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