
PCM: A Proof-Carrying Message Protocol for Verifiable Multi-Agent Communication
Proof-Carrying Messages (PCM) is a protocol where each claim an AI agent sends carries evidence: records from an append-only Merkle log the agent cannot write, with inclusion proofs, signed by an attesting signer. Receivers verify offline in about 1 ms and label each claim proven, unproven or failed. On 926 messages (712 lies in 16 classes), PCM accepts 10 lies (1.4%), all stale evidence; plain A2A accepts all 712.
agents, researchยท Added 31 Oct 2026, published 29 Oct 2026
