AgentClock Working draft

AgentClock · Extend-Only, Threshold-Attested Authority Renewal

Extending Authority Without a New Grant

Every time-bound credential assumes its issuer is reachable. AgentClock is what a severed agent does instead of halting or self-renewing — extend its own authority, unwidened, on the signed word of a peer quorum.

An agent's authority is extended when a quorum of its peers has independently verified — from a single broadcast request — that the extension is bounded, unwidened, and no different in scope from what the issuer already granted, not when the agent simply declares itself still valid. A Renewal Chain is that verdict: an ordered sequence of quorum-attested proofs, each aggregating ⌈2N/3⌉ Ed25519 signatures over a JCS-canonical request, verifiable offline by any relying party without trusting whoever assembled it. It is a bridge to the issuer's own word, not a replacement for it — superseded the instant reconnection happens.

Three options for a severed agent

The design space at credential expiry under partition is small enough to enumerate exhaustively — which is itself a useful property.

Halt

Fail-closed

Authority ends at the TTL. Safe against credential abuse; a standing invitation to an adversary — disrupt communications for longer than one credential lifetime and any agent in the mesh goes dark.

Self-grant

Fail-open

The agent signs its own extension. No threshold, no external check, no bound. A compromised agent becomes self-sovereign — there is no revocation story at all, connected or not.

Borrow

Extend-only, threshold-attested

The agent asks the only authority-adjacent parties reachable during the partition — its peers — and the protocol constrains what they can grant: bounded, unwidened, and auditable.

The chain. A renewal is valid only with ⌈2N/3⌉ distinct peer attestations (N ≥ 4), never widens the scope it started with, and is capped by a ceiling measured from original issuance — a hard halt regardless of mesh health once reached.

Out of scope. AgentClock does not enforce revocation delivered during a partition — a decision cannot reach a node that is unreachable. It bounds and prices that residual; it does not hide it.