vendor/c2-chacha/README.md

   1 # The ChaCha family of stream ciphers
   2
   3 ## Features
   4
   5 - pure Rust implementation
   6 - supports the RustCrypto API
   7 - builds on stable Rust
   8 - portable
   9 - fast: within 15% of throughput of a hand-optimized ASM SIMD implementation
  10   (floodberry/chacha-opt) on my machine (a Xeon X5650, using ppv-lite86)
  11 - no-std compatible (std required only for runtime algorithm selection)
  12
  13 ## Supported Variants
  14
  15 ChaCha20: used in chacha20-poly1305 in TLS, OpenSSH; arc4random in the BSDs,
  16 Linux /dev/urandom since 4.8.
  17
  18 Ietf: IETF RFC 7539. Longer nonce, short block counter.
  19
  20 XChaCha20: constructed analogously to XSalsa20; a mixing step during
  21 initialization allows using a long nonce and along with a full-sized block
  22 counter.
  23
  24 ChaCha12, ChaCha8: faster; lower security margin of safety.