针对SOSEMANUK的猜测-确定攻击

Guess and Determine Attack on SOSEMANUK

通过分析流密码算法SOSEMANUK的一个设计弱点,提出一种针对SOSEMANUK密钥流生成器的猜测-确定攻击。该攻击只需要猜测7个32 bit内部状态变量,就可以确定唯一的12个状态变量,攻击算法只需要6个密钥字且计算复杂度为O(2196)。攻击结果表明,该设计存在安全漏洞,SOSEMANUK抗猜测-确定攻击的计算复杂度远低于O(2256)。

By analyzing the weakness in design of the stream cipher SOSEMANUK, this paper presents Guess and Determine on it. It guesses 7-words internal state, each word contains 32 bit, and then all the internal state can be achieved, the process requires only 6 keystream words. Guess and Determine attack on the cipher is introduced with a computational complexity of O（2196）. The results show that the equation which is analyzed exists security vulnerabilities, moreover the computational complexity of attack is far lower than O（2：56）.