Identity Accord Protocol: A Peer Ceremony for Bilateral Agreements Between Identity-Substrate-Bound Principals

This memo specifies the Identity Accord Protocol, a peer ceremony by which two principals, each represented by an organisational identity substrate and acting under a recorded delegation from a legal entity, execute a bilateral agreement as a portable, self-verifying COSE- signed CBOR document. The protocol composes DNS-based substrate discovery, Ed25519 sovereign signatures, an append-only identity log, and a tamper-evidence descriptor quorum into a single artefact that is verifiable by any third party with access to the public DNS, the parties' identity logs, and an on-chain anchor of the agreement's content hash. The protocol does not require a central registry, a designated verifier, or any infrastructure operated by the specification's author; verification succeeds when the author's reference deployment is offline. The canonical bilateral target is a mutual non-disclosure agreement, but the wire format generalises to any bilateral consent envelope between two legal entities each represented by an identity substrate. An associated MCP tool surface, an associated pre-send enforcement gate, and an associated disclosure-ledger schema are specified, all of which are optional layers above the wire format. The memo is Informational; the underlying COSE and CBOR formats are normative per [RFC9052] and [RFC8949].