ChaCha is a stream cipher family created by Daniel J. Bernstein. The most common
ChaCha variant is ChaCha20 (20 rounds). ChaCha20 is standardized in RFC 7539.
This package provides implementations of three ChaCha versions:
- ChaCha20 with a 64 bit nonce (can en/decrypt up to 2^64 * 64 bytes for one
key-nonce combination)
- ChaCha20 with a 96 bit nonce (can en/decrypt up to 2^32 * 64 bytes ~ 256 GB
for one key-nonce combination)
- XChaCha20 with a 192 bit nonce (can en/decrypt up to 2^64 * 64 bytes for one
key-nonce combination)
Furthermore the chacha sub package implements ChaCha20/12 and ChaCha20/8. These
versions use 12 or 8 rounds inste -d of 20. But it's recommended to use ChaCha20
(with 20 rounds) - it will be fast enough for almost all purposes.
