对LZ混沌序列密码算法的分割攻击

摘要

分析基于混沌的伪随机序列密码算法的安全性,发现该算法具有所产生密钥流序列的前几个值对密钥低位比特的变化不够敏感的性质,不适合将混沌映射的参数作为密钥.为此,提出一个能够有效降低密钥熵的分割攻击方法,理论分析和实验结果证实了该方法的有效性.%This paper analyzes the security of a chaos-based stream cipher, it is found that the first several key stream bits of this chaotic cipher are not sensitive to the least significant bits of key, the parameter of chaotic mapping is not suitable as a key. Based on this information leaking, a divide-and-conquer attack is presented to decrease the entropy of key, and its effectiveness is confirmed by theoretic analysis and trials.