Design of Optimal Diffusion Layers for SPN Block Ciphers  

作　　者：崔灵果 曹元大 

机构地区：[1]School of Information Science and Technology, Beijing Institute of Technology, Beijing 100081, China,School of Computer Science and Technology, Beijing Institute of Technology, Beijing 100081, China [2]School of Computer Science and Technology, Beijing Institute of Technology, Beijing 100081, China

出　　处：《Journal of Beijing Institute of Technology》2006年第3期292-295,共4页北京理工大学学报（英文版）

摘　　要：The diffusion layers in substitution-permutation network（SPN） block ciphers are almost invertible linear transformations, which is optimal if the branch number reaches the maximum value. The method of constructing involutory optimal diffusion layers is proposed based on the Cauchy matrix, which can decrease the cost of implementation. The analysis to experimental results indicates that the diffusion layer ensures the security of the SPN block cipher against differential cryptanalysis（DC） and linear cryptanalysis（LC）, and decreases half the cost of implementation.The diffusion layers in substitution-permutation network（SPN） block ciphers are almost invertible linear transformations, which is optimal if the branch number reaches the maximum value. The method of constructing involutory optimal diffusion layers is proposed based on the Cauchy matrix, which can decrease the cost of implementation. The analysis to experimental results indicates that the diffusion layer ensures the security of the SPN block cipher against differential cryptanalysis（DC） and linear cryptanalysis（LC）, and decreases half the cost of implementation.

关 键 词：substitution-permutation network（SPN） diffusion layer involutory transformation 

分 类 号：TP393.1[自动化与计算机技术—计算机应用技术]