Go And ChaCha

The demo of the code we will show is here.

So what encryption method is your browser using just now? AES? Well, there’s a good chance that it is ChaCha, and it is kinda taking over as a preferred method for symmetric key encryption within TLS connections. Why? Well, it’s much faster than AES. It is also well suited to IoT devices. And, well … it isn’t AES!

Google worry that AES has a virtual monopoly on secret key encryption, so what would happen it is was cracked? They thus, in an RFC, proposed the usage of a stream cipher known as ChaCha20:

ChaCha20 takes a 256-bit key and a 32-bit nonce and then creates a key stream, which is then XORed with the plaintext stream. In software, it is three times faster than AES, and is well suited to lower-powered devices and in real time communications.

Method

ChaCha20 and Salsa take a 256-bit key (or a 128-bit version) and a 32-bit nonce This creates a key stream, which is then XORed with the plaintext stream. In software, it is more than three times faster than AES, and is well suited to lower-powered devices and in real-time communications.

ChaCha operates on 32-bit bits with a key of 256 bits (K=(k0, k1, k2, k3, k4, k5, k6, k7). This output blocks of 512-bits for the key stream (Z), and which is EX-ORed with the plaintext stream.