Cryptographic Implementation

import { DoubleRatchet } from "@agentvault/crypto";

// After X3DH handshake, initialize the ratchet
const ratchet = DoubleRatchet.initSender(sharedSecret, remotePublicKey);

// Encrypt a message
const { header, ciphertext } = await ratchet.encrypt(
  new TextEncoder().encode("Hello, agent!")
);

// Send header + ciphertext to the server (server sees only ciphertext)

import { DoubleRatchet } from "@agentvault/crypto";

// After X3DH handshake, initialize the ratchet
const ratchet = DoubleRatchet.initReceiver(sharedSecret, localKeyPair);

// Decrypt an incoming message
const plaintext = await ratchet.decrypt(header, ciphertext);
const message = new TextDecoder().decode(plaintext);

from nacl.public import PrivateKey, Box
from nacl.signing import SigningKey
from nacl.utils import random

# Generate identity key pair
signing_key = SigningKey.generate()
verify_key = signing_key.verify_key

# Generate X25519 key pair for DH
private_key = PrivateKey.generate()
public_key = private_key.public_key

# XChaCha20-Poly1305 encryption via Box
box = Box(private_key, remote_public_key)
ciphertext = box.encrypt(plaintext)

import sodium from "libsodium-wrappers";

await sodium.ready;

// Generate identity key pair
const identityKeyPair = sodium.crypto_sign_keypair();

// Generate X25519 key pair
const dhKeyPair = sodium.crypto_kx_keypair();

// XChaCha20-Poly1305 encryption
const nonce = sodium.randombytes_buf(
  sodium.crypto_aead_xchacha20poly1305_ietf_NPUBBYTES,
);
const ciphertext = sodium.crypto_aead_xchacha20poly1305_ietf_encrypt(
  plaintext,
  null,    // additional data
  null,    // nsec (unused)
  nonce,
  key,
);