ARX结构多比特约束和差分特性研究

发布时间：2019-05-06 10:57

【摘要】：ARX结构是指由模加、循环移位和逐位异或三种运算组合而成的一种密码算法部件。三种运算之间的相互作用和算法的多轮迭代特性,使得ARX结构算法的抗差分攻击能力很难量化分析。目前关于ARX结构算法的差分特性的研究成果较少,研究ARX结构密码算法抗差分攻击能力是一个很有现实价值和理论意义的课题。本文主要从多比特约束和差分路径搜索两个方面对ARX结构差分特性进行了研究,主要工作如下:1.利用了多比特约束条件,找出了模加运算中输入输出差分不兼容的情形,指出了Skein算法已有的差分路径的不兼容性;找出了模加运算和循环移位运算相结合的部件中输入输出差分不兼容的情形。2.提出了一种ARX结构差分路径搜索算法,找到了Chacha算法的一条差分重量为13的3轮差分路径。该搜索算法融入了预先分析和差分正确性检测的环节,与已有的搜索算法相比,具有较强的针对性和有效性。
[Abstract]:ARX structure is a cipher algorithm component which is composed of modular addition, cyclic shift and bit-by-bit XOR. The interaction among the three operations and the multiple iterations of the algorithm make it difficult to quantify the anti-differential attack capability of the ARX structure algorithm. At present, there are few research results on the differential characteristics of ARX structure algorithm. It is of great practical value and theoretical significance to study the ability of ARX structure cryptosystem to resist differential attack. In this paper, we mainly study the differential characteristics of ARX structure from two aspects: multi-bit constraint and differential path search. The main work is as follows: 1. By using the multi-bit constraint condition, the incompatibility of input-output difference in modular addition is found, and the incompatibility of the differential path of Skein algorithm is pointed out. The incompatibility of input and output difference between modular addition and cyclic shift operation is found. 2. A ARX-structured differential path search algorithm is proposed, and a 3-round differential path with a difference weight of 13 is found in the Chacha algorithm. The search algorithm combines the pre-analysis and differential correctness detection. Compared with the existing search algorithm, the search algorithm has strong pertinence and effectiveness.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN918.2

【共引文献】