AEZ implementation for node

This is an implementation of the AEZ authenticated-encryption scheme in JavaScript for node.

The code is based upon Yawning's implementation in Go and the reference implementation in C.

I am by no means an expert in high performance JavaScript or the underlying cryptography. So this library might be really slow.

The current version passes all test vectors generated with this hacked version of aez. But the author does not give any guarantees that the algorithm is implemented correctly for every edge case!

How to install

NPM:

npm install --save aez

yarn:

yarn add aez

How to use

NOTE: Every parameter that is not a number should be of type Buffer (or array of Buffer).

const aez = require('aez');
const Buffer = require('safe-buffer').Buffer;

const key = Buffer.from('1311f8fc80a7ea28d78dd7723f09c44c1754cd35160ca8e7133ae3d7f636a19a', 'hex'); // sha256 of 'my-secret-key', but you should use a key derivation function like scrypt or PBKDF2!
const salt = Buffer.from('abba0110', 'hex'); // some random salt
const plaintext = Buffer.from('please encrypt me!', 'utf8');
const tau = 4;

const cipherText = aez.encrypt(key, null, [salt], tau, plaintext);
console.log('The encrypted string is: ' + cipherText.toString('hex'));

const decryptedText = aez.decrypt(key, null, [salt], tau, cipherText);
console.log('The decrypted string is: ' + decryptedText.toString());

API

aez.encrypt(key : Buffer, nonce : Buffer, additionalData : Buffer[], tau : Number, plaintext : Buffer) : Buffer

Encrypts a plaintext buffer with the given key, nonce and additionalData.

aez.decrypt(key : Buffer, nonce : Buffer, additionalData : Buffer[], tau : Number, ciphertext : Buffer) : Buffer

Decrypts a ciphertext buffer with the given key, nonce and additionalData.

If the key is incorrect, null is returned.

Performance

The code is not yet optimized for performance.

The following throughputs were achieved on an Intel Core i7-6500U running on linux/amd64:

$ node test/aez_benchmark.js
Message size: 1 bytes x 18,225 ops/sec ±2.01% (79 runs sampled) 60 us/op 16.3 kB/s
Message size: 32 bytes x 18,561 ops/sec ±1.88% (87 runs sampled) 58 us/op 540.6 kB/s
Message size: 512 bytes x 7,669 ops/sec ±1.46% (88 runs sampled) 139 us/op 3.5 MB/s
Message size: 1024 bytes x 4,804 ops/sec ±1.26% (89 runs sampled) 221 us/op 4.4 MB/s
Message size: 2048 bytes x 2,607 ops/sec ±3.51% (84 runs sampled) 406 us/op 4.8 MB/s
Message size: 16384 bytes x 413 ops/sec ±1.27% (87 runs sampled) 2558 us/op 6.1 MB/s
Message size: 32768 bytes x 215 ops/sec ±0.62% (83 runs sampled) 4910 us/op 6.4 MB/s
Message size: 65536 bytes x 109 ops/sec ±0.72% (79 runs sampled) 9642 us/op 6.5 MB/s
Message size: 1024768 bytes x 7.23 ops/sec ±0.82% (22 runs sampled) 140133 us/op 7.0 MB/s
Done in 49.59s.