P-MATRIX: A Mutual Verification Protocol for Runtime Governance Across Autonomous Nodes

This paper defines a mutual verification protocol for runtime governance across multiple autonomous nodes. The protocol specifies a four-stage chain — state vector exchange, independent verification, transition decision, and enforcement boundary — through which peer nodes evaluate each other's policy alignment state and impose graduated restrictions when deviations are detected. The protocol defines five structural properties and four normative protocol invariants. Non-executive by design: it specifies protocol structure, not implementation. Grounded in Korean Patent Application No. 10-2026-0016343.