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bxue-l2 · Nov 30, 2023 · 65fc825 · 65fc825
1 parent 8a8123f
commit 65fc825
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Showing 2 changed files with 16 additions and 6 deletions.
diff --git a/core/validator.go b/core/validator.go
@@ -33,6 +33,7 @@ func NewChunkValidator(enc Encoder, asgn AssignmentCoordinator, cst ChainState,
 	}
 }
 
+// preprocessBlob for each Quorum
 func (v *chunkValidator) preprocessBlob(quorumHeader *BlobQuorumInfo, blob *BlobMessage, operatorState *OperatorState) ([]*Chunk, *Assignment, *EncodingParams, error) {
 	if quorumHeader.AdversaryThreshold >= quorumHeader.QuorumThreshold {
 		return nil, nil, nil, errors.New("invalid header: quorum threshold does not exceed adversary threshold")
@@ -175,12 +176,13 @@ func (v *chunkValidator) ValidateBatch(blobs []*BlobMessage, operatorState *Oper
 		}
 	}
 
+	// Parallelize the universal verification for each subBatch
 	numSubBatch := len(subBatchMap)
 	out := make(chan error, numSubBatch)
 	for params, subBatch := range subBatchMap {
 		params := params
 		subBatch := subBatch
-		go v.UniversalVerifyWorker(params, &subBatch, out)
+		go v.universalVerifyWorker(params, &subBatch, out)
 	}
 
 	for i := 0; i < numSubBatch; i++ {
@@ -193,7 +195,7 @@ func (v *chunkValidator) ValidateBatch(blobs []*BlobMessage, operatorState *Oper
 	return nil
 }
 
-func (v *chunkValidator) UniversalVerifyWorker(params EncodingParams, subBatch *SubBatch, out chan error) {
+func (v *chunkValidator) universalVerifyWorker(params EncodingParams, subBatch *SubBatch, out chan error) {
 
 	err := v.encoder.UniversalVerifyChunks(params, subBatch.Samples, subBatch.NumBlobs)
 	if err != nil {

diff --git a/pkg/encoding/kzgEncoder/multiframe.go b/pkg/encoding/kzgEncoder/multiframe.go
@@ -10,12 +10,14 @@ import (
 	bls "github.com/Layr-Labs/eigenda/pkg/kzg/bn254"
 )
 
+// Sample is the basic unit for a verification
+// A blob may contain multiple Samples
 type Sample struct {
 	Commitment bls.G1Point
 	Proof      bls.G1Point
-	Row        int
+	Row        int // corresponds to a row in the verification matrix
 	Coeffs     []bls.Fr
-	X          uint // X is int , at which index is evaluated
+	X          uint // X is assignment
 }
 
 // generate a random value using Fiat Shamir transform
@@ -47,7 +49,12 @@ func GenRandomness(params rs.EncodingParams, samples []Sample, m int) (bls.Fr, e
 	return randomFr, nil
 }
 
-// m is number of blob
+// UniversalVerify implements batch verification on a set of chunks given the same chunk dimension (chunkLen, numChunk).
+// The details is given in Ethereum Research post whose authors are George Kadianakis, George Kadianakis, George Kadianakis
+// https://ethresear.ch/t/a-universal-verification-equation-for-data-availability-sampling/13240
+//
+// m is number of blob, samples is a list of chunks
+// Inside the code, ft stands for first term; st for the second term; tt for the third term
 func (group *KzgEncoderGroup) UniversalVerify(params rs.EncodingParams, samples []Sample, m int) error {
 	verifier, _ := group.GetKzgVerifier(params)
 	ks := verifier.Ks
@@ -122,6 +129,8 @@ func (group *KzgEncoderGroup) UniversalVerify(params rs.EncodingParams, samples
 	leadingDs := make([]bls.Fr, n)
 
 	for k := 0; k < n; k++ {
+		// It is important to obtain the leading coset here
+		// As the params from the eigenda Core might not have NumChunks be the power of 2
 		x, err := rs.GetLeadingCosetIndex(
 			uint64(samples[k].X),
 			params.NumChunks,
@@ -141,7 +150,6 @@ func (group *KzgEncoderGroup) UniversalVerify(params rs.EncodingParams, samples
 		bls.CopyFr(&leadingDs[k], &hPow)
 	}
 
-	//
 	for k := 0; k < n; k++ {
 		rk := randomsFr[k]
 		bls.MulModFr(&ttCoeffs[k], &rk, &leadingDs[k])