Discussion for EIP-8411: Fast Execution Payload Broadcast
This EIP replaces the execution_payload gossipsub topic introduced by EIP-7732 with a new execution_payload_chunks topic. The payload envelope is split into chunks, and the builder commits to the chunk set with a Merkle root (payload_chunks_root) carried in the execution bid, so each chunk is independently verifiable via a single bid signature check plus an inclusion proof.
Motivation: EIP-7732 enables larger execution payloads via higher gas limits, which increases propagation latency. The current single-message execution_payload topic scales poorly for large payloads: in-flight duplicates are hard to cancel once a peer starts receiving a large message, and a peer must download the full message before it can start forwarding it. Chunking mitigates both problems - duplicate transfers are capped at chunk size, and peers can start forwarding a chunk as soon as it arrives.