基于密码结构的扩散层构造  

Construction of diffusion layers based on cipher structures

作　　者：李鹏飞[1,2] 

机构地区：[1]中国科学院信息工程研究所信息安全国家重点实验室,北京100093 [2]中国科学院大学网络空间安全学院,北京100049

出　　处：《网络与信息安全学报》2017年第6期65-76,共12页Chinese Journal of Network and Information Security

基　　金：国家自然科学基金资助项目(No.61379142)~~

摘　　要：以分组密码扩散层为研究对象,根据轻量级分组密码的特点,基于2种密码结构构造轻量级扩散层,分别是基于Feistel结构构造面向软件实现的扩散层和基于LFSR构造面向硬件实现的扩散层。利用三轮Feistel结构,轮函数采用基于循环移位和异或的线性变换,构造出作用在8个4 bit和8 bit S盒上分支数为7的轻量级对合扩散层。基于LFSR构造出作用在4个4 bit和8 bit S盒上的次最优扩散层和作用在8个4 bit和8 bit S盒上分支数为7的扩散层。另外,利用LFSR构造出了6、7、8维MDBL矩阵以及16、18、32维分支数分别为7、7、12的大维数二进制矩阵。研究结果在分组密码的设计方面具有较高的应用价值。Taked diffusion layers of block cipher algorithms as the research object, lightweight diffusion layers were constructed by two cipher structures based on the characteristics of diffusion layers of lightweight block cipher algorithms, which were the construction of software-oriented diffusion layers based on Feistel structure and the construction of hardware-oriented diffusion layers based on LFSR. Lightweight involution diffusion layers with branch numbers 7 over eight 4-bit and 8-bit S-boxes were constructed by 3-round Feistel structure and the round functions adopt linear transformations with rotation and XORs. Some suboptimal diffusion layers over four 4 bit and 8 bit S-boxes and diffusion layers with branch numbers 7 over eight 4 bit and 8 bit S boxes based on LFSR were constructed. In addition, 6, 7, 8 dimension MDBL matrices and many 16, 18, 32 dimension binary matrices with big dimension and branch numbers 7, 7, 12 based on LFSR were constructed. The experimental results have high practical significance in realm of the design of block cipher algorithms.

关 键 词：分组密码 扩散层 FEISTEL结构 反馈移位寄存器 MDBL矩阵 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]