PQ Verifiable Archive

Post-quantum tamper-evidence for any signed document. Anchor a SHA-256 hash to Algorand mainnet, get back a self-contained proof bundle signed with ML-DSA-65 (NIST FIPS-204) that anyone can verify offline — decades from now, without trusting any vendor.

Works with any signing tool: DocuSign, HelloSign, Adobe Sign, or a plain PDF. You bring the signed document; this adds the quantum-resistant notarization layer.

Live on Algorand mainnet. Real transactions, real ML-DSA-65 signatures, working offline verifier.

Why this exists

Today's e-signature platforms use RSA or ECDSA. Both are broken by a large-enough quantum computer. NIST finalized ML-DSA (FIPS-204) in 2024 and CNSA 2.0 mandates PQC migration in federal procurement by ~2030–2035. Documents signed today need to be verifiable in 2040.

What's different

Property	DocuSign / Adobe Sign	PQ Verifiable Archive
Quantum-resistant	No (RSA / ECDSA)	Yes — ML-DSA-65 + Algorand Falcon-512 state proofs
Offline-verifiable	No — requires vendor servers	Yes — 3 of 5 checks need no network at all
Vendor-independent	No — trust the platform	Yes — verify against a public permissionless chain
PII on-chain	n/a	None — only irreversible SHA-256 hashes are anchored
Works with any signer	No	Yes — bring any signed PDF
Standards	RSA / ECDSA	NIST FIPS-204, SHA-256, JCS (RFC 8785)

Use as an MCP tool (AI agents)

Add to claude_desktop_config.json or .claude/settings.json:

{
  "mcpServers": {
    "pq-verifiable-archive": {
      "command": "npx",
      "args": ["tsx", "/path/to/pq-verifiable-archive/src/mcp-server.ts"],
      "env": {
        "ALGORAND_MNEMONIC": "your 25-word mnemonic",
        "DOCUSIGN_MLDSA_PUBLIC_KEY": "hex-encoded ML-DSA-65 public key",
        "DOCUSIGN_MLDSA_PRIVATE_KEY": "hex-encoded ML-DSA-65 private key",
        "DOCUSIGN_KEY_REGISTRATION_TXN_ID": "algorand txn id from npm run register-key"
      }
    }
  }
}

Claude (or any MCP-compatible agent) can then call:

• anchor_document — anchor a SHA-256 hash to Algorand, receive a proof bundle
• verify_bundle — run all 5 post-quantum verification checks on any bundle

Self-hosted MCP is free. You pay only Algorand's network fee (~$0.0002 per anchor).

Hosted API (pay-per-use)

If you don't want to run your own node, call the hosted REST endpoint:

# Without payment — returns 402 with payment instructions
curl -X POST https://pq-verifiable-archive-production.up.railway.app/api/anchor \
  -H "Content-Type: application/json" \
  -d '{"hash":"<sha256 hex>","envelope_id":"contract-001"}'

# With x402 payment ($0.01 USDC on Algorand)
curl -X POST https://pq-verifiable-archive-production.up.railway.app/api/anchor \
  -H "Content-Type: application/json" \
  -H "payment-signature: <x402 payment header>" \
  -d '{"hash":"<sha256 hex>","envelope_id":"contract-001"}'

Price: $0.01 per anchor. Verification is always free.

OpenAPI spec: /openapi.json — machine-readable for LLMs, tools, and code generators.

Self-hosted quick start

git clone https://github.com/m-reynaldo35/pq-verifiable-archive.git
cd pq-verifiable-archive
npm install
cp .env.example .env   # fill in ALGORAND_MNEMONIC + ML-DSA keys
npm run generate-wallet   # or use existing wallet
npm run register-key      # registers your ML-DSA-65 key on Algorand
npm start                 # HTTP server on :3000
npm run mcp               # MCP server (stdio) for AI agents

Generate a sample document and verify it:

npx tsx scripts/generate-sample-pdf.ts
npm run verify -- --bundle bundles/sample-contract-bundle.json --pdf assets/sample-contract.pdf

Required env vars (see .env.example): ALGORAND_MNEMONIC, DOCUSIGN_MLDSA_PUBLIC_KEY, DOCUSIGN_MLDSA_PRIVATE_KEY, DOCUSIGN_KEY_REGISTRATION_TXN_ID.

Optional: X402_TREASURY_ADDRESS to enable pay-per-anchor on /api/anchor.

How verification works

The verifier (npm run verify) exits 0 = VALID, 1 = INVALID, 2 = operational error.

Step	Check	Offline?
1	ML-DSA-65 signature over bundle (NIST FIPS-204)	Yes
2	SHA-256(PDF) matches bundle.documentHash	Yes
3	Merkle proof walks from hash to root	Yes
4	Algorand txn note contains merkle root	AlgoNode (not DocuSign)
5	Falcon-512 state proof covers the anchor round	AlgoNode (not DocuSign)

Who uses this

• HR platforms — offer letters, NDAs, termination agreements with quantum-proof audit trail
• Legal tech — tamper-evident contract archive that survives vendor shutdown
• Healthcare — patient consent forms (no PII on-chain — HIPAA-compatible)
• AI agents — autonomous agents executing agreements need immutable, verifiable receipts
• Anyone signing documents today that need to be verifiable in 2040

Proof bundle (example)

{
  "protocol": "pqva/1",
  "envelopeId": "contract-2026-001",
  "documentHash": "0569e7cb...",
  "merkleRoot": "97d5d40b...",
  "merkleProof": ["9b1b4a3c...", "34b53407..."],
  "algorandTxnId": "QIS2LWKE...",
  "algorandRound": 62052659,
  "blockTimestamp": "2026-06-11T13:50:11.808Z",
  "stateProofRound": 62052864,
  "docusignSigners": [
    { "name": "Jordan Avery", "email": "jordan@acme.example", "signedAt": "2026-06-11T13:48:02Z" }
  ],
  "algorithm": "ml-dsa-65",
  "mldsaPublicKey": "...",
  "signature": "75483d62..."
}

Full schema: docs/architecture.md

Tech stack

Component	Choice
Post-quantum signatures	@noble/post-quantum — ML-DSA-65 (NIST FIPS-204)
Blockchain	Algorand mainnet — Falcon-512 state proofs
AI agent interface	@modelcontextprotocol/sdk — MCP stdio server
Payments	@x402-avm/express — x402 on Algorand (GoPlausible)
Merkle trees	merkletreejs — SHA-256
Canonical JSON	canonicalize — JCS, RFC 8785
Runtime	TypeScript + Node.js via tsx

License

MIT — free to use, self-host, and fork.