一种基于复合域的SM4算法S盒FPGA实现方法研究

Research on an FPGA Implementation Scheme for S Box in SM4 Algorithm Based on Composite Field

SM4算法是一种国产对称密码算法,在SM4算法的FPGA实现中,经常使用8位完全查找表法或者是复合域方法实现,而这两种方法没有综合考虑面积、计算速度等因素,方案设计过程存在缺陷。因此针对该问题本文研究了几种复合域SM4算法S盒FPGA实现方法的优点及实现过程,分析比较了8比特完全查找表方案、复合域+2比特查找表混合方案这两者之间的优缺点,最终提出了复合域+4比特查找表混合方案实现的SM4⁃Sboxilt⁃LJX方案,此方案综合考虑了实现时的面积、计算速度因素,为三种方案中的最优方案。本文在Quartus软件上验证了三种实现方案的资源占用、最大工作频率、S盒运行时间和功耗,综合四个方面分析比较三种方案的优缺点,证明本文提出的SM4⁃Sboxilt⁃LJX方案是三种方案中的最优SM4算法S盒FPGA实现方案。

SM4 algorithm is a domestic symmetric cryptography,whose FPGA implementation is always realized by the complete 8-bits lookup table method and the composite field method.Without consider⁃ing the area and the computation speed in these two methods,some issues occur in the scheme design process.To address the issues,merits and realization processes of some FPGA implementation schemes for the S box in SM4 algorithm based on composite field are studied.Merits and demerits of the com⁃plete 8-bits lookup table scheme and the composite field with 2-bits lookup table hybrid scheme are compared and deeply analyzed,based on which,a composite field with 4-bits lookup table hybrid scheme named SM4⁃Sboxilt⁃LJX scheme is proposed.In the proposed SM4⁃Sboxilt⁃LJX scheme,area and computation speed are fully considered,exhibiting higher performance than the two schemes.A⁃bove⁃mentioned three schemes are validated in Quartus in terms of resources occupancy,maximum op⁃erating frequency,time and power consumption of the S box to comprehensively conclude the merits and demerits of each.Results show that our proposed SM4⁃Sboxilt⁃LJX scheme has the greatest performance among the three schemes.