react-native-privyx-crypto

Post-quantum hybrid cryptography for React Native.

Combines X25519 (ECDH) + ML-KEM-768 (post-quantum KEM) with AES-256-GCM encryption. Uses prebuilt native binaries — no Rust toolchain required.

Installation

npm install react-native-privyx-crypto

For iOS, after installing:

cd ios && pod install

Usage

import {
  generateX25519KeyPair,
  generateMlKemKeyPair,
  x25519DeriveSecret,
  mlKemEncapsulate,
  mlKemDecapsulate,
  deriveHybridSecret,
  encrypt,
  decrypt,
  generateIV,
} from 'react-native-privyx-crypto';

Key Generation

// Generate X25519 (ECDH) key pair
const x25519 = await generateX25519KeyPair();
// { publicKey: 'base64...', privateKey: 'base64...' }

// Generate ML-KEM-768 (post-quantum) key pair
const mlkem = await generateMlKemKeyPair();
// { publicKey: 'base64...', privateKey: 'base64...' }

Key Exchange (Initiator)

// Alice derives shared secret using her private key + Bob's public keys
const x25519Secret = await x25519DeriveSecret(alice.privateKey, bob.x25519PublicKey);

const mlkemEnc = await mlKemEncapsulate(bob.mlkemPublicKey);
// { sharedSecret: 'base64...', ciphertext: 'base64...' }

const hybridSecret = await deriveHybridSecret(x25519Secret, mlkemEnc.sharedSecret);

Key Exchange (Responder)

// Bob derives shared secret using his private key + Alice's ciphertext
const x25519Secret = await x25519DeriveSecret(bob.privateKey, alice.x25519PublicKey);

const mlkemSecret = await mlKemDecapsulate(bob.mlkemPrivateKey, mlkemCiphertext);

const hybridSecret = await deriveHybridSecret(x25519Secret, mlkemSecret);

Both parties arrive at the same hybridSecret.

Encrypt / Decrypt

const iv = await generateIV();
const ciphertext = await encrypt('Hello, post-quantum world!', hybridSecret, iv);

const plaintext = await decrypt(ciphertext, iv, hybridSecret);

API

All functions return Promise. All keys and ciphertexts are base64-encoded strings.

Function	Returns
generateX25519KeyPair()	{ publicKey, privateKey }
generateMlKemKeyPair()	{ publicKey, privateKey }
x25519DeriveSecret(privateKey, publicKey)	string (shared secret)
mlKemEncapsulate(publicKey)	{ sharedSecret, ciphertext }
mlKemDecapsulate(privateKey, ciphertext)	string (shared secret)
deriveHybridSecret(x25519Secret, mlkemSecret)	string (SHA-256 hybrid)
encrypt(plaintext, sharedSecret, iv)	string (base64 ciphertext)
decrypt(ciphertext, iv, sharedSecret)	string (plaintext)
generateIV()	string (base64 12-byte IV)

Supported Platforms

Platform	Architectures
Android	arm64-v8a, armeabi-v7a, x86_64
iOS (device)	arm64
iOS (simulator)	arm64-sim, x86_64-sim

Requirements

• React Native >= 0.71
• Android minSdk 24+
• iOS 15.1+

License

MIT