Improved Differential and Linear Active S-Boxes Search Techniques for Feistel Type Ciphers

作     者：ZHANG Lei WU Wenling 

作者机构：Trusted Computing and Information Assurance LaboratoryInstitute of Software State Key Laboratory of Computer ScienceInstitute of Software 

出 版 物：《Chinese Journal of Electronics》 (电子学报(英文))

年 卷 期：2015年第24卷第2期

页      面：343-348页

核心收录：

学科分类：11[军事学] 1105[军事学-军队指挥学] 0839[工学-网络空间安全] 08[工学] 110505[军事学-密码学] 110503[军事学-军事通信学] 

基　　金：supported by the National Natural Science Foundation of China(No.61202420,No.61272476,No.61232009) the National Basic Research Program of China(973 Program)(No.2013CB338002) 

主　　题：Block cipher Feistel type ciphers Differential and linear active S-boxes Automatic search technique 

摘      要：We propose improved differential and linear active S-boxes search techniques for Feistel type ciphers. We give a uniform representation of Feistel type structures which can benefit the analysis of differential propagation. By analyzing the properties of Feistel type environment, we present some important observations of differential propagation and propose a notion of equivalent state set which can narrow down the search space noticeably. We present a practical algorithm to improve the search of active S-boxes for Feistel type ciphers. It is basically a Viterbi search operating on equivalent state set and also adopts the pruning mechanism. Our experimental results show that the improved algorithm have advantages in respect to memory and time complexities, and it can be applied efficiently to Feistel cipher with large blocks. The search program can be implemented in normal PC, which will be more practical and useful for the designers and cryptanalysts.