optimize get blobs (#15902)

* init

* reverting some functions

* rolling back a change and fixing linting

* wip

* wip

* fixing test

* breaking up proofs and cells for cleaner code

* fixing test and type

* fixing safe conversion

* fixing test

* fixing more tests

* fixing even more tests

* fix the 0 indices option

* adding a test for coverage

* small test update

* changelog

* radek's suggestions

* Update beacon-chain/core/peerdas/validator.go

Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com>

* addressing comments on kzg package

* addressing suggestions for reconstruction

* more manu feedback items

* removing unneeded files

* removing unneeded setter

---------

Co-authored-by: james-prysm <jhe@offchainlabs.com>
Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com>

beacon-chain/blockchain/kzg/BUILD.bazel

@@ -23,6 +23,7 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "kzg_test.go",
         "trusted_setup_test.go",
         "validation_test.go",
     ],

beacon-chain/blockchain/kzg/kzg.go

@@ -34,12 +34,6 @@ type Bytes48 = ckzg4844.Bytes48
 // Bytes32 is a 32-byte array.
 type Bytes32 = ckzg4844.Bytes32
 
-// CellsAndProofs represents the Cells and Proofs corresponding to a single blob.
-type CellsAndProofs struct {
-	Cells  []Cell
-	Proofs []Proof
-}
-
 // BlobToKZGCommitment computes a KZG commitment from a given blob.
 func BlobToKZGCommitment(blob *Blob) (Commitment, error) {
 	var kzgBlob kzg4844.Blob
@@ -65,7 +59,7 @@ func ComputeCells(blob *Blob) ([]Cell, error) {
 
 	cells := make([]Cell, len(ckzgCells))
 	for i := range ckzgCells {
-		cells[i] = Cell(ckzgCells[i])
+		copy(cells[i][:], ckzgCells[i][:])
 	}
 
 	return cells, nil
@@ -78,22 +72,35 @@ func ComputeBlobKZGProof(blob *Blob, commitment Commitment) (Proof, error) {
 
 	proof, err := kzg4844.ComputeBlobProof(&kzgBlob, kzg4844.Commitment(commitment))
 	if err != nil {
-		return [48]byte{}, err
+		return Proof{}, err
 	}
-	return Proof(proof), nil
+	var result Proof
+	copy(result[:], proof[:])
+	return result, nil
 }
 
 // ComputeCellsAndKZGProofs computes the cells and cells KZG proofs from a given blob.
-func ComputeCellsAndKZGProofs(blob *Blob) (CellsAndProofs, error) {
+func ComputeCellsAndKZGProofs(blob *Blob) ([]Cell, []Proof, error) {
 	var ckzgBlob ckzg4844.Blob
 	copy(ckzgBlob[:], blob[:])
 
 	ckzgCells, ckzgProofs, err := ckzg4844.ComputeCellsAndKZGProofs(&ckzgBlob)
 	if err != nil {
-		return CellsAndProofs{}, err
+		return nil, nil, err
 	}
 
-	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
+	if len(ckzgCells) != len(ckzgProofs) {
+		return nil, nil, errors.New("mismatched cells and proofs length")
+	}
+
+	cells := make([]Cell, len(ckzgCells))
+	proofs := make([]Proof, len(ckzgProofs))
+	for i := range ckzgCells {
+		copy(cells[i][:], ckzgCells[i][:])
+		copy(proofs[i][:], ckzgProofs[i][:])
+	}
+
+	return cells, proofs, nil
 }
 
 // VerifyCellKZGProofBatch verifies the KZG proofs for a given slice of commitments, cells indices, cells and proofs.
@@ -103,44 +110,57 @@ func VerifyCellKZGProofBatch(commitmentsBytes []Bytes48, cellIndices []uint64, c
 	ckzgCells := make([]ckzg4844.Cell, len(cells))
 
 	for i := range cells {
-		ckzgCells[i] = ckzg4844.Cell(cells[i])
+		copy(ckzgCells[i][:], cells[i][:])
 	}
 	return ckzg4844.VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, ckzgCells, proofsBytes)
 }
 
-// RecoverCellsAndKZGProofs recovers the complete cells and KZG proofs from a given set of cell indices and partial cells.
+// RecoverCells recovers the complete cells from a given set of cell indices and partial cells.
 // Note: `len(cellIndices)` must be equal to `len(partialCells)` and `cellIndices` must be sorted in ascending order.
-func RecoverCellsAndKZGProofs(cellIndices []uint64, partialCells []Cell) (CellsAndProofs, error) {
+func RecoverCells(cellIndices []uint64, partialCells []Cell) ([]Cell, error) {
 	// Convert `Cell` type to `ckzg4844.Cell`
 	ckzgPartialCells := make([]ckzg4844.Cell, len(partialCells))
 	for i := range partialCells {
-		ckzgPartialCells[i] = ckzg4844.Cell(partialCells[i])
+		copy(ckzgPartialCells[i][:], partialCells[i][:])
+	}
+
+	ckzgCells, err := ckzg4844.RecoverCells(cellIndices, ckzgPartialCells)
+	if err != nil {
+		return nil, errors.Wrap(err, "recover cells")
+	}
+
+	cells := make([]Cell, len(ckzgCells))
+	for i := range ckzgCells {
+		copy(cells[i][:], ckzgCells[i][:])
+	}
+
+	return cells, nil
+}
+
+// RecoverCellsAndKZGProofs recovers the complete cells and KZG proofs from a given set of cell indices and partial cells.
+// Note: `len(cellIndices)` must be equal to `len(partialCells)` and `cellIndices` must be sorted in ascending order.
+func RecoverCellsAndKZGProofs(cellIndices []uint64, partialCells []Cell) ([]Cell, []Proof, error) {
+	// Convert `Cell` type to `ckzg4844.Cell`
+	ckzgPartialCells := make([]ckzg4844.Cell, len(partialCells))
+	for i := range partialCells {
+		copy(ckzgPartialCells[i][:], partialCells[i][:])
 	}
 
 	ckzgCells, ckzgProofs, err := ckzg4844.RecoverCellsAndKZGProofs(cellIndices, ckzgPartialCells)
 	if err != nil {
-		return CellsAndProofs{}, errors.Wrap(err, "recover cells and KZG proofs")
+		return nil, nil, errors.Wrap(err, "recover cells and KZG proofs")
 	}
 
-	return makeCellsAndProofs(ckzgCells[:], ckzgProofs[:])
-}
-
-// makeCellsAndProofs converts cells/proofs to the CellsAndProofs type defined in this package.
-func makeCellsAndProofs(ckzgCells []ckzg4844.Cell, ckzgProofs []ckzg4844.KZGProof) (CellsAndProofs, error) {
 	if len(ckzgCells) != len(ckzgProofs) {
-		return CellsAndProofs{}, errors.New("different number of cells/proofs")
+		return nil, nil, errors.New("mismatched cells and proofs length")
 	}
 
-	cells := make([]Cell, 0, len(ckzgCells))
-	proofs := make([]Proof, 0, len(ckzgProofs))
-
+	cells := make([]Cell, len(ckzgCells))
+	proofs := make([]Proof, len(ckzgProofs))
 	for i := range ckzgCells {
-		cells = append(cells, Cell(ckzgCells[i]))
-		proofs = append(proofs, Proof(ckzgProofs[i]))
+		copy(cells[i][:], ckzgCells[i][:])
+		copy(proofs[i][:], ckzgProofs[i][:])
 	}
 
-	return CellsAndProofs{
-		Cells:  cells,
-		Proofs: proofs,
-	}, nil
+	return cells, proofs, nil
 }

beacon-chain/blockchain/kzg/kzg_test.go

@@ -0,0 +1,236 @@
+package kzg
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v7/crypto/random"
+	"github.com/OffchainLabs/prysm/v7/testing/require"
+)
+
+func TestComputeCells(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("valid blob", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		cells, err := ComputeCells(&blob)
+		require.NoError(t, err)
+		require.Equal(t, 128, len(cells))
+	})
+}
+
+func TestComputeBlobKZGProof(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("valid blob and commitment", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		proof, err := ComputeBlobKZGProof(&blob, commitment)
+		require.NoError(t, err)
+		require.Equal(t, BytesPerProof, len(proof))
+		require.NotEqual(t, Proof{}, proof, "proof should not be empty")
+	})
+}
+
+func TestComputeCellsAndKZGProofs(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("valid blob returns matching cells and proofs", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		cells, proofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+		require.Equal(t, 128, len(cells))
+		require.Equal(t, 128, len(proofs))
+		require.Equal(t, len(cells), len(proofs), "cells and proofs should have matching lengths")
+	})
+}
+
+func TestVerifyCellKZGProofBatch(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("valid proof batch", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		cells, proofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Verify a subset of cells
+		cellIndices := []uint64{0, 1, 2, 3, 4}
+		selectedCells := make([]Cell, len(cellIndices))
+		commitmentsBytes := make([]Bytes48, len(cellIndices))
+		proofsBytes := make([]Bytes48, len(cellIndices))
+
+		for i, idx := range cellIndices {
+			selectedCells[i] = cells[idx]
+			copy(commitmentsBytes[i][:], commitment[:])
+			copy(proofsBytes[i][:], proofs[idx][:])
+		}
+
+		valid, err := VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, selectedCells, proofsBytes)
+		require.NoError(t, err)
+		require.Equal(t, true, valid)
+	})
+
+	t.Run("invalid proof should fail", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+
+		cells, _, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Use invalid proofs
+		cellIndices := []uint64{0}
+		selectedCells := []Cell{cells[0]}
+		commitmentsBytes := make([]Bytes48, 1)
+		copy(commitmentsBytes[0][:], commitment[:])
+
+		// Create an invalid proof
+		invalidProof := Bytes48{}
+		proofsBytes := []Bytes48{invalidProof}
+
+		valid, err := VerifyCellKZGProofBatch(commitmentsBytes, cellIndices, selectedCells, proofsBytes)
+		require.NotNil(t, err)
+		require.Equal(t, false, valid)
+	})
+}
+
+func TestRecoverCells(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("recover from partial cells", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		cells, err := ComputeCells(&blob)
+		require.NoError(t, err)
+
+		// Use half of the cells
+		partialIndices := make([]uint64, 64)
+		partialCells := make([]Cell, 64)
+		for i := range 64 {
+			partialIndices[i] = uint64(i)
+			partialCells[i] = cells[i]
+		}
+
+		recoveredCells, err := RecoverCells(partialIndices, partialCells)
+		require.NoError(t, err)
+		require.Equal(t, 128, len(recoveredCells))
+
+		// Verify recovered cells match original
+		for i := range cells {
+			require.Equal(t, cells[i], recoveredCells[i])
+		}
+	})
+
+	t.Run("insufficient cells should fail", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		cells, err := ComputeCells(&blob)
+		require.NoError(t, err)
+
+		// Use only 32 cells (less than 50% required)
+		partialIndices := make([]uint64, 32)
+		partialCells := make([]Cell, 32)
+		for i := range 32 {
+			partialIndices[i] = uint64(i)
+			partialCells[i] = cells[i]
+		}
+
+		_, err = RecoverCells(partialIndices, partialCells)
+		require.NotNil(t, err)
+	})
+}
+
+func TestRecoverCellsAndKZGProofs(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("recover cells and proofs from partial cells", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		cells, proofs, err := ComputeCellsAndKZGProofs(&blob)
+		require.NoError(t, err)
+
+		// Use half of the cells
+		partialIndices := make([]uint64, 64)
+		partialCells := make([]Cell, 64)
+		for i := range 64 {
+			partialIndices[i] = uint64(i)
+			partialCells[i] = cells[i]
+		}
+
+		recoveredCells, recoveredProofs, err := RecoverCellsAndKZGProofs(partialIndices, partialCells)
+		require.NoError(t, err)
+		require.Equal(t, 128, len(recoveredCells))
+		require.Equal(t, 128, len(recoveredProofs))
+		require.Equal(t, len(recoveredCells), len(recoveredProofs), "recovered cells and proofs should have matching lengths")
+
+		// Verify recovered cells match original
+		for i := range cells {
+			require.Equal(t, cells[i], recoveredCells[i])
+			require.Equal(t, proofs[i], recoveredProofs[i])
+		}
+	})
+
+	t.Run("insufficient cells should fail", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		cells, err := ComputeCells(&blob)
+		require.NoError(t, err)
+
+		// Use only 32 cells (less than 50% required)
+		partialIndices := make([]uint64, 32)
+		partialCells := make([]Cell, 32)
+		for i := range 32 {
+			partialIndices[i] = uint64(i)
+			partialCells[i] = cells[i]
+		}
+
+		_, _, err = RecoverCellsAndKZGProofs(partialIndices, partialCells)
+		require.NotNil(t, err)
+	})
+}
+
+func TestBlobToKZGCommitment(t *testing.T) {
+	require.NoError(t, Start())
+
+	t.Run("valid blob", func(t *testing.T) {
+		randBlob := random.GetRandBlob(123)
+		var blob Blob
+		copy(blob[:], randBlob[:])
+
+		commitment, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+		require.Equal(t, 48, len(commitment))
+
+		// Verify commitment is deterministic
+		commitment2, err := BlobToKZGCommitment(&blob)
+		require.NoError(t, err)
+		require.Equal(t, commitment, commitment2)
+	})
+}

beacon-chain/blockchain/kzg/validation_test.go

@@ -203,13 +203,13 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 		require.NoError(t, err)
 
 		// Compute cells and proofs
-		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		_, proofs, 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][:]
+			cellProofs[i] = proofs[i][:]
 		}
 
 		blobs := [][]byte{blob[:]}
@@ -236,7 +236,7 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 			require.NoError(t, err)
 
 			// Compute cells and proofs
-			cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+			_, proofs, err := ComputeCellsAndKZGProofs(&blob)
 			require.NoError(t, err)
 
 			blobs[i] = blob[:]
@@ -244,7 +244,7 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 
 			// Add cell proofs for this blob
 			for j := range numberOfColumns {
-				allCellProofs = append(allCellProofs, cellsAndProofs.Proofs[j][:])
+				allCellProofs = append(allCellProofs, proofs[j][:])
 			}
 		}
 
@@ -319,7 +319,7 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 		randBlob := random.GetRandBlob(123)
 		var blob Blob
 		copy(blob[:], randBlob[:])
-		cellsAndProofs, err := ComputeCellsAndKZGProofs(&blob)
+		_, proofs, err := ComputeCellsAndKZGProofs(&blob)
 		require.NoError(t, err)
 
 		// Generate wrong commitment from different blob
@@ -331,7 +331,7 @@ func TestVerifyCellKZGProofBatchFromBlobData(t *testing.T) {
 
 		cellProofs := make([][]byte, numberOfColumns)
 		for i := range numberOfColumns {
-			cellProofs[i] = cellsAndProofs.Proofs[i][:]
+			cellProofs[i] = proofs[i][:]
 		}
 
 		blobs := [][]byte{blob[:]}

beacon-chain/core/peerdas/BUILD.bazel

@@ -43,6 +43,7 @@ go_test(
         "das_core_test.go",
         "info_test.go",
         "p2p_interface_test.go",
+        "reconstruction_helpers_test.go",
         "reconstruction_test.go",
         "utils_test.go",
         "validator_test.go",

beacon-chain/core/peerdas/p2p_interface_test.go

@@ -387,10 +387,10 @@ func generateRandomSidecars(t testing.TB, seed, blobCount int64) []blocks.ROData
 	sBlock, err := blocks.NewSignedBeaconBlock(dbBlock)
 	require.NoError(t, err)
 
-	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
+	cellsPerBlob, proofsPerBlob := util.GenerateCellsAndProofs(t, blobs)
 	rob, err := blocks.NewROBlock(sBlock)
 	require.NoError(t, err)
-	sidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+	sidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 	require.NoError(t, err)
 
 	return sidecars

beacon-chain/core/peerdas/reconstruction.go

@@ -2,6 +2,7 @@ package peerdas
 
 import (
 	"sort"
+	"sync"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
 	fieldparams "github.com/OffchainLabs/prysm/v7/config/fieldparams"
@@ -28,6 +29,80 @@ func MinimumColumnCountToReconstruct() uint64 {
 	return (params.BeaconConfig().NumberOfColumns + 1) / 2
 }
 
+// recoverCellsForBlobs reconstructs cells for specified blobs from the given data column sidecars.
+// This is optimized to only recover cells without computing proofs.
+// Returns a map from blob index to recovered cells.
+func recoverCellsForBlobs(verifiedRoSidecars []blocks.VerifiedRODataColumn, blobIndices []int) (map[int][]kzg.Cell, error) {
+	sidecarCount := len(verifiedRoSidecars)
+	var wg errgroup.Group
+
+	cellsPerBlob := make(map[int][]kzg.Cell, len(blobIndices))
+	var mu sync.Mutex
+
+	for _, blobIndex := range blobIndices {
+		wg.Go(func() error {
+			cellsIndices := make([]uint64, 0, sidecarCount)
+			cells := make([]kzg.Cell, 0, sidecarCount)
+
+			for _, sidecar := range verifiedRoSidecars {
+				cell := sidecar.Column[blobIndex]
+				cells = append(cells, kzg.Cell(cell))
+				cellsIndices = append(cellsIndices, sidecar.Index)
+			}
+
+			recoveredCells, err := kzg.RecoverCells(cellsIndices, cells)
+			if err != nil {
+				return errors.Wrapf(err, "recover cells for blob %d", blobIndex)
+			}
+
+			mu.Lock()
+			cellsPerBlob[blobIndex] = recoveredCells
+			mu.Unlock()
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, errors.Wrap(err, "wait for RecoverCells")
+	}
+	return cellsPerBlob, nil
+}
+
+// recoverCellsAndProofsForBlobs reconstructs both cells and proofs for specified blobs from the given data column sidecars.
+func recoverCellsAndProofsForBlobs(verifiedRoSidecars []blocks.VerifiedRODataColumn, blobIndices []int) ([][]kzg.Cell, [][]kzg.Proof, error) {
+	sidecarCount := len(verifiedRoSidecars)
+	var wg errgroup.Group
+
+	cellsPerBlob := make([][]kzg.Cell, len(blobIndices))
+	proofsPerBlob := make([][]kzg.Proof, len(blobIndices))
+
+	for i, blobIndex := range blobIndices {
+		wg.Go(func() error {
+			cellsIndices := make([]uint64, 0, sidecarCount)
+			cells := make([]kzg.Cell, 0, sidecarCount)
+
+			for _, sidecar := range verifiedRoSidecars {
+				cell := sidecar.Column[blobIndex]
+				cells = append(cells, kzg.Cell(cell))
+				cellsIndices = append(cellsIndices, sidecar.Index)
+			}
+
+			recoveredCells, recoveredProofs, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
+			if err != nil {
+				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", blobIndex)
+			}
+			cellsPerBlob[i] = recoveredCells
+			proofsPerBlob[i] = recoveredProofs
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, nil, errors.Wrap(err, "wait for RecoverCellsAndKZGProofs")
+	}
+	return cellsPerBlob, proofsPerBlob, nil
+}
+
 // ReconstructDataColumnSidecars reconstructs all the data column sidecars from the given input data column sidecars.
 // All input sidecars must be committed to the same block.
 // `inVerifiedRoSidecars` should contain enough sidecars to reconstruct the missing columns, and should not contain any duplicate.
@@ -66,38 +141,16 @@ func ReconstructDataColumnSidecars(verifiedRoSidecars []blocks.VerifiedRODataCol
 	})
 
 	// Recover cells and compute proofs in parallel.
-	var wg errgroup.Group
-	cellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
-	for blobIndex := range uint64(blobCount) {
-		wg.Go(func() error {
-			cellsIndices := make([]uint64, 0, sidecarCount)
-			cells := make([]kzg.Cell, 0, sidecarCount)
-
-			for _, sidecar := range verifiedRoSidecars {
-				cell := sidecar.Column[blobIndex]
-				cells = append(cells, kzg.Cell(cell))
-				cellsIndices = append(cellsIndices, sidecar.Index)
-			}
-
-			// Recover the cells and proofs for the corresponding blob
-			cellsAndProofsForBlob, err := kzg.RecoverCellsAndKZGProofs(cellsIndices, cells)
-
-			if err != nil {
-				return errors.Wrapf(err, "recover cells and KZG proofs for blob %d", blobIndex)
-			}
-
-			// It is safe for multiple goroutines to concurrently write to the same slice,
-			// as long as they are writing to different indices, which is the case here.
-			cellsAndProofs[blobIndex] = cellsAndProofsForBlob
-			return nil
-		})
+	blobIndices := make([]int, blobCount)
+	for i := range blobIndices {
+		blobIndices[i] = i
+	}
+	cellsPerBlob, proofsPerBlob, err := recoverCellsAndProofsForBlobs(verifiedRoSidecars, blobIndices)
+	if err != nil {
+		return nil, errors.Wrap(err, "recover cells and proofs for blobs")
 	}
 
-	if err := wg.Wait(); err != nil {
-		return nil, errors.Wrap(err, "wait for RecoverCellsAndKZGProofs")
-	}
-
-	outSidecars, err := DataColumnSidecars(cellsAndProofs, PopulateFromSidecar(referenceSidecar))
+	outSidecars, err := DataColumnSidecars(cellsPerBlob, proofsPerBlob, PopulateFromSidecar(referenceSidecar))
 	if err != nil {
 		return nil, errors.Wrap(err, "data column sidecars from items")
 	}
@@ -113,18 +166,192 @@ func ReconstructDataColumnSidecars(verifiedRoSidecars []blocks.VerifiedRODataCol
 	return reconstructedVerifiedRoSidecars, nil
 }
 
-// ReconstructBlobs constructs verified read only blobs sidecars from verified read only blob sidecars.
+// reconstructIfNeeded validates the input data column sidecars and returns the prepared sidecars
+// (reconstructed if necessary). This function performs common validation and reconstruction logic used by
+// both ReconstructBlobs and ReconstructBlobSidecars.
+func reconstructIfNeeded(verifiedDataColumnSidecars []blocks.VerifiedRODataColumn) ([]blocks.VerifiedRODataColumn, error) {
+	if len(verifiedDataColumnSidecars) == 0 {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// Check if the sidecars are sorted by index and do not contain duplicates.
+	previousColumnIndex := verifiedDataColumnSidecars[0].Index
+	for _, dataColumnSidecar := range verifiedDataColumnSidecars[1:] {
+		columnIndex := dataColumnSidecar.Index
+		if columnIndex <= previousColumnIndex {
+			return nil, ErrDataColumnSidecarsNotSortedByIndex
+		}
+
+		previousColumnIndex = columnIndex
+	}
+
+	// Check if we have enough columns.
+	cellsPerBlob := fieldparams.CellsPerBlob
+	if len(verifiedDataColumnSidecars) < cellsPerBlob {
+		return nil, ErrNotEnoughDataColumnSidecars
+	}
+
+	// If all column sidecars corresponding to (non-extended) blobs are present, no need to reconstruct.
+	if verifiedDataColumnSidecars[cellsPerBlob-1].Index == uint64(cellsPerBlob-1) {
+		return verifiedDataColumnSidecars, nil
+	}
+
+	// We need to reconstruct the data column sidecars.
+	return ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
+}
+
+// ReconstructBlobSidecars constructs verified read only blobs sidecars from verified read only blob sidecars.
 // The following constraints must be satisfied:
 //   - All `dataColumnSidecars` has to be committed to the same block, and
 //   - `dataColumnSidecars` must be sorted by index and should not contain duplicates.
 //   - `dataColumnSidecars` must contain either all sidecars corresponding to (non-extended) blobs,
-//     or either enough sidecars to reconstruct the blobs.
-func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
+//   - either enough sidecars to reconstruct the blobs.
+func ReconstructBlobSidecars(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.VerifiedRODataColumn, indices []int) ([]*blocks.VerifiedROBlob, error) {
 	// Return early if no blobs are requested.
 	if len(indices) == 0 {
 		return nil, nil
 	}
 
+	// Validate and prepare data columns (reconstruct if necessary).
+	// This also checks if input is empty.
+	preparedDataColumnSidecars, err := reconstructIfNeeded(verifiedDataColumnSidecars)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the blob index is too high.
+	commitments, err := block.Block().Body().BlobKzgCommitments()
+	if err != nil {
+		return nil, errors.Wrap(err, "blob KZG commitments")
+	}
+
+	for _, blobIndex := range indices {
+		if blobIndex >= len(commitments) {
+			return nil, ErrBlobIndexTooHigh
+		}
+	}
+
+	// Check if the data column sidecars are aligned with the block.
+	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(preparedDataColumnSidecars))
+	for _, verifiedDataColumnSidecar := range preparedDataColumnSidecars {
+		dataColumnSidecar := verifiedDataColumnSidecar.RODataColumn
+		dataColumnSidecars = append(dataColumnSidecars, dataColumnSidecar)
+	}
+
+	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
+		return nil, errors.Wrap(err, "data columns align with block")
+	}
+
+	// Convert verified data column sidecars to verified blob sidecars.
+	blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, preparedDataColumnSidecars, indices)
+	if err != nil {
+		return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
+	}
+
+	return blobSidecars, nil
+}
+
+// ComputeCellsAndProofsFromFlat computes the cells and proofs from blobs and cell flat proofs.
+func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([][]kzg.Cell, [][]kzg.Proof, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+	blobCount := uint64(len(blobs))
+	cellProofsCount := uint64(len(cellProofs))
+
+	cellsCount := blobCount * numberOfColumns
+	if cellsCount != cellProofsCount {
+		return nil, nil, ErrBlobsCellsProofsMismatch
+	}
+
+	cellsPerBlob := make([][]kzg.Cell, 0, blobCount)
+	proofsPerBlob := make([][]kzg.Proof, 0, blobCount)
+	for i, blob := range blobs {
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blob) != len(kzgBlob) {
+			return nil, nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "compute cells")
+		}
+
+		var proofs []kzg.Proof
+		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
+				return nil, nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			proofs = append(proofs, kzgProof)
+		}
+
+		cellsPerBlob = append(cellsPerBlob, cells)
+		proofsPerBlob = append(proofsPerBlob, proofs)
+	}
+
+	return cellsPerBlob, proofsPerBlob, nil
+}
+
+// ComputeCellsAndProofsFromStructured computes the cells and proofs from blobs and cell proofs.
+func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([][]kzg.Cell, [][]kzg.Proof, error) {
+	numberOfColumns := params.BeaconConfig().NumberOfColumns
+
+	cellsPerBlob := make([][]kzg.Cell, 0, len(blobsAndProofs))
+	proofsPerBlob := make([][]kzg.Proof, 0, len(blobsAndProofs))
+	for _, blobAndProof := range blobsAndProofs {
+		if blobAndProof == nil {
+			return nil, nil, ErrNilBlobAndProof
+		}
+
+		var kzgBlob kzg.Blob
+		if copy(kzgBlob[:], blobAndProof.Blob) != len(kzgBlob) {
+			return nil, nil, errors.New("wrong blob size - should never happen")
+		}
+
+		// Compute the extended cells from the (non-extended) blob.
+		cells, err := kzg.ComputeCells(&kzgBlob)
+		if err != nil {
+			return nil, nil, errors.Wrap(err, "compute cells")
+		}
+
+		kzgProofs := make([]kzg.Proof, 0, numberOfColumns)
+		for _, kzgProofBytes := range blobAndProof.KzgProofs {
+			if len(kzgProofBytes) != kzg.BytesPerProof {
+				return nil, nil, errors.New("wrong KZG proof size - should never happen")
+			}
+
+			var kzgProof kzg.Proof
+			if copy(kzgProof[:], kzgProofBytes) != len(kzgProof) {
+				return nil, nil, errors.New("wrong copied KZG proof size - should never happen")
+			}
+
+			kzgProofs = append(kzgProofs, kzgProof)
+		}
+
+		cellsPerBlob = append(cellsPerBlob, cells)
+		proofsPerBlob = append(proofsPerBlob, kzgProofs)
+	}
+
+	return cellsPerBlob, proofsPerBlob, nil
+}
+
+// ReconstructBlobs reconstructs blobs from data column sidecars without computing KZG proofs or creating sidecars.
+// This is an optimized version for when only the blob data is needed (e.g., for the GetBlobs endpoint).
+// The following constraints must be satisfied:
+//   - All `dataColumnSidecars` must be committed to the same block, and
+//   - `dataColumnSidecars` must be sorted by index and should not contain duplicates.
+//   - `dataColumnSidecars` must contain either all sidecars corresponding to (non-extended) blobs,
+//   - or enough sidecars to reconstruct the blobs.
+func ReconstructBlobs(verifiedDataColumnSidecars []blocks.VerifiedRODataColumn, indices []int, blobCount int) ([][]byte, error) {
+	// If no specific indices are requested, populate with all blob indices.
+	if len(indices) == 0 {
+		indices = make([]int, blobCount)
+		for i := range indices {
+			indices[i] = i
+		}
+	}
+
 	if len(verifiedDataColumnSidecars) == 0 {
 		return nil, ErrNotEnoughDataColumnSidecars
 	}
@@ -146,136 +373,70 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 		return nil, ErrNotEnoughDataColumnSidecars
 	}
 
-	// Check if the blob index is too high.
-	commitments, err := block.Block().Body().BlobKzgCommitments()
-	if err != nil {
-		return nil, errors.Wrap(err, "blob KZG commitments")
+	// Verify that the actual blob count from the first sidecar matches the expected count
+	referenceSidecar := verifiedDataColumnSidecars[0]
+	actualBlobCount := len(referenceSidecar.Column)
+	if actualBlobCount != blobCount {
+		return nil, errors.Errorf("blob count mismatch: expected %d, got %d", blobCount, actualBlobCount)
 	}
 
+	// Check if the blob index is too high.
 	for _, blobIndex := range indices {
-		if blobIndex >= len(commitments) {
+		if blobIndex >= blobCount {
 			return nil, ErrBlobIndexTooHigh
 		}
 	}
 
-	// Check if the data column sidecars are aligned with the block.
-	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(verifiedDataColumnSidecars))
-	for _, verifiedDataColumnSidecar := range verifiedDataColumnSidecars {
-		dataColumnSidecar := verifiedDataColumnSidecar.RODataColumn
-		dataColumnSidecars = append(dataColumnSidecars, dataColumnSidecar)
+	// Check if all columns have the same length and are committed to the same block.
+	blockRoot := referenceSidecar.BlockRoot()
+	for _, sidecar := range verifiedDataColumnSidecars[1:] {
+		if len(sidecar.Column) != blobCount {
+			return nil, ErrColumnLengthsDiffer
+		}
+
+		if sidecar.BlockRoot() != blockRoot {
+			return nil, ErrBlockRootMismatch
+		}
 	}
 
-	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
-		return nil, errors.Wrap(err, "data columns align with block")
-	}
+	// Check if we have all non-extended columns (0..63) - if so, no reconstruction needed.
+	hasAllNonExtendedColumns := verifiedDataColumnSidecars[cellsPerBlob-1].Index == uint64(cellsPerBlob-1)
 
-	// If all column sidecars corresponding to (non-extended) blobs are present, no need to reconstruct.
-	if verifiedDataColumnSidecars[cellsPerBlob-1].Index == uint64(cellsPerBlob-1) {
-		// Convert verified data column sidecars to verified blob sidecars.
-		blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, verifiedDataColumnSidecars, indices)
+	var reconstructedCells map[int][]kzg.Cell
+	if !hasAllNonExtendedColumns {
+		// Need to reconstruct cells (but NOT proofs) for the requested blobs only.
+		var err error
+		reconstructedCells, err = recoverCellsForBlobs(verifiedDataColumnSidecars, indices)
 		if err != nil {
-			return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
+			return nil, errors.Wrap(err, "recover cells")
 		}
-
-		return blobSidecars, nil
 	}
 
-	// We need to reconstruct the data column sidecars.
-	reconstructedDataColumnSidecars, err := ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
-	if err != nil {
-		return nil, errors.Wrap(err, "reconstruct data column sidecars")
-	}
+	// Extract blob data without computing proofs.
+	blobs := make([][]byte, 0, len(indices))
+	for _, blobIndex := range indices {
+		var blob kzg.Blob
 
-	// Convert verified data column sidecars to verified blob sidecars.
-	blobSidecars, err := blobSidecarsFromDataColumnSidecars(block, reconstructedDataColumnSidecars, indices)
-	if err != nil {
-		return nil, errors.Wrap(err, "blob sidecars from data column sidecars")
-	}
-
-	return blobSidecars, nil
-}
-
-// ComputeCellsAndProofsFromFlat computes the cells and proofs from blobs and cell flat proofs.
-func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([]kzg.CellsAndProofs, error) {
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-	blobCount := uint64(len(blobs))
-	cellProofsCount := uint64(len(cellProofs))
-
-	cellsCount := blobCount * numberOfColumns
-	if cellsCount != cellProofsCount {
-		return nil, ErrBlobsCellsProofsMismatch
-	}
-
-	cellsAndProofs := make([]kzg.CellsAndProofs, 0, blobCount)
-	for i, blob := range blobs {
-		var kzgBlob kzg.Blob
-		if copy(kzgBlob[:], blob) != len(kzgBlob) {
-			return nil, errors.New("wrong blob size - should never happen")
-		}
-
-		// Compute the extended cells from the (non-extended) blob.
-		cells, err := kzg.ComputeCells(&kzgBlob)
-		if err != nil {
-			return nil, errors.Wrap(err, "compute cells")
-		}
-
-		var proofs []kzg.Proof
-		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
-			var kzgProof kzg.Proof
-			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
-				return nil, errors.New("wrong KZG proof size - should never happen")
+		// Compute the content of the blob.
+		for columnIndex := range cellsPerBlob {
+			var cell []byte
+			if hasAllNonExtendedColumns {
+				// Use existing cells from sidecars
+				cell = verifiedDataColumnSidecars[columnIndex].Column[blobIndex]
+			} else {
+				// Use reconstructed cells
+				cell = reconstructedCells[blobIndex][columnIndex][:]
 			}
 
-			proofs = append(proofs, kzgProof)
+			if copy(blob[kzg.BytesPerCell*columnIndex:], cell) != kzg.BytesPerCell {
+				return nil, errors.New("wrong cell size - should never happen")
+			}
 		}
 
-		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: proofs}
-		cellsAndProofs = append(cellsAndProofs, cellsProofs)
+		blobs = append(blobs, blob[:])
 	}
 
-	return cellsAndProofs, nil
-}
-
-// ComputeCellsAndProofs computes the cells and proofs from blobs and cell proofs.
-func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([]kzg.CellsAndProofs, error) {
-	numberOfColumns := params.BeaconConfig().NumberOfColumns
-
-	cellsAndProofs := make([]kzg.CellsAndProofs, 0, len(blobsAndProofs))
-	for _, blobAndProof := range blobsAndProofs {
-		if blobAndProof == nil {
-			return nil, ErrNilBlobAndProof
-		}
-
-		var kzgBlob kzg.Blob
-		if copy(kzgBlob[:], blobAndProof.Blob) != len(kzgBlob) {
-			return nil, errors.New("wrong blob size - should never happen")
-		}
-
-		// Compute the extended cells from the (non-extended) blob.
-		cells, err := kzg.ComputeCells(&kzgBlob)
-		if err != nil {
-			return nil, errors.Wrap(err, "compute cells")
-		}
-
-		kzgProofs := make([]kzg.Proof, 0, numberOfColumns)
-		for _, kzgProofBytes := range blobAndProof.KzgProofs {
-			if len(kzgProofBytes) != kzg.BytesPerProof {
-				return nil, errors.New("wrong KZG proof size - should never happen")
-			}
-
-			var kzgProof kzg.Proof
-			if copy(kzgProof[:], kzgProofBytes) != len(kzgProof) {
-				return nil, errors.New("wrong copied KZG proof size - should never happen")
-			}
-
-			kzgProofs = append(kzgProofs, kzgProof)
-		}
-
-		cellsProofs := kzg.CellsAndProofs{Cells: cells, Proofs: kzgProofs}
-		cellsAndProofs = append(cellsAndProofs, cellsProofs)
-	}
-
-	return cellsAndProofs, nil
+	return blobs, nil
 }
 
 // blobSidecarsFromDataColumnSidecars converts verified data column sidecars to verified blob sidecars.

beacon-chain/core/peerdas/reconstruction_helpers_test.go

@@ -0,0 +1,79 @@
+package peerdas_test
+
+// Test helpers for reconstruction tests
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/peerdas"
+	"github.com/OffchainLabs/prysm/v7/config/params"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/blocks"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
+	"github.com/OffchainLabs/prysm/v7/testing/require"
+	"github.com/OffchainLabs/prysm/v7/testing/util"
+)
+
+// testBlobSetup holds common test data for blob reconstruction tests.
+type testBlobSetup struct {
+	blobCount                     int
+	blobs                         []kzg.Blob
+	roBlock                       blocks.ROBlock
+	roDataColumnSidecars          []blocks.RODataColumn
+	verifiedRoDataColumnSidecars  []blocks.VerifiedRODataColumn
+}
+
+// setupTestBlobs creates a complete test setup with blobs, cells, proofs, and data column sidecars.
+func setupTestBlobs(t *testing.T, blobCount int) *testBlobSetup {
+	_, roBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [32]byte{}, 42, blobCount)
+
+	blobs := make([]kzg.Blob, blobCount)
+	for i := range blobCount {
+		copy(blobs[i][:], roBlobSidecars[i].Blob)
+	}
+
+	cellsPerBlob, proofsPerBlob := util.GenerateCellsAndProofs(t, blobs)
+
+	fs := util.SlotAtEpoch(t, params.BeaconConfig().FuluForkEpoch)
+	roBlock, _, _ := util.GenerateTestFuluBlockWithSidecars(t, blobCount, util.WithSlot(fs))
+
+	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(roBlock))
+	require.NoError(t, err)
+
+	verifiedRoSidecars := toVerifiedSidecars(roDataColumnSidecars)
+
+	return &testBlobSetup{
+		blobCount:                    blobCount,
+		blobs:                        blobs,
+		roBlock:                      roBlock,
+		roDataColumnSidecars:         roDataColumnSidecars,
+		verifiedRoDataColumnSidecars: verifiedRoSidecars,
+	}
+}
+
+// toVerifiedSidecars converts a slice of RODataColumn to VerifiedRODataColumn.
+func toVerifiedSidecars(roDataColumnSidecars []blocks.RODataColumn) []blocks.VerifiedRODataColumn {
+	verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))
+	for _, roDataColumnSidecar := range roDataColumnSidecars {
+		verifiedRoSidecar := blocks.NewVerifiedRODataColumn(roDataColumnSidecar)
+		verifiedRoSidecars = append(verifiedRoSidecars, verifiedRoSidecar)
+	}
+	return verifiedRoSidecars
+}
+
+// filterEvenIndexedSidecars returns only the even-indexed sidecars (0, 2, 4, ...).
+// This is useful for forcing reconstruction in tests.
+func filterEvenIndexedSidecars(sidecars []blocks.VerifiedRODataColumn) []blocks.VerifiedRODataColumn {
+	filtered := make([]blocks.VerifiedRODataColumn, 0, len(sidecars)/2)
+	for i := 0; i < len(sidecars); i += 2 {
+		filtered = append(filtered, sidecars[i])
+	}
+	return filtered
+}
+
+// setupFuluForkEpoch sets up the test configuration with Fulu fork after Electra.
+func setupFuluForkEpoch(t *testing.T) primitives.Slot {
+	params.SetupTestConfigCleanup(t)
+	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().ElectraForkEpoch + 4096*2
+	return util.SlotAtEpoch(t, params.BeaconConfig().FuluForkEpoch)
+}

beacon-chain/core/peerdas/reconstruction_test.go

@@ -124,7 +124,7 @@ func TestReconstructDataColumnSidecars(t *testing.T) {
 	})
 }
 
-func TestReconstructBlobs(t *testing.T) {
+func TestReconstructBlobSidecars(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	params.BeaconConfig().FuluForkEpoch = params.BeaconConfig().ElectraForkEpoch + 4096*2
 
@@ -133,13 +133,13 @@ func TestReconstructBlobs(t *testing.T) {
 	fs := util.SlotAtEpoch(t, params.BeaconConfig().FuluForkEpoch)
 
 	t.Run("no index", func(t *testing.T) {
-		actual, err := peerdas.ReconstructBlobs(emptyBlock, nil, nil)
+		actual, err := peerdas.ReconstructBlobSidecars(emptyBlock, nil, nil)
 		require.NoError(t, err)
 		require.IsNil(t, actual)
 	})
 
 	t.Run("empty input", func(t *testing.T) {
-		_, err := peerdas.ReconstructBlobs(emptyBlock, nil, []int{0})
+		_, err := peerdas.ReconstructBlobSidecars(emptyBlock, nil, []int{0})
 		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
 	})
 
@@ -149,7 +149,7 @@ func TestReconstructBlobs(t *testing.T) {
 		// Arbitrarily change the order of the sidecars.
 		verifiedRoSidecars[3], verifiedRoSidecars[2] = verifiedRoSidecars[2], verifiedRoSidecars[3]
 
-		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		_, err := peerdas.ReconstructBlobSidecars(emptyBlock, verifiedRoSidecars, []int{0})
 		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
 	})
 
@@ -159,7 +159,7 @@ func TestReconstructBlobs(t *testing.T) {
 		// [0, 1, 1, 3, 4, ...]
 		verifiedRoSidecars[2] = verifiedRoSidecars[1]
 
-		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		_, err := peerdas.ReconstructBlobSidecars(emptyBlock, verifiedRoSidecars, []int{0})
 		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
 	})
 
@@ -169,7 +169,7 @@ func TestReconstructBlobs(t *testing.T) {
 		// [0, 1, 2, 1, 4, ...]
 		verifiedRoSidecars[3] = verifiedRoSidecars[1]
 
-		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		_, err := peerdas.ReconstructBlobSidecars(emptyBlock, verifiedRoSidecars, []int{0})
 		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
 	})
 
@@ -177,7 +177,7 @@ func TestReconstructBlobs(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
 
 		inputSidecars := verifiedRoSidecars[:fieldparams.CellsPerBlob-1]
-		_, err := peerdas.ReconstructBlobs(emptyBlock, inputSidecars, []int{0})
+		_, err := peerdas.ReconstructBlobSidecars(emptyBlock, inputSidecars, []int{0})
 		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
 	})
 
@@ -186,7 +186,7 @@ func TestReconstructBlobs(t *testing.T) {
 
 		roBlock, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, blobCount)
 
-		_, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, []int{1, blobCount})
+		_, err := peerdas.ReconstructBlobSidecars(roBlock, verifiedRoSidecars, []int{1, blobCount})
 		require.ErrorIs(t, err, peerdas.ErrBlobIndexTooHigh)
 	})
 
@@ -194,7 +194,7 @@ func TestReconstructBlobs(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{1}), util.WithSlot(fs))
 		roBlock, _, _ := util.GenerateTestFuluBlockWithSidecars(t, 3, util.WithParentRoot([fieldparams.RootLength]byte{2}), util.WithSlot(fs))
 
-		_, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, []int{0})
+		_, err := peerdas.ReconstructBlobSidecars(roBlock, verifiedRoSidecars, []int{0})
 		require.ErrorContains(t, peerdas.ErrRootMismatch.Error(), err)
 	})
 
@@ -207,7 +207,8 @@ func TestReconstructBlobs(t *testing.T) {
 		// Compute cells and proofs from blob sidecars.
 		var wg errgroup.Group
 		blobs := make([][]byte, blobCount)
-		inputCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		inputCellsPerBlob := make([][]kzg.Cell, blobCount)
+		inputProofsPerBlob := make([][]kzg.Proof, blobCount)
 		for i := range blobCount {
 			blob := roBlobSidecars[i].Blob
 			blobs[i] = blob
@@ -217,14 +218,15 @@ func TestReconstructBlobs(t *testing.T) {
 				count := copy(kzgBlob[:], blob)
 				require.Equal(t, len(kzgBlob), count)
 
-				cp, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 				if err != nil {
 					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
 				}
 
 				// It is safe for multiple goroutines to concurrently write to the same slice,
 				// as long as they are writing to different indices, which is the case here.
-				inputCellsAndProofs[i] = cp
+				inputCellsPerBlob[i] = cells
+				inputProofsPerBlob[i] = proofs
 
 				return nil
 			})
@@ -235,18 +237,18 @@ func TestReconstructBlobs(t *testing.T) {
 
 		// Flatten proofs.
 		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
-		for _, cp := range inputCellsAndProofs {
-			for _, proof := range cp.Proofs {
+		for _, proofs := range inputProofsPerBlob {
+			for _, proof := range proofs {
 				cellProofs = append(cellProofs, proof[:])
 			}
 		}
 
 		// Compute celles and proofs from the blobs and cell proofs.
-		cellsAndProofs, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
+		cellsPerBlob, proofsPerBlob, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
 		require.NoError(t, err)
 
 		// Construct data column sidears from the signed block and cells and proofs.
-		roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(roBlock))
+		roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(roBlock))
 		require.NoError(t, err)
 
 		// Convert to verified data column sidecars.
@@ -260,7 +262,7 @@ func TestReconstructBlobs(t *testing.T) {
 
 		t.Run("no reconstruction needed", func(t *testing.T) {
 			// Reconstruct blobs.
-			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(roBlock, verifiedRoSidecars, indices)
+			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobSidecars(roBlock, verifiedRoSidecars, indices)
 			require.NoError(t, err)
 
 			// Compare blobs.
@@ -280,7 +282,7 @@ func TestReconstructBlobs(t *testing.T) {
 			}
 
 			// Reconstruct blobs.
-			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(roBlock, filteredSidecars, indices)
+			reconstructedVerifiedRoBlobSidecars, err := peerdas.ReconstructBlobSidecars(roBlock, filteredSidecars, indices)
 			require.NoError(t, err)
 
 			// Compare blobs.
@@ -296,6 +298,135 @@ func TestReconstructBlobs(t *testing.T) {
 
 }
 
+func TestReconstructBlobs(t *testing.T) {
+	setupFuluForkEpoch(t)
+	require.NoError(t, kzg.Start())
+
+	t.Run("empty indices with blobCount > 0", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Call with empty indices - should return all blobs
+		reconstructedBlobs, err := peerdas.ReconstructBlobs(setup.verifiedRoDataColumnSidecars, []int{}, setup.blobCount)
+		require.NoError(t, err)
+		require.Equal(t, setup.blobCount, len(reconstructedBlobs))
+
+		// Verify each blob matches
+		for i := 0; i < setup.blobCount; i++ {
+			require.DeepEqual(t, setup.blobs[i][:], reconstructedBlobs[i])
+		}
+	})
+
+	t.Run("specific indices", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Request only blobs at indices 0 and 2
+		indices := []int{0, 2}
+		reconstructedBlobs, err := peerdas.ReconstructBlobs(setup.verifiedRoDataColumnSidecars, indices, setup.blobCount)
+		require.NoError(t, err)
+		require.Equal(t, len(indices), len(reconstructedBlobs))
+
+		// Verify requested blobs match
+		for i, blobIndex := range indices {
+			require.DeepEqual(t, setup.blobs[blobIndex][:], reconstructedBlobs[i])
+		}
+	})
+
+	t.Run("blob count mismatch", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Pass wrong blob count
+		wrongBlobCount := 5
+		_, err := peerdas.ReconstructBlobs(setup.verifiedRoDataColumnSidecars, []int{0}, wrongBlobCount)
+		require.ErrorContains(t, "blob count mismatch", err)
+	})
+
+	t.Run("empty data columns", func(t *testing.T) {
+		_, err := peerdas.ReconstructBlobs([]blocks.VerifiedRODataColumn{}, []int{0}, 1)
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("index too high", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Request blob index that's too high
+		_, err := peerdas.ReconstructBlobs(setup.verifiedRoDataColumnSidecars, []int{setup.blobCount}, setup.blobCount)
+		require.ErrorIs(t, err, peerdas.ErrBlobIndexTooHigh)
+	})
+
+	t.Run("not enough columns", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Only provide 63 columns (need at least 64)
+		inputSidecars := setup.verifiedRoDataColumnSidecars[:fieldparams.CellsPerBlob-1]
+		_, err := peerdas.ReconstructBlobs(inputSidecars, []int{0}, setup.blobCount)
+		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
+	})
+
+	t.Run("not sorted", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Swap two sidecars to make them unsorted
+		setup.verifiedRoDataColumnSidecars[3], setup.verifiedRoDataColumnSidecars[2] = setup.verifiedRoDataColumnSidecars[2], setup.verifiedRoDataColumnSidecars[3]
+
+		_, err := peerdas.ReconstructBlobs(setup.verifiedRoDataColumnSidecars, []int{0}, setup.blobCount)
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
+	t.Run("with reconstruction needed", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Keep only even-indexed columns (will need reconstruction)
+		filteredSidecars := filterEvenIndexedSidecars(setup.verifiedRoDataColumnSidecars)
+
+		// Reconstruct all blobs
+		reconstructedBlobs, err := peerdas.ReconstructBlobs(filteredSidecars, []int{}, setup.blobCount)
+		require.NoError(t, err)
+		require.Equal(t, setup.blobCount, len(reconstructedBlobs))
+
+		// Verify all blobs match
+		for i := range setup.blobCount {
+			require.DeepEqual(t, setup.blobs[i][:], reconstructedBlobs[i])
+		}
+	})
+
+	t.Run("no reconstruction needed - all non-extended columns present", func(t *testing.T) {
+		setup := setupTestBlobs(t, 3)
+
+		// Use all columns (no reconstruction needed since we have all non-extended columns 0-63)
+		reconstructedBlobs, err := peerdas.ReconstructBlobs(setup.verifiedRoDataColumnSidecars, []int{1}, setup.blobCount)
+		require.NoError(t, err)
+		require.Equal(t, 1, len(reconstructedBlobs))
+
+		// Verify blob matches
+		require.DeepEqual(t, setup.blobs[1][:], reconstructedBlobs[0])
+	})
+
+	t.Run("reconstruct only requested blob indices", func(t *testing.T) {
+		// This test verifies the optimization: when reconstruction is needed and specific
+		// blob indices are requested, we only reconstruct those blobs, not all of them.
+		setup := setupTestBlobs(t, 6)
+
+		// Keep only even-indexed columns (will need reconstruction)
+		// This ensures we don't have all non-extended columns (0-63)
+		filteredSidecars := filterEvenIndexedSidecars(setup.verifiedRoDataColumnSidecars)
+
+		// Request only specific blob indices (not all of them)
+		requestedIndices := []int{1, 3, 5}
+		reconstructedBlobs, err := peerdas.ReconstructBlobs(filteredSidecars, requestedIndices, setup.blobCount)
+		require.NoError(t, err)
+
+		// Should only get the requested blobs back (not all 6)
+		require.Equal(t, len(requestedIndices), len(reconstructedBlobs),
+			"should only reconstruct requested blobs, not all blobs")
+
+		// Verify each requested blob matches the original
+		for i, blobIndex := range requestedIndices {
+			require.DeepEqual(t, setup.blobs[blobIndex][:], reconstructedBlobs[i],
+				"blob at index %d should match", blobIndex)
+		}
+	})
+}
+
 func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 	// Start the trusted setup.
 	err := kzg.Start()
@@ -310,7 +441,7 @@ func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 		// Create proofs for 2 blobs worth of columns
 		cellProofs := make([][]byte, 2*numberOfColumns)
 
-		_, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
+		_, _, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
 		require.ErrorIs(t, err, peerdas.ErrBlobsCellsProofsMismatch)
 	})
 
@@ -323,7 +454,8 @@ func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 
 		// Extract blobs and compute expected cells and proofs
 		blobs := make([][]byte, blobCount)
-		expectedCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		expectedCellsPerBlob := make([][]kzg.Cell, blobCount)
+		expectedProofsPerBlob := make([][]kzg.Proof, blobCount)
 		var wg errgroup.Group
 
 		for i := range blobCount {
@@ -335,12 +467,13 @@ func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 				count := copy(kzgBlob[:], blob)
 				require.Equal(t, len(kzgBlob), count)
 
-				cp, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 				if err != nil {
 					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
 				}
 
-				expectedCellsAndProofs[i] = cp
+				expectedCellsPerBlob[i] = cells
+				expectedProofsPerBlob[i] = proofs
 				return nil
 			})
 		}
@@ -350,30 +483,30 @@ func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 
 		// Flatten proofs
 		cellProofs := make([][]byte, 0, blobCount*numberOfColumns)
-		for _, cp := range expectedCellsAndProofs {
-			for _, proof := range cp.Proofs {
+		for _, proofs := range expectedProofsPerBlob {
+			for _, proof := range proofs {
 				cellProofs = append(cellProofs, proof[:])
 			}
 		}
 
 		// Test ComputeCellsAndProofs
-		actualCellsAndProofs, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
+		actualCellsPerBlob, actualProofsPerBlob, err := peerdas.ComputeCellsAndProofsFromFlat(blobs, cellProofs)
 		require.NoError(t, err)
-		require.Equal(t, blobCount, len(actualCellsAndProofs))
+		require.Equal(t, blobCount, len(actualCellsPerBlob))
 
 		// Verify the results match expected
 		for i := range blobCount {
-			require.Equal(t, len(expectedCellsAndProofs[i].Cells), len(actualCellsAndProofs[i].Cells))
-			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), len(actualCellsAndProofs[i].Proofs))
+			require.Equal(t, len(expectedCellsPerBlob[i]), len(actualCellsPerBlob[i]))
+			require.Equal(t, len(expectedProofsPerBlob[i]), len(actualProofsPerBlob[i]))
 
 			// Compare cells
-			for j, expectedCell := range expectedCellsAndProofs[i].Cells {
-				require.Equal(t, expectedCell, actualCellsAndProofs[i].Cells[j])
+			for j, expectedCell := range expectedCellsPerBlob[i] {
+				require.Equal(t, expectedCell, actualCellsPerBlob[i][j])
 			}
 
 			// Compare proofs
-			for j, expectedProof := range expectedCellsAndProofs[i].Proofs {
-				require.Equal(t, expectedProof, actualCellsAndProofs[i].Proofs[j])
+			for j, expectedProof := range expectedProofsPerBlob[i] {
+				require.Equal(t, expectedProof, actualProofsPerBlob[i][j])
 			}
 		}
 	})
@@ -381,7 +514,7 @@ func TestComputeCellsAndProofsFromFlat(t *testing.T) {
 
 func TestComputeCellsAndProofsFromStructured(t *testing.T) {
 	t.Run("nil blob and proof", func(t *testing.T) {
-		_, err := peerdas.ComputeCellsAndProofsFromStructured([]*pb.BlobAndProofV2{nil})
+		_, _, err := peerdas.ComputeCellsAndProofsFromStructured([]*pb.BlobAndProofV2{nil})
 		require.ErrorIs(t, err, peerdas.ErrNilBlobAndProof)
 	})
 
@@ -397,7 +530,8 @@ func TestComputeCellsAndProofsFromStructured(t *testing.T) {
 
 		// Extract blobs and compute expected cells and proofs
 		blobsAndProofs := make([]*pb.BlobAndProofV2, blobCount)
-		expectedCellsAndProofs := make([]kzg.CellsAndProofs, blobCount)
+		expectedCellsPerBlob := make([][]kzg.Cell, blobCount)
+		expectedProofsPerBlob := make([][]kzg.Proof, blobCount)
 
 		var wg errgroup.Group
 		for i := range blobCount {
@@ -408,14 +542,15 @@ func TestComputeCellsAndProofsFromStructured(t *testing.T) {
 				count := copy(kzgBlob[:], blob)
 				require.Equal(t, len(kzgBlob), count)
 
-				cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+				cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 				if err != nil {
 					return errors.Wrapf(err, "compute cells and kzg proofs for blob %d", i)
 				}
-				expectedCellsAndProofs[i] = cellsAndProofs
+				expectedCellsPerBlob[i] = cells
+				expectedProofsPerBlob[i] = proofs
 
-				kzgProofs := make([][]byte, 0, len(cellsAndProofs.Proofs))
-				for _, proof := range cellsAndProofs.Proofs {
+				kzgProofs := make([][]byte, 0, len(proofs))
+				for _, proof := range proofs {
 					kzgProofs = append(kzgProofs, proof[:])
 				}
 
@@ -433,24 +568,24 @@ func TestComputeCellsAndProofsFromStructured(t *testing.T) {
 		require.NoError(t, err)
 
 		// Test ComputeCellsAndProofs
-		actualCellsAndProofs, err := peerdas.ComputeCellsAndProofsFromStructured(blobsAndProofs)
+		actualCellsPerBlob, actualProofsPerBlob, err := peerdas.ComputeCellsAndProofsFromStructured(blobsAndProofs)
 		require.NoError(t, err)
-		require.Equal(t, blobCount, len(actualCellsAndProofs))
+		require.Equal(t, blobCount, len(actualCellsPerBlob))
 
 		// Verify the results match expected
 		for i := range blobCount {
-			require.Equal(t, len(expectedCellsAndProofs[i].Cells), len(actualCellsAndProofs[i].Cells))
-			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), len(actualCellsAndProofs[i].Proofs))
-			require.Equal(t, len(expectedCellsAndProofs[i].Proofs), cap(actualCellsAndProofs[i].Proofs))
+			require.Equal(t, len(expectedCellsPerBlob[i]), len(actualCellsPerBlob[i]))
+			require.Equal(t, len(expectedProofsPerBlob[i]), len(actualProofsPerBlob[i]))
+			require.Equal(t, len(expectedProofsPerBlob[i]), cap(actualProofsPerBlob[i]))
 
 			// Compare cells
-			for j, expectedCell := range expectedCellsAndProofs[i].Cells {
-				require.Equal(t, expectedCell, actualCellsAndProofs[i].Cells[j])
+			for j, expectedCell := range expectedCellsPerBlob[i] {
+				require.Equal(t, expectedCell, actualCellsPerBlob[i][j])
 			}
 
 			// Compare proofs
-			for j, expectedProof := range expectedCellsAndProofs[i].Proofs {
-				require.Equal(t, expectedProof, actualCellsAndProofs[i].Proofs[j])
+			for j, expectedProof := range expectedProofsPerBlob[i] {
+				require.Equal(t, expectedProof, actualProofsPerBlob[i][j])
 			}
 		}
 	})

beacon-chain/core/peerdas/validator.go

@@ -93,19 +93,20 @@ func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validat
 	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroups), nil
 }
 
-// DataColumnSidecars, given ConstructionPopulator and the cells/proofs associated with each blob in the
+// DataColumnSidecars given ConstructionPopulator and the cells/proofs associated with each blob in the
 // block, assembles sidecars which can be distributed to peers.
+// cellsPerBlob and proofsPerBlob are parallel slices where each index represents a blob sidecar.
 // This is an adapted version of
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars,
 // which is designed to be used both when constructing sidecars from a block and from a sidecar, replacing
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_block and
 // https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/validator.md#get_data_column_sidecars_from_column_sidecar
-func DataColumnSidecars(rows []kzg.CellsAndProofs, src ConstructionPopulator) ([]blocks.RODataColumn, error) {
-	if len(rows) == 0 {
+func DataColumnSidecars(cellsPerBlob [][]kzg.Cell, proofsPerBlob [][]kzg.Proof, src ConstructionPopulator) ([]blocks.RODataColumn, error) {
+	if len(cellsPerBlob) == 0 {
 		return nil, nil
 	}
 	start := time.Now()
-	cells, proofs, err := rotateRowsToCols(rows, params.BeaconConfig().NumberOfColumns)
+	cells, proofs, err := rotateRowsToCols(cellsPerBlob, proofsPerBlob, params.BeaconConfig().NumberOfColumns)
 	if err != nil {
 		return nil, errors.Wrap(err, "rotate cells and proofs")
 	}
@@ -197,26 +198,31 @@ func (b *BlockReconstructionSource) extract() (*blockInfo, error) {
 
 // rotateRowsToCols takes a 2D slice of cells and proofs, where the x is rows (blobs) and y is columns,
 // and returns a 2D slice where x is columns and y is rows.
-func rotateRowsToCols(rows []kzg.CellsAndProofs, numCols uint64) ([][][]byte, [][][]byte, error) {
-	if len(rows) == 0 {
+func rotateRowsToCols(cellsPerBlob [][]kzg.Cell, proofsPerBlob [][]kzg.Proof, numCols uint64) ([][][]byte, [][][]byte, error) {
+	if len(cellsPerBlob) == 0 {
 		return nil, nil, nil
 	}
+	if len(cellsPerBlob) != len(proofsPerBlob) {
+		return nil, nil, errors.New("cells and proofs length mismatch")
+	}
 	cellCols := make([][][]byte, numCols)
 	proofCols := make([][][]byte, numCols)
-	for i, cp := range rows {
-		if uint64(len(cp.Cells)) != numCols {
+	for i := range cellsPerBlob {
+		cells := cellsPerBlob[i]
+		proofs := proofsPerBlob[i]
+		if uint64(len(cells)) != numCols {
 			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough cells")
 		}
-		if len(cp.Cells) != len(cp.Proofs) {
+		if len(cells) != len(proofs) {
 			return nil, nil, errors.Wrap(ErrNotEnoughDataColumnSidecars, "not enough proofs")
 		}
 		for j := uint64(0); j < numCols; j++ {
 			if i == 0 {
-				cellCols[j] = make([][]byte, len(rows))
-				proofCols[j] = make([][]byte, len(rows))
+				cellCols[j] = make([][]byte, len(cellsPerBlob))
+				proofCols[j] = make([][]byte, len(cellsPerBlob))
 			}
-			cellCols[j][i] = cp.Cells[j][:]
-			proofCols[j][i] = cp.Proofs[j][:]
+			cellCols[j][i] = cells[j][:]
+			proofCols[j][i] = proofs[j][:]
 		}
 	}
 	return cellCols, proofCols, nil

beacon-chain/core/peerdas/validator_test.go

@@ -68,16 +68,16 @@ func TestDataColumnSidecars(t *testing.T) {
 		require.NoError(t, err)
 
 		// Create cells and proofs.
-		cellsAndProofs := []kzg.CellsAndProofs{
-			{
-				Cells:  make([]kzg.Cell, params.BeaconConfig().NumberOfColumns),
-				Proofs: make([]kzg.Proof, params.BeaconConfig().NumberOfColumns),
-			},
+		cellsPerBlob := [][]kzg.Cell{
+			make([]kzg.Cell, params.BeaconConfig().NumberOfColumns),
+		}
+		proofsPerBlob := [][]kzg.Proof{
+			make([]kzg.Proof, params.BeaconConfig().NumberOfColumns),
 		}
 
 		rob, err := blocks.NewROBlock(signedBeaconBlock)
 		require.NoError(t, err)
-		_, err = peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		_, err = peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 		require.ErrorIs(t, err, peerdas.ErrSizeMismatch)
 	})
 
@@ -92,18 +92,18 @@ func TestDataColumnSidecars(t *testing.T) {
 
 		// Create cells and proofs with insufficient cells for the number of columns.
 		// This simulates a scenario where cellsAndProofs has fewer cells than expected columns.
-		cellsAndProofs := []kzg.CellsAndProofs{
-			{
-				Cells:  make([]kzg.Cell, 10),  // Only 10 cells
-				Proofs: make([]kzg.Proof, 10), // Only 10 proofs
-			},
+		cellsPerBlob := [][]kzg.Cell{
+			make([]kzg.Cell, 10), // Only 10 cells
+		}
+		proofsPerBlob := [][]kzg.Proof{
+			make([]kzg.Proof, 10), // Only 10 proofs
 		}
 
 		// This should fail because the function will try to access columns up to NumberOfColumns
 		// but we only have 10 cells/proofs.
 		rob, err := blocks.NewROBlock(signedBeaconBlock)
 		require.NoError(t, err)
-		_, err = peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		_, err = peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
 	})
 
@@ -118,17 +118,17 @@ func TestDataColumnSidecars(t *testing.T) {
 
 		// Create cells and proofs with sufficient cells but insufficient proofs.
 		numberOfColumns := params.BeaconConfig().NumberOfColumns
-		cellsAndProofs := []kzg.CellsAndProofs{
-			{
-				Cells:  make([]kzg.Cell, numberOfColumns),
-				Proofs: make([]kzg.Proof, 5), // Only 5 proofs, less than columns
-			},
+		cellsPerBlob := [][]kzg.Cell{
+			make([]kzg.Cell, numberOfColumns),
+		}
+		proofsPerBlob := [][]kzg.Proof{
+			make([]kzg.Proof, 5), // Only 5 proofs, less than columns
 		}
 
 		// This should fail when trying to access proof beyond index 4.
 		rob, err := blocks.NewROBlock(signedBeaconBlock)
 		require.NoError(t, err)
-		_, err = peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		_, err = peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 		require.ErrorIs(t, err, peerdas.ErrNotEnoughDataColumnSidecars)
 		require.ErrorContains(t, "not enough proofs", err)
 	})
@@ -150,28 +150,26 @@ func TestDataColumnSidecars(t *testing.T) {
 
 		// Create cells and proofs with correct dimensions.
 		numberOfColumns := params.BeaconConfig().NumberOfColumns
-		cellsAndProofs := []kzg.CellsAndProofs{
-			{
-				Cells:  make([]kzg.Cell, numberOfColumns),
-				Proofs: make([]kzg.Proof, numberOfColumns),
-			},
-			{
-				Cells:  make([]kzg.Cell, numberOfColumns),
-				Proofs: make([]kzg.Proof, numberOfColumns),
-			},
+		cellsPerBlob := [][]kzg.Cell{
+			make([]kzg.Cell, numberOfColumns),
+			make([]kzg.Cell, numberOfColumns),
+		}
+		proofsPerBlob := [][]kzg.Proof{
+			make([]kzg.Proof, numberOfColumns),
+			make([]kzg.Proof, numberOfColumns),
 		}
 
 		// Set distinct values in cells and proofs for testing
 		for i := range numberOfColumns {
-			cellsAndProofs[0].Cells[i][0] = byte(i)
-			cellsAndProofs[0].Proofs[i][0] = byte(i)
-			cellsAndProofs[1].Cells[i][0] = byte(i + 128)
-			cellsAndProofs[1].Proofs[i][0] = byte(i + 128)
+			cellsPerBlob[0][i][0] = byte(i)
+			proofsPerBlob[0][i][0] = byte(i)
+			cellsPerBlob[1][i][0] = byte(i + 128)
+			proofsPerBlob[1][i][0] = byte(i + 128)
 		}
 
 		rob, err := blocks.NewROBlock(signedBeaconBlock)
 		require.NoError(t, err)
-		sidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+		sidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 		require.NoError(t, err)
 		require.NotNil(t, sidecars)
 		require.Equal(t, int(numberOfColumns), len(sidecars))
@@ -215,28 +213,26 @@ func TestReconstructionSource(t *testing.T) {
 
 	// Create cells and proofs with correct dimensions.
 	numberOfColumns := params.BeaconConfig().NumberOfColumns
-	cellsAndProofs := []kzg.CellsAndProofs{
-		{
-			Cells:  make([]kzg.Cell, numberOfColumns),
-			Proofs: make([]kzg.Proof, numberOfColumns),
-		},
-		{
-			Cells:  make([]kzg.Cell, numberOfColumns),
-			Proofs: make([]kzg.Proof, numberOfColumns),
-		},
+	cellsPerBlob := [][]kzg.Cell{
+		make([]kzg.Cell, numberOfColumns),
+		make([]kzg.Cell, numberOfColumns),
+	}
+	proofsPerBlob := [][]kzg.Proof{
+		make([]kzg.Proof, numberOfColumns),
+		make([]kzg.Proof, numberOfColumns),
 	}
 
 	// Set distinct values in cells and proofs for testing
 	for i := range numberOfColumns {
-		cellsAndProofs[0].Cells[i][0] = byte(i)
-		cellsAndProofs[0].Proofs[i][0] = byte(i)
-		cellsAndProofs[1].Cells[i][0] = byte(i + 128)
-		cellsAndProofs[1].Proofs[i][0] = byte(i + 128)
+		cellsPerBlob[0][i][0] = byte(i)
+		proofsPerBlob[0][i][0] = byte(i)
+		cellsPerBlob[1][i][0] = byte(i + 128)
+		proofsPerBlob[1][i][0] = byte(i + 128)
 	}
 
 	rob, err := blocks.NewROBlock(signedBeaconBlock)
 	require.NoError(t, err)
-	sidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+	sidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 	require.NoError(t, err)
 	require.NotNil(t, sidecars)
 	require.Equal(t, int(numberOfColumns), len(sidecars))

beacon-chain/execution/engine_client.go

@@ -660,18 +660,18 @@ func (s *Service) ConstructDataColumnSidecars(ctx context.Context, populator pee
 		return nil, wrapWithBlockRoot(err, root, "commitments")
 	}
 
-	cellsAndProofs, err := s.fetchCellsAndProofsFromExecution(ctx, commitments)
+	cellsPerBlob, proofsPerBlob, err := s.fetchCellsAndProofsFromExecution(ctx, commitments)
 	if err != nil {
 		return nil, wrapWithBlockRoot(err, root, "fetch cells and proofs from execution client")
 	}
 
 	// Return early if nothing is returned from the EL.
-	if len(cellsAndProofs) == 0 {
+	if len(cellsPerBlob) == 0 {
 		return nil, nil
 	}
 
 	// Construct data column sidears from the signed block and cells and proofs.
-	roSidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, populator)
+	roSidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, populator)
 	if err != nil {
 		return nil, wrapWithBlockRoot(err, populator.Root(), "data column sidcars from column sidecar")
 	}
@@ -684,7 +684,7 @@ func (s *Service) ConstructDataColumnSidecars(ctx context.Context, populator pee
 }
 
 // fetchCellsAndProofsFromExecution fetches cells and proofs from the execution client (using engine_getBlobsV2 execution API method)
-func (s *Service) fetchCellsAndProofsFromExecution(ctx context.Context, kzgCommitments [][]byte) ([]kzg.CellsAndProofs, error) {
+func (s *Service) fetchCellsAndProofsFromExecution(ctx context.Context, kzgCommitments [][]byte) ([][]kzg.Cell, [][]kzg.Proof, error) {
 	// Collect KZG hashes for all blobs.
 	versionedHashes := make([]common.Hash, 0, len(kzgCommitments))
 	for _, commitment := range kzgCommitments {
@@ -695,21 +695,21 @@ func (s *Service) fetchCellsAndProofsFromExecution(ctx context.Context, kzgCommi
 	// Fetch all blobsAndCellsProofs from the execution client.
 	blobAndProofV2s, err := s.GetBlobsV2(ctx, versionedHashes)
 	if err != nil {
-		return nil, errors.Wrapf(err, "get blobs V2")
+		return nil, nil, errors.Wrapf(err, "get blobs V2")
 	}
 
 	// Return early if nothing is returned from the EL.
 	if len(blobAndProofV2s) == 0 {
-		return nil, nil
+		return nil, nil, nil
 	}
 
 	// Compute cells and proofs from the blobs and cell proofs.
-	cellsAndProofs, err := peerdas.ComputeCellsAndProofsFromStructured(blobAndProofV2s)
+	cellsPerBlob, proofsPerBlob, err := peerdas.ComputeCellsAndProofsFromStructured(blobAndProofV2s)
 	if err != nil {
-		return nil, errors.Wrap(err, "compute cells and proofs")
+		return nil, nil, errors.Wrap(err, "compute cells and proofs")
 	}
 
-	return cellsAndProofs, nil
+	return cellsPerBlob, proofsPerBlob, nil
 }
 
 // upgradeSidecarsToVerifiedSidecars upgrades a list of data column sidecars into verified data column sidecars.

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

@@ -3786,12 +3786,12 @@ func Test_validateBlobs(t *testing.T) {
 		numberOfColumns := params.BeaconConfig().NumberOfColumns
 		cellProofs := make([][]byte, uint64(blobCount)*numberOfColumns)
 		for blobIdx := 0; blobIdx < blobCount; blobIdx++ {
-			cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlobs[blobIdx])
+			_, proofs, 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][:]
+				cellProofs[cellProofIdx] = proofs[colIdx][:]
 			}
 		}
 

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

@@ -38,7 +38,7 @@ func (s *Server) Blobs(w http.ResponseWriter, r *http.Request) {
 	segments := strings.Split(r.URL.Path, "/")
 	blockId := segments[len(segments)-1]
 
-	verifiedBlobs, rpcErr := s.Blocker.Blobs(ctx, blockId, options.WithIndices(indices))
+	verifiedBlobs, rpcErr := s.Blocker.BlobSidecars(ctx, blockId, options.WithIndices(indices))
 	if rpcErr != nil {
 		code := core.ErrorReasonToHTTP(rpcErr.Reason)
 		switch code {
@@ -134,9 +134,6 @@ func (s *Server) GetBlobs(w http.ResponseWriter, r *http.Request) {
 	segments := strings.Split(r.URL.Path, "/")
 	blockId := segments[len(segments)-1]
 
-	var verifiedBlobs []*blocks.VerifiedROBlob
-	var rpcErr *core.RpcError
-
 	// Check if versioned_hashes parameter is provided
 	versionedHashesStr := r.URL.Query()["versioned_hashes"]
 	versionedHashes := make([][]byte, len(versionedHashesStr))
@@ -149,7 +146,7 @@ func (s *Server) GetBlobs(w http.ResponseWriter, r *http.Request) {
 			versionedHashes[i] = hash
 		}
 	}
-	verifiedBlobs, rpcErr = s.Blocker.Blobs(ctx, blockId, options.WithVersionedHashes(versionedHashes))
+	blobsData, rpcErr := s.Blocker.Blobs(ctx, blockId, options.WithVersionedHashes(versionedHashes))
 	if rpcErr != nil {
 		code := core.ErrorReasonToHTTP(rpcErr.Reason)
 		switch code {
@@ -175,9 +172,9 @@ func (s *Server) GetBlobs(w http.ResponseWriter, r *http.Request) {
 
 	if httputil.RespondWithSsz(r) {
 		sszLen := fieldparams.BlobSize
-		sszData := make([]byte, len(verifiedBlobs)*sszLen)
-		for i := range verifiedBlobs {
-			copy(sszData[i*sszLen:(i+1)*sszLen], verifiedBlobs[i].Blob)
+		sszData := make([]byte, len(blobsData)*sszLen)
+		for i := range blobsData {
+			copy(sszData[i*sszLen:(i+1)*sszLen], blobsData[i])
 		}
 
 		w.Header().Set(api.VersionHeader, version.String(blk.Version()))
@@ -196,9 +193,9 @@ func (s *Server) GetBlobs(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	data := make([]string, len(verifiedBlobs))
-	for i, v := range verifiedBlobs {
-		data[i] = hexutil.Encode(v.Blob)
+	data := make([]string, len(blobsData))
+	for i, blob := range blobsData {
+		data[i] = hexutil.Encode(blob)
 	}
 	resp := &structs.GetBlobsResponse{
 		Data:                data,

beacon-chain/rpc/lookup/blocker.go

@@ -60,7 +60,8 @@ func (e BlockIdParseError) Error() string {
 // Blocker is responsible for retrieving blocks.
 type Blocker interface {
 	Block(ctx context.Context, id []byte) (interfaces.ReadOnlySignedBeaconBlock, error)
-	Blobs(ctx context.Context, id string, opts ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError)
+	BlobSidecars(ctx context.Context, id string, opts ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError)
+	Blobs(ctx context.Context, id string, opts ...options.BlobsOption) ([][]byte, *core.RpcError)
 	DataColumns(ctx context.Context, id string, indices []int) ([]blocks.VerifiedRODataColumn, *core.RpcError)
 }
 
@@ -224,23 +225,18 @@ func (p *BeaconDbBlocker) Block(ctx context.Context, id []byte) (interfaces.Read
 	return blk, nil
 }
 
-// Blobs returns the fetched blobs for a given block ID with configurable options.
-// Options can specify either blob indices or versioned hashes for retrieval.
-// The identifier can be one of:
-//   - "head" (canonical head in node's view)
-//   - "genesis"
-//   - "finalized"
-//   - "justified"
-//   - <slot>
-//   - <hex encoded block root with '0x' prefix>
-//   - <block root>
-//
-// cases:
-//   - no block, 404
-//   - block exists, has commitments, inside retention period (greater of protocol- or user-specified) serve then w/ 200 unless we hit an error reading them.
-//     we are technically not supposed to import a block to forkchoice unless we have the blobs, so the nuance here is if we can't find the file and we are inside the protocol-defined retention period, then it's actually a 500.
-//   - block exists, has commitments, outside retention period (greater of protocol- or user-specified) - ie just like block exists, no commitment
-func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, opts ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+// blobsContext holds common information needed for blob retrieval
+type blobsContext struct {
+	root        [fieldparams.RootLength]byte
+	roBlock     blocks.ROBlock
+	commitments [][]byte
+	indices     []int
+	postFulu    bool
+}
+
+// resolveBlobsContext extracts common blob retrieval logic including block resolution,
+// validation, and index conversion from versioned hashes.
+func (p *BeaconDbBlocker) resolveBlobsContext(ctx context.Context, id string, opts ...options.BlobsOption) (*blobsContext, *core.RpcError) {
 	// Apply options
 	cfg := &options.BlobsConfig{}
 	for _, opt := range opts {
@@ -279,11 +275,6 @@ func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, opts ...options.
 		return nil, &core.RpcError{Err: errors.Wrapf(err, "failed to retrieve kzg commitments from block %#x", root), Reason: core.Internal}
 	}
 
-	// If there are no commitments return 200 w/ empty list
-	if len(commitments) == 0 {
-		return make([]*blocks.VerifiedROBlob, 0), nil
-	}
-
 	// Compute the first Fulu slot.
 	fuluForkSlot := primitives.Slot(math.MaxUint64)
 	if fuluForkEpoch := params.BeaconConfig().FuluForkEpoch; fuluForkEpoch != primitives.Epoch(math.MaxUint64) {
@@ -333,16 +324,156 @@ func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, opts ...options.
 		}
 	}
 
+	isPostFulu := false
+	// Create ROBlock with root for post-Fulu blocks
+	var roBlockWithRoot blocks.ROBlock
 	if roBlock.Slot() >= fuluForkSlot {
-		roBlock, err := blocks.NewROBlockWithRoot(roSignedBlock, root)
+		roBlockWithRoot, err = blocks.NewROBlockWithRoot(roSignedBlock, root)
 		if err != nil {
 			return nil, &core.RpcError{Err: errors.Wrapf(err, "failed to create roBlock with root %#x", root), Reason: core.Internal}
 		}
-
-		return p.blobsFromStoredDataColumns(roBlock, indices)
+		isPostFulu = true
 	}
 
-	return p.blobsFromStoredBlobs(commitments, root, indices)
+	return &blobsContext{
+		root:        root,
+		roBlock:     roBlockWithRoot,
+		commitments: commitments,
+		indices:     indices,
+		postFulu:    isPostFulu,
+	}, nil
+}
+
+// BlobSidecars returns the fetched blob sidecars (with full KZG proofs) for a given block ID.
+// Options can specify either blob indices or versioned hashes for retrieval.
+// The identifier can be one of:
+//   - "head" (canonical head in node's view)
+//   - "genesis"
+//   - "finalized"
+//   - "justified"
+//   - <slot>
+//   - <hex encoded block root with '0x' prefix>
+func (p *BeaconDbBlocker) BlobSidecars(ctx context.Context, id string, opts ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+	bctx, rpcErr := p.resolveBlobsContext(ctx, id, opts...)
+	if rpcErr != nil {
+		return nil, rpcErr
+	}
+
+	// If there are no commitments return 200 w/ empty list
+	if len(bctx.commitments) == 0 {
+		return make([]*blocks.VerifiedROBlob, 0), nil
+	}
+
+	// Check if this is a post-Fulu block (uses data columns)
+	if bctx.postFulu {
+		return p.blobSidecarsFromStoredDataColumns(bctx.roBlock, bctx.indices)
+	}
+
+	// Pre-Fulu block (uses blob sidecars)
+	return p.blobsFromStoredBlobs(bctx.commitments, bctx.root, bctx.indices)
+}
+
+// Blobs returns just the blob data without computing KZG proofs or creating full sidecars.
+// This is an optimized endpoint for when only blob data is needed (e.g., GetBlobs endpoint).
+// The identifier can be one of:
+//   - "head" (canonical head in node's view)
+//   - "genesis"
+//   - "finalized"
+//   - "justified"
+//   - <slot>
+//   - <hex encoded block root with '0x' prefix>
+func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, opts ...options.BlobsOption) ([][]byte, *core.RpcError) {
+	bctx, rpcErr := p.resolveBlobsContext(ctx, id, opts...)
+	if rpcErr != nil {
+		return nil, rpcErr
+	}
+
+	// If there are no commitments return 200 w/ empty list
+	if len(bctx.commitments) == 0 {
+		return make([][]byte, 0), nil
+	}
+
+	// Check if this is a post-Fulu block (uses data columns)
+	if bctx.postFulu {
+		return p.blobsDataFromStoredDataColumns(bctx.root, bctx.indices, len(bctx.commitments))
+	}
+
+	// Pre-Fulu block (uses blob sidecars)
+	return p.blobsDataFromStoredBlobs(bctx.root, bctx.indices)
+}
+
+// blobsDataFromStoredBlobs retrieves just blob data (without proofs) from stored blob sidecars.
+func (p *BeaconDbBlocker) blobsDataFromStoredBlobs(root [fieldparams.RootLength]byte, indices []int) ([][]byte, *core.RpcError) {
+	summary := p.BlobStorage.Summary(root)
+
+	// If no indices are provided, use all indices that are available in the summary.
+	if len(indices) == 0 {
+		maxBlobCount := summary.MaxBlobsForEpoch()
+		for index := 0; uint64(index) < maxBlobCount; index++ { // needed for safe conversion
+			if summary.HasIndex(uint64(index)) {
+				indices = append(indices, index)
+			}
+		}
+	}
+
+	// Retrieve blob sidecars from the store and extract just the blob data.
+	blobsData := make([][]byte, 0, len(indices))
+	for _, index := range indices {
+		if !summary.HasIndex(uint64(index)) {
+			return nil, &core.RpcError{
+				Err:    fmt.Errorf("requested index %d not found", index),
+				Reason: core.NotFound,
+			}
+		}
+
+		blobSidecar, err := p.BlobStorage.Get(root, uint64(index))
+		if err != nil {
+			return nil, &core.RpcError{
+				Err:    fmt.Errorf("could not retrieve blob for block root %#x at index %d", root, index),
+				Reason: core.Internal,
+			}
+		}
+
+		blobsData = append(blobsData, blobSidecar.Blob)
+	}
+
+	return blobsData, nil
+}
+
+// blobsDataFromStoredDataColumns retrieves blob data from stored data columns without computing KZG proofs.
+func (p *BeaconDbBlocker) blobsDataFromStoredDataColumns(root [fieldparams.RootLength]byte, indices []int, blobCount int) ([][]byte, *core.RpcError) {
+	// Count how many columns we have in the store.
+	summary := p.DataColumnStorage.Summary(root)
+	stored := summary.Stored()
+	count := uint64(len(stored))
+
+	if count < peerdas.MinimumColumnCountToReconstruct() {
+		// There is no way to reconstruct the data columns.
+		return nil, &core.RpcError{
+			Err:    errors.Errorf("the node does not custody enough data columns to reconstruct blobs - please start the beacon node with the `--%s` flag to ensure this call to succeed, or retry later if it is already the case", flags.SubscribeAllDataSubnets.Name),
+			Reason: core.NotFound,
+		}
+	}
+
+	// Retrieve from the database needed data columns.
+	verifiedRoDataColumnSidecars, err := p.neededDataColumnSidecars(root, stored)
+	if err != nil {
+		return nil, &core.RpcError{
+			Err:    errors.Wrap(err, "needed data column sidecars"),
+			Reason: core.Internal,
+		}
+	}
+
+	// Use optimized path to get just blob data without computing proofs.
+	blobsData, err := peerdas.ReconstructBlobs(verifiedRoDataColumnSidecars, indices, blobCount)
+	if err != nil {
+		return nil, &core.RpcError{
+			Err:    errors.Wrap(err, "reconstruct blobs data"),
+			Reason: core.Internal,
+		}
+	}
+
+	return blobsData, nil
 }
 
 // blobsFromStoredBlobs retrieves blob sidercars corresponding to `indices` and `root` from the store.
@@ -393,13 +524,12 @@ func (p *BeaconDbBlocker) blobsFromStoredBlobs(commitments [][]byte, root [field
 	return blobs, nil
 }
 
-// blobsFromStoredDataColumns retrieves data column sidecars from the store,
-// reconstructs the whole matrix if needed, converts the matrix to blobs,
-// and then returns converted blobs corresponding to `indices` and `root`.
+// blobSidecarsFromStoredDataColumns retrieves data column sidecars from the store,
+// reconstructs the whole matrix if needed, converts the matrix to blob sidecars with full KZG proofs.
 // This function expects data column sidecars to be stored (aka. no blob sidecars).
 // If not enough data column sidecars are available to convert blobs from them
 // (either directly or after reconstruction), an error is returned.
-func (p *BeaconDbBlocker) blobsFromStoredDataColumns(block blocks.ROBlock, indices []int) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+func (p *BeaconDbBlocker) blobSidecarsFromStoredDataColumns(block blocks.ROBlock, indices []int) ([]*blocks.VerifiedROBlob, *core.RpcError) {
 	root := block.Root()
 
 	// Use all indices if none are provided.
@@ -439,8 +569,8 @@ func (p *BeaconDbBlocker) blobsFromStoredDataColumns(block blocks.ROBlock, indic
 		}
 	}
 
-	// Reconstruct blob sidecars from data column sidecars.
-	verifiedRoBlobSidecars, err := peerdas.ReconstructBlobs(block, verifiedRoDataColumnSidecars, indices)
+	// Reconstruct blob sidecars with full KZG proofs.
+	verifiedRoBlobSidecars, err := peerdas.ReconstructBlobSidecars(block, verifiedRoDataColumnSidecars, indices)
 	if err != nil {
 		return nil, &core.RpcError{
 			Err:    errors.Wrap(err, "blobs from data columns"),

beacon-chain/rpc/lookup/blocker_test.go

@@ -182,7 +182,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 			BeaconDB: db,
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef")
+		_, rpcErr := blocker.BlobSidecars(ctx, "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 		require.StringContains(t, "not found", rpcErr.Err.Error())
@@ -194,7 +194,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 			ChainInfoFetcher: &mockChain.ChainService{},
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, "999999")
+		_, rpcErr := blocker.BlobSidecars(ctx, "999999")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 		require.StringContains(t, "no blocks found at slot", rpcErr.Err.Error())
@@ -206,7 +206,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 		}
 
 		// Note: genesis blocks don't support blobs, so this returns BadRequest
-		_, rpcErr := blocker.Blobs(ctx, "genesis")
+		_, rpcErr := blocker.BlobSidecars(ctx, "genesis")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
 		require.StringContains(t, "not supported for Phase 0", rpcErr.Err.Error())
@@ -222,7 +222,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 			},
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, "finalized")
+		_, rpcErr := blocker.BlobSidecars(ctx, "finalized")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 		require.StringContains(t, "finalized block", rpcErr.Err.Error())
@@ -239,7 +239,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 			},
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, "justified")
+		_, rpcErr := blocker.BlobSidecars(ctx, "justified")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 		require.StringContains(t, "justified block", rpcErr.Err.Error())
@@ -251,7 +251,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 			BeaconDB: db,
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, "invalid-hex")
+		_, rpcErr := blocker.BlobSidecars(ctx, "invalid-hex")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
 		require.StringContains(t, "could not parse block ID", rpcErr.Err.Error())
@@ -268,7 +268,7 @@ func TestBlobsErrorHandling(t *testing.T) {
 			BeaconDB: db,
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, "100")
+		_, rpcErr := blocker.BlobSidecars(ctx, "100")
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.Internal), rpcErr.Reason)
 	})
@@ -306,16 +306,18 @@ func TestGetBlob(t *testing.T) {
 	fuluBlock, fuluBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, fs, blobCount)
 	fuluBlockRoot := fuluBlock.Root()
 
-	cellsAndProofsList := make([]kzg.CellsAndProofs, 0, len(fuluBlobSidecars))
+	cellsPerBlobList := make([][]kzg.Cell, 0, len(fuluBlobSidecars))
+	proofsPerBlobList := make([][]kzg.Proof, 0, len(fuluBlobSidecars))
 	for _, blob := range fuluBlobSidecars {
 		var kzgBlob kzg.Blob
 		copy(kzgBlob[:], blob.Blob)
-		cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+		cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 		require.NoError(t, err)
-		cellsAndProofsList = append(cellsAndProofsList, cellsAndProofs)
+		cellsPerBlobList = append(cellsPerBlobList, cells)
+		proofsPerBlobList = append(proofsPerBlobList, proofs)
 	}
 
-	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofsList, peerdas.PopulateFromBlock(fuluBlock))
+	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsPerBlobList, proofsPerBlobList, peerdas.PopulateFromBlock(fuluBlock))
 	require.NoError(t, err)
 
 	verifiedRoDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))
@@ -329,7 +331,7 @@ func TestGetBlob(t *testing.T) {
 
 	t.Run("genesis", func(t *testing.T) {
 		blocker := &BeaconDbBlocker{}
-		_, rpcErr := blocker.Blobs(ctx, "genesis")
+		_, rpcErr := blocker.BlobSidecars(ctx, "genesis")
 		require.Equal(t, http.StatusBadRequest, core.ErrorReasonToHTTP(rpcErr.Reason))
 		require.StringContains(t, "not supported for Phase 0 fork", rpcErr.Err.Error())
 	})
@@ -347,7 +349,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: blobStorage,
 		}
 
-		retrievedVerifiedSidecars, rpcErr := blocker.Blobs(ctx, "head")
+		retrievedVerifiedSidecars, rpcErr := blocker.BlobSidecars(ctx, "head")
 		require.IsNil(t, rpcErr)
 		require.Equal(t, blobCount, len(retrievedVerifiedSidecars))
 
@@ -374,7 +376,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: blobStorage,
 		}
 
-		verifiedSidecars, rpcErr := blocker.Blobs(ctx, "finalized")
+		verifiedSidecars, rpcErr := blocker.BlobSidecars(ctx, "finalized")
 		require.IsNil(t, rpcErr)
 		require.Equal(t, blobCount, len(verifiedSidecars))
 	})
@@ -389,7 +391,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: blobStorage,
 		}
 
-		verifiedSidecars, rpcErr := blocker.Blobs(ctx, "justified")
+		verifiedSidecars, rpcErr := blocker.BlobSidecars(ctx, "justified")
 		require.IsNil(t, rpcErr)
 		require.Equal(t, blobCount, len(verifiedSidecars))
 	})
@@ -403,7 +405,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: blobStorage,
 		}
 
-		verifiedBlobs, rpcErr := blocker.Blobs(ctx, hexutil.Encode(denebBlockRoot[:]))
+		verifiedBlobs, rpcErr := blocker.BlobSidecars(ctx, hexutil.Encode(denebBlockRoot[:]))
 		require.IsNil(t, rpcErr)
 		require.Equal(t, blobCount, len(verifiedBlobs))
 	})
@@ -418,7 +420,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: blobStorage,
 		}
 
-		verifiedBlobs, rpcErr := blocker.Blobs(ctx, dsStr)
+		verifiedBlobs, rpcErr := blocker.BlobSidecars(ctx, dsStr)
 		require.IsNil(t, rpcErr)
 		require.Equal(t, blobCount, len(verifiedBlobs))
 	})
@@ -435,7 +437,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: blobStorage,
 		}
 
-		retrievedVerifiedSidecars, rpcErr := blocker.Blobs(ctx, dsStr, options.WithIndices([]int{index}))
+		retrievedVerifiedSidecars, rpcErr := blocker.BlobSidecars(ctx, dsStr, options.WithIndices([]int{index}))
 		require.IsNil(t, rpcErr)
 		require.Equal(t, 1, len(retrievedVerifiedSidecars))
 
@@ -459,7 +461,7 @@ func TestGetBlob(t *testing.T) {
 			BlobStorage: filesystem.NewEphemeralBlobStorage(t),
 		}
 
-		verifiedBlobs, rpcErr := blocker.Blobs(ctx, dsStr)
+		verifiedBlobs, rpcErr := blocker.BlobSidecars(ctx, dsStr)
 		require.IsNil(t, rpcErr)
 		require.Equal(t, 0, len(verifiedBlobs))
 	})
@@ -475,7 +477,7 @@ func TestGetBlob(t *testing.T) {
 		}
 
 		noBlobIndex := len(storedBlobSidecars) + 1
-		_, rpcErr := blocker.Blobs(ctx, dsStr, options.WithIndices([]int{0, noBlobIndex}))
+		_, rpcErr := blocker.BlobSidecars(ctx, dsStr, options.WithIndices([]int{0, noBlobIndex}))
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 	})
@@ -489,7 +491,7 @@ func TestGetBlob(t *testing.T) {
 			BeaconDB:    db,
 			BlobStorage: blobStorage,
 		}
-		_, rpcErr := blocker.Blobs(ctx, dsStr, options.WithIndices([]int{0, math.MaxInt}))
+		_, rpcErr := blocker.BlobSidecars(ctx, dsStr, options.WithIndices([]int{0, math.MaxInt}))
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
 	})
@@ -508,7 +510,7 @@ func TestGetBlob(t *testing.T) {
 			DataColumnStorage: dataColumnStorage,
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, hexutil.Encode(fuluBlockRoot[:]))
+		_, rpcErr := blocker.BlobSidecars(ctx, hexutil.Encode(fuluBlockRoot[:]))
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 	})
@@ -527,7 +529,7 @@ func TestGetBlob(t *testing.T) {
 			DataColumnStorage: dataColumnStorage,
 		}
 
-		retrievedVerifiedRoBlobs, rpcErr := blocker.Blobs(ctx, hexutil.Encode(fuluBlockRoot[:]))
+		retrievedVerifiedRoBlobs, rpcErr := blocker.BlobSidecars(ctx, hexutil.Encode(fuluBlockRoot[:]))
 		require.IsNil(t, rpcErr)
 		require.Equal(t, len(fuluBlobSidecars), len(retrievedVerifiedRoBlobs))
 
@@ -552,7 +554,7 @@ func TestGetBlob(t *testing.T) {
 			DataColumnStorage: dataColumnStorage,
 		}
 
-		retrievedVerifiedRoBlobs, rpcErr := blocker.Blobs(ctx, hexutil.Encode(fuluBlockRoot[:]))
+		retrievedVerifiedRoBlobs, rpcErr := blocker.BlobSidecars(ctx, hexutil.Encode(fuluBlockRoot[:]))
 		require.IsNil(t, rpcErr)
 		require.Equal(t, len(fuluBlobSidecars), len(retrievedVerifiedRoBlobs))
 
@@ -581,7 +583,7 @@ func TestGetBlob(t *testing.T) {
 			BeaconDB: db,
 		}
 
-		_, rpcErr := blocker.Blobs(ctx, hexutil.Encode(predenebBlockRoot[:]))
+		_, rpcErr := blocker.BlobSidecars(ctx, hexutil.Encode(predenebBlockRoot[:]))
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.BadRequest), rpcErr.Reason)
 		require.Equal(t, http.StatusBadRequest, core.ErrorReasonToHTTP(rpcErr.Reason))
@@ -621,7 +623,7 @@ func TestGetBlob(t *testing.T) {
 		}
 
 		// Should successfully retrieve blobs even when FuluForkEpoch is not set
-		retrievedBlobs, rpcErr := blocker.Blobs(ctx, hexutil.Encode(denebBlockRoot[:]))
+		retrievedBlobs, rpcErr := blocker.BlobSidecars(ctx, hexutil.Encode(denebBlockRoot[:]))
 		require.IsNil(t, rpcErr)
 		require.Equal(t, 2, len(retrievedBlobs))
 
@@ -665,16 +667,18 @@ func TestBlobs_CommitmentOrdering(t *testing.T) {
 	require.Equal(t, 3, len(commitments))
 
 	// Convert blob sidecars to data column sidecars for Fulu
-	cellsAndProofsList := make([]kzg.CellsAndProofs, 0, len(fuluBlobs))
+	cellsPerBlobList := make([][]kzg.Cell, 0, len(fuluBlobs))
+	proofsPerBlobList := make([][]kzg.Proof, 0, len(fuluBlobs))
 	for _, blob := range fuluBlobs {
 		var kzgBlob kzg.Blob
 		copy(kzgBlob[:], blob.Blob)
-		cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+		cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 		require.NoError(t, err)
-		cellsAndProofsList = append(cellsAndProofsList, cellsAndProofs)
+		cellsPerBlobList = append(cellsPerBlobList, cells)
+		proofsPerBlobList = append(proofsPerBlobList, proofs)
 	}
 
-	dataColumnSidecarPb, err := peerdas.DataColumnSidecars(cellsAndProofsList, peerdas.PopulateFromBlock(fuluBlock))
+	dataColumnSidecarPb, err := peerdas.DataColumnSidecars(cellsPerBlobList, proofsPerBlobList, peerdas.PopulateFromBlock(fuluBlock))
 	require.NoError(t, err)
 
 	verifiedRoDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(dataColumnSidecarPb))
@@ -713,7 +717,7 @@ func TestBlobs_CommitmentOrdering(t *testing.T) {
 		// Request versioned hashes in reverse order: 2, 1, 0
 		requestedHashes := [][]byte{hash2[:], hash1[:], hash0[:]}
 
-		verifiedBlobs, rpcErr := blocker.Blobs(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
+		verifiedBlobs, rpcErr := blocker.BlobSidecars(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
 		if rpcErr != nil {
 			t.Errorf("RPC Error: %v (reason: %v)", rpcErr.Err, rpcErr.Reason)
 			return
@@ -738,7 +742,7 @@ func TestBlobs_CommitmentOrdering(t *testing.T) {
 		// Request hashes for indices 1 and 0 (out of order)
 		requestedHashes := [][]byte{hash1[:], hash0[:]}
 
-		verifiedBlobs, rpcErr := blocker.Blobs(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
+		verifiedBlobs, rpcErr := blocker.BlobSidecars(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
 		if rpcErr != nil {
 			t.Errorf("RPC Error: %v (reason: %v)", rpcErr.Err, rpcErr.Reason)
 			return
@@ -764,7 +768,7 @@ func TestBlobs_CommitmentOrdering(t *testing.T) {
 		// Request only the fake hash
 		requestedHashes := [][]byte{fakeHash}
 
-		_, rpcErr := blocker.Blobs(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
+		_, rpcErr := blocker.BlobSidecars(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 		require.StringContains(t, "versioned hash(es) not found in block", rpcErr.Err.Error())
@@ -784,7 +788,7 @@ func TestBlobs_CommitmentOrdering(t *testing.T) {
 		// Request valid hash with two fake hashes
 		requestedHashes := [][]byte{fakeHash1, hash0[:], fakeHash2}
 
-		_, rpcErr := blocker.Blobs(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
+		_, rpcErr := blocker.BlobSidecars(ctx, "finalized", options.WithVersionedHashes(requestedHashes))
 		require.NotNil(t, rpcErr)
 		require.Equal(t, core.ErrorReason(core.NotFound), rpcErr.Reason)
 		require.StringContains(t, "versioned hash(es) not found in block", rpcErr.Err.Error())
@@ -829,16 +833,18 @@ func TestGetDataColumns(t *testing.T) {
 	fuluBlock, fuluBlobSidecars := util.GenerateTestElectraBlockWithSidecar(t, [fieldparams.RootLength]byte{}, fuluForkSlot, blobCount)
 	fuluBlockRoot := fuluBlock.Root()
 
-	cellsAndProofsList := make([]kzg.CellsAndProofs, 0, len(fuluBlobSidecars))
+	cellsPerBlobList := make([][]kzg.Cell, 0, len(fuluBlobSidecars))
+	proofsPerBlobList := make([][]kzg.Proof, 0, len(fuluBlobSidecars))
 	for _, blob := range fuluBlobSidecars {
 		var kzgBlob kzg.Blob
 		copy(kzgBlob[:], blob.Blob)
-		cellsAndProofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
+		cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&kzgBlob)
 		require.NoError(t, err)
-		cellsAndProofsList = append(cellsAndProofsList, cellsAndProofs)
+		cellsPerBlobList = append(cellsPerBlobList, cells)
+		proofsPerBlobList = append(proofsPerBlobList, proofs)
 	}
 
-	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofsList, peerdas.PopulateFromBlock(fuluBlock))
+	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsPerBlobList, proofsPerBlobList, peerdas.PopulateFromBlock(fuluBlock))
 	require.NoError(t, err)
 
 	verifiedRoDataColumnSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roDataColumnSidecars))

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

@@ -413,13 +413,13 @@ func (vs *Server) handleUnblindedBlock(
 
 	if block.Version() >= version.Fulu {
 		// Compute cells and proofs from the blobs and cell proofs.
-		cellsAndProofs, err := peerdas.ComputeCellsAndProofsFromFlat(rawBlobs, proofs)
+		cellsPerBlob, proofsPerBlob, err := peerdas.ComputeCellsAndProofsFromFlat(rawBlobs, proofs)
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "compute cells and proofs")
 		}
 
 		// Construct data column sidecars from the signed block and cells and proofs.
-		roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(block))
+		roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(block))
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "data column sidcars")
 		}

beacon-chain/rpc/testutil/mock_blocker.go

@@ -39,8 +39,13 @@ func (m *MockBlocker) Block(_ context.Context, b []byte) (interfaces.ReadOnlySig
 	return m.SlotBlockMap[primitives.Slot(slotNumber)], nil
 }
 
+// BlobSidecars --
+func (*MockBlocker) BlobSidecars(_ context.Context, _ string, _ ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+	return nil, &core.RpcError{}
+}
+
 // Blobs --
-func (*MockBlocker) Blobs(_ context.Context, _ string, _ ...options.BlobsOption) ([]*blocks.VerifiedROBlob, *core.RpcError) {
+func (*MockBlocker) Blobs(_ context.Context, _ string, _ ...options.BlobsOption) ([][]byte, *core.RpcError) {
 	return nil, &core.RpcError{}
 }
 

beacon-chain/verification/data_column_test.go

@@ -28,8 +28,8 @@ func GenerateTestDataColumns(t *testing.T, parent [fieldparams.RootLength]byte,
 		blobs = append(blobs, kzg.Blob(roBlobs[i].Blob))
 	}
 
-	cellsAndProofs := util.GenerateCellsAndProofs(t, blobs)
-	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(roBlock))
+	cellsPerBlob, proofsPerBlob := util.GenerateCellsAndProofs(t, blobs)
+	roDataColumnSidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(roBlock))
 	require.NoError(t, err)
 
 	return roDataColumnSidecars

changelog/james-prysm_optimize-get-blobs.md

@@ -0,0 +1,3 @@
+### Ignored
+
+- optimization to remove cell and blob proof computation on blob rest api.

testing/spectest/general/fulu__kzg__compute_cells_and_kzg_proofs_test.go

@@ -42,18 +42,16 @@ func TestComputeCellsAndKzgProofs(t *testing.T) {
 			}
 			b := kzgPrysm.Blob(blob)
 
-			cellsAndProofsForBlob, err := kzgPrysm.ComputeCellsAndKZGProofs(&b)
+			cells, proofs, err := kzgPrysm.ComputeCellsAndKZGProofs(&b)
 			if test.Output != nil {
 				require.NoError(t, err)
 				var combined [][]string
-				cs := cellsAndProofsForBlob.Cells
-				csRaw := make([]string, 0, len(cs))
-				for _, c := range cs {
+				csRaw := make([]string, 0, len(cells))
+				for _, c := range cells {
 					csRaw = append(csRaw, hexutil.Encode(c[:]))
 				}
-				ps := cellsAndProofsForBlob.Proofs
-				psRaw := make([]string, 0, len(ps))
-				for _, p := range ps {
+				psRaw := make([]string, 0, len(proofs))
+				for _, p := range proofs {
 					psRaw = append(psRaw, hexutil.Encode(p[:]))
 				}
 				combined = append(combined, csRaw)

testing/spectest/general/fulu__kzg__recover_cells_and_kzg_proofs_test.go

@@ -69,18 +69,16 @@ func TestRecoverCellsAndKzgProofs(t *testing.T) {
 			}
 
 			// Recover the cells and proofs for the corresponding blob
-			cellsAndProofsForBlob, err := kzgPrysm.RecoverCellsAndKZGProofs(cellIndices, cells)
+			recoveredCells, recoveredProofs, err := kzgPrysm.RecoverCellsAndKZGProofs(cellIndices, cells)
 			if test.Output != nil {
 				require.NoError(t, err)
 				var combined [][]string
-				cs := cellsAndProofsForBlob.Cells
-				csRaw := make([]string, 0, len(cs))
-				for _, c := range cs {
+				csRaw := make([]string, 0, len(recoveredCells))
+				for _, c := range recoveredCells {
 					csRaw = append(csRaw, hexutil.Encode(c[:]))
 				}
-				ps := cellsAndProofsForBlob.Proofs
-				psRaw := make([]string, 0, len(ps))
-				for _, p := range ps {
+				psRaw := make([]string, 0, len(recoveredProofs))
+				for _, p := range recoveredProofs {
 					psRaw = append(psRaw, hexutil.Encode(p[:]))
 				}
 				combined = append(combined, csRaw)

testing/util/fulu.go

@@ -146,11 +146,11 @@ func GenerateTestFuluBlockWithSidecars(t *testing.T, blobCount int, options ...F
 	signedBeaconBlock, err := blocks.NewSignedBeaconBlock(block)
 	require.NoError(t, err)
 
-	cellsAndProofs := GenerateCellsAndProofs(t, blobs)
+	cellsPerBlob, proofsPerBlob := GenerateCellsAndProofs(t, blobs)
 
 	rob, err := blocks.NewROBlockWithRoot(signedBeaconBlock, root)
 	require.NoError(t, err)
-	roSidecars, err := peerdas.DataColumnSidecars(cellsAndProofs, peerdas.PopulateFromBlock(rob))
+	roSidecars, err := peerdas.DataColumnSidecars(cellsPerBlob, proofsPerBlob, peerdas.PopulateFromBlock(rob))
 	require.NoError(t, err)
 
 	verifiedRoSidecars := make([]blocks.VerifiedRODataColumn, 0, len(roSidecars))
@@ -167,12 +167,14 @@ func GenerateTestFuluBlockWithSidecars(t *testing.T, blobCount int, options ...F
 	return roBlock, roSidecars, verifiedRoSidecars
 }
 
-func GenerateCellsAndProofs(t testing.TB, blobs []kzg.Blob) []kzg.CellsAndProofs {
-	cellsAndProofs := make([]kzg.CellsAndProofs, len(blobs))
+func GenerateCellsAndProofs(t testing.TB, blobs []kzg.Blob) ([][]kzg.Cell, [][]kzg.Proof) {
+	cellsPerBlob := make([][]kzg.Cell, len(blobs))
+	proofsPerBlob := make([][]kzg.Proof, len(blobs))
 	for i := range blobs {
-		cp, err := kzg.ComputeCellsAndKZGProofs(&blobs[i])
+		cells, proofs, err := kzg.ComputeCellsAndKZGProofs(&blobs[i])
 		require.NoError(t, err)
-		cellsAndProofs[i] = cp
+		cellsPerBlob[i] = cells
+		proofsPerBlob[i] = proofs
 	}
-	return cellsAndProofs
+	return cellsPerBlob, proofsPerBlob
 }