Add verify_blob_kzg_proof condition

specs/deneb/p2p-interface.md

@@ -167,7 +167,8 @@ The following validations MUST pass before forwarding the `blob_sidecar` on the
 - _[REJECT]_ The sidecar is from a higher slot than the sidecar's block's parent (defined by `block_header.parent_root`).
 - _[REJECT]_ The proposer signature of `blob_sidecar.signed_block_header`, is valid with respect to the `block_header.proposer_index` pubkey.
 - _[REJECT]_ The sidecar's inclusion proof is valid as verified by `verify_blob_sidecar_inclusion_proof`.
-- _[IGNORE]_ The sidecar is the first sidecar for the tuple (block_header.slot, block_header.proposer_index, blob_sidecar.index) with valid header signature and sidecar inclusion proof
+- _[REJECT]_ The sidecar's blob is valid as verified by `verify_blob_kzg_proof(blob_sidecar.blob, blob_sidecar.kzg_commitment, blob_sidecar.kzg_proof)`.
+- _[IGNORE]_ The sidecar is the first sidecar for the tuple (block_header.slot, block_header.proposer_index, blob_sidecar.index) with valid header signature, sidecar inclusion proof, and kzg proof.
 - _[REJECT]_ The sidecar is proposed by the expected `proposer_index` for the block's slot in the context of the current shuffling (defined by `block_header.parent_root`/`block_header.slot`).
   If the `proposer_index` cannot immediately be verified against the expected shuffling, the sidecar MAY be queued for later processing while proposers for the block's branch are calculated -- in such a case _do not_ `REJECT`, instead `IGNORE` this message.