Research And Design Of RISC Cipher Specific Instruction Microprocessor

Traditionally, cryptography can be implemented with two methods: one is in processor routine; the other is directly in hardware, such as application-specific cryptographic chip. The problem of processor is low executive performance, but it has sufficient flexibility. As for application-specific cryptographic chip, the operation speed can achieve wonderfully high level, but aiming at one or few algorithms makes it lacks of prevalent adaptability. Aiming at the above contradiction, this paper has researched and designed the cipher specific instruction processor which can implement the block cipher efficiently and flexibly based on RISC general purpose processor.The paper has analysed the problem of cryptography implemented by RISC processor, proposed a hybrid architecture of RISC cipher specific instruction processor combining the special requirements for cipher application. The architecture has designed RISC newly, including the cipher processing functions, and it can improve the ability of cipher processing.The paper has extended a set of new instruction ,which can implement the crypto operations including S-boxes substitution, general bit permutations, arbitrary rotates, Galois field multiplication and modular arithmetic efficiently, and it has improved the performance of operations; The paper has designed an architecture of mixed memory which can access memory flexibly ,which has adopted the mode of storaging data by data memory unit and specific memory unit corporately,and it has quickened the speed of processor accessing data; The paper has researched the structure hazard ,data hazard and control hazard in cipher processing and designed a 5-stage pipeline for block ciphers. Finally, the design has been implemented on FPGA.The whole design has made verifications on a convenient platform, and the performance of the processor has been evaluated. The experiment results indicate that RISC cipher specific instruction microprocessor that the paper designed can realize block ciphers flexibly and effectively,and it can satisfy the most of block cipher algorithms demands.