@anoncitizen/core

Core TypeScript SDK for privacy-preserving Aadhaar identity verification using zero-knowledge proofs.

Installation

npm install @anoncitizen/core

Usage

import { AnonCitizen } from "@anoncitizen/core";

const ac = new AnonCitizen({
  wasmUrl: "./aadhaar-verifier.wasm",
  zkeyUrl: "./aadhaar-verifier.zkey",
  verificationKey: vkey,
});

// Set UIDAI RSA public key
ac.setPublicKey(uidaiCertPem);

// Parse Aadhaar QR code
const payload = await ac.parseQR(qrData);

// Generate ZK proof with selective disclosure
const proof = await ac.prove({
  qrData,
  nullifierSeed: 42n,
  revealAgeAbove18: true,
  revealGender: false,
  revealState: false,
  revealPinCode: false,
});

// Verify off-chain
const result = await ac.verify(proof);
console.log(result.valid);       // true
console.log(result.ageAbove18);  // true
console.log(result.nullifier);   // BigInt

// Format for on-chain verification
const calldata = ac.formatForContract(proof);

API

AnonCitizen class

• constructor(config) — Initialize with WASM/zkey URLs and optional verification key
• setPublicKey(certOrKey) — Set UIDAI RSA public key (PEM, DER, or pre-parsed)
• parseQR(qrData) — Parse Aadhaar QR code into structured payload
• prove(request) — Generate a Groth16 ZK proof
• verify(proof) — Verify proof off-chain
• formatForContract(proof) — Format proof for Solidity contract call

Standalone functions

• parseQRCode(qrData) — Parse QR without SDK instance
• generateProof(payload, publicKey, request, wasmPath, zkeyPath) — Low-level proof generation
• verifyProofOffChain(proof, verificationKey) — Low-level verification
• formatProofForContract(proof) — Format for on-chain use
• hashSignal(signal) — Poseidon hash for signal binding
• generateNullifierSeed(appId) — Deterministic nullifier seed from app ID

Circuit Artifacts

The WASM and zkey files are not bundled with this package. Host them on IPFS or a CDN and provide URLs in the config.

License

MIT