基于正交拟群的流密码算法

Stream Cipher Based on Mutually Orthogonal Quasigroups

利用正交拟群的特点,克服Edon80的弱点,设计了称为Double40的二进制加法同步流密码算法.它基于一对8阶相互正交的自正交拟群,使得Johansson和Hell的密钥恢复攻击对Double40无法奏效.

Edon80 is a hardware binary additive synchronous stream cipher submitted to the last phase of the e STREAM project. The core of the cipher consists of quasigroup string e-transformations and employs four quasigroups of order 4. The best attack on Edon80 is the key recovery attack given by Johansson and Hell, which can recover the key with complexity around 272. In this paper, using the characteristics of orthogonal quasigroup to overcome the shorting of Edon80, a binary additive synchronous stream cipher named Double40 is designed. It is based on a pair of mutually orthogonal quasigroups of order 8 which are self-orthogonal. The developed algorithm disables the key recovery attack of Johansson and Hell on Double40.