Robin算法一个新的不可能差分攻击

A Novel Impossible Differential Attack on Robin Algorithm

Robin算法是采用比特切片设计的一个分组密码算法,本文研究给出该算法之不可能差分攻击区分器的一定改良。具体地,在前人的研究基础上,改变一个约束条件而推导出关于Robin算法的-一个重要性质。根据该性质,利用轮密钥之间的线性关系可构造出新的区分器形式,从而降低选择明文数N。基于该区分器攻击的时间复杂度为大约2^(118.21)次6轮加密运算、数据复杂度为2^(111.18)(较已有结果降低了大约2^(8))。

Robin algorithm is a block cipher algorithm designed with bit slices.In this paper,a partly improved distinguisher against the impossible differential attack on Robin algorithm is studied and presented.Concretely,an important character of Robin algorithm is derived by changing a constraint condition on tlie basis of previous researches.According to the derived character,the linear relationship between the round keys is used to construct a novel distinguisher form to reduce tlie number of selected plaintexts.Time complexity of the attack based on the distinguisher is 2^(118.21) times 6-round encryptions and data complexity is 2^(111.18) that is about 2^(8) reduced compared with the available results.