一类密钥流生成器的相关分析  

Cryptanalysis on a Kind of Keystream Generator

作　　者：马卫局[1] 冯登国[2] 巫治平[1] 张斌[3] 

机构地区：[1]中国科学院研究生院信息安全国家重点实验室,北京100039 [2]中国科学院软件研究所,北京100080 [3]新加坡国立大学信息通信实验室,新加坡119613

出　　处：《电子与信息学报》2004年第8期1282-1287,共6页Journal of Electronics & Information Technology

基　　金：国家攀登计划973项目(G1999035802);国家杰出青年科学基金(60025205)资助课题

摘　　要：多输出逻辑函数是构造密码系统的重要工具,相关免疫性是设计安全逻辑函数的重要准则.该文利用一种较为简单的方法证明了多输出逻辑函数相关免疫性两种刻划的等价性.还对一类利用多输出逻辑函数相关免疫函数构造的密钥流生成器进行了相关性分析,证明了这种构造方法是不成立的,并不能达到构造者期望的相关免疫性,并且分别利用Walsh变换技术和线性序列电路逼近方法找出了这类密钥流生成器的漏洞,从而说明这类生成器在相关攻击下是脆弱的.Multiple outputs logic function is an important tool for constructing cryptography systems, and correlation immunity is a critical criterion in designing secure logic functions. In this paper, a very simple method is used to prove that two descriptions of correlation immunity of multiple outputs logic function are equivalent indeed. The correlation properties of a kind of keystream generator are analyzed, which is defined by multiple outputs logic functions. It is found that this constructing method is wrong, which means that the immunity expected by the construction cannot be obtained. Walsh transform technique and linear sequential circuit approximation method are applied to find the weakness of this kind keystream generator respectively. That is to say the keystream generator constructed by this method is vulnerable.

关 键 词：相关系数 相关免疫性 密钥流生成器 

分 类 号：TN918.1[电子电信—通信与信息系统]