1. Purpose

Define the architecture, cryptographic primitives, and development patterns for generating verifiable proofs of license authenticity and compliance in TLaaS (LEX), integrating Zero‑Knowledge Proofs (ZKPs) for privacy-preserving verification. Maintain compatibility with TLAAS (DLA) for automated compliance checks and DAL for governance-controlled verification policies.

2. Design Principles

• Privacy by Design: Only minimal, non-sensitive data exposed to verifiers.
• Mathematical Soundness: Use well-established ZKP frameworks (Groth16, PlonK, Halo2) with formal verification.
• On‑Chain Verifiability: Proofs must be checkable via Ethereum-compatible verifier contracts.
• Extensibility: Support new proof systems without major architecture changes.

3. Proof Types

• License Existence Proof: Confirms license issuance without revealing license details.
• Compliance Proof: Verifies compliance with jurisdictional rules without exposing full records.
• Ownership Proof: Shows current holder control without revealing identity.

4. Cryptographic Workflow

1. Commitment Phase:
2. Proof Generation Phase:
3. Verification Phase:

5. Example ZKP Circuit (Circom)

pragma circom 2.0.0;

include "poseidon.circom";

template LicenseCompliance() {
    signal input licenseHash;
    signal input complianceFlag; // 1 if compliant
    signal output out;

    component poseidon = Poseidon(2);
    poseidon.inputs[0] <== licenseHash;
    poseidon.inputs[1] <== complianceFlag;

    out <== poseidon.out[0];
}

component main = LicenseCompliance();

6. Solidity Verifier Integration

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "./Verifier.sol"; // Generated by snarkjs or similar

contract LicenseZKVerifier {
    Verifier public verifier;

    constructor(address _verifier) {
        verifier = Verifier(_verifier);
    }

    function verifyProof(bytes memory proof, uint256[] memory publicInputs) external view returns (bool) {
        return verifier.verifyProof(proof, publicInputs);
    }
}

7. Security Considerations

• Use multi-party computation (MPC) for trusted setups.
• Rotate proving keys periodically.
• Ensure proof systems are resistant to known vulnerabilities.

8. Integration with TLAAS & DAL

• TLAAS (DLA): Consumes proofs before activating or renewing licenses.
• DAL: Defines compliance circuit parameters; can require re-proofs under new rules.

9. Operational Runbook

• Maintain proving/verification key registry.
• Audit circuits annually.
• Archive historical proofs for dispute resolution.

10. Acceptance Criteria

• Proof verification gas cost ≤ 500k.
• Zero false positives/negatives in compliance checks.
• Backward compatibility with existing licenses.

Next Article: Off‑Chain Compute Oracles for Advanced Compliance Checking