混沌密码系统弱密钥随机性分析  

Weak key analysis for chaotic cipher based on randomness properties

作　　者：尹汝明[1] 袁坚[1] 山秀明[1] 王希勤[1] 

机构地区：[1]清华大学电子工程系,北京100084

出　　处：《中国科学：信息科学》2011年第7期777-788,共12页Scientia Sinica(Informationis)

基　　金：国家自然科学基金(批准号:60674048)资助项目

摘　　要：弱密钥问题是混沌密码系统设计中的关键问题,已有研究主要从混沌序列退化角度进行分析.然而,本文指出保证混沌序列不退化的密钥参数仍可能构成混沌密码的弱密钥.本文提出以混沌密码序列随机性作为评价标准,应用严格的统计检验方法对混沌密码的弱密钥进行检测.进一步,对一类混沌密码系统进行了弱密钥研究,检测出了该系统大量未被发现的弱密钥.这确证了所提出方法的有效性.另一方面,虽然已有较多研究采用统计检验对混沌比特序列进行测试,但将统计检验用于分析混沌密码弱密钥或弱序列的研究还很少见.本文给出的统计检验弱序列分析,对当前混沌密码统计检验研究是一个很好的补充.Weak key analysis is a key issue in the design of chaotic ciphers.While most of the existing research focusing on the degradation of the chaotic sequences which cause weak keys,we point out that the parameters for which the chaotic sequences do not degrade are still possible to be weak keys.In this paper,we propose a new approach based on the rigorous statistical test to improve the weak key analysis.The weak keys of a specific chaotic cipher are investigated by using our method and a large number of new weak keys are detected.These results verify that our method is more effective.On the other hand,although statistical tests are now widely adopted to test the chaos-based bit sequences,there are few reports of analysis results on the weak keys or weak sequences of chaotic cipher.Thus our work may be helpful for current research on statistical tests of chaotic cipher.

关 键 词：混沌 密码学 统计检验 弱密钥 序列随机性 

分 类 号：TN918.1[电子电信—通信与信息系统]