Differential Analysis of ARX Block Ciphers Based on an Improved Genetic Algorithm  

作　　者：KANG Man LI Yongqiang JIAO Lin WANG Mingsheng 

机构地区：[1]State Key Laboratory of Information Security,Institute of Information Engineering,Chinese Academy of Sciences,Beijing 100195,China [2]School of Cyber Security,University of Chinese Academy of Sciences,Beijing 071051,China [3]State Key Laboratory of Cryptology,Beijing 100878,China

出　　处：《Chinese Journal of Electronics》2023年第2期225-236,共12页电子学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(61772516,61902030,61772517).

摘　　要：Differential cryptanalysis is one of the most critical analysis methods to evaluate the security strength of cryptographic algorithms.This paper first applies the genetic algorithm to search for differential characteristics in differential cryptanalysis.A new algorithm is proposed as the fitness function to generate a high-probability differential characteristic from a given input difference.Based on the differential of the differential characteristic found by genetic algorithm,Boolean satisfiability(SAT)is used to search all its differential characteristics to calculate the exact differential probability.In addition,a penalty-like function is also proposed to guide the search direction for the application of the stochastic algorithm to differential cryptanalysis.Our new automated cryptanalysis method is applied to SPECK32 and SPECK48.As a result,the 10-round differential probability of SPECK32 is improved to 2^(−30.34),and a 12-round differential of SPECK48 with differential probability 2−46.78 is achieved.Furthermore,the corresponding differential attacks are also performed.The experimental results show our method’s validity and outstanding performance in differential cryptanalysis.

关 键 词：Genetic algorithm Differential cryptanalysis SPECK Satisfiability(SAT) 

分 类 号：TP309[自动化与计算机技术—计算机系统结构] TP18[自动化与计算机技术—计算机科学与技术]