密码学函数迭代原理信息论分析

Information Analysis of Iterative Principle of Cryptographic Function

在密码编码学中 ,经常利用密码学函数迭代技术来实现密码算法 ,其所依赖的理论基础包括相关免疫理论 ,扩散准则 ,雪崩原理等 .本文利用信息论原理以及随机过程理论给出了密码学函数迭代原理分析 ,得到了经过密码学函数迭代之后 ,输出为均匀分布时 ,输入输出互信息极限为零的充分必要条件 ,以及在一定条件下输入输出互信息收敛速度的一个上界 .

In cryptographic design,people often use the method of iterative principle of cryptographic function to give the cryptographic algorithm.In this paper,using the information theory and random process method,we get the necessary and sufficient condition of the iterative mutual information becoming to zero and one upper bound of the rate of its convergence under some condition.