Block cipher algorithm based on multidimensional dynamic S-box and LFSR

The block cipher algorithm was proposed based on confusion replacement of multidimensional dynamic S-box and n-grade linear feedback shift register. First of all, the plaintext was disturbed by matrix transformation and multidimensional dynamic S-box of confusion replacement was carried out. Thus the nonlinear degree of safety for the cipher text was enhanced. Then, through the column confused function group of bytes in a cyclic shift, cipher text diffusivity was improved. Finally, the n-grade linkage linear feedback shift register was used to generate dynamic key, strengthen the key randomness of each round, which can make the algorithm has a cipher-block chaining mode. Performance analysis results show that compared to the AES (advanced encryption standard) algorithm and the DES (data encryption standard) algorithm, the proposed algorithm can enhance the safety with little impact on encryption speed at the same time. Through the comparison of correlation coefficient test and differential cryptanalysis, it can be proved that the algorithm can effectively resist linear cryptanalysis and differential analysis of attack, such as the main stream cipher attack. ©, 2015, Huazhong University of Science and Technology. All right reserved.