简化SIMON类算法的立方测试与分析

Cube test and analysis for reduced SIMON family of block ciphers

针对轻量级分组密码算法SIMON的安全性分析,对SIMON32/64算法抵抗立方攻击的能力和算法内部结构对密钥比特的混淆和扩散性能力进行了评估。基于SIMON类算法的密钥编排特点和轮函数结构,结合立方分析的基本思想,利用FPGA测试平台设计了一个SIMON32/64的立方攻击和密钥中比特检测算法。攻击结果表明,在立方变元取6维至24维时,对于7轮SIMON32/64算法,通过立方攻击能够直接恢复47 bit密钥,攻击时间复杂度约为218.08;对于8轮SIMON32/64算法,能够直接恢复39 bit密钥,攻击时间复杂度约为225.00。对于10轮、11轮SIMON32/64算法,通过立方测试均能够捕获到密钥中比特。

Focusing on the safety analysis of the SIMON lightweight block cipher, this paper proposed a method on this algorithm against the cube attack and cube neutral-bit detection. Using the FPGA test platform, this paper proposed a SIMON32/ 64 cube attack and cube neutral-bit detection algorithm by combining the basic idea of cube analysis. Simulation experiments show that when the cube variables are in the range of 6 to 24 dimensions, refering to 7-round SIMON32/64 algorithm, the algorithm can recover 47 bit key directly with time complexity of 2^18.08 by using cube attack. Moreover, it can recover 39 bit key on 8-round SIMON32/64 algorithm with time complexity of 2^25.00 by using cube attack. With regard to 10-round, 11-round SIMON32/64 algorithm, it can capture neutral secret key bits by using cube test.