Realization of a resource sharing fast encryption and decryption AES algorithm

In this paper, a method of resource sharing fast encryption and decryption algorithm is proposed. By changing the traditional encrypting and decrypting s_box of AES and using a look-up table to realize the resource sharing during the encryption and decryption, the area of the hardware is effectively reduced. Moreover, the series-mixed transform of AES encryption and decryption is improved in order to save and share resource. This approach can optimize the round key expansion, series-mixed transform and its inverse transform and so on. And this method reuses key computing components like s-box, series mixed transform ect. And employed parallel processing of flow results and keys, which enables a chip to support 128bit, 192bit, 256bit encryption and decryption algorithm at the same time. Experiment results based FPGA shows this method has better performance.