针对WSN流密码加密方案的代数攻击及改进

Algebraic Attack and Improvement on WSN Stream Cipher Encryption Scheme

通过对Yao等人提出的无线传感器网络(WSN)流密码系统(ICMTMA’11)进行分析,找到系统中布尔函数的一个非零低次零化子,再利用代数攻击降低攻击复杂度。为增强WSN流密码加密方案的安全性,采用二阶级联方法构造一个新的布尔函数,其代数免疫度与原函数相比增加1,由此提高抗攻击能力。理论分析结果表明,新方案将原方案的攻击复杂度由255提高至266,可以更好地抵抗代数攻击。

By analyzing Yao＇s stream cipher scheme of Wireless Sensor Network（WSN）, this paper finds a nonzero low times annihilator in the design of Boolean function, and reduces the attack complexity by algebraic attack. In order to enhance the security of WSN stream cipher scheme, this paper constructs a new Boolean function with the second-order concatenation. Compared with original Boolean function, algebra immune degree of the new function increases 1. Analysis results shows that attack complexity of the new scheme promotes the attack complexity from 2^55 to 2^66, proving that the new scheme can resist algebraic attack more effectively.