ACE-GF-based Attestation Relay for PQC - Lightweight Mempool Propagation Without On-Path Proofs

TL;DR

This paper introduces AR-ACE, a lightweight relay protocol for post-quantum blockchains that reduces proof bandwidth by forwarding only compact attestations instead of full validity proofs, enhancing efficiency and PQC readiness.

Contribution

AR-ACE proposes a novel proof-off-path relay design that significantly reduces proof bandwidth in PQC blockchain propagation, maintaining security with on-chain authorization.

Findings

Order-of-magnitude reduction in proof-related bandwidth

Maintains security with compact attestations

PQC-ready with on-chain authorization

Abstract

In post-quantum blockchain settings, objects that require validity proofs (e.g., blob roots, execution-layer or consensus-layer signature aggregates) must be broadcast through mempool and relay networks. Recursive STARKs have been proposed to aggregate such proofs so that each node forwards one proof per tick plus objects without proofs, capping per-node proof bandwidth at roughly 128 KB degree per tick. We observe that propagation does not inherently require validity proofs on the path-only a lightweight assurance that an object is eligible for relay. We present AR-ACE (ACE-GF-based Attestation Relay for PQC), in which relay nodes forward objects plus compact attestations (e.g., identity-bound signatures or commitments) and do not generate, hold, or forward any full validity proof. Only the builder (or final verifier) performs a single aggregated validity proof over the set of objects it includes. This proof-off-path design removes proof overhead from the propagation path entirely, yielding an order-of-magnitude reduction in proof-related relay bandwidth relative to proof-carrying propagation. When instantiated with ACE-GF-derived attestation keys, AR-ACE preserves a unified identity story with on-chain authorization and is PQC-ready. We specify a protocol model, state design goals and security considerations, define security games, and provide a structural bandwidth comparison with recursive-STARK-based propagation.