Twofish : A 128-bit block cipher
Twofish : A 128-bit block cipher
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发表时间：
1998
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通讯作者：
B. Schneier
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作者：
B. Schneier
Twofish是一个128位的密码，它接受可变的长度键，最高可达256位。密码是一个16轮Feistel网络，具有由四个密钥依赖的8乘8位S-Boxes组成的两种射击F函数，一个固定的4 x-4最大距离可分开的矩阵（2），A伪哈达马德变换，位旋转和精心设计的关键时间表。每个字节时钟周期为17.8时，对五角星Pro上的Twofish加密进行了完全优化的实现，并以每个字节为单位1660时钟周期进行了8位智能卡实现。 Twofish可以在14000门的硬件中实现。圆形功能和关键时间表的设计允许速度，软件大小，密钥设置时间，门计数和内存之间进行各种折衷。我们已经广泛地隐身了二元。我们最好的攻击以2个选定的明文和2次努力打破了5轮。
Twofish is a 128-bit block cipher that accepts a variable-length key up to 256 bits. The cipher is a 16-round Feistel network with a bijective F function made up of four key-dependent 8-by-8-bit S-boxes, a fixed 4-by-4 maximum distance separable matrix over GF(2), a pseudo-Hadamard transform, bitwise rotations, and a carefully designed key schedule. A fully optimized implementation of Twofish encrypts on a Pentium Pro at 17.8 clock cycles per byte, and an 8-bit smart card implementation encrypts at 1660 clock cycles per byte. Twofish can be implemented in hardware in 14000 gates. The design of both the round function and the key schedule permits a wide variety of tradeoffs between speed, software size, key setup time, gate count, and memory. We have extensively cryptanalyzed Twofish; our best attack breaks 5 rounds with 2 chosen plaintexts and 2 effort.