对八阵图算法的不可能差分密码分析和线性密码分析

Impossible Differential Cryptanalysis and Linear Cryptanalysis for Eight-Sided Fortress Algorithm

该文对八阵图(ESF)算法抵抗不可能差分密码分析和线性密码分析的能力进行了研究。ESF算法是一种具有Feistel结构的轻量级分组密码算法,它的轮函数为代换置换(SP)结构。该文首先用新的不可能差分区分器分析了12轮ESF算法,随后用线性密码分析的方法分析了9轮ESF算法。计算得出12轮不可能差分分析的数据复杂度大约为O(2^(67)),时间复杂度约为O(2^(110.7)),而9轮线性密码分析的数据复杂度仅为O(2^(35)),时间复杂度不大于O(2^(15.6))。结果表明ESF算法足够抵抗不可能差分密码分析,而抵抗线性密码分析的能力相对较弱。

The ability of Eight-Sided Fortress(ESF)algorithm to resist impossible differential cryptanalysis and linear cryptanalysis is studied in this paper.The ESF algorithm is a lightweight block cipher algorithm with Feistel structure,and its round function is Substitution-Permutation(SP)structure.Firstly,12 rounds of ESF algorithm is analyzed in this paper by a new impossible differential distinguisher,and then 9 rounds of ESF algorithm is analyzed by linear cryptanalysis.It is calculated that the data complexity of 12 rounds of impossible differential analysis is about O(2^(67)),and the time complexity is about O(2^(110.7)),while the data complexity of 9 rounds of linear cryptanalysis is only O(2^(35)),and the time complexity is no more than O(2^(15.6)).The results show that ESF algorithm is able to resist impossible differential cryptanalysis,while its ability to resist linear cryptanalysis is relatively weak.