| Internet-Draft | PSI | August 2026 |
| Singh | Expires 3 March 2027 | [Page] |
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.¶
This revision documents a deployed public reference implementation and adds optional post-quantum signature profiles and Bitcoin timestamp anchoring.¶
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The proliferation of artificial intelligence systems across critical sectors has created an urgent need for verifiable compliance mechanisms. The EU AI Act mandates technical conformity assessment for high-risk AI systems. Existing compliance approaches suffer from IP exposure risk, non-verifiability, and reliance on trust.¶
The PSI Protocol addresses these limitations through cryptographic verification primitives that enable mathematical proof of compliance without disclosing protected intellectual property. PSI v1.2 introduces Deterministic Mode (blocking non-compliant actions before commit) and the Sovereign Tribunal (human ratification).¶
Added Section 17, documenting a deployed public reference implementation with public verification endpoints.¶
Added an optional post-quantum signature profile (LMS-W4-SHA256 per NIST SP 800-208 and ML-DSA-65 per FIPS 204).¶
Added Bitcoin timestamp anchoring via OpenTimestamps.¶
Editorial corrections.¶
Commit: An atomic action submitted for compliance verification.¶
Predicate: A machine-readable regulatory requirement (e.g. EU AI Act Article 14).¶
Commit Hash: SHA-256(JCS(action || predicate_id || timestamp)).¶
Merkle Root: The root hash of the binary tree containing ledger entries.¶
MPC Node: One of three independent verification nodes.¶
Proof Bundle: A JSON document containing all cryptographic artifacts for verification.¶
Sovereign Tribunal: A panel of 5 independent auditors providing human ratification.¶
PIL: Protocol Intervention Layer (runtime execution gate).¶
Receipt: A signed record attesting that one entry was sealed, carrying its digest, signature, Merkle leaf and identifier.¶
The PSI Protocol operates as a 4-stage pipeline:¶
Stage 1 - COMMIT: Input action and predicate. Run deterministic pre-flight check. Compute commit_hash and merkle_leaf.¶
Stage 2 - CHALLENGE: Evaluate commit against predicate violation patterns. Compute challenge_hash and record status.¶
Stage 3 - PROVE: Generate Merkle inclusion proof. Generate Groth16-compatible ZK commitment over BN128 fields.¶
Stage 4 - VERIFY: 3 MPC nodes independently verify the proof. 2/3 consensus required. Sign result with Ed25519.¶
PSI uses SHA-256. Input MUST be canonicalized using RFC 8785 (JCS) before hashing.¶
Ed25519 (RFC 8032) is used for non-repudiation of Merkle roots and auditor verdicts.¶
Binary Merkle trees are constructed from leaf hashes. Deterministic ordering and leaf duplication for odd counts are required.¶
ZK commitments use BN128 finite field arithmetic. Proof elements (pi_A, pi_B, pi_C) demonstrate knowledge of action satisfying the predicate without revealing the action.¶
A monotonic sequence counter with gap detection prevents omission attacks on the ledger.¶
Long-lived evidence MAY additionally be signed with a hybrid post-quantum profile: LMS-W4-SHA256 stateful hash-based signatures (NIST SP 800-208) and/or ML-DSA-65 (FIPS 204), alongside Ed25519. Verification of the classical signature remains mandatory; the post-quantum layer extends the horizon of non-repudiation.¶
1. Commit: Generate ID, JCS canonical hash, and persist.¶
2. Challenge: Match against violation patterns; assign status.¶
3. Prove: Generate Merkle proof path and ZK commitment.¶
4. Verify: MPC nodes audit integrity and sign root hash.¶
The PIL evaluates actions BEFORE commit. If action matches HIGH or UNACCEPTABLE risk patterns, the PIL blocks execution and prevents ledger entry.¶
Trees are computed by recursively hashing lexicographically sorted sibling pairs. ProofPath includes sibling hashes and positions.¶
Verification is distributed across Alpha, Beta, and Gamma nodes. Consensus ensures that no single entity can forge a compliance certificate.¶
BN128 field operations provide the privacy layer. The system uses Groth16 elements to prove predicates without data disclosure.¶
Human oversight is provided by 5 auditors. 3/5 threshold is required for final ratification of automated verdicts.¶
Contains machine-readable rules for EU AI Act, MiFID II, DORA, NIST AI RMF, and AU Privacy Act.¶
Standardized JSON including merkle_root, ed25519_signature, and zk_proof points.¶
Article 12: Immutable logging + RFC 8785.¶
Article 14: Human Oversight PIL + Sovereign Tribunal.¶
Article 15: MPC consensus + ZK-Integrity.¶
Protocol mitigates log tampering, false-negatives, and single points of failure. IP protection is guaranteed by ZK mathematics.¶
Requests registration of application/psi-proof+json and the psi:// URI scheme.¶
Extends PSI to space-based compute. Defines LAM levels for radiation-tolerant proof generation on satellite hardware.¶
A public reference implementation of the PSI Protocol was deployed in August 2026, including a sealed genesis declaration and a public append-only ledger of sealed records. The following properties are normative for any deployment claiming PSI conformance.¶
Every receipt MUST be independently verifiable through at least one public endpoint, without account creation and without fee. The reference implementation publishes two independent verification doors:¶
If the doors ever disagree, the correction MUST be public and the finder credited.¶
Each seal produces a receipt carrying the canonical SHA-256 digest of the sealed record, an Ed25519 signature, the Merkle leaf hash, and a unique receipt identifier. Verification MUST be reproducible from the published bytes alone.¶
Ledger roots MAY be anchored to the Bitcoin blockchain via OpenTimestamps. An anchor MUST be reported as pending until a real Bitcoin block includes it.¶
Reference code: https://github.com/kawal393/psi-seal-spec (MIT).¶
RFC 2119, RFC 8032, RFC 8785, EU 2024/1689, NIST SP 800-208, NIST FIPS 204, OpenTimestamps (https://opentimestamps.org).¶