摘要： 研究廖旎焕等人提出的广义映射混沌扩频序列算法(电子与信息学报，2006年第7期)，发现该算法所产生的混沌序列具有前几个值对密钥的低位比特变化不够敏感的性质，提出一个能有效降低密钥熵的分割攻击方法。在密钥长度为64 bit且参数d﹦3, h﹦0时，该分割攻击方法的成功率为0.979 7，平均计算复杂性约为243.46，可在PC上实现。

关键词: 混沌密码, 密码分析, 分割攻击, 扩频序列

Abstract: This paper analyzes chaotic spreading sequences generated by extended chaotic map presented by Liao Ni-huan et al, and finds that the first several values of chaotic spreading sequences are not sensitive to the key. Based on the characteristic of non-sensitivity, a divide-and-conquer attack that can decrease entropy of key efficiently is proposed. When the length of key is 64 bit and the parameters d=3, h=0, the success rate of the divide-and-conquer attack is 0.979 7, and the average complexity is about 243.46. The attack can be implemented on a PC.

Key words: chaotic cipher, cryptanalysis, divide-and-conquer attack, spreading sequence

中图分类号: 

• TN918.1