A Method for Obtaining Cryptogra hically Strong 8x8 S-boxes
Xun Yi, Shi Zhi Xin, Xiaochun Cheng, Hu You, Kwok‐Yan Lam · 1997
In this paper, a method for obtaining cryp- tographically strong 8 x 8 S-boxes is presented. The method is based on the mini version of a new block cipher with block size 8 bits and can be easily and efficiently performed on a computer. The cryptographic strength of some 8 x 8 S-boxes randomly produced by the method is analyzed. The results show (1) All of them are bijective; (2) The nonlinear- ity of each output bit of them is usually about 100; (3) All of them approximately satisfy the strict avalanche criterion and output bits independence criterion; (4) They all have an almost equiprobable input/output XOR distribution; (5) Their inverse S-boxes also possess the former four properties.