Proof of Sovereign Integrity (PSI): A Cryptographic Protocol for Verifiable AI Regulatory Compliance

This document specifies the Proof of Sovereign Integrity (PSI) Protocol, version 1.2, a cryptographic framework enabling organizations to prove compliance with AI regulations (including the EU AI Act 2024/1689, NIST AI RMF, UK AI Safety Institute guidelines, and equivalent frameworks) without disclosing proprietary model architectures, training data, or inference logic. PSI achieves this through a combination of SHA-256 hash-chained audit trails, Ed25519 digital signatures, Merkle inclusion proofs, Groth16-compatible zero-knowledge commitments over BN128 fields, and a 3-node Multi-Party Computation (MPC) consensus mechanism with 2/3 threshold verification.