随着4 bit S盒在轻量级密码算法中的广泛应用,如何捕获这些4 bit S盒输入及输出的代数关系成为了目前的研究热点之一。根据S盒的输入及输出关系,提出了n bit S盒的非线性回路代数关系的通用求解算法。针对4 bit S盒设计了高效的非线性...随着4 bit S盒在轻量级密码算法中的广泛应用,如何捕获这些4 bit S盒输入及输出的代数关系成为了目前的研究热点之一。根据S盒的输入及输出关系,提出了n bit S盒的非线性回路代数关系的通用求解算法。针对4 bit S盒设计了高效的非线性回路代数关系求解算法,并对国际公认的16类最优4 bit S盒及多个著名的轻量级密码算法中的S盒进行了测试分析。同时,还对上述轻量级密码算法中S盒所属等价类进行了检测。研究结果表明:16类S盒代表元中只有3类不存在二次回路代数关系;同属等价类S盒可能会有不同的二次回路代数关系;MANTIS、PRIDE、Marvin等轻量级算法的S盒存在多个二次回路代数关系。即这些包含低次回路代数关系的S盒存在潜在的安全缺陷。展开更多
A new attack on block ciphers is introduced, which is termed linear-differential cryptanalysis. It bases the combining of linear cryptanalysis and differential cryptanalysis, and works by using linear-differential pro...A new attack on block ciphers is introduced, which is termed linear-differential cryptanalysis. It bases the combining of linear cryptanalysis and differential cryptanalysis, and works by using linear-differential probability （LDP）. Moreover, we present a new method for upper bounding the maximum linear-differential probability （MLDP） for 2 rounds of substitution permutation network （SPN） cipher structure. When our result applies to 2-round advanced encryption standard（AES）, It is shown that the upper bound of MLDP is up to 1.68×2^-19, which extends the known results for the 2-round SPN. Furthermore, when using a recursive technique, we obtain that the MLDP for 4 rounds of AES is bounded by 2^-73.展开更多
文摘随着4 bit S盒在轻量级密码算法中的广泛应用,如何捕获这些4 bit S盒输入及输出的代数关系成为了目前的研究热点之一。根据S盒的输入及输出关系,提出了n bit S盒的非线性回路代数关系的通用求解算法。针对4 bit S盒设计了高效的非线性回路代数关系求解算法,并对国际公认的16类最优4 bit S盒及多个著名的轻量级密码算法中的S盒进行了测试分析。同时,还对上述轻量级密码算法中S盒所属等价类进行了检测。研究结果表明:16类S盒代表元中只有3类不存在二次回路代数关系;同属等价类S盒可能会有不同的二次回路代数关系;MANTIS、PRIDE、Marvin等轻量级算法的S盒存在多个二次回路代数关系。即这些包含低次回路代数关系的S盒存在潜在的安全缺陷。
基金Supported by the National Natural Science Foun-dation of China(60503010) and the Foundation of National Laboratory for Modern communications(51436030105DZ0105)
文摘A new attack on block ciphers is introduced, which is termed linear-differential cryptanalysis. It bases the combining of linear cryptanalysis and differential cryptanalysis, and works by using linear-differential probability （LDP）. Moreover, we present a new method for upper bounding the maximum linear-differential probability （MLDP） for 2 rounds of substitution permutation network （SPN） cipher structure. When our result applies to 2-round advanced encryption standard（AES）, It is shown that the upper bound of MLDP is up to 1.68×2^-19, which extends the known results for the 2-round SPN. Furthermore, when using a recursive technique, we obtain that the MLDP for 4 rounds of AES is bounded by 2^-73.
