低轮Blow-CAST-Fish算法的差分攻击

摘要

By analyzing the collision of four S-boxes which are subkeys of Blow-CAST-Fish, this paper develops the differential characteristic of function F with non-zero inputxor and a zero outputxor, performs a differential cryptanalysis of the algorithm to recover the rest of the subkeys, and tests the proportion of weak keys which can produce the differential characteristic. Based on this, it succeeds in using the 6-round differential characteristic with the probability 2-61 under 2-12 of the total key space to attack 8-round Blow-CAST-Fish.%对作为Blow-CAST-Fish算法子密钥的4个S盒的碰撞性进行分析,构造输入差分为非零、输出差分为零的轮函数F的差分特征,通过对算法进行差分分析,获取相关子密钥,并测试使特征成立的弱密钥概率.在此基础上,成功利用特征概率为2-61、弱密钥概率为2-12的6轮差分特征攻击8轮Blow-CAST-Fish算法.