流密码Grain v1的密钥恢复攻击及其改进  

Key Recovery Attack on Stream Cipher Grain v1 and Its Improvement

作　　者：杨文峰[1] 胡予濮[1] 高军涛[1] 

机构地区：[1]西安电子科技大学计算机网络与信息安全教育部重点实验室,陕西西安710071

出　　处：《西南交通大学学报》2010年第5期745-750,共6页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(60673072;60803149);国家973计划资助项目(2007CB311201);广西信息与通讯技术重点实验室开放基金资助项目(20902)

摘　　要：为探讨流密码Grain v1的安全性,通过研究Grain v1密钥流生成器的结构,指出了Grain v1密钥流生成器设计的3个弱点,在此基础上提出了一种基于中间状态的流密码Grain v1的密钥恢复攻击.该攻击的计算复杂度和空间复杂度分别等价于Grain v1密钥流生成器的计算复杂度和空间复杂度.为了抵抗所提出的攻击,对Grain v1密钥流生成器的设计进行了改进.安全性分析表明,改进设计能够抵抗所提出的密钥恢复攻击.In order to probe into the security of the stream cipher Grain v1,three design weaknesses of the Grain v1 key-stream generator were pointed out by studying its structure.Based on the above work,a key recovery attack on the stream cipher Grain v1 with an intermediate state was proposed.Time complexity and memory complexity of the proposed attack are equal to the time complexity and memory complexity of the Grain v1 key-stream generator respectively.In order to resist the proposed attack,an improvement on the Grain v1 key-stream generator was made.The security analysis shows that the improved generator is secure against the proposed key recovery attack.

关 键 词：密码分析 线性移位寄存器 布尔函数 流密码Grain 

分 类 号：TN918[电子电信—通信与信息系统]