Algorithm Design Based On SM4 And ECC Digital Envelope

With the development of the times,information security has become an issue that cannot be ignored.Single cryptosystem can't meet the demand of the society.Hybrid cryptosystems will become an important trend.Digital envelope is a method that the key of symmetric cryptosystem are encrypted and published by public-key cryptosystem.The SM4 algorithm is a symmetric cryptosystem with high data throughput and low hardware consumption.The ECC(Elliptic Curve Cryptography)algorithm is a public-key cryptosystem with higher security.In this paper,we aim at designing an algorithm based on improved SM4 and ECC digital envelopes.Firstly,based on SM4 algorithm and ECC algorithm,this paper proposes a hybrid encryption and decryption algorithm.The algorithm uses SM4 algorithm for encryption and ECC algorithm for decryption.The key expansion module of the SM4 uses the randomly generated sequence as a new FK parameter,it can improve the security of the SM4 algorithm.The ECC module use digital-serial multiplier,shortening the critical path and increasing the clock frequency.Then,the algorithm of this paper is implemented by top-down approach.The digital envelope algorithm is divided by child modules,and the modules' architecture and the Verilog HDL code are designed.At last,the V6 FPGA board of Xilinx is selected for the algorithm module verification.And we choose the TSMC 90 nm process library for Design Compiler.In this paper,we use the V6 FPGA board of Xilinx for the algorithm module verification and the high clock frequency can reach 205 MHz.The resource utilization ratio only accounts for 49%.The data throughput rate of SM4 module can reach 262 Mbps and the scalar multiplication can be completed 20541 times one second,which achieves the expectation.Design Compiler using the TSMC 90 nm process library,and it runs 400 MHz.The algorithm combines the advantages of the symmetric cryptosystem and the public-key cryptosystem.It solves the problems of the key distribution management difficulty of the symmetric cryptosystem and the low throughput of the public-key cryptosystem.Therefore,the algorithm proposed in this paper has a good development prospect.