SMS4算法的不可能差分攻击研究

Research on Impossible Differential Attack of Cipher SMS4

为研究分组加密算法SMS4抵抗不可能差分攻击的能力,使用了14轮不可能差分路径,给出了相关攻击结果。基于1条14轮不可能差分路径,对16轮和18轮的SMS4算法进行了攻击,改进了关于17轮的SMS4的不可能差分攻击的结果,将数据复杂度降低到O(269.47)。计算结果表明:攻击16轮SMS4算法所需的数据复杂度为O(2103),时间复杂度为O(292);攻击18轮的SMS4算法所需的数据复杂度为O(2104),时间复杂度为O(2123.84)。

To analyze impossible differential cryptanalysis on the block cipher SMS4,the results were presented based on one 14-round impossible differential route.One impossible differential attack was applied to 16-round and 18-round reduced SMS4,and improved result on 17 round CLEFFIA-256 was given with the number of chosen plaintexts being reduced to O（269.47）.Computing result shows that the attack of 16-round SMS4 needs O（2103）choosing plaintext operations,and O（292）encrypting computations,and the attack of 18-round SMS4 needs O（2104）choosing plaintext operations and O（2123.84）encrypting computations.