dnscrypt-proxy/vendor/github.com/aead/chacha20/README.md

83 lines
3.6 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

[![Godoc Reference](https://godoc.org/github.com/aead/chacha20?status.svg)](https://godoc.org/github.com/aead/chacha20)
[![Build Status](https://travis-ci.org/aead/chacha20.svg?branch=master)](https://travis-ci.org/aead/chacha20)
[![Go Report Card](https://goreportcard.com/badge/aead/chacha20)](https://goreportcard.com/report/aead/chacha20)
## The ChaCha20 stream cipher
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](https://tools.ietf.org/html/rfc7539 "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 instead of 20.
But it's recommended to use ChaCha20 (with 20 rounds) - it will be fast enough for almost all purposes.
### Installation
Install in your GOPATH: `go get -u github.com/aead/chacha20`
### Requirements
All go versions >= 1.8.7 are supported.
The code may also work on Go 1.7 but this is not tested.
### Performance
#### AMD64
Hardware: Intel i7-6500U 2.50GHz x 2
System: Linux Ubuntu 16.04 - kernel: 4.4.0-62-generic
Go version: 1.8.0
```
AVX2
name speed cpb
ChaCha20_64-4 573MB/s ± 0% 4.16
ChaCha20_1K-4 2.19GB/s ± 0% 1.06
XChaCha20_64-4 261MB/s ± 0% 9.13
XChaCha20_1K-4 1.69GB/s ± 4% 1.37
XORKeyStream64-4 474MB/s ± 2% 5.02
XORKeyStream1K-4 2.09GB/s ± 1% 1.11
XChaCha20_XORKeyStream64-4 262MB/s ± 0% 9.09
XChaCha20_XORKeyStream1K-4 1.71GB/s ± 1% 1.36
SSSE3
name speed cpb
ChaCha20_64-4 583MB/s ± 0% 4.08
ChaCha20_1K-4 1.15GB/s ± 1% 2.02
XChaCha20_64-4 267MB/s ± 0% 8.92
XChaCha20_1K-4 984MB/s ± 5% 2.42
XORKeyStream64-4 492MB/s ± 1% 4.84
XORKeyStream1K-4 1.10GB/s ± 5% 2.11
XChaCha20_XORKeyStream64-4 266MB/s ± 0% 8.96
XChaCha20_XORKeyStream1K-4 1.00GB/s ± 2% 2.32
```
#### 386
Hardware: Intel i7-6500U 2.50GHz x 2
System: Linux Ubuntu 16.04 - kernel: 4.4.0-62-generic
Go version: 1.8.0
```
SSSE3
name                        speed cpb
ChaCha20_64-4               570MB/s ± 0% 4.18
ChaCha20_1K-4               650MB/s ± 0% 3.66
XChaCha20_64-4              223MB/s ± 0% 10.69
XChaCha20_1K-4              584MB/s ± 1% 4.08
XORKeyStream64-4            392MB/s ± 1% 6.08
XORKeyStream1K-4            629MB/s ± 1% 3.79
XChaCha20_XORKeyStream64-4  222MB/s ± 0% 10.73
XChaCha20_XORKeyStream1K-4  585MB/s ± 0% 4.07
SSE2
name speed cpb
ChaCha20_64-4 509MB/s ± 0% 4.68
ChaCha20_1K-4 553MB/s ± 2% 4.31
XChaCha20_64-4 201MB/s ± 0% 11.86
XChaCha20_1K-4 498MB/s ± 4% 4.78
XORKeyStream64-4 359MB/s ± 1% 6.64
XORKeyStream1K-4 545MB/s ± 0% 4.37
XChaCha20_XORKeyStream64-4 201MB/s ± 1% 11.86
XChaCha20_XORKeyStream1K-4 507MB/s ± 0% 4.70
```