减轮Serpent算法差分-线性分析的新结果  

New Results of Differential-Linear Cryptanalysis on Reduced-Round Serpent

作　　者：陈少真[1,2] 付志新 任炯炯 CHEN Shaozhen;FU Zhixin;REN Jiongjiong(Information Engineering University, Zhengzhou 450001, China;State Key Laboratory of Cryptology, Beijing 100878, China)

机构地区：[1]信息工程大学,河南郑州450001 [2]密码科学技术国家重点实验室,北京100878

出　　处：《信息工程大学学报》2020年第6期699-704,共6页Journal of Information Engineering University

基　　金：数学工程与先进计算国家重点实验室开放基金课题(2018A03);国家密码发展基金资助项目(MMJJ20180203);信息保障技术重点实验室开放基金课题(KJ-17-002)。

摘　　要：Serpent算法是进入AES竞赛最后一轮的密码算法之一,分析了该算法的S盒和线性变换等组件性质,归纳出了其在差分和掩码传播过程中的若干规律。以此为基础搜索得到6条9轮差分-线性区分器,其中最好的1条区分器理论偏差达到2-57,优于现有最佳同轮数差分-线性区分器,能够更好地将随机置换和密码算法区分开。利用搜索到的区分器对减轮Serpent算法进行了差分-线性分析,并基于时空折中思想对攻击进行了改进,相比已有分析结果,在选择明文数量和攻击时间复杂度上均有一定改进。Serpent is one of the ciphers that entered the final round of the AES competition.This paper analyzes the S-box and linear transformation of the cipher in detail,and summarizes several rules in the process of differential and mask propagation.Based on this,six 9-round differential-linear distinguishers are obtained,and the best one of them has a theoretical bias of 2-57,higher than the best existing differential-linear distinguisher,which can better distinguish random transformation from Serpent.Differential-linear cryptanalysis of Serpent are performed based on the searched distinguisher,and improved based on the idea of space-time tradeoff.Compared with the existing results of differential-linear cryptanalysis on Serpent,the number of chosen plaintexts and time complexity are both reduced.

关 键 词：Serpent算法 差分-线性分析 时空折中 

分 类 号：TN918.1[电子电信—通信与信息系统]