go threefish

三條魚

Threefish 是一種可調整的分組密碼，作為 Skein 哈希函數的一部分而開發，作為 NIST 哈希函數競賽的提交材料。 Threefish 支援 256、512 和 1024 位元的區塊大小。

完整的 Threefish 規格可在註腳¹中找到。

測試向量是從最新的參考實作中提取的² 。

加密和解密循環已展開，每次迭代包含八輪。這允許將旋轉常數嵌入到程式碼中而無需重複。論文¹詳細描述了這種做法，該論文還提供了詳細的性能資訊。

安裝

若要在 go 專案中作為依賴項安裝：

 go get -U github.com/schultz-is/go-threefish 

用法

此套件中的密碼實作實作了crypto/cipher cipher.Block介面。此程式庫傳回的執行個體可與支援 256、512 或 1024 位元區塊大小的任何區塊密碼模式一起使用。

 package main

import (
	"crypto/cipher"
	"crypto/rand"
	"fmt"

	"github.com/schultz-is/go-threefish"
)

func main () {
	message := make ([] byte , 128 )
	copy ( message , [] byte ( "secret message" ))

	// Assign a key. Generally this is derived from a known secret value. Often
	// a passphrase is derived using a key derivation function such as PBKDF2.
	key := make ([] byte , 128 )
	_ , err := rand . Read ( key )
	if err != nil {
		panic ( err )
	}

	// Assign a tweak value. This allows customization of the block cipher as in
	// the UBI block chaining mode. Support for the tweak value is not available
	// in the block ciphers modes supported by the standard library.
	tweak := make ([] byte , 16 )
	_ , err = rand . Read ( tweak )
	if err != nil {
		panic ( err )
	}

	// Instantiate and initialize a block cipher.
	block , err := threefish . New1024 ( key , tweak )
	if err != nil {
		panic ( err )
	}

	// When using CBC mode, the IV needs to be unique but does not need to be
	// secure. For this reason, it can be prepended to the ciphertext.
	ciphertext := make ([] byte , block . BlockSize () + len ( message ))
	iv := ciphertext [: block . BlockSize ()]
	_ , err = rand . Read ( iv )
	if err != nil {
		panic ( err )
	}

	mode := cipher . NewCBCEncrypter ( block , iv )
	mode . CryptBlocks ( ciphertext [ block . BlockSize ():], message )

	fmt . Printf ( "%x n " , ciphertext )
}

測試

可以執行單元測試，並可以透過​​提供的 Makefile 查看測試覆蓋率。

 make test
make cover 

標竿管理

可以運行基準測試，並可以透過​​提供的 Makefile 產生 CPU 和記憶體設定檔。

 make benchmark
go tool pprof cpu.prof
go tool pprof mem.prof 

表現

2020 Mac Mini M1

 name                      time/op  speed
Threefish256/encrypt-8     85 ns   372 MB/s
Threefish256/decrypt-8    111 ns   287 MB/s
Threefish512/encrypt-8    234 ns   272 MB/s
Threefish512/decrypt-8    363 ns   175 MB/s
Threefish1024/encrypt-8   581 ns   220 MB/s
Threefish1024/decrypt-8   685 ns   186 MB/s

2019 MacBook Pro 2.3GHz 英特爾 i9

 name                      time/op  speed
Threefish256/encrypt-16   124 ns   259 MB/s
Threefish256/decrypt-16   156 ns   206 MB/s
Threefish512/encrypt-16   338 ns   189 MB/s
Threefish512/decrypt-16   310 ns   206 MB/s
Threefish1024/encrypt-16  804 ns   159 MB/s
Threefish1024/decrypt-16  778 ns   165 MB/s 

註腳

1. http://www.skein-hash.info/sites/default/files/skein1.3.pdf ↩ ↩ ²

2. http://www.skein-hash.info/sites/default/files/NIST_CD_102610.zip ↩