot:              slot,
+		BlockRoot:         root[:],
+		SubcommitteeIndex: subcommitteeIndex,
+		AggregationBits:   bits.Bytes(),
+		Signature:         bls.AggregateSignatures(uncompressedSigs).Marshal(),
+	}, nil
+}

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

@@ -3,13 +3,67 @@ package validator
 import (
 	"testing"
 
+	chainmock "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/synccommittee"
+	mockSync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v6/crypto/bls"
+	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
+	"github.com/prysmaticlabs/go-bitfield"
 )
 
+func TestProposer_GetSyncAggregate_OK(t *testing.T) {
+	st, err := util.NewBeaconStateAltair()
+	require.NoError(t, err)
+	proposerServer := &Server{
+		HeadFetcher:       &chainmock.ChainService{State: st},
+		SyncChecker:       &mockSync.Sync{IsSyncing: false},
+		SyncCommitteePool: synccommittee.NewStore(),
+	}
+
+	r := params.BeaconConfig().ZeroHash
+	conts := []*ethpb.SyncCommitteeContribution{
+		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
+		{Slot: 2, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
+		{Slot: 2, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
+		{Slot: 2, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
+		{Slot: 2, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
+	}
+
+	for _, cont := range conts {
+		require.NoError(t, proposerServer.SyncCommitteePool.SaveSyncCommitteeContribution(cont))
+	}
+
+	aggregate, err := proposerServer.getSyncAggregate(t.Context(), 1, bytesutil.ToBytes32(conts[0].BlockRoot))
+	require.NoError(t, err)
+	require.DeepEqual(t, bitfield.Bitvector32{0xf, 0xf, 0xf, 0xf}, aggregate.SyncCommitteeBits)
+
+	aggregate, err = proposerServer.getSyncAggregate(t.Context(), 2, bytesutil.ToBytes32(conts[0].BlockRoot))
+	require.NoError(t, err)
+	require.DeepEqual(t, bitfield.Bitvector32{0xaa, 0xaa, 0xaa, 0xaa}, aggregate.SyncCommitteeBits)
+
+	aggregate, err = proposerServer.getSyncAggregate(t.Context(), 3, bytesutil.ToBytes32(conts[0].BlockRoot))
+	require.NoError(t, err)
+	require.DeepEqual(t, bitfield.NewBitvector32(), aggregate.SyncCommitteeBits)
+}
+
 func TestServer_SetSyncAggregate_EmptyCase(t *testing.T) {
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockAltair())
 	require.NoError(t, err)
@@ -25,3 +79,123 @@ func TestServer_SetSyncAggregate_EmptyCase(t *testing.T) {
 	}
 	require.DeepEqual(t, want, agg)
 }
+
+func TestProposer_GetSyncAggregate_IncludesSyncCommitteeMessages(t *testing.T) {
+	// TEST SETUP
+	// - validator 0 is selected twice in subcommittee 0 (indexes [0,1])
+	// - validator 1 is selected once in subcommittee 0 (index 2)
+	// - validator 2 is selected twice in subcommittee 1 (indexes [0,1])
+	// - validator 3 is selected once in subcommittee 1 (index 2)
+	// - sync committee aggregates in the pool have index 3 set for both subcommittees
+
+	subcommitteeSize := params.BeaconConfig().SyncCommitteeSize / params.BeaconConfig().SyncCommitteeSubnetCount
+
+	helpers.ClearCache()
+	st, err := util.NewBeaconStateAltair()
+	require.NoError(t, err)
+	vals := make([]*ethpb.Validator, 4)
+	vals[0] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf0}, 48)}
+	vals[1] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf1}, 48)}
+	vals[2] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf2}, 48)}
+	vals[3] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf3}, 48)}
+	require.NoError(t, st.SetValidators(vals))
+	sc := &ethpb.SyncCommittee{
+		Pubkeys: make([][]byte, params.BeaconConfig().SyncCommitteeSize),
+	}
+	sc.Pubkeys[0] = vals[0].PublicKey
+	sc.Pubkeys[1] = vals[0].PublicKey
+	sc.Pubkeys[2] = vals[1].PublicKey
+	sc.Pubkeys[subcommitteeSize] = vals[2].PublicKey
+	sc.Pubkeys[subcommitteeSize+1] = vals[2].PublicKey
+	sc.Pubkeys[subcommitteeSize+2] = vals[3].PublicKey
+	require.NoError(t, st.SetCurrentSyncCommittee(sc))
+	proposerServer := &Server{
+		HeadFetcher:       &chainmock.ChainService{State: st},
+		SyncChecker:       &mockSync.Sync{IsSyncing: false},
+		SyncCommitteePool: synccommittee.NewStore(),
+	}
+
+	r := params.BeaconConfig().ZeroHash
+	msgs := []*ethpb.SyncCommitteeMessage{
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 0, Signature: bls.NewAggregateSignature().Marshal()},
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 1, Signature: bls.NewAggregateSignature().Marshal()},
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 2, Signature: bls.NewAggregateSignature().Marshal()},
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 3, Signature: bls.NewAggregateSignature().Marshal()},
+	}
+	for _, msg := range msgs {
+		require.NoError(t, proposerServer.SyncCommitteePool.SaveSyncCommitteeMessage(msg))
+	}
+	subcommittee0AggBits := ethpb.NewSyncCommitteeAggregationBits()
+	subcommittee0AggBits.SetBitAt(3, true)
+	subcommittee1AggBits := ethpb.NewSyncCommitteeAggregationBits()
+	subcommittee1AggBits.SetBitAt(3, true)
+	conts := []*ethpb.SyncCommitteeContribution{
+		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: subcommittee0AggBits, BlockRoot: r[:]},
+		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: subcommittee1AggBits, BlockRoot: r[:]},
+	}
+	for _, cont := range conts {
+		require.NoError(t, proposerServer.SyncCommitteePool.SaveSyncCommitteeContribution(cont))
+	}
+
+	// The final sync aggregates must have indexes [0,1,2,3] set for both subcommittees
+	sa, err := proposerServer.getSyncAggregate(t.Context(), 1, r)
+	require.NoError(t, err)
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(0))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(1))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(2))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(3))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(subcommitteeSize))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(subcommitteeSize+1))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(subcommitteeSize+2))
+	assert.Equal(t, true, sa.SyncCommitteeBits.BitAt(subcommitteeSize+3))
+}
+
+func Test_aggregatedSyncCommitteeMessages_NoIntersectionWithPoolContributions(t *testing.T) {
+	helpers.ClearCache()
+	st, err := util.NewBeaconStateAltair()
+	require.NoError(t, err)
+	vals := make([]*ethpb.Validator, 4)
+	vals[0] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf0}, 48)}
+	vals[1] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf1}, 48)}
+	vals[2] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf2}, 48)}
+	vals[3] = &ethpb.Validator{PublicKey: bytesutil.PadTo([]byte{0xf3}, 48)}
+	require.NoError(t, st.SetValidators(vals))
+	sc := &ethpb.SyncCommittee{
+		Pubkeys: make([][]byte, params.BeaconConfig().SyncCommitteeSize),
+	}
+	sc.Pubkeys[0] = vals[0].PublicKey
+	sc.Pubkeys[1] = vals[1].PublicKey
+	sc.Pubkeys[2] = vals[2].PublicKey
+	sc.Pubkeys[3] = vals[3].PublicKey
+	require.NoError(t, st.SetCurrentSyncCommittee(sc))
+	proposerServer := &Server{
+		HeadFetcher:       &chainmock.ChainService{State: st},
+		SyncChecker:       &mockSync.Sync{IsSyncing: false},
+		SyncCommitteePool: synccommittee.NewStore(),
+	}
+
+	r := params.BeaconConfig().ZeroHash
+	msgs := []*ethpb.SyncCommitteeMessage{
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 0, Signature: bls.NewAggregateSignature().Marshal()},
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 1, Signature: bls.NewAggregateSignature().Marshal()},
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 2, Signature: bls.NewAggregateSignature().Marshal()},
+		{Slot: 1, BlockRoot: r[:], ValidatorIndex: 3, Signature: bls.NewAggregateSignature().Marshal()},
+	}
+	for _, msg := range msgs {
+		require.NoError(t, proposerServer.SyncCommitteePool.SaveSyncCommitteeMessage(msg))
+	}
+	subcommitteeAggBits := ethpb.NewSyncCommitteeAggregationBits()
+	subcommitteeAggBits.SetBitAt(3, true)
+	cont := &ethpb.SyncCommitteeContribution{
+		Slot:              1,
+		SubcommitteeIndex: 0,
+		Signature:         bls.NewAggregateSignature().Marshal(),
+		AggregationBits:   subcommitteeAggBits,
+		BlockRoot:         r[:],
+	}
+
+	aggregated, err := proposerServer.aggregatedSyncCommitteeMessages(t.Context(), 1, r, []*ethpb.SyncCommitteeContribution{cont})
+	require.NoError(t, err)
+	require.Equal(t, 1, len(aggregated))
+	assert.Equal(t, false, aggregated[0].AggregationBits.BitAt(3))
+}

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

@@ -4,16 +4,23 @@ import (
 	"context"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	v "github.com/OffchainLabs/prysm/v6/beacon-chain/core/validators"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 )
 
 func (vs *Server) getSlashings(ctx context.Context, head state.BeaconState) ([]*ethpb.ProposerSlashing, []ethpb.AttSlashing) {
+	var err error
+
+	exitInfo := v.ExitInformation(head)
+	if err := helpers.UpdateTotalActiveBalanceCache(head, exitInfo.TotalActiveBalance); err != nil {
+		log.WithError(err).Warn("Could not update total active balance cache")
+	}
 	proposerSlashings := vs.SlashingsPool.PendingProposerSlashings(ctx, head, false /*noLimit*/)
 	validProposerSlashings := make([]*ethpb.ProposerSlashing, 0, len(proposerSlashings))
 	for _, slashing := range proposerSlashings {
-		_, err := blocks.ProcessProposerSlashing(ctx, head, slashing, v.SlashValidator)
+		_, err = blocks.ProcessProposerSlashing(ctx, head, slashing, exitInfo)
 		if err != nil {
 			log.WithError(err).Warn("Could not validate proposer slashing for block inclusion")
 			continue
@@ -23,7 +30,7 @@ func (vs *Server) getSlashings(ctx context.Context, head state.BeaconState) ([]*
 	attSlashings := vs.SlashingsPool.PendingAttesterSlashings(ctx, head, false /*noLimit*/)
 	validAttSlashings := make([]ethpb.AttSlashing, 0, len(attSlashings))
 	for _, slashing := range attSlashings {
-		_, err := blocks.ProcessAttesterSlashing(ctx, head, slashing, v.SlashValidator)
+		_, err = blocks.ProcessAttesterSlashing(ctx, head, slashing, exitInfo)
 		if err != nil {
 			log.WithError(err).Warn("Could not validate attester slashing for block inclusion")
 			continue

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)
@@ -2953,49 +3096,6 @@ func TestProposer_DeleteAttsInPool_Aggregated(t *testing.T) {
 	assert.Equal(t, 0, len(atts), "Did not delete unaggregated attestation")
 }
 
-func TestProposer_GetSyncAggregate_OK(t *testing.T) {
-	proposerServer := &Server{
-		SyncChecker:       &mockSync.Sync{IsSyncing: false},
-		SyncCommitteePool: synccommittee.NewStore(),
-	}
-
-	r := params.BeaconConfig().ZeroHash
-	conts := []*ethpb.SyncCommitteeContribution{
-		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b0001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1001}, BlockRoot: r[:]},
-		{Slot: 1, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b1110}, BlockRoot: r[:]},
-		{Slot: 2, SubcommitteeIndex: 0, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
-		{Slot: 2, SubcommitteeIndex: 1, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
-		{Slot: 2, SubcommitteeIndex: 2, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
-		{Slot: 2, SubcommitteeIndex: 3, Signature: bls.NewAggregateSignature().Marshal(), AggregationBits: []byte{0b10101010}, BlockRoot: r[:]},
-	}
-
-	for _, cont := range conts {
-		require.NoError(t, proposerServer.SyncCommitteePool.SaveSyncCommitteeContribution(cont))
-	}
-
-	aggregate, err := proposerServer.getSyncAggregate(t.Context(), 1, bytesutil.ToBytes32(conts[0].BlockRoot))
-	require.NoError(t, err)
-	require.DeepEqual(t, bitfield.Bitvector32{0xf, 0xf, 0xf, 0xf}, aggregate.SyncCommitteeBits)
-
-	aggregate, err = proposerServer.getSyncAggregate(t.Context(), 2, bytesutil.ToBytes32(conts[0].BlockRoot))
-	require.NoError(t, err)
-	require.DeepEqual(t, bitfield.Bitvector32{0xaa, 0xaa, 0xaa, 0xaa}, aggregate.SyncCommitteeBits)
-
-	aggregate, err = proposerServer.getSyncAggregate(t.Context(), 3, bytesutil.ToBytes32(conts[0].BlockRoot))
-	require.NoError(t, err)
-	require.DeepEqual(t, bitfield.NewBitvector32(), aggregate.SyncCommitteeBits)
-}
-
 func TestProposer_PrepareBeaconProposer(t *testing.T) {
 	type args struct {
 		request *ethpb.PrepareBeaconProposerRequest

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
@@ -238,6 +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",

beacon-chain/rpc/testutil/mock_sidecars.go

@@ -0,0 +1,44 @@
+package testutil
+
+import ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+
+// CreateDataColumnSidecar generates a filled dummy data column sidecar
+func CreateDataColumnSidecar(index uint64, data []byte) *ethpb.DataColumnSidecar {
+	return &ethpb.DataColumnSidecar{
+		Index:  index,
+		Column: [][]byte{data},
+		SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+			Header: &ethpb.BeaconBlockHeader{
+				Slot:          1,
+				ProposerIndex: 1,
+				ParentRoot:    make([]byte, 32),
+				StateRoot:     make([]byte, 32),
+				BodyRoot:      make([]byte, 32),
+			},
+			Signature: make([]byte, 96),
+		},
+		KzgCommitments:               [][]byte{make([]byte, 48)},
+		KzgProofs:                    [][]byte{make([]byte, 48)},
+		KzgCommitmentsInclusionProof: [][]byte{make([]byte, 32)},
+	}
+}
+
+// CreateBlobSidecar generates a filled dummy data blob sidecar
+func CreateBlobSidecar(index uint64, blob []byte) *ethpb.BlobSidecar {
+	return &ethpb.BlobSidecar{
+		Index: index,
+		Blob:  blob,
+		SignedBlockHeader: &ethpb.SignedBeaconBlockHeader{
+			Header: &ethpb.BeaconBlockHeader{
+				Slot:          1,
+				ProposerIndex: 1,
+				ParentRoot:    make([]byte, 32),
+				StateRoot:     make([]byte, 32),
+				BodyRoot:      make([]byte, 32),
+			},
+			Signature: make([]byte, 96),
+		},
+		KzgCommitment: make([]byte, 48),
+		KzgProof:      make([]byte, 48),
+	}
+}

beacon-chain/startup/clock.go

@@ -67,6 +67,13 @@ func WithNower(n Nower) ClockOpt {
 	}
 }
 
+// WithTimeAsNow will create a Nower based on the given time.Time and set it as the Now() implementation.
+func WithTimeAsNow(t time.Time) ClockOpt {
+	return func(g *Clock) {
+		g.now = func() time.Time { return t }
+	}
+}
+
 // NewClock constructs a Clock value from a genesis timestamp (t) and a Genesis Validator Root (vr).
 // The WithNower ClockOpt can be used in tests to specify an alternate `time.Now` implementation,
 // for instance to return a value for `Now` spanning a certain number of slots from genesis time, to control the current slot.

beacon-chain/state/interfaces.go

@@ -265,6 +265,7 @@ type WriteOnlyEth1Data interface {
 	AppendEth1DataVotes(val *ethpb.Eth1Data) error
 	SetEth1DepositIndex(val uint64) error
 	ExitEpochAndUpdateChurn(exitBalance primitives.Gwei) (primitives.Epoch, error)
+	ExitEpochAndUpdateChurnForTotalBal(totalActiveBalance primitives.Gwei, exitBalance primitives.Gwei) (primitives.Epoch, error)
 }
 
 // WriteOnlyValidators defines a struct which only has write access to validators methods.

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

@@ -44,11 +44,27 @@ func (b *BeaconState) ExitEpochAndUpdateChurn(exitBalance primitives.Gwei) (prim
 		return 0, err
 	}
 
+	return b.exitEpochAndUpdateChurn(primitives.Gwei(activeBal), exitBalance)
+}
+
+// ExitEpochAndUpdateChurnForTotalBal has the same functionality as ExitEpochAndUpdateChurn,
+// the only difference being how total active balance is obtained. In ExitEpochAndUpdateChurn
+// it is calculated inside the function and in ExitEpochAndUpdateChurnForTotalBal it's a
+// function argument.
+func (b *BeaconState) ExitEpochAndUpdateChurnForTotalBal(totalActiveBalance primitives.Gwei, exitBalance primitives.Gwei) (primitives.Epoch, error) {
+	if b.version < version.Electra {
+		return 0, errNotSupported("ExitEpochAndUpdateChurnForTotalBal", b.version)
+	}
+
+	return b.exitEpochAndUpdateChurn(totalActiveBalance, exitBalance)
+}
+
+func (b *BeaconState) exitEpochAndUpdateChurn(totalActiveBalance primitives.Gwei, exitBalance primitives.Gwei) (primitives.Epoch, error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 
 	earliestExitEpoch := max(b.earliestExitEpoch, helpers.ActivationExitEpoch(slots.ToEpoch(b.slot)))
-	perEpochChurn := helpers.ActivationExitChurnLimit(primitives.Gwei(activeBal)) // Guaranteed to be non-zero.
+	perEpochChurn := helpers.ActivationExitChurnLimit(totalActiveBalance) // Guaranteed to be non-zero.
 
 	// New epoch for exits
 	var exitBalanceToConsume primitives.Gwei

beacon-chain/sync/BUILD.bazel

@@ -5,7 +5,6 @@ go_library(
     srcs = [
         "batch_verifier.go",
         "block_batcher.go",
-        "broadcast_bls_changes.go",
         "context.go",
         "custody.go",
         "data_column_sidecars.go",
@@ -165,7 +164,6 @@ go_test(
         "batch_verifier_test.go",
         "blobs_test.go",
         "block_batcher_test.go",
-        "broadcast_bls_changes_test.go",
         "context_test.go",
         "custody_test.go",
         "data_column_sidecars_test.go",
@@ -194,6 +192,7 @@ go_test(
         "slot_aware_cache_test.go",
         "subscriber_beacon_aggregate_proof_test.go",
         "subscriber_beacon_blocks_test.go",
+        "subscriber_data_column_sidecar_test.go",
         "subscriber_test.go",
         "subscription_topic_handler_test.go",
         "sync_fuzz_test.go",
@@ -266,6 +265,7 @@ go_test(
         "//crypto/rand:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz/equality:go_default_library",
+        "//genesis:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/attestation:go_default_library",

beacon-chain/sync/broadcast_bls_changes.go

@@ -1,88 +0,0 @@
-package sync
-
-import (
-	"context"
-	"time"
-
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/blocks"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	types "github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/crypto/rand"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/OffchainLabs/prysm/v6/time/slots"
-)
-
-const broadcastBLSChangesRateLimit = 128
-
-// This routine broadcasts known BLS changes at the Capella fork.
-func (s *Service) broadcastBLSChanges(currSlot types.Slot) {
-	capellaSlotStart, err := slots.EpochStart(params.BeaconConfig().CapellaForkEpoch)
-	if err != nil {
-		// only possible error is an overflow, so we exit early from the method
-		return
-	}
-	if currSlot != capellaSlotStart {
-		return
-	}
-	changes, err := s.cfg.blsToExecPool.PendingBLSToExecChanges()
-	if err != nil {
-		log.WithError(err).Error("could not get BLS to execution changes")
-	}
-	if len(changes) == 0 {
-		return
-	}
-	source := rand.NewGenerator()
-	length := len(changes)
-	broadcastChanges := make([]*ethpb.SignedBLSToExecutionChange, length)
-	for i := 0; i < length; i++ {
-		idx := source.Intn(len(changes))
-		broadcastChanges[i] = changes[idx]
-		changes = append(changes[:idx], changes[idx+1:]...)
-	}
-
-	go s.rateBLSChanges(s.ctx, broadcastChanges)
-}
-
-func (s *Service) broadcastBLSBatch(ctx context.Context, ptr *[]*ethpb.SignedBLSToExecutionChange) {
-	limit := broadcastBLSChangesRateLimit
-	if len(*ptr) < broadcastBLSChangesRateLimit {
-		limit = len(*ptr)
-	}
-	st, err := s.cfg.chain.HeadStateReadOnly(ctx)
-	if err != nil {
-		log.WithError(err).Error("could not get head state")
-		return
-	}
-	for _, ch := range (*ptr)[:limit] {
-		if ch != nil {
-			_, err := blocks.ValidateBLSToExecutionChange(st, ch)
-			if err != nil {
-				log.WithError(err).Error("could not validate BLS to execution change")
-				continue
-			}
-			if err := s.cfg.p2p.Broadcast(ctx, ch); err != nil {
-				log.WithError(err).Error("could not broadcast BLS to execution changes.")
-			}
-		}
-	}
-	*ptr = (*ptr)[limit:]
-}
-
-func (s *Service) rateBLSChanges(ctx context.Context, changes []*ethpb.SignedBLSToExecutionChange) {
-	s.broadcastBLSBatch(ctx, &changes)
-	if len(changes) == 0 {
-		return
-	}
-	ticker := time.NewTicker(500 * time.Millisecond)
-	for {
-		select {
-		case <-s.ctx.Done():
-			return
-		case <-ticker.C:
-			s.broadcastBLSBatch(ctx, &changes)
-			if len(changes) == 0 {
-				return
-			}
-		}
-	}
-}

beacon-chain/sync/broadcast_bls_changes_test.go

@@ -1,157 +0,0 @@
-package sync
-
-import (
-	"testing"
-	"time"
-
-	mockChain "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/signing"
-	testingdb "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/operations/blstoexec"
-	mockp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/state/stategen"
-	mockSync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
-	"github.com/OffchainLabs/prysm/v6/config/params"
-	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
-	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
-	"github.com/OffchainLabs/prysm/v6/testing/assert"
-	"github.com/OffchainLabs/prysm/v6/testing/require"
-	"github.com/OffchainLabs/prysm/v6/testing/util"
-	"github.com/OffchainLabs/prysm/v6/time/slots"
-	logTest "github.com/sirupsen/logrus/hooks/test"
-)
-
-func TestBroadcastBLSChanges(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	c := params.BeaconConfig()
-	c.CapellaForkEpoch = c.BellatrixForkEpoch.Add(2)
-	params.OverrideBeaconConfig(c)
-	chainService := &mockChain.ChainService{
-		Genesis:        time.Now(),
-		ValidatorsRoot: [32]byte{'A'},
-	}
-	s := NewService(t.Context(),
-		WithP2P(mockp2p.NewTestP2P(t)),
-		WithInitialSync(&mockSync.Sync{IsSyncing: false}),
-		WithChainService(chainService),
-		WithOperationNotifier(chainService.OperationNotifier()),
-		WithBlsToExecPool(blstoexec.NewPool()),
-	)
-	var emptySig [96]byte
-	s.cfg.blsToExecPool.InsertBLSToExecChange(&ethpb.SignedBLSToExecutionChange{
-		Message: &ethpb.BLSToExecutionChange{
-			ValidatorIndex:     10,
-			FromBlsPubkey:      make([]byte, 48),
-			ToExecutionAddress: make([]byte, 20),
-		},
-		Signature: emptySig[:],
-	})
-
-	capellaStart, err := slots.EpochStart(params.BeaconConfig().CapellaForkEpoch)
-	require.NoError(t, err)
-	s.broadcastBLSChanges(capellaStart + 1)
-}
-
-func TestRateBLSChanges(t *testing.T) {
-	logHook := logTest.NewGlobal()
-	params.SetupTestConfigCleanup(t)
-	c := params.BeaconConfig()
-	c.CapellaForkEpoch = c.BellatrixForkEpoch.Add(2)
-	params.OverrideBeaconConfig(c)
-	chainService := &mockChain.ChainService{
-		Genesis:        time.Now(),
-		ValidatorsRoot: [32]byte{'A'},
-	}
-	p1 := mockp2p.NewTestP2P(t)
-	s := NewService(t.Context(),
-		WithP2P(p1),
-		WithInitialSync(&mockSync.Sync{IsSyncing: false}),
-		WithChainService(chainService),
-		WithOperationNotifier(chainService.OperationNotifier()),
-		WithBlsToExecPool(blstoexec.NewPool()),
-	)
-	beaconDB := testingdb.SetupDB(t)
-	s.cfg.stateGen = stategen.New(beaconDB, doublylinkedtree.New())
-	s.cfg.beaconDB = beaconDB
-	s.initCaches()
-	st, keys := util.DeterministicGenesisStateCapella(t, 256)
-	s.cfg.chain = &mockChain.ChainService{
-		ValidatorsRoot: [32]byte{'A'},
-		Genesis:        time.Now().Add(-time.Second * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Duration(10)),
-		State:          st,
-	}
-
-	for i := 0; i < 200; i++ {
-		message := &ethpb.BLSToExecutionChange{
-			ValidatorIndex:     primitives.ValidatorIndex(i),
-			FromBlsPubkey:      keys[i+1].PublicKey().Marshal(),
-			ToExecutionAddress: bytesutil.PadTo([]byte("address"), 20),
-		}
-		epoch := params.BeaconConfig().CapellaForkEpoch + 1
-		domain, err := signing.Domain(st.Fork(), epoch, params.BeaconConfig().DomainBLSToExecutionChange, st.GenesisValidatorsRoot())
-		assert.NoError(t, err)
-		htr, err := signing.Data(message.HashTreeRoot, domain)
-		assert.NoError(t, err)
-		signed := &ethpb.SignedBLSToExecutionChange{
-			Message:   message,
-			Signature: keys[i+1].Sign(htr[:]).Marshal(),
-		}
-
-		s.cfg.blsToExecPool.InsertBLSToExecChange(signed)
-	}
-
-	require.Equal(t, false, p1.BroadcastCalled.Load())
-	slot, err := slots.EpochStart(params.BeaconConfig().CapellaForkEpoch)
-	require.NoError(t, err)
-	s.broadcastBLSChanges(slot)
-	time.Sleep(100 * time.Millisecond) // Need a sleep for the go routine to be ready
-	require.Equal(t, true, p1.BroadcastCalled.Load())
-	require.LogsDoNotContain(t, logHook, "could not")
-
-	p1.BroadcastCalled.Store(false)
-	time.Sleep(500 * time.Millisecond) // Need a sleep for the second batch to be broadcast
-	require.Equal(t, true, p1.BroadcastCalled.Load())
-	require.LogsDoNotContain(t, logHook, "could not")
-}
-
-func TestBroadcastBLSBatch_changes_slice(t *testing.T) {
-	message := &ethpb.BLSToExecutionChange{
-		FromBlsPubkey:      make([]byte, 48),
-		ToExecutionAddress: make([]byte, 20),
-	}
-	signed := &ethpb.SignedBLSToExecutionChange{
-		Message:   message,
-		Signature: make([]byte, 96),
-	}
-	changes := make([]*ethpb.SignedBLSToExecutionChange, 200)
-	for i := 0; i < len(changes); i++ {
-		changes[i] = signed
-	}
-	p1 := mockp2p.NewTestP2P(t)
-	chainService := &mockChain.ChainService{
-		Genesis:        time.Now(),
-		ValidatorsRoot: [32]byte{'A'},
-	}
-	s := NewService(t.Context(),
-		WithP2P(p1),
-		WithInitialSync(&mockSync.Sync{IsSyncing: false}),
-		WithChainService(chainService),
-		WithOperationNotifier(chainService.OperationNotifier()),
-		WithBlsToExecPool(blstoexec.NewPool()),
-	)
-	beaconDB := testingdb.SetupDB(t)
-	s.cfg.stateGen = stategen.New(beaconDB, doublylinkedtree.New())
-	s.cfg.beaconDB = beaconDB
-	s.initCaches()
-	st, _ := util.DeterministicGenesisStateCapella(t, 32)
-	s.cfg.chain = &mockChain.ChainService{
-		ValidatorsRoot: [32]byte{'A'},
-		Genesis:        time.Now().Add(-time.Second * time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Duration(10)),
-		State:          st,
-	}
-
-	s.broadcastBLSBatch(s.ctx, &changes)
-	require.Equal(t, 200-128, len(changes))
-}

beacon-chain/sync/custody.go

@@ -106,6 +106,9 @@ func (s *Service) custodyGroupCount() (uint64, error) {
 // validatorsCustodyRequirements computes the custody requirements based on the
 // finalized state and the tracked validators.
 func (s *Service) validatorsCustodyRequirement() (uint64, error) {
+	if s.trackedValidatorsCache == nil {
+		return 0, nil
+	}
 	// Get the indices of the tracked validators.
 	indices := s.trackedValidatorsCache.Indices()
 

beacon-chain/sync/data_column_sidecars.go

@@ -29,13 +29,14 @@ import (
 // DataColumnSidecarsParams stores the common parameters needed to
 // fetch data column sidecars from peers.
 type DataColumnSidecarsParams struct {
-	Ctx         context.Context                     // Context
-	Tor         blockchain.TemporalOracle           // Temporal oracle, useful to get the current slot
-	P2P         prysmP2P.P2P                        // P2P network interface
-	RateLimiter *leakybucket.Collector              // Rate limiter for outgoing requests
-	CtxMap      ContextByteVersions                 // Context map, useful to know if a message is mapped to the correct fork
-	Storage     filesystem.DataColumnStorageReader  // Data columns storage
-	NewVerifier verification.NewDataColumnsVerifier // Data columns verifier to check to conformity of incoming data column sidecars
+	Ctx                     context.Context                     // Context
+	Tor                     blockchain.TemporalOracle           // Temporal oracle, useful to get the current slot
+	P2P                     prysmP2P.P2P                        // P2P network interface
+	RateLimiter             *leakybucket.Collector              // Rate limiter for outgoing requests
+	CtxMap                  ContextByteVersions                 // Context map, useful to know if a message is mapped to the correct fork
+	Storage                 filesystem.DataColumnStorageReader  // Data columns storage
+	NewVerifier             verification.NewDataColumnsVerifier // Data columns verifier to check to conformity of incoming data column sidecars
+	DownscorePeerOnRPCFault bool                                // Downscore a peer if it commits an RPC fault. Not responding sidecars at all is considered as a fault.
 }
 
 // FetchDataColumnSidecars retrieves data column sidecars from storage and peers for the given

beacon-chain/sync/fork_watcher.go

@@ -12,6 +12,7 @@ import (
 // Is a background routine that observes for new incoming forks. Depending on the epoch
 // it will be in charge of subscribing/unsubscribing the relevant topics at the fork boundaries.
 func (s *Service) forkWatcher() {
+	<-s.initialSyncComplete
 	slotTicker := slots.NewSlotTicker(s.cfg.clock.GenesisTime(), params.BeaconConfig().SecondsPerSlot)
 	for {
 		select {
@@ -28,9 +29,6 @@ func (s *Service) forkWatcher() {
 				log.WithError(err).Error("Unable to check for fork in the previous epoch")
 				continue
 			}
-			// Broadcast BLS changes at the Capella fork boundary
-			s.broadcastBLSChanges(currSlot)
-
 		case <-s.ctx.Done():
 			log.Debug("Context closed, exiting goroutine")
 			slotTicker.Done()

beacon-chain/sync/fork_watcher_test.go

@@ -2,96 +2,84 @@ package sync
 
 import (
 	"context"
+	"fmt"
+	"sync"
 	"testing"
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/async/abool"
 	mockChain "github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/testing"
-	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
 	mockSync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/genesis"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
 )
 
+func defaultClockWithTimeAtEpoch(epoch primitives.Epoch) *startup.Clock {
+	now := genesis.Time().Add(params.EpochsDuration(epoch, params.BeaconConfig()))
+	return startup.NewClock(genesis.Time(), genesis.ValidatorsRoot(), startup.WithTimeAsNow(now))
+}
+
+func testForkWatcherService(t *testing.T, current primitives.Epoch) *Service {
+	closedChan := make(chan struct{})
+	close(closedChan)
+	peer2peer := p2ptest.NewTestP2P(t)
+	chainService := &mockChain.ChainService{
+		Genesis:        genesis.Time(),
+		ValidatorsRoot: genesis.ValidatorsRoot(),
+	}
+	ctx, cancel := context.WithTimeout(t.Context(), 10*time.Millisecond)
+	r := &Service{
+		ctx:    ctx,
+		cancel: cancel,
+		cfg: &config{
+			p2p:         peer2peer,
+			chain:       chainService,
+			clock:       defaultClockWithTimeAtEpoch(current),
+			initialSync: &mockSync.Sync{IsSyncing: false},
+		},
+		chainStarted:        abool.New(),
+		subHandler:          newSubTopicHandler(),
+		initialSyncComplete: closedChan,
+	}
+	return r
+}
+
 func TestService_CheckForNextEpochFork(t *testing.T) {
+	closedChan := make(chan struct{})
+	close(closedChan)
 	params.SetupTestConfigCleanup(t)
+	genesis.StoreEmbeddedDuringTest(t, params.BeaconConfig().ConfigName)
+	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().ElectraForkEpoch + 1096*2
+	params.BeaconConfig().InitializeForkSchedule()
+
 	tests := []struct {
-		name         string
-		svcCreator   func(t *testing.T) *Service
-		currEpoch    primitives.Epoch
-		wantErr      bool
-		postSvcCheck func(t *testing.T, s *Service)
+		name                string
+		svcCreator          func(t *testing.T) *Service
+		checkRegistration   func(t *testing.T, s *Service)
+		forkEpoch           primitives.Epoch
+		epochAtRegistration func(primitives.Epoch) primitives.Epoch
+		nextForkEpoch       primitives.Epoch
 	}{
 		{
-			name: "no fork in the next epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				gt := time.Now().Add(time.Duration(-params.BeaconConfig().SlotsPerEpoch.Mul(uint64(params.BeaconConfig().SlotsPerEpoch))) * time.Second)
-				vr := [32]byte{'A'}
-				chainService := &mockChain.ChainService{
-					Genesis:        gt,
-					ValidatorsRoot: vr,
-				}
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       startup.NewClock(gt, vr),
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				return r
-			},
-			currEpoch: 10,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-
-			},
+			name:                "no fork in the next epoch",
+			forkEpoch:           params.BeaconConfig().AltairForkEpoch,
+			epochAtRegistration: func(e primitives.Epoch) primitives.Epoch { return e - 2 },
+			nextForkEpoch:       params.BeaconConfig().BellatrixForkEpoch,
+			checkRegistration:   func(t *testing.T, s *Service) {},
 		},
 		{
-			name: "altair fork in the next epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				gt := time.Now().Add(-4 * oneEpoch())
-				vr := [32]byte{'A'}
-				chainService := &mockChain.ChainService{
-					Genesis:        gt,
-					ValidatorsRoot: vr,
-				}
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.AltairForkEpoch = 5
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       startup.NewClock(gt, vr),
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(5)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
+			name:                "altair fork in the next epoch",
+			forkEpoch:           params.BeaconConfig().AltairForkEpoch,
+			epochAtRegistration: func(e primitives.Epoch) primitives.Epoch { return e - 1 },
+			nextForkEpoch:       params.BeaconConfig().BellatrixForkEpoch,
+			checkRegistration: func(t *testing.T, s *Service) {
+				digest := params.ForkDigest(params.BeaconConfig().AltairForkEpoch)
 				rpcMap := make(map[string]bool)
 				for _, p := range s.cfg.p2p.Host().Mux().Protocols() {
 					rpcMap[string(p)] = true
@@ -99,375 +87,132 @@ func TestService_CheckForNextEpochFork(t *testing.T) {
 				assert.Equal(t, true, rpcMap[p2p.RPCBlocksByRangeTopicV2+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 				assert.Equal(t, true, rpcMap[p2p.RPCBlocksByRootTopicV2+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 				assert.Equal(t, true, rpcMap[p2p.RPCMetaDataTopicV2+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
+				expected := fmt.Sprintf(p2p.SyncContributionAndProofSubnetTopicFormat+s.cfg.p2p.Encoding().ProtocolSuffix(), digest)
+				assert.Equal(t, true, s.subHandler.topicExists(expected), "subnet topic doesn't exist")
+				// TODO: we should check subcommittee indices here but we need to work with the committee cache to do it properly
+				/*
+					subIndices := mapFromCount(params.BeaconConfig().SyncCommitteeSubnetCount)
+					for idx := range subIndices {
+						topic := fmt.Sprintf(p2p.SyncCommitteeSubnetTopicFormat, digest, idx)
+						expected := topic + s.cfg.p2p.Encoding().ProtocolSuffix()
+						assert.Equal(t, true, s.subHandler.topicExists(expected), fmt.Sprintf("subnet topic %s doesn't exist", expected))
+					}
+				*/
 			},
 		},
 		{
-			name: "bellatrix fork in the next epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				chainService := &mockChain.ChainService{
-					Genesis:        time.Now().Add(-4 * oneEpoch()),
-					ValidatorsRoot: [32]byte{'A'},
-				}
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.AltairForkEpoch = 3
-				bCfg.BellatrixForkEpoch = 5
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot),
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(5)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
+			name: "capella fork in the next epoch",
+			checkRegistration: func(t *testing.T, s *Service) {
+				digest := params.ForkDigest(params.BeaconConfig().CapellaForkEpoch)
 				rpcMap := make(map[string]bool)
 				for _, p := range s.cfg.p2p.Host().Mux().Protocols() {
 					rpcMap[string(p)] = true
 				}
+
+				expected := fmt.Sprintf(p2p.BlsToExecutionChangeSubnetTopicFormat+s.cfg.p2p.Encoding().ProtocolSuffix(), digest)
+				assert.Equal(t, true, s.subHandler.topicExists(expected), "subnet topic doesn't exist")
 			},
+			forkEpoch:           params.BeaconConfig().CapellaForkEpoch,
+			nextForkEpoch:       params.BeaconConfig().DenebForkEpoch,
+			epochAtRegistration: func(e primitives.Epoch) primitives.Epoch { return e - 1 },
 		},
 		{
 			name: "deneb fork in the next epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				gt := time.Now().Add(-4 * oneEpoch())
-				vr := [32]byte{'A'}
-				chainService := &mockChain.ChainService{
-					Genesis:        gt,
-					ValidatorsRoot: vr,
-				}
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.DenebForkEpoch = 5
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       startup.NewClock(gt, vr),
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(5)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
+			checkRegistration: func(t *testing.T, s *Service) {
+				digest := params.ForkDigest(params.BeaconConfig().DenebForkEpoch)
 				rpcMap := make(map[string]bool)
 				for _, p := range s.cfg.p2p.Host().Mux().Protocols() {
 					rpcMap[string(p)] = true
 				}
+				subIndices := mapFromCount(params.BeaconConfig().BlobsidecarSubnetCount)
+				for idx := range subIndices {
+					topic := fmt.Sprintf(p2p.BlobSubnetTopicFormat, digest, idx)
+					expected := topic + s.cfg.p2p.Encoding().ProtocolSuffix()
+					assert.Equal(t, true, s.subHandler.topicExists(expected), fmt.Sprintf("subnet topic %s doesn't exist", expected))
+				}
 				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRangeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRootTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 			},
+			forkEpoch:           params.BeaconConfig().DenebForkEpoch,
+			nextForkEpoch:       params.BeaconConfig().ElectraForkEpoch,
+			epochAtRegistration: func(e primitives.Epoch) primitives.Epoch { return e - 1 },
 		},
 		{
 			name: "electra fork in the next epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				gt := time.Now().Add(-4 * oneEpoch())
-				vr := [32]byte{'A'}
-				chainService := &mockChain.ChainService{
-					Genesis:        gt,
-					ValidatorsRoot: vr,
+			checkRegistration: func(t *testing.T, s *Service) {
+				digest := params.ForkDigest(params.BeaconConfig().ElectraForkEpoch)
+				subIndices := mapFromCount(params.BeaconConfig().BlobsidecarSubnetCountElectra)
+				for idx := range subIndices {
+					topic := fmt.Sprintf(p2p.BlobSubnetTopicFormat, digest, idx)
+					expected := topic + s.cfg.p2p.Encoding().ProtocolSuffix()
+					assert.Equal(t, true, s.subHandler.topicExists(expected), fmt.Sprintf("subnet topic %s doesn't exist", expected))
 				}
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.ElectraForkEpoch = 5
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       startup.NewClock(gt, vr),
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(5)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
-				rpcMap := make(map[string]bool)
-				for _, p := range s.cfg.p2p.Host().Mux().Protocols() {
-					rpcMap[string(p)] = true
-				}
-				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRangeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
-				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRootTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 			},
+			forkEpoch:           params.BeaconConfig().ElectraForkEpoch,
+			nextForkEpoch:       params.BeaconConfig().FuluForkEpoch,
+			epochAtRegistration: func(e primitives.Epoch) primitives.Epoch { return e - 1 },
 		},
 		{
 			name: "fulu fork in the next epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				gt := time.Now().Add(-4 * oneEpoch())
-				vr := [32]byte{'A'}
-				chainService := &mockChain.ChainService{
-					Genesis:        gt,
-					ValidatorsRoot: vr,
-				}
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.FuluForkEpoch = 5
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       startup.NewClock(gt, vr),
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted:           abool.New(),
-					subHandler:             newSubTopicHandler(),
-					trackedValidatorsCache: cache.NewTrackedValidatorsCache(),
-				}
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(5)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
+			checkRegistration: func(t *testing.T, s *Service) {
 				rpcMap := make(map[string]bool)
 				for _, p := range s.cfg.p2p.Host().Mux().Protocols() {
 					rpcMap[string(p)] = true
 				}
-				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRangeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
-				assert.Equal(t, true, rpcMap[p2p.RPCBlobSidecarsByRootTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 				assert.Equal(t, true, rpcMap[p2p.RPCMetaDataTopicV3+s.cfg.p2p.Encoding().ProtocolSuffix()], "topic doesn't exist")
 			},
+			forkEpoch:           params.BeaconConfig().FuluForkEpoch,
+			nextForkEpoch:       params.BeaconConfig().FuluForkEpoch,
+			epochAtRegistration: func(e primitives.Epoch) primitives.Epoch { return e - 1 },
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			s := tt.svcCreator(t)
-			if err := s.registerForUpcomingFork(tt.currEpoch); (err != nil) != tt.wantErr {
-				t.Errorf("registerForUpcomingFork() error = %v, wantErr %v", err, tt.wantErr)
+			current := tt.epochAtRegistration(tt.forkEpoch)
+			s := testForkWatcherService(t, current)
+			wg := attachSpawner(s)
+			require.NoError(t, s.registerForUpcomingFork(s.cfg.clock.CurrentEpoch()))
+			wg.Wait()
+			tt.checkRegistration(t, s)
+
+			if current != tt.forkEpoch-1 {
+				return
 			}
-			tt.postSvcCheck(t, s)
+
+			// Ensure the topics were registered for the upcoming fork
+			digest := params.ForkDigest(tt.forkEpoch)
+			assert.Equal(t, true, s.subHandler.digestExists(digest))
+
+			// After this point we are checking deregistration, which doesn't apply if there isn't a higher
+			// nextForkEpoch.
+			if tt.forkEpoch >= tt.nextForkEpoch {
+				return
+			}
+
+			nextDigest := params.ForkDigest(tt.nextForkEpoch)
+			// Move the clock to just before the next fork epoch and ensure deregistration is correct
+			wg = attachSpawner(s)
+			s.cfg.clock = defaultClockWithTimeAtEpoch(tt.nextForkEpoch - 1)
+			require.NoError(t, s.registerForUpcomingFork(s.cfg.clock.CurrentEpoch()))
+			wg.Wait()
+			// deregister as if it is the epoch after the next fork epoch
+			require.NoError(t, s.deregisterFromPastFork(tt.nextForkEpoch+1))
+			assert.Equal(t, false, s.subHandler.digestExists(digest))
+			assert.Equal(t, true, s.subHandler.digestExists(nextDigest))
 		})
 	}
 }
 
-func TestService_CheckForPreviousEpochFork(t *testing.T) {
-	params.SetupTestConfigCleanup(t)
-	tests := []struct {
-		name         string
-		svcCreator   func(t *testing.T) *Service
-		currEpoch    primitives.Epoch
-		wantErr      bool
-		postSvcCheck func(t *testing.T, s *Service)
-	}{
-		{
-			name: "no fork in the previous epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				chainService := &mockChain.ChainService{
-					Genesis:        time.Now().Add(-oneEpoch()),
-					ValidatorsRoot: [32]byte{'A'},
-				}
-				clock := startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot)
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       clock,
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				err := r.registerRPCHandlers()
-				assert.NoError(t, err)
-				return r
-			},
-			currEpoch: 10,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				ptcls := s.cfg.p2p.Host().Mux().Protocols()
-				pMap := make(map[string]bool)
-				for _, p := range ptcls {
-					pMap[string(p)] = true
-				}
-				assert.Equal(t, true, pMap[p2p.RPCGoodByeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCStatusTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCPingTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCMetaDataTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCBlocksByRangeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCBlocksByRootTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-			},
-		},
-		{
-			name: "altair fork in the previous epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				chainService := &mockChain.ChainService{
-					Genesis:        time.Now().Add(-4 * oneEpoch()),
-					ValidatorsRoot: [32]byte{'A'},
-				}
-				clock := startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot)
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.AltairForkEpoch = 3
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       clock,
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				prevGenesis := chainService.Genesis
-				// To allow registration of v1 handlers
-				chainService.Genesis = time.Now().Add(-1 * oneEpoch())
-				err := r.registerRPCHandlers()
-				assert.NoError(t, err)
-
-				chainService.Genesis = prevGenesis
-				previous, err := r.rpcHandlerByTopicFromFork(version.Phase0)
-				assert.NoError(t, err)
-
-				next, err := r.rpcHandlerByTopicFromFork(version.Altair)
-				assert.NoError(t, err)
-
-				handlerByTopic := addedRPCHandlerByTopic(previous, next)
-
-				for topic, handler := range handlerByTopic {
-					r.registerRPC(topic, handler)
-				}
-
-				digest := params.ForkDigest(0)
-				assert.NoError(t, err)
-				r.registerSubscribers(0, digest)
-				assert.Equal(t, true, r.subHandler.digestExists(digest))
-
-				digest = params.ForkDigest(3)
-				r.registerSubscribers(3, digest)
-				assert.Equal(t, true, r.subHandler.digestExists(digest))
-
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(0)
-				assert.Equal(t, false, s.subHandler.digestExists(digest))
-				digest = params.ForkDigest(3)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
-
-				ptcls := s.cfg.p2p.Host().Mux().Protocols()
-				pMap := make(map[string]bool)
-				for _, p := range ptcls {
-					pMap[string(p)] = true
-				}
-				assert.Equal(t, true, pMap[p2p.RPCGoodByeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCStatusTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCPingTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCMetaDataTopicV2+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCBlocksByRangeTopicV2+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, true, pMap[p2p.RPCBlocksByRootTopicV2+s.cfg.p2p.Encoding().ProtocolSuffix()])
-
-				assert.Equal(t, false, pMap[p2p.RPCMetaDataTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, false, pMap[p2p.RPCBlocksByRangeTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-				assert.Equal(t, false, pMap[p2p.RPCBlocksByRootTopicV1+s.cfg.p2p.Encoding().ProtocolSuffix()])
-			},
-		},
-		{
-			name: "bellatrix fork in the previous epoch",
-			svcCreator: func(t *testing.T) *Service {
-				peer2peer := p2ptest.NewTestP2P(t)
-				chainService := &mockChain.ChainService{
-					Genesis:        time.Now().Add(-4 * oneEpoch()),
-					ValidatorsRoot: [32]byte{'A'},
-				}
-				clock := startup.NewClock(chainService.Genesis, chainService.ValidatorsRoot)
-				bCfg := params.BeaconConfig().Copy()
-				bCfg.AltairForkEpoch = 1
-				bCfg.BellatrixForkEpoch = 3
-				params.OverrideBeaconConfig(bCfg)
-				params.BeaconConfig().InitializeForkSchedule()
-				ctx, cancel := context.WithCancel(t.Context())
-				r := &Service{
-					ctx:    ctx,
-					cancel: cancel,
-					cfg: &config{
-						p2p:         peer2peer,
-						chain:       chainService,
-						clock:       clock,
-						initialSync: &mockSync.Sync{IsSyncing: false},
-					},
-					chainStarted: abool.New(),
-					subHandler:   newSubTopicHandler(),
-				}
-				digest := params.ForkDigest(1)
-				r.registerSubscribers(1, digest)
-				assert.Equal(t, true, r.subHandler.digestExists(digest))
-
-				digest = params.ForkDigest(3)
-				r.registerSubscribers(3, digest)
-				assert.Equal(t, true, r.subHandler.digestExists(digest))
-
-				return r
-			},
-			currEpoch: 4,
-			wantErr:   false,
-			postSvcCheck: func(t *testing.T, s *Service) {
-				digest := params.ForkDigest(1)
-				assert.Equal(t, false, s.subHandler.digestExists(digest))
-				digest = params.ForkDigest(3)
-				assert.Equal(t, true, s.subHandler.digestExists(digest))
-			},
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			s := tt.svcCreator(t)
-			if err := s.deregisterFromPastFork(tt.currEpoch); (err != nil) != tt.wantErr {
-				t.Errorf("registerForUpcomingFork() error = %v, wantErr %v", err, tt.wantErr)
-			}
-			tt.postSvcCheck(t, s)
-		})
+func attachSpawner(s *Service) *sync.WaitGroup {
+	wg := new(sync.WaitGroup)
+	s.subscriptionSpawner = func(f func()) {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			f()
+		}()
 	}
+	return wg
 }
 
 // oneEpoch returns the duration of one epoch.

beacon-chain/sync/initial-sync/BUILD.bazel

@@ -34,6 +34,7 @@ go_library(
         "//beacon-chain/verification:go_default_library",
         "//cmd/beacon-chain/flags:go_default_library",
         "//config/features:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
@@ -108,7 +109,9 @@ go_test(
         "//time:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//p2p/enr:go_default_library",
+        "@com_github_libp2p_go_libp2p//:go_default_library",
         "@com_github_libp2p_go_libp2p//core:go_default_library",
+        "@com_github_libp2p_go_libp2p//core/crypto:go_default_library",
         "@com_github_libp2p_go_libp2p//core/network:go_default_library",
         "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_paulbellamy_ratecounter//:go_default_library",

beacon-chain/sync/initial-sync/blocks_fetcher.go

@@ -450,7 +450,12 @@ func (f *blocksFetcher) fetchBlocksFromPeer(
 	for _, p := range peers {
 		blocks, err := f.requestBlocks(ctx, req, p)
 		if err != nil {
-			log.WithField("peer", p).WithError(err).Debug("Could not request blocks by range from peer")
+			log.WithFields(logrus.Fields{
+				"peer":      p,
+				"startSlot": req.StartSlot,
+				"count":     req.Count,
+				"step":      req.Step,
+			}).WithError(err).Debug("Could not request blocks by range from peer")
 			continue
 		}
 		f.p2p.Peers().Scorers().BlockProviderScorer().Touch(p)

beacon-chain/sync/initial-sync/service.go

@@ -22,6 +22,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	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/crypto/rand"
@@ -209,6 +210,8 @@ func (s *Service) Start() {
 
 // fetchOriginSidecars fetches origin sidecars
 func (s *Service) fetchOriginSidecars(peers []peer.ID) error {
+	const delay = 10 * time.Second // The delay between each attempt to fetch origin data column sidecars
+
 	blockRoot, err := s.cfg.DB.OriginCheckpointBlockRoot(s.ctx)
 	if errors.Is(err, db.ErrNotFoundOriginBlockRoot) {
 		return nil
@@ -234,7 +237,7 @@ func (s *Service) fetchOriginSidecars(peers []peer.ID) error {
 	blockVersion := roBlock.Version()
 
 	if blockVersion >= version.Fulu {
-		if err := s.fetchOriginColumns(peers, roBlock); err != nil {
+		if err := s.fetchOriginColumns(roBlock, delay); err != nil {
 			return errors.Wrap(err, "fetch origin columns")
 		}
 		return nil
@@ -391,7 +394,11 @@ func (s *Service) fetchOriginBlobs(pids []peer.ID, rob blocks.ROBlock) error {
 	return fmt.Errorf("no connected peer able to provide blobs for checkpoint sync block %#x", r)
 }
 
-func (s *Service) fetchOriginColumns(pids []peer.ID, roBlock blocks.ROBlock) error {
+func (s *Service) fetchOriginColumns(roBlock blocks.ROBlock, delay time.Duration) error {
+	const (
+		errorMessage     = "Failed to fetch origin data column sidecars"
+		warningIteration = 10
+	)
 	samplesPerSlot := params.BeaconConfig().SamplesPerSlot
 
 	// Return early if the origin block has no blob commitments.
@@ -420,21 +427,40 @@ func (s *Service) fetchOriginColumns(pids []peer.ID, roBlock blocks.ROBlock) err
 	root := roBlock.Root()
 
 	params := sync.DataColumnSidecarsParams{
-		Ctx:         s.ctx,
-		Tor:         s.clock,
-		P2P:         s.cfg.P2P,
-		CtxMap:      s.ctxMap,
-		Storage:     s.cfg.DataColumnStorage,
-		NewVerifier: s.newDataColumnsVerifier,
+		Ctx:                     s.ctx,
+		Tor:                     s.clock,
+		P2P:                     s.cfg.P2P,
+		CtxMap:                  s.ctxMap,
+		Storage:                 s.cfg.DataColumnStorage,
+		NewVerifier:             s.newDataColumnsVerifier,
+		DownscorePeerOnRPCFault: true,
 	}
 
-	verfifiedRoDataColumnsByRoot, err := sync.FetchDataColumnSidecars(params, []blocks.ROBlock{roBlock}, info.CustodyColumns)
-	if err != nil {
-		return errors.Wrap(err, "fetch data column sidecars")
+	var verifiedRoDataColumnsByRoot map[[fieldparams.RootLength]byte][]blocks.VerifiedRODataColumn
+	for attempt := uint64(0); ; attempt++ {
+		verifiedRoDataColumnsByRoot, err = sync.FetchDataColumnSidecars(params, []blocks.ROBlock{roBlock}, info.CustodyColumns)
+		if err == nil {
+			break
+		}
+
+		log := log.WithError(err).WithFields(logrus.Fields{
+			"attempt": attempt,
+			"delay":   delay,
+		})
+
+		if attempt%warningIteration == 0 && attempt > 0 {
+			log.Warning(errorMessage)
+			time.Sleep(delay)
+
+			continue
+		}
+
+		log.Debug(errorMessage)
+		time.Sleep(delay)
 	}
 
 	// Save origin data columns to disk.
-	verifiedRoDataColumnsSidecars, ok := verfifiedRoDataColumnsByRoot[root]
+	verifiedRoDataColumnsSidecars, ok := verifiedRoDataColumnsByRoot[root]
 	if !ok {
 		return fmt.Errorf("cannot extract origins data column sidecars for block root %#x - should never happen", root)
 	}
@@ -447,7 +473,7 @@ func (s *Service) fetchOriginColumns(pids []peer.ID, roBlock blocks.ROBlock) err
 		"blockRoot":   fmt.Sprintf("%#x", roBlock.Root()),
 		"blobCount":   len(commitments),
 		"columnCount": len(verifiedRoDataColumnsSidecars),
-	}).Info("Successfully downloaded data columns for checkpoint sync block")
+	}).Info("Successfully downloaded data column sidecars for checkpoint sync block")
 
 	return nil
 }

beacon-chain/sync/initial-sync/service_test.go

@@ -2,6 +2,7 @@ package initialsync
 
 import (
 	"context"
+	"fmt"
 	"sync"
 	"testing"
 	"time"
@@ -13,8 +14,12 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/filesystem"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/kv"
 	dbtest "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	p2ptest "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
+	testp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
+	prysmSync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/verification"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -22,10 +27,14 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/paulbellamy/ratecounter"
 	logTest "github.com/sirupsen/logrus/hooks/test"
@@ -663,3 +672,147 @@ func TestFetchOriginSidecars(t *testing.T) {
 		}
 	})
 }
+
+func TestFetchOriginColumns(t *testing.T) {
+	// Load the trusted setup.
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	// Setup test environment
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.FuluForkEpoch = 0
+	params.OverrideBeaconConfig(cfg)
+
+	const (
+		delay     = 0
+		blobCount = 1
+	)
+
+	t.Run("block has no commitments", func(t *testing.T) {
+		service := new(Service)
+
+		// Create a block with no blob commitments
+		block := util.NewBeaconBlockFulu()
+		signedBlock, err := blocks.NewSignedBeaconBlock(block)
+		require.NoError(t, err)
+		roBlock, err := blocks.NewROBlock(signedBlock)
+		require.NoError(t, err)
+
+		err = service.fetchOriginColumns(roBlock, delay)
+		require.NoError(t, err)
+	})
+
+	t.Run("FetchDataColumnSidecars succeeds immediately", func(t *testing.T) {
+		storage := filesystem.NewEphemeralDataColumnStorage(t)
+		p2p := p2ptest.NewTestP2P(t)
+
+		service := &Service{
+			cfg: &Config{
+				P2P:               p2p,
+				DataColumnStorage: storage,
+			},
+		}
+
+		// Create a block with blob commitments and sidecars
+		roBlock, _, verifiedSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
+
+		// Store all sidecars in advance so FetchDataColumnSidecars succeeds immediately
+		err := storage.Save(verifiedSidecars)
+		require.NoError(t, err)
+
+		err = service.fetchOriginColumns(roBlock, delay)
+		require.NoError(t, err)
+	})
+
+	t.Run("first attempt to FetchDataColumnSidecars fails but second attempt succeeds", func(t *testing.T) {
+		numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+		storage := filesystem.NewEphemeralDataColumnStorage(t)
+
+		// Custody columns with this private key and 4-cgc: 31, 81, 97, 105
+		privateKeyBytes := [32]byte{1}
+		privateKey, err := crypto.UnmarshalSecp256k1PrivateKey(privateKeyBytes[:])
+		require.NoError(t, err)
+
+		protocol := fmt.Sprintf("%s/ssz_snappy", p2p.RPCDataColumnSidecarsByRangeTopicV1)
+
+		p2p, other := testp2p.NewTestP2P(t), testp2p.NewTestP2P(t, libp2p.Identity(privateKey))
+		p2p.Peers().SetConnectionState(other.PeerID(), peers.Connected)
+		p2p.Connect(other)
+
+		p2p.Peers().SetChainState(other.PeerID(), &ethpb.StatusV2{
+			HeadSlot: 5,
+		})
+
+		other.ENR().Set(peerdas.Cgc(numberOfCustodyGroups))
+		p2p.Peers().UpdateENR(other.ENR(), other.PeerID())
+
+		expectedRequest := &ethpb.DataColumnSidecarsByRangeRequest{
+			StartSlot: 0,
+			Count:     1,
+			Columns:   []uint64{1, 17, 19, 42, 75, 87, 102, 117},
+		}
+
+		clock := startup.NewClock(time.Now(), [fieldparams.RootLength]byte{})
+
+		gs := startup.NewClockSynchronizer()
+		err = gs.SetClock(startup.NewClock(time.Unix(4113849600, 0), [fieldparams.RootLength]byte{}))
+		require.NoError(t, err)
+
+		waiter := verification.NewInitializerWaiter(gs, nil, nil)
+		initializer, err := waiter.WaitForInitializer(t.Context())
+		require.NoError(t, err)
+
+		newDataColumnsVerifier := newDataColumnsVerifierFromInitializer(initializer)
+
+		// Create a block with blob commitments and sidecars
+		roBlock, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
+
+		ctxMap, err := prysmSync.ContextByteVersionsForValRoot(params.BeaconConfig().GenesisValidatorsRoot)
+		require.NoError(t, err)
+
+		service := &Service{
+			ctx:                    t.Context(),
+			clock:                  clock,
+			newDataColumnsVerifier: newDataColumnsVerifier,
+			cfg: &Config{
+				P2P:               p2p,
+				DataColumnStorage: storage,
+			},
+			ctxMap: ctxMap,
+		}
+
+		// Do not respond any sidecar on the first attempt, and respond everything requested on the second one.
+		firstAttempt := true
+		other.SetStreamHandler(protocol, func(stream network.Stream) {
+			actualRequest := new(ethpb.DataColumnSidecarsByRangeRequest)
+			err := other.Encoding().DecodeWithMaxLength(stream, actualRequest)
+			assert.NoError(t, err)
+			assert.DeepEqual(t, expectedRequest, actualRequest)
+
+			if firstAttempt {
+				firstAttempt = false
+				err = stream.CloseWrite()
+				assert.NoError(t, err)
+				return
+			}
+
+			for _, column := range actualRequest.Columns {
+				err = prysmSync.WriteDataColumnSidecarChunk(stream, clock, other.Encoding(), verifiedRoSidecars[column].DataColumnSidecar)
+				assert.NoError(t, err)
+			}
+
+			err = stream.CloseWrite()
+			assert.NoError(t, err)
+		})
+
+		err = service.fetchOriginColumns(roBlock, delay)
+		require.NoError(t, err)
+
+		// Check all corresponding sidecars are saved in the store.
+		summary := storage.Summary(roBlock.Root())
+		for _, index := range expectedRequest.Columns {
+			require.Equal(t, true, summary.HasIndex(index))
+		}
+	})
+}

beacon-chain/sync/rpc_send_request.go

@@ -92,22 +92,72 @@ func SendBeaconBlocksByRangeRequest(
 		// The response MUST contain no more than `count` blocks, and no more than
 		// MAX_REQUEST_BLOCKS blocks.
 		currentEpoch := slots.ToEpoch(tor.CurrentSlot())
-		if i >= req.Count || i >= params.MaxRequestBlock(currentEpoch) {
+		maxBlocks := params.MaxRequestBlock(currentEpoch)
+		if i >= req.Count {
+			log.WithFields(logrus.Fields{
+				"blockIndex":     i,
+				"requestedCount": req.Count,
+				"blockSlot":      blk.Block().Slot(),
+				"peer":           pid,
+				"reason":         "exceeded requested count",
+			}).Debug("Peer returned invalid data: too many blocks")
+			return nil, ErrInvalidFetchedData
+		}
+		if i >= maxBlocks {
+			log.WithFields(logrus.Fields{
+				"blockIndex":   i,
+				"maxBlocks":    maxBlocks,
+				"currentEpoch": currentEpoch,
+				"blockSlot":    blk.Block().Slot(),
+				"peer":         pid,
+				"reason":       "exceeded MAX_REQUEST_BLOCKS",
+			}).Debug("Peer returned invalid data: exceeded protocol limit")
 			return nil, ErrInvalidFetchedData
 		}
 		// Returned blocks MUST be in the slot range [start_slot, start_slot + count * step).
-		if blk.Block().Slot() < req.StartSlot || blk.Block().Slot() >= req.StartSlot.Add(req.Count*req.Step) {
+		endSlot := req.StartSlot.Add(req.Count * req.Step)
+		if blk.Block().Slot() < req.StartSlot {
+			log.WithFields(logrus.Fields{
+				"blockSlot":      blk.Block().Slot(),
+				"requestedStart": req.StartSlot,
+				"peer":           pid,
+				"reason":         "block slot before requested start",
+			}).Debug("Peer returned invalid data: block too early")
+			return nil, ErrInvalidFetchedData
+		}
+		if blk.Block().Slot() >= endSlot {
+			log.WithFields(logrus.Fields{
+				"blockSlot":      blk.Block().Slot(),
+				"requestedStart": req.StartSlot,
+				"requestedEnd":   endSlot,
+				"requestedCount": req.Count,
+				"requestedStep":  req.Step,
+				"peer":           pid,
+				"reason":         "block slot >= start + count*step",
+			}).Debug("Peer returned invalid data: block beyond range")
 			return nil, ErrInvalidFetchedData
 		}
 		// Returned blocks, where they exist, MUST be sent in a consecutive order.
 		// Consecutive blocks MUST have values in `step` increments (slots may be skipped in between).
 		isSlotOutOfOrder := false
+		outOfOrderReason := ""
 		if prevSlot >= blk.Block().Slot() {
 			isSlotOutOfOrder = true
+			outOfOrderReason = "slot not increasing"
 		} else if req.Step != 0 && blk.Block().Slot().SubSlot(prevSlot).Mod(req.Step) != 0 {
 			isSlotOutOfOrder = true
+			slotDiff := blk.Block().Slot().SubSlot(prevSlot)
+			outOfOrderReason = fmt.Sprintf("slot diff %d not multiple of step %d", slotDiff, req.Step)
 		}
 		if !isFirstChunk && isSlotOutOfOrder {
+			log.WithFields(logrus.Fields{
+				"blockSlot":     blk.Block().Slot(),
+				"prevSlot":      prevSlot,
+				"requestedStep": req.Step,
+				"blockIndex":    i,
+				"peer":          pid,
+				"reason":        outOfOrderReason,
+			}).Debug("Peer returned invalid data: blocks out of order")
 			return nil, ErrInvalidFetchedData
 		}
 		prevSlot = blk.Block().Slot()
@@ -453,6 +503,10 @@ func SendDataColumnSidecarsByRangeRequest(
 	// Send the request.
 	stream, err := p.P2P.Send(p.Ctx, request, topic, pid)
 	if err != nil {
+		if p.DownscorePeerOnRPCFault {
+			downscorePeer(p.P2P, pid, "cannotSendDataColumnSidecarsByRangeRequest")
+		}
+
 		return nil, errors.Wrap(err, "p2p send")
 	}
 	defer closeStream(stream, log)
@@ -467,6 +521,10 @@ func SendDataColumnSidecarsByRangeRequest(
 
 		validatorSlotWithinBounds, err := isSidecarSlotWithinBounds(request)
 		if err != nil {
+			if p.DownscorePeerOnRPCFault {
+				downscorePeer(p.P2P, pid, "servedSidecarSlotOutOfBounds")
+			}
+
 			return nil, errors.Wrap(err, "is sidecar slot within bounds")
 		}
 
@@ -476,9 +534,17 @@ func SendDataColumnSidecarsByRangeRequest(
 			isSidecarIndexRequested(request),
 		)
 		if errors.Is(err, io.EOF) {
+			if p.DownscorePeerOnRPCFault && len(roDataColumns) == 0 {
+				downscorePeer(p.P2P, pid, "noReturnedSidecar")
+			}
+
 			return roDataColumns, nil
 		}
 		if err != nil {
+			if p.DownscorePeerOnRPCFault {
+				downscorePeer(p.P2P, pid, "readChunkedDataColumnSidecarError")
+			}
+
 			return nil, errors.Wrap(err, "read chunked data column sidecar")
 		}
 
@@ -491,6 +557,10 @@ func SendDataColumnSidecarsByRangeRequest(
 
 	// All requested sidecars were delivered by the peer. Expecting EOF.
 	if _, err := readChunkedDataColumnSidecar(stream, p.P2P, p.CtxMap); !errors.Is(err, io.EOF) {
+		if p.DownscorePeerOnRPCFault {
+			downscorePeer(p.P2P, pid, "tooManyResponseDataColumnSidecars")
+		}
+
 		return nil, errors.Wrapf(errMaxResponseDataColumnSidecarsExceeded, "requestedCount=%d", totalCount)
 	}
 
@@ -528,7 +598,8 @@ func isSidecarIndexRequested(request *ethpb.DataColumnSidecarsByRangeRequest) Da
 	return func(sidecar blocks.RODataColumn) error {
 		columnIndex := sidecar.Index
 		if !requestedIndices[columnIndex] {
-			return errors.Errorf("data column sidecar index %d not found in requested indices", columnIndex)
+			requested := sortedSliceFromMap(requestedIndices)
+			return errors.Errorf("data column sidecar index %d returned by the peer but not found in requested indices %v", columnIndex, requested)
 		}
 
 		return nil
@@ -566,6 +637,10 @@ func SendDataColumnSidecarsByRootRequest(p DataColumnSidecarsParams, peer goPeer
 	// Send the request to the peer.
 	stream, err := p.P2P.Send(p.Ctx, identifiers, topic, peer)
 	if err != nil {
+		if p.DownscorePeerOnRPCFault {
+			downscorePeer(p.P2P, peer, "cannotSendDataColumnSidecarsByRootRequest")
+		}
+
 		return nil, errors.Wrap(err, "p2p api send")
 	}
 	defer closeStream(stream, log)
@@ -577,9 +652,17 @@ func SendDataColumnSidecarsByRootRequest(p DataColumnSidecarsParams, peer goPeer
 	for range count {
 		roDataColumn, err := readChunkedDataColumnSidecar(stream, p.P2P, p.CtxMap, isSidecarIndexRootRequested(identifiers))
 		if errors.Is(err, io.EOF) {
+			if p.DownscorePeerOnRPCFault && len(roDataColumns) == 0 {
+				downscorePeer(p.P2P, peer, "noReturnedSidecar")
+			}
+
 			return roDataColumns, nil
 		}
 		if err != nil {
+			if p.DownscorePeerOnRPCFault {
+				downscorePeer(p.P2P, peer, "readChunkedDataColumnSidecarError")
+			}
+
 			return nil, errors.Wrap(err, "read chunked data column sidecar")
 		}
 
@@ -592,6 +675,10 @@ func SendDataColumnSidecarsByRootRequest(p DataColumnSidecarsParams, peer goPeer
 
 	// All requested sidecars were delivered by the peer. Expecting EOF.
 	if _, err := readChunkedDataColumnSidecar(stream, p.P2P, p.CtxMap); !errors.Is(err, io.EOF) {
+		if p.DownscorePeerOnRPCFault {
+			downscorePeer(p.P2P, peer, "tooManyResponseDataColumnSidecars")
+		}
+
 		return nil, errors.Wrapf(errMaxResponseDataColumnSidecarsExceeded, "requestedCount=%d", count)
 	}
 
@@ -689,3 +776,13 @@ func readChunkedDataColumnSidecar(
 
 	return &roDataColumn, nil
 }
+
+func downscorePeer(p2p p2p.P2P, peerID peer.ID, reason string, fields ...logrus.Fields) {
+	log := log
+	for _, field := range fields {
+		log = log.WithFields(field)
+	}
+
+	newScore := p2p.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}

beacon-chain/sync/rpc_status_test.go

@@ -316,11 +316,14 @@ func TestHandshakeHandlers_Roundtrip(t *testing.T) {
 			clock:         startup.NewClock(chain.Genesis, chain.ValidatorsRoot),
 			beaconDB:      db,
 			stateNotifier: chain.StateNotifier(),
+			initialSync:   &mockSync.Sync{IsSyncing: false},
 		},
 		rateLimiter:  newRateLimiter(p1),
 		clockWaiter:  cw,
 		chainStarted: abool.New(),
+		subHandler:   newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, r)
 	clock := startup.NewClockSynchronizer()
 	require.NoError(t, clock.SetClock(startup.NewClock(time.Now(), [32]byte{})))
 	r.verifierWaiter = verification.NewInitializerWaiter(clock, chain.ForkChoiceStore, r.cfg.stateGen)
@@ -337,9 +340,12 @@ func TestHandshakeHandlers_Roundtrip(t *testing.T) {
 			clock:         startup.NewClock(chain2.Genesis, chain2.ValidatorsRoot),
 			p2p:           p2,
 			stateNotifier: chain.StateNotifier(),
+			initialSync:   &mockSync.Sync{IsSyncing: false},
 		},
 		rateLimiter: newRateLimiter(p2),
+		subHandler:  newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, r2)
 	clock = startup.NewClockSynchronizer()
 	require.NoError(t, clock.SetClock(startup.NewClock(time.Now(), [32]byte{})))
 	r2.verifierWaiter = verification.NewInitializerWaiter(clock, chain2.ForkChoiceStore, r2.cfg.stateGen)
@@ -909,13 +915,16 @@ func TestStatusRPCRequest_BadPeerHandshake(t *testing.T) {
 			p2p:           p1,
 			chain:         chain,
 			stateNotifier: chain.StateNotifier(),
+			initialSync:   &mockSync.Sync{IsSyncing: false},
 		},
 
 		ctx:          ctx,
 		rateLimiter:  newRateLimiter(p1),
 		clockWaiter:  cw,
 		chainStarted: abool.New(),
+		subHandler:   newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, r)
 	clock := startup.NewClockSynchronizer()
 	require.NoError(t, clock.SetClock(startup.NewClock(time.Now(), [32]byte{})))
 	r.verifierWaiter = verification.NewInitializerWaiter(clock, chain.ForkChoiceStore, r.cfg.stateGen)

beacon-chain/sync/service.go

@@ -178,6 +178,7 @@ type Service struct {
 	lcStore                          *lightClient.Store
 	dataColumnLogCh                  chan dataColumnLogEntry
 	registeredNetworkEntry           params.NetworkScheduleEntry
+	subscriptionSpawner              func(func()) // see Service.spawn for details
 }
 
 // NewService initializes new regular sync service.
@@ -254,7 +255,7 @@ func (s *Service) Start() {
 	s.newColumnsVerifier = newDataColumnsVerifierFromInitializer(v)
 
 	go s.verifierRoutine()
-	go s.startTasksPostInitialSync()
+	go s.startDiscoveryAndSubscriptions()
 	go s.processDataColumnLogs()
 
 	s.cfg.p2p.AddConnectionHandler(s.reValidatePeer, s.sendGoodbye)
@@ -384,32 +385,31 @@ func (s *Service) waitForChainStart() {
 	s.markForChainStart()
 }
 
-func (s *Service) startTasksPostInitialSync() {
+func (s *Service) startDiscoveryAndSubscriptions() {
 	// Wait for the chain to start.
 	s.waitForChainStart()
 
-	select {
-	case <-s.initialSyncComplete:
-		// Compute the current epoch.
-		currentSlot := slots.CurrentSlot(s.cfg.clock.GenesisTime())
-		currentEpoch := slots.ToEpoch(currentSlot)
-
-		// Compute the current fork forkDigest.
-		forkDigest, err := s.currentForkDigest()
-		if err != nil {
-			log.WithError(err).Error("Could not retrieve current fork digest")
-			return
-		}
-
-		// Register respective pubsub handlers at state synced event.
-		s.registerSubscribers(currentEpoch, forkDigest)
-
-		// Start the fork watcher.
-		go s.forkWatcher()
-
-	case <-s.ctx.Done():
-		log.Debug("Context closed, exiting goroutine")
+	if s.ctx.Err() != nil {
+		log.Debug("Context closed, exiting StartDiscoveryAndSubscription")
+		return
 	}
+
+	// Compute the current epoch.
+	currentSlot := slots.CurrentSlot(s.cfg.clock.GenesisTime())
+	currentEpoch := slots.ToEpoch(currentSlot)
+
+	// Compute the current fork forkDigest.
+	forkDigest, err := s.currentForkDigest()
+	if err != nil {
+		log.WithError(err).Error("Could not retrieve current fork digest")
+		return
+	}
+
+	// Register respective pubsub handlers at state synced event.
+	s.registerSubscribers(currentEpoch, forkDigest)
+
+	// Start the fork watcher.
+	go s.forkWatcher()
 }
 
 func (s *Service) writeErrorResponseToStream(responseCode byte, reason string, stream libp2pcore.Stream) {

beacon-chain/sync/service_test.go

@@ -69,7 +69,7 @@ func TestSyncHandlers_WaitToSync(t *testing.T) {
 	}
 
 	topic := "/eth2/%x/beacon_block"
-	go r.startTasksPostInitialSync()
+	go r.startDiscoveryAndSubscriptions()
 	time.Sleep(100 * time.Millisecond)
 
 	var vr [32]byte
@@ -150,7 +150,7 @@ func TestSyncHandlers_WaitTillSynced(t *testing.T) {
 
 	syncCompleteCh := make(chan bool)
 	go func() {
-		r.startTasksPostInitialSync()
+		r.startDiscoveryAndSubscriptions()
 		syncCompleteCh <- true
 	}()
 
@@ -206,8 +206,9 @@ func TestSyncService_StopCleanly(t *testing.T) {
 		clockWaiter:         gs,
 		initialSyncComplete: make(chan struct{}),
 	}
+	markInitSyncComplete(t, &r)
 
-	go r.startTasksPostInitialSync()
+	go r.startDiscoveryAndSubscriptions()
 	var vr [32]byte
 	require.NoError(t, gs.SetClock(startup.NewClock(time.Now(), vr)))
 	r.waitForChainStart()
@@ -220,9 +221,6 @@ func TestSyncService_StopCleanly(t *testing.T) {
 	time.Sleep(2 * time.Second)
 	require.Equal(t, true, r.chainStarted.IsSet(), "Did not receive chain start event.")
 
-	close(r.initialSyncComplete)
-	time.Sleep(1 * time.Second)
-
 	require.NotEqual(t, 0, len(r.cfg.p2p.PubSub().GetTopics()))
 	require.NotEqual(t, 0, len(r.cfg.p2p.Host().Mux().Protocols()))
 

beacon-chain/sync/subscriber.go

@@ -6,6 +6,7 @@ import (
 	"reflect"
 	"runtime/debug"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
@@ -35,40 +36,114 @@ import (
 
 const pubsubMessageTimeout = 30 * time.Second
 
-type (
-	// wrappedVal represents a gossip validator which also returns an error along with the result.
-	wrappedVal func(context.Context, peer.ID, *pubsub.Message) (pubsub.ValidationResult, error)
-
-	// subHandler represents handler for a given subscription.
-	subHandler func(context.Context, proto.Message) error
-
-	// parameters used for the `subscribeWithParameters` function.
-	subscribeParameters struct {
-		topicFormat string
-		validate    wrappedVal
-		handle      subHandler
-		digest      [4]byte
-
-		// getSubnetsToJoin is a function that returns all subnets the node should join.
-		getSubnetsToJoin func(currentSlot primitives.Slot) map[uint64]bool
-
-		// getSubnetsRequiringPeers is a function that returns all subnets that require peers to be found
-		// but for which no subscriptions are needed.
-		getSubnetsRequiringPeers func(currentSlot primitives.Slot) map[uint64]bool
-	}
-
-	subscribeToSubnetsParameters struct {
-		subscriptionBySubnet map[uint64]*pubsub.Subscription
-		topicFormat          string
-		digest               [4]byte
-		validate             wrappedVal
-		handle               subHandler
-		getSubnetsToJoin     func(currentSlot primitives.Slot) map[uint64]bool
-	}
-)
-
 var errInvalidDigest = errors.New("invalid digest")
 
+// wrappedVal represents a gossip validator which also returns an error along with the result.
+type wrappedVal func(context.Context, peer.ID, *pubsub.Message) (pubsub.ValidationResult, error)
+
+// subHandler represents handler for a given subscription.
+type subHandler func(context.Context, proto.Message) error
+
+// subscribeParameters holds the parameters that are needed to construct a set of subscriptions topics for a given
+// set of gossipsub subnets.
+type subscribeParameters struct {
+	topicFormat string
+	validate    wrappedVal
+	handle      subHandler
+	digest      [4]byte
+	// getSubnetsToJoin is a function that returns all subnets the node should join.
+	getSubnetsToJoin func(currentSlot primitives.Slot) map[uint64]bool
+	// getSubnetsRequiringPeers is a function that returns all subnets that require peers to be found
+	// but for which no subscriptions are needed.
+	getSubnetsRequiringPeers func(currentSlot primitives.Slot) map[uint64]bool
+}
+
+// shortTopic is a less verbose version of topic strings used for logging.
+func (p subscribeParameters) shortTopic() string {
+	short := p.topicFormat
+	fmtLen := len(short)
+	if fmtLen >= 3 && short[fmtLen-3:] == "_%d" {
+		short = short[:fmtLen-3]
+	}
+	return fmt.Sprintf(short, p.digest)
+}
+
+func (p subscribeParameters) logFields() logrus.Fields {
+	return logrus.Fields{
+		"topic": p.shortTopic(),
+	}
+}
+
+// fullTopic is the fully qualified topic string, given to gossipsub.
+func (p subscribeParameters) fullTopic(subnet uint64, suffix string) string {
+	return fmt.Sprintf(p.topicFormat, p.digest, subnet) + suffix
+}
+
+// subnetTracker keeps track of which subnets we are subscribed to, out of the set of
+// possible subnets described by a `subscribeParameters`.
+type subnetTracker struct {
+	subscribeParameters
+	mu            sync.RWMutex
+	subscriptions map[uint64]*pubsub.Subscription
+}
+
+func newSubnetTracker(p subscribeParameters) *subnetTracker {
+	return &subnetTracker{
+		subscribeParameters: p,
+		subscriptions:       make(map[uint64]*pubsub.Subscription),
+	}
+}
+
+// unwanted takes a list of wanted subnets and returns a list of currently subscribed subnets that are not included.
+func (t *subnetTracker) unwanted(wanted map[uint64]bool) []uint64 {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	unwanted := make([]uint64, 0, len(t.subscriptions))
+	for subnet := range t.subscriptions {
+		if wanted == nil || !wanted[subnet] {
+			unwanted = append(unwanted, subnet)
+		}
+	}
+	return unwanted
+}
+
+// missing takes a list of wanted subnets and returns a list of wanted subnets that are not currently tracked.
+func (t *subnetTracker) missing(wanted map[uint64]bool) []uint64 {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	missing := make([]uint64, 0, len(wanted))
+	for subnet := range wanted {
+		if _, ok := t.subscriptions[subnet]; !ok {
+			missing = append(missing, subnet)
+		}
+	}
+	return missing
+}
+
+// cancelSubscription cancels and removes the subscription for a given subnet.
+func (t *subnetTracker) cancelSubscription(subnet uint64) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	defer delete(t.subscriptions, subnet)
+
+	sub := t.subscriptions[subnet]
+	if sub == nil {
+		return
+	}
+	sub.Cancel()
+}
+
+// track asks subscriptionTracker to hold on to the subscription for a given subnet so
+// that we can remember that it is tracked and cancel its context when it's time to unsubscribe.
+func (t *subnetTracker) track(subnet uint64, sub *pubsub.Subscription) {
+	if sub == nil {
+		return
+	}
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.subscriptions[subnet] = sub
+}
+
 // noopValidator is a no-op that only decodes the message, but does not check its contents.
 func (s *Service) noopValidator(_ context.Context, _ peer.ID, msg *pubsub.Message) (pubsub.ValidationResult, error) {
 	m, err := s.decodePubsubMessage(msg)
@@ -112,131 +187,146 @@ func (s *Service) activeSyncSubnetIndices(currentSlot primitives.Slot) map[uint6
 	return mapFromSlice(subscriptions)
 }
 
+// spawn allows the Service to use a custom function for launching goroutines.
+// This is useful in tests where we can set spawner to a sync.WaitGroup and
+// wait for the spawned goroutines to finish.
+func (s *Service) spawn(f func()) {
+	if s.subscriptionSpawner != nil {
+		s.subscriptionSpawner(f)
+	} else {
+		go f()
+	}
+}
+
 // Register PubSub subscribers
 func (s *Service) registerSubscribers(epoch primitives.Epoch, digest [4]byte) {
-	s.subscribe(
-		p2p.BlockSubnetTopicFormat,
-		s.validateBeaconBlockPubSub,
-		s.beaconBlockSubscriber,
-		digest,
-	)
-	s.subscribe(
-		p2p.AggregateAndProofSubnetTopicFormat,
-		s.validateAggregateAndProof,
-		s.beaconAggregateProofSubscriber,
-		digest,
-	)
-	s.subscribe(
-		p2p.ExitSubnetTopicFormat,
-		s.validateVoluntaryExit,
-		s.voluntaryExitSubscriber,
-		digest,
-	)
-	s.subscribe(
-		p2p.ProposerSlashingSubnetTopicFormat,
-		s.validateProposerSlashing,
-		s.proposerSlashingSubscriber,
-		digest,
-	)
-	s.subscribe(
-		p2p.AttesterSlashingSubnetTopicFormat,
-		s.validateAttesterSlashing,
-		s.attesterSlashingSubscriber,
-		digest,
-	)
-	s.subscribeWithParameters(subscribeParameters{
-		topicFormat:              p2p.AttestationSubnetTopicFormat,
-		validate:                 s.validateCommitteeIndexBeaconAttestation,
-		handle:                   s.committeeIndexBeaconAttestationSubscriber,
-		digest:                   digest,
-		getSubnetsToJoin:         s.persistentAndAggregatorSubnetIndices,
-		getSubnetsRequiringPeers: attesterSubnetIndices,
+	s.spawn(func() {
+		s.subscribe(p2p.BlockSubnetTopicFormat, s.validateBeaconBlockPubSub, s.beaconBlockSubscriber, digest)
+	})
+	s.spawn(func() {
+		s.subscribe(p2p.AggregateAndProofSubnetTopicFormat, s.validateAggregateAndProof, s.beaconAggregateProofSubscriber, digest)
+	})
+	s.spawn(func() {
+		s.subscribe(p2p.ExitSubnetTopicFormat, s.validateVoluntaryExit, s.voluntaryExitSubscriber, digest)
+	})
+	s.spawn(func() {
+		s.subscribe(p2p.ProposerSlashingSubnetTopicFormat, s.validateProposerSlashing, s.proposerSlashingSubscriber, digest)
+	})
+	s.spawn(func() {
+		s.subscribe(p2p.AttesterSlashingSubnetTopicFormat, s.validateAttesterSlashing, s.attesterSlashingSubscriber, digest)
+	})
+	s.spawn(func() {
+		s.subscribeWithParameters(subscribeParameters{
+			topicFormat:              p2p.AttestationSubnetTopicFormat,
+			validate:                 s.validateCommitteeIndexBeaconAttestation,
+			handle:                   s.committeeIndexBeaconAttestationSubscriber,
+			digest:                   digest,
+			getSubnetsToJoin:         s.persistentAndAggregatorSubnetIndices,
+			getSubnetsRequiringPeers: attesterSubnetIndices,
+		})
 	})
 
 	// New gossip topic in Altair
 	if params.BeaconConfig().AltairForkEpoch <= epoch {
-		s.subscribe(
-			p2p.SyncContributionAndProofSubnetTopicFormat,
-			s.validateSyncContributionAndProof,
-			s.syncContributionAndProofSubscriber,
-			digest,
-		)
-
-		s.subscribeWithParameters(subscribeParameters{
-			topicFormat:      p2p.SyncCommitteeSubnetTopicFormat,
-			validate:         s.validateSyncCommitteeMessage,
-			handle:           s.syncCommitteeMessageSubscriber,
-			digest:           digest,
-			getSubnetsToJoin: s.activeSyncSubnetIndices,
+		s.spawn(func() {
+			s.subscribe(
+				p2p.SyncContributionAndProofSubnetTopicFormat,
+				s.validateSyncContributionAndProof,
+				s.syncContributionAndProofSubscriber,
+				digest,
+			)
+		})
+		s.spawn(func() {
+			s.subscribeWithParameters(subscribeParameters{
+				topicFormat:      p2p.SyncCommitteeSubnetTopicFormat,
+				validate:         s.validateSyncCommitteeMessage,
+				handle:           s.syncCommitteeMessageSubscriber,
+				digest:           digest,
+				getSubnetsToJoin: s.activeSyncSubnetIndices,
+			})
 		})
 
 		if features.Get().EnableLightClient {
-			s.subscribe(
-				p2p.LightClientOptimisticUpdateTopicFormat,
-				s.validateLightClientOptimisticUpdate,
-				s.lightClientOptimisticUpdateSubscriber,
-				digest,
-			)
-			s.subscribe(
-				p2p.LightClientFinalityUpdateTopicFormat,
-				s.validateLightClientFinalityUpdate,
-				s.lightClientFinalityUpdateSubscriber,
-				digest,
-			)
+			s.spawn(func() {
+				s.subscribe(
+					p2p.LightClientOptimisticUpdateTopicFormat,
+					s.validateLightClientOptimisticUpdate,
+					s.lightClientOptimisticUpdateSubscriber,
+					digest,
+				)
+			})
+			s.spawn(func() {
+				s.subscribe(
+					p2p.LightClientFinalityUpdateTopicFormat,
+					s.validateLightClientFinalityUpdate,
+					s.lightClientFinalityUpdateSubscriber,
+					digest,
+				)
+			})
 		}
 	}
 
 	// New gossip topic in Capella
 	if params.BeaconConfig().CapellaForkEpoch <= epoch {
-		s.subscribe(
-			p2p.BlsToExecutionChangeSubnetTopicFormat,
-			s.validateBlsToExecutionChange,
-			s.blsToExecutionChangeSubscriber,
-			digest,
-		)
+		s.spawn(func() {
+			s.subscribe(
+				p2p.BlsToExecutionChangeSubnetTopicFormat,
+				s.validateBlsToExecutionChange,
+				s.blsToExecutionChangeSubscriber,
+				digest,
+			)
+		})
 	}
 
 	// New gossip topic in Deneb, removed in Electra
 	if params.BeaconConfig().DenebForkEpoch <= epoch && epoch < params.BeaconConfig().ElectraForkEpoch {
-		s.subscribeWithParameters(subscribeParameters{
-			topicFormat: p2p.BlobSubnetTopicFormat,
-			validate:    s.validateBlob,
-			handle:      s.blobSubscriber,
-			digest:      digest,
-			getSubnetsToJoin: func(primitives.Slot) map[uint64]bool {
-				return mapFromCount(params.BeaconConfig().BlobsidecarSubnetCount)
-			},
+		s.spawn(func() {
+			s.subscribeWithParameters(subscribeParameters{
+				topicFormat: p2p.BlobSubnetTopicFormat,
+				validate:    s.validateBlob,
+				handle:      s.blobSubscriber,
+				digest:      digest,
+				getSubnetsToJoin: func(primitives.Slot) map[uint64]bool {
+					return mapFromCount(params.BeaconConfig().BlobsidecarSubnetCount)
+				},
+			})
 		})
 	}
 
 	// New gossip topic in Electra, removed in Fulu
 	if params.BeaconConfig().ElectraForkEpoch <= epoch && epoch < params.BeaconConfig().FuluForkEpoch {
-		s.subscribeWithParameters(subscribeParameters{
-			topicFormat: p2p.BlobSubnetTopicFormat,
-			validate:    s.validateBlob,
-			handle:      s.blobSubscriber,
-			digest:      digest,
-			getSubnetsToJoin: func(currentSlot primitives.Slot) map[uint64]bool {
-				return mapFromCount(params.BeaconConfig().BlobsidecarSubnetCountElectra)
-			},
+		s.spawn(func() {
+			s.subscribeWithParameters(subscribeParameters{
+				topicFormat: p2p.BlobSubnetTopicFormat,
+				validate:    s.validateBlob,
+				handle:      s.blobSubscriber,
+				digest:      digest,
+				getSubnetsToJoin: func(currentSlot primitives.Slot) map[uint64]bool {
+					return mapFromCount(params.BeaconConfig().BlobsidecarSubnetCountElectra)
+				},
+			})
 		})
 	}
 
 	// New gossip topic in Fulu.
 	if params.BeaconConfig().FuluForkEpoch <= epoch {
-		s.subscribeWithParameters(subscribeParameters{
-			topicFormat:      p2p.DataColumnSubnetTopicFormat,
-			validate:         s.validateDataColumn,
-			handle:           s.dataColumnSubscriber,
-			digest:           digest,
-			getSubnetsToJoin: s.dataColumnSubnetIndices,
+		s.spawn(func() {
+			s.subscribeWithParameters(subscribeParameters{
+				topicFormat:              p2p.DataColumnSubnetTopicFormat,
+				validate:                 s.validateDataColumn,
+				handle:                   s.dataColumnSubscriber,
+				digest:                   digest,
+				getSubnetsToJoin:         s.dataColumnSubnetIndices,
+				getSubnetsRequiringPeers: s.allDataColumnSubnets,
+			})
 		})
 	}
 }
 
 // subscribe to a given topic with a given validator and subscription handler.
 // The base protobuf message is used to initialize new messages for decoding.
-func (s *Service) subscribe(topic string, validator wrappedVal, handle subHandler, digest [4]byte) *pubsub.Subscription {
+func (s *Service) subscribe(topic string, validator wrappedVal, handle subHandler, digest [4]byte) {
+	<-s.initialSyncComplete
 	_, e, err := params.ForkDataFromDigest(digest)
 	if err != nil {
 		// Impossible condition as it would mean digest does not exist.
@@ -247,7 +337,7 @@ func (s *Service) subscribe(topic string, validator wrappedVal, handle subHandle
 		// Impossible condition as it would mean topic does not exist.
 		panic(fmt.Sprintf("%s is not mapped to any message in GossipTopicMappings", topic)) // lint:nopanic -- Impossible condition.
 	}
-	return s.subscribeWithBase(s.addDigestToTopic(topic, digest), validator, handle)
+	s.subscribeWithBase(s.addDigestToTopic(topic, digest), validator, handle)
 }
 
 func (s *Service) subscribeWithBase(topic string, validator wrappedVal, handle subHandler) *pubsub.Subscription {
@@ -412,61 +502,38 @@ func (s *Service) wrapAndReportValidation(topic string, v wrappedVal) (string, p
 // pruneSubscriptions unsubscribes from topics we are currently subscribed to but that are
 // not in the list of wanted subnets.
 // This function mutates the `subscriptionBySubnet` map, which is used to keep track of the current subscriptions.
-func (s *Service) pruneSubscriptions(
-	subscriptionBySubnet map[uint64]*pubsub.Subscription,
-	wantedSubnets map[uint64]bool,
-	topicFormat string,
-	digest [4]byte,
-) {
-	for subnet, subscription := range subscriptionBySubnet {
-		if subscription == nil {
-			// Should not happen, but just in case.
-			delete(subscriptionBySubnet, subnet)
-			continue
-		}
-
-		if wantedSubnets[subnet] {
-			// Nothing to prune.
-			continue
-		}
-
-		// We are subscribed to a subnet that is no longer wanted.
-		subscription.Cancel()
-		fullTopic := fmt.Sprintf(topicFormat, digest, subnet) + s.cfg.p2p.Encoding().ProtocolSuffix()
-		s.unSubscribeFromTopic(fullTopic)
-		delete(subscriptionBySubnet, subnet)
+func (s *Service) pruneSubscriptions(t *subnetTracker, wantedSubnets map[uint64]bool) {
+	for _, subnet := range t.unwanted(wantedSubnets) {
+		t.cancelSubscription(subnet)
+		s.unSubscribeFromTopic(t.fullTopic(subnet, s.cfg.p2p.Encoding().ProtocolSuffix()))
 	}
 }
 
 // subscribeToSubnets subscribes to needed subnets and unsubscribe from unneeded ones.
 // This functions mutates the `subscriptionBySubnet` map, which is used to keep track of the current subscriptions.
-func (s *Service) subscribeToSubnets(p subscribeToSubnetsParameters) error {
+func (s *Service) subscribeToSubnets(t *subnetTracker) error {
 	// Do not subscribe if not synced.
 	if s.chainStarted.IsSet() && s.cfg.initialSync.Syncing() {
 		return nil
 	}
 
-	valid, err := isDigestValid(p.digest, s.cfg.clock)
+	valid, err := isDigestValid(t.digest, s.cfg.clock)
 	if err != nil {
 		return errors.Wrap(err, "is digest valid")
 	}
 
 	// Unsubscribe from all subnets if digest is not valid. It's likely to be the case after a hard fork.
 	if !valid {
-		wantedSubnets := map[uint64]bool{}
-		s.pruneSubscriptions(p.subscriptionBySubnet, wantedSubnets, p.topicFormat, p.digest)
+		s.pruneSubscriptions(t, nil)
 		return errInvalidDigest
 	}
 
-	subnetsToJoin := p.getSubnetsToJoin(s.cfg.clock.CurrentSlot())
-	s.pruneSubscriptions(p.subscriptionBySubnet, subnetsToJoin, p.topicFormat, p.digest)
-	for subnet := range subnetsToJoin {
-		subnetTopic := fmt.Sprintf(p.topicFormat, p.digest, subnet)
-
-		if _, exists := p.subscriptionBySubnet[subnet]; !exists {
-			subscription := s.subscribeWithBase(subnetTopic, p.validate, p.handle)
-			p.subscriptionBySubnet[subnet] = subscription
-		}
+	subnetsToJoin := t.getSubnetsToJoin(s.cfg.clock.CurrentSlot())
+	s.pruneSubscriptions(t, subnetsToJoin)
+	for _, subnet := range t.missing(subnetsToJoin) {
+		// TODO: subscribeWithBase appends the protocol suffix, other methods don't. Make this consistent.
+		topic := t.fullTopic(subnet, "")
+		t.track(subnet, s.subscribeWithBase(topic, t.validate, t.handle))
 	}
 
 	return nil
@@ -474,110 +541,81 @@ func (s *Service) subscribeToSubnets(p subscribeToSubnetsParameters) error {
 
 // subscribeWithParameters subscribes to a list of subnets.
 func (s *Service) subscribeWithParameters(p subscribeParameters) {
-	shortTopicFormat := p.topicFormat
-	shortTopicFormatLen := len(shortTopicFormat)
-	if shortTopicFormatLen >= 3 && shortTopicFormat[shortTopicFormatLen-3:] == "_%d" {
-		shortTopicFormat = shortTopicFormat[:shortTopicFormatLen-3]
-	}
-	shortTopic := fmt.Sprintf(shortTopicFormat, p.digest)
+	tracker := newSubnetTracker(p)
+	// Try once immediately so we don't have to wait until the next slot.
+	s.ensureSubnetPeersAndSubscribe(tracker)
 
-	parameters := subscribeToSubnetsParameters{
-		subscriptionBySubnet: make(map[uint64]*pubsub.Subscription),
-		topicFormat:          p.topicFormat,
-		digest:               p.digest,
-		validate:             p.validate,
-		handle:               p.handle,
-		getSubnetsToJoin:     p.getSubnetsToJoin,
+	go s.logMinimumPeersPerSubnet(p)
+
+	slotTicker := slots.NewSlotTicker(s.cfg.clock.GenesisTime(), params.BeaconConfig().SecondsPerSlot)
+	defer slotTicker.Done()
+	for {
+		select {
+		case <-slotTicker.C():
+			s.ensureSubnetPeersAndSubscribe(tracker)
+		case <-s.ctx.Done():
+			return
+		}
 	}
-	err := s.subscribeToSubnets(parameters)
-	if err != nil {
-		log.WithError(err).Error("Could not subscribe to subnets")
+}
+
+func (s *Service) ensureSubnetPeersAndSubscribe(tracker *subnetTracker) {
+	timeout := time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
+	minPeers := flags.Get().MinimumPeersPerSubnet
+	logFields := tracker.logFields()
+	neededSubnets := computeAllNeededSubnets(s.cfg.clock.CurrentSlot(), tracker.getSubnetsToJoin, tracker.getSubnetsRequiringPeers)
+
+	if err := s.subscribeToSubnets(tracker); err != nil {
+		if errors.Is(err, errInvalidDigest) {
+			log.WithFields(logFields).Debug("Digest is invalid, stopping subscription")
+			return
+		}
+		log.WithFields(logFields).WithError(err).Error("Could not subscribe to subnets")
+		return
 	}
 
-	slotDuration := time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
+	ctx, cancel := context.WithTimeout(s.ctx, timeout)
+	defer cancel()
+	if err := s.cfg.p2p.FindAndDialPeersWithSubnets(ctx, tracker.topicFormat, tracker.digest, minPeers, neededSubnets); err != nil && !errors.Is(err, context.DeadlineExceeded) {
+		log.WithFields(logFields).WithError(err).Debug("Could not find peers with subnets")
+	}
+}
+
+func (s *Service) logMinimumPeersPerSubnet(p subscribeParameters) {
+	logFields := p.logFields()
 	minimumPeersPerSubnet := flags.Get().MinimumPeersPerSubnet
-	// Subscribe to expected subnets and search for peers if needed at every slot.
-	go func() {
-		currentSlot := s.cfg.clock.CurrentSlot()
-		neededSubnets := computeAllNeededSubnets(currentSlot, p.getSubnetsToJoin, p.getSubnetsRequiringPeers)
-		func() {
-			ctx, cancel := context.WithTimeout(s.ctx, slotDuration)
-			defer cancel()
-
-			if err := s.cfg.p2p.FindAndDialPeersWithSubnets(ctx, p.topicFormat, p.digest, minimumPeersPerSubnet, neededSubnets); err != nil && !errors.Is(err, context.DeadlineExceeded) {
-				log.WithError(err).Debug("Could not find peers with subnets")
-			}
-		}()
-
-		slotTicker := slots.NewSlotTicker(s.cfg.clock.GenesisTime(), params.BeaconConfig().SecondsPerSlot)
-		defer slotTicker.Done()
-
-		for {
-			select {
-			case <-slotTicker.C():
-				currentSlot := s.cfg.clock.CurrentSlot()
-				neededSubnets := computeAllNeededSubnets(currentSlot, p.getSubnetsToJoin, p.getSubnetsRequiringPeers)
-
-				if err := s.subscribeToSubnets(parameters); err != nil {
-					if errors.Is(err, errInvalidDigest) {
-						log.WithField("topics", shortTopic).Debug("Digest is invalid, stopping subscription")
-						return
-					}
-					log.WithError(err).Error("Could not subscribe to subnets")
-					continue
-				}
-
-				func() {
-					ctx, cancel := context.WithTimeout(s.ctx, slotDuration)
-					defer cancel()
-
-					if err := s.cfg.p2p.FindAndDialPeersWithSubnets(ctx, p.topicFormat, p.digest, minimumPeersPerSubnet, neededSubnets); err != nil && !errors.Is(err, context.DeadlineExceeded) {
-						log.WithError(err).Debug("Could not find peers with subnets")
-					}
-				}()
-
-			case <-s.ctx.Done():
-				return
-			}
-		}
-	}()
-
 	// Warn the user if we are not subscribed to enough peers in the subnets.
-	go func() {
-		log := log.WithField("minimum", minimumPeersPerSubnet)
-		logTicker := time.NewTicker(5 * time.Minute)
-		defer logTicker.Stop()
+	log := log.WithField("minimum", minimumPeersPerSubnet)
+	logTicker := time.NewTicker(5 * time.Minute)
+	defer logTicker.Stop()
 
-		for {
-			select {
-			case <-logTicker.C:
-				currentSlot := s.cfg.clock.CurrentSlot()
-				subnetsToFindPeersIndex := computeAllNeededSubnets(currentSlot, p.getSubnetsToJoin, p.getSubnetsRequiringPeers)
+	for {
+		select {
+		case <-logTicker.C:
+			currentSlot := s.cfg.clock.CurrentSlot()
+			subnetsToFindPeersIndex := computeAllNeededSubnets(currentSlot, p.getSubnetsToJoin, p.getSubnetsRequiringPeers)
 
-				isSubnetWithMissingPeers := false
-				// Find new peers for wanted subnets if needed.
-				for index := range subnetsToFindPeersIndex {
-					topic := fmt.Sprintf(p.topicFormat, p.digest, index)
+			isSubnetWithMissingPeers := false
+			// Find new peers for wanted subnets if needed.
+			for index := range subnetsToFindPeersIndex {
+				topic := fmt.Sprintf(p.topicFormat, p.digest, index)
 
-					// Check if we have enough peers in the subnet. Skip if we do.
-					if count := s.connectedPeersCount(topic); count < minimumPeersPerSubnet {
-						isSubnetWithMissingPeers = true
-						log.WithFields(logrus.Fields{
-							"topic":  topic,
-							"actual": count,
-						}).Warning("Not enough connected peers")
-					}
+				// Check if we have enough peers in the subnet. Skip if we do.
+				if count := s.connectedPeersCount(topic); count < minimumPeersPerSubnet {
+					isSubnetWithMissingPeers = true
+					log.WithFields(logrus.Fields{
+						"topic":  topic,
+						"actual": count,
+					}).Warning("Not enough connected peers")
 				}
-
-				if !isSubnetWithMissingPeers {
-					log.WithField("topic", shortTopic).Info("All subnets have enough connected peers")
-				}
-
-			case <-s.ctx.Done():
-				return
 			}
+			if !isSubnetWithMissingPeers {
+				log.WithFields(logFields).Debug("All subnets have enough connected peers")
+			}
+		case <-s.ctx.Done():
+			return
 		}
-	}()
+	}
 }
 
 func (s *Service) unSubscribeFromTopic(topic string) {

beacon-chain/sync/subscriber_data_column_sidecar.go

@@ -6,7 +6,9 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
 	opfeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/operation"
+	"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/pkg/errors"
 	"google.golang.org/protobuf/proto"
 )
@@ -52,3 +54,31 @@ func (s *Service) receiveDataColumnSidecar(ctx context.Context, sidecar blocks.V
 
 	return nil
 }
+
+// allDataColumnSubnets returns the data column subnets for which we need to find peers
+// but don't need to subscribe to. This is used to ensure we have peers available in all subnets
+// when we are serving validators. When a validator proposes a block, they need to publish data
+// column sidecars on all subnets. This method returns a nil map when there is no validators custody
+// requirement.
+func (s *Service) allDataColumnSubnets(_ primitives.Slot) map[uint64]bool {
+	validatorsCustodyRequirement, err := s.validatorsCustodyRequirement()
+	if err != nil {
+		log.WithError(err).Error("Could not retrieve validators custody requirement")
+		return nil
+	}
+
+	// If no validators are tracked, return early
+	if validatorsCustodyRequirement == 0 {
+		return nil
+	}
+
+	// When we have validators with custody requirements, we need peers in all subnets
+	// because validators need to be able to publish data columns to all subnets when proposing
+	dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+	allSubnets := make(map[uint64]bool, dataColumnSidecarSubnetCount)
+	for i := range dataColumnSidecarSubnetCount {
+		allSubnets[i] = true
+	}
+
+	return allSubnets
+}

beacon-chain/sync/subscriber_data_column_sidecar_test.go

@@ -0,0 +1,65 @@
+package sync
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
+	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/state/stategen"
+	"github.com/OffchainLabs/prysm/v6/config/params"
+	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v6/testing/assert"
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+	"github.com/OffchainLabs/prysm/v6/testing/util"
+)
+
+func TestAllDataColumnSubnets(t *testing.T) {
+	t.Run("returns nil when no validators tracked", func(t *testing.T) {
+		// Service with no tracked validators
+		svc := &Service{
+			ctx:                    t.Context(),
+			trackedValidatorsCache: cache.NewTrackedValidatorsCache(),
+		}
+
+		result := svc.allDataColumnSubnets(primitives.Slot(0))
+		assert.Equal(t, true, len(result) == 0, "Expected nil or empty map when no validators are tracked")
+	})
+
+	t.Run("returns all subnets logic test", func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		ctx := t.Context()
+
+		db := dbtest.SetupDB(t)
+
+		// Create and save genesis state
+		genesisState, _ := util.DeterministicGenesisState(t, 64)
+		require.NoError(t, db.SaveGenesisData(ctx, genesisState))
+
+		// Create stategen and initialize with genesis state
+		stateGen := stategen.New(db, doublylinkedtree.New())
+		_, err := stateGen.Resume(ctx, genesisState)
+		require.NoError(t, err)
+
+		// At least one tracked validator.
+		tvc := cache.NewTrackedValidatorsCache()
+		tvc.Set(cache.TrackedValidator{Active: true, Index: 1})
+
+		svc := &Service{
+			ctx:                    ctx,
+			trackedValidatorsCache: tvc,
+			cfg: &config{
+				stateGen: stateGen,
+				beaconDB: db,
+			},
+		}
+
+		dataColumnSidecarSubnetCount := params.BeaconConfig().DataColumnSidecarSubnetCount
+		result := svc.allDataColumnSubnets(0)
+		assert.Equal(t, dataColumnSidecarSubnetCount, uint64(len(result)))
+
+		for i := range dataColumnSidecarSubnetCount {
+			assert.Equal(t, true, result[i])
+		}
+	})
+}

beacon-chain/sync/subscriber_test.go

@@ -58,6 +58,7 @@ func TestSubscribe_ReceivesValidMessage(t *testing.T) {
 		subHandler:   newSubTopicHandler(),
 		chainStarted: abool.New(),
 	}
+	markInitSyncComplete(t, &r)
 	var err error
 	p2pService.Digest, err = r.currentForkDigest()
 	require.NoError(t, err)
@@ -83,6 +84,11 @@ func TestSubscribe_ReceivesValidMessage(t *testing.T) {
 	}
 }
 
+func markInitSyncComplete(_ *testing.T, s *Service) {
+	s.initialSyncComplete = make(chan struct{})
+	close(s.initialSyncComplete)
+}
+
 func TestSubscribe_UnsubscribeTopic(t *testing.T) {
 	p2pService := p2ptest.NewTestP2P(t)
 	gt := time.Now()
@@ -101,6 +107,7 @@ func TestSubscribe_UnsubscribeTopic(t *testing.T) {
 		chainStarted: abool.New(),
 		subHandler:   newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, &r)
 	var err error
 	p2pService.Digest, err = r.currentForkDigest()
 	require.NoError(t, err)
@@ -152,6 +159,7 @@ func TestSubscribe_ReceivesAttesterSlashing(t *testing.T) {
 		chainStarted:              abool.New(),
 		subHandler:                newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, &r)
 	topic := "/eth2/%x/attester_slashing"
 	var wg sync.WaitGroup
 	wg.Add(1)
@@ -205,6 +213,7 @@ func TestSubscribe_ReceivesProposerSlashing(t *testing.T) {
 		chainStarted:              abool.New(),
 		subHandler:                newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, &r)
 	topic := "/eth2/%x/proposer_slashing"
 	var wg sync.WaitGroup
 	wg.Add(1)
@@ -253,6 +262,8 @@ func TestSubscribe_HandlesPanic(t *testing.T) {
 		subHandler:   newSubTopicHandler(),
 		chainStarted: abool.New(),
 	}
+	markInitSyncComplete(t, &r)
+
 	var err error
 	p.Digest, err = r.currentForkDigest()
 	require.NoError(t, err)
@@ -292,25 +303,33 @@ func TestRevalidateSubscription_CorrectlyFormatsTopic(t *testing.T) {
 	}
 	digest, err := r.currentForkDigest()
 	require.NoError(t, err)
-	subscriptions := make(map[uint64]*pubsub.Subscription, params.BeaconConfig().MaxCommitteesPerSlot)
 
-	defaultTopic := "/eth2/testing/%#x/committee%d"
+	params := subscribeParameters{
+		topicFormat: "/eth2/testing/%#x/committee%d",
+		digest:      digest,
+	}
+	tracker := newSubnetTracker(params)
+
 	// committee index 1
-	fullTopic := fmt.Sprintf(defaultTopic, digest, 1) + r.cfg.p2p.Encoding().ProtocolSuffix()
+	c1 := uint64(1)
+	fullTopic := params.fullTopic(c1, r.cfg.p2p.Encoding().ProtocolSuffix())
 	_, topVal := r.wrapAndReportValidation(fullTopic, r.noopValidator)
 	require.NoError(t, r.cfg.p2p.PubSub().RegisterTopicValidator(fullTopic, topVal))
-	subscriptions[1], err = r.cfg.p2p.SubscribeToTopic(fullTopic)
+	sub1, err := r.cfg.p2p.SubscribeToTopic(fullTopic)
 	require.NoError(t, err)
+	tracker.track(c1, sub1)
 
 	// committee index 2
-	fullTopic = fmt.Sprintf(defaultTopic, digest, 2) + r.cfg.p2p.Encoding().ProtocolSuffix()
+	c2 := uint64(2)
+	fullTopic = params.fullTopic(c2, r.cfg.p2p.Encoding().ProtocolSuffix())
 	_, topVal = r.wrapAndReportValidation(fullTopic, r.noopValidator)
 	err = r.cfg.p2p.PubSub().RegisterTopicValidator(fullTopic, topVal)
 	require.NoError(t, err)
-	subscriptions[2], err = r.cfg.p2p.SubscribeToTopic(fullTopic)
+	sub2, err := r.cfg.p2p.SubscribeToTopic(fullTopic)
 	require.NoError(t, err)
+	tracker.track(c2, sub2)
 
-	r.pruneSubscriptions(subscriptions, map[uint64]bool{2: true}, defaultTopic, digest)
+	r.pruneSubscriptions(tracker, map[uint64]bool{c2: true})
 	require.LogsDoNotContain(t, hook, "Could not unregister topic validator")
 }
 
@@ -539,7 +558,7 @@ func TestSubscribeWithSyncSubnets_DynamicOK(t *testing.T) {
 	cache.SyncSubnetIDs.AddSyncCommitteeSubnets([]byte("pubkey"), currEpoch, []uint64{0, 1}, 10*time.Second)
 	digest, err := r.currentForkDigest()
 	assert.NoError(t, err)
-	r.subscribeWithParameters(subscribeParameters{
+	go r.subscribeWithParameters(subscribeParameters{
 		topicFormat:      p2p.SyncCommitteeSubnetTopicFormat,
 		digest:           digest,
 		getSubnetsToJoin: r.activeSyncSubnetIndices,
@@ -580,6 +599,7 @@ func TestSubscribeWithSyncSubnets_DynamicSwitchFork(t *testing.T) {
 		chainStarted: abool.New(),
 		subHandler:   newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, &r)
 	// Empty cache at the end of the test.
 	defer cache.SyncSubnetIDs.EmptyAllCaches()
 	cache.SyncSubnetIDs.AddSyncCommitteeSubnets([]byte("pubkey"), 0, []uint64{0, 1}, 10*time.Second)
@@ -589,12 +609,11 @@ func TestSubscribeWithSyncSubnets_DynamicSwitchFork(t *testing.T) {
 	require.Equal(t, [4]byte(params.BeaconConfig().DenebForkVersion), version)
 	require.Equal(t, params.BeaconConfig().DenebForkEpoch, e)
 
-	sp := subscribeToSubnetsParameters{
-		subscriptionBySubnet: make(map[uint64]*pubsub.Subscription),
-		topicFormat:          p2p.SyncCommitteeSubnetTopicFormat,
-		digest:               digest,
-		getSubnetsToJoin:     r.activeSyncSubnetIndices,
-	}
+	sp := newSubnetTracker(subscribeParameters{
+		topicFormat:      p2p.SyncCommitteeSubnetTopicFormat,
+		digest:           digest,
+		getSubnetsToJoin: r.activeSyncSubnetIndices,
+	})
 	require.NoError(t, r.subscribeToSubnets(sp))
 	assert.Equal(t, 2, len(r.cfg.p2p.PubSub().GetTopics()))
 	topicMap := map[string]bool{}
@@ -697,6 +716,7 @@ func TestSubscribe_ReceivesLCOptimisticUpdate(t *testing.T) {
 		lcStore:      lightClient.NewLightClientStore(d, &p2ptest.FakeP2P{}, new(event.Feed)),
 		subHandler:   newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, &r)
 	topic := p2p.LightClientOptimisticUpdateTopicFormat
 	var wg sync.WaitGroup
 	wg.Add(1)
@@ -764,6 +784,7 @@ func TestSubscribe_ReceivesLCFinalityUpdate(t *testing.T) {
 		lcStore:      lightClient.NewLightClientStore(d, &p2ptest.FakeP2P{}, new(event.Feed)),
 		subHandler:   newSubTopicHandler(),
 	}
+	markInitSyncComplete(t, &r)
 	topic := p2p.LightClientFinalityUpdateTopicFormat
 	var wg sync.WaitGroup
 	wg.Add(1)

beacon-chain/sync/validate_bls_to_execution_change_test.go

@@ -427,6 +427,7 @@ func TestService_ValidateBlsToExecutionChange(t *testing.T) {
 			cw := startup.NewClockSynchronizer()
 			opts := []Option{WithClockWaiter(cw)}
 			svc := NewService(ctx, append(opts, tt.svcopts...)...)
+			markInitSyncComplete(t, svc)
 			svc, tt.args.topic = tt.setupSvc(svc, tt.args.msg, tt.args.topic)
 			go svc.Start()
 			if tt.clock == nil {

beacon-chain/sync/validate_sync_committee_message_test.go

@@ -409,6 +409,7 @@ func TestService_ValidateSyncCommitteeMessage(t *testing.T) {
 			svc := NewService(ctx, append(opts, tt.svcopts...)...)
 			var clock *startup.Clock
 			svc, tt.args.topic, clock = tt.setupSvc(svc, tt.args.msg, tt.args.topic)
+			markInitSyncComplete(t, svc)
 			go svc.Start()
 			require.NoError(t, cw.SetClock(clock))
 			svc.verifierWaiter = verification.NewInitializerWaiter(cw, chainService.ForkChoiceStore, svc.cfg.stateGen)

beacon-chain/sync/validate_sync_contribution_proof_test.go

@@ -856,7 +856,7 @@ func TestService_ValidateSyncContributionAndProof(t *testing.T) {
 			svc, clock = tt.setupSvc(svc, tt.args.msg)
 			require.NoError(t, cw.SetClock(clock))
 			svc.verifierWaiter = verification.NewInitializerWaiter(cw, chainService.ForkChoiceStore, svc.cfg.stateGen)
-
+			markInitSyncComplete(t, svc)
 			go svc.Start()
 			marshalledObj, err := tt.args.msg.MarshalSSZ()
 			assert.NoError(t, err)

changelog/2025-08-25-docs-links.md

@@ -0,0 +1,2 @@
+### Changed
+- Updated outdated documentation links for Web3Signer and Why Bazel.

changelog/Galoretka_fix-leakybucket-test-duplicate.md

@@ -0,0 +1,2 @@
+## Ignored
+- Remove duplicate test case in `container/leaky-bucket/collector_test.go` to reduce redundancy. (#15672)

changelog/james-prysm_alpaha6-spec-tests.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Updated consensus spec from v1.6.0-alpha.5 to v1.6.0-alpha.6

changelog/james-prysm_block-proposal-fulu.md

@@ -0,0 +1,3 @@
+### Added
+
+- Fulu block proposal changes for beacon api and gRPC.

changelog/james-prysm_deprecate-publish-blos.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Deprecated and added error to /prysm/v1/beacon/blobs endpoint for post Fulu fork.

changelog/james-prysm_fulu-web3signer.md

@@ -0,0 +1,7 @@
+### Added
+
+- Adding Fulu types for web3signer.
+
+### Changed
+
+- changed validatorpb.SignRequest_AggregateAttestationAndProof signing type to use AggregateAttestationAndProofV2 on web3signer.

changelog/james-prysm_post-block-ssz.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Switching default of validator client rest call for submit block from JSON to SSZ. Fallback json will be attempted.