A Discussion on Design Rules of Block Cipher Through Analyzing DES Algorithm

Block cipher is always a general technique for solving the issue of information system security.As the typical algorithm of block cipher system,DES has been substituted by the safer Rijindael algorithm,but the design idea and rules in DES are still worthwhile to study and use for reference.The general design rules of block cipher is discussed by analyzing the encryption process,key generating,encryption function and decryption process of DES algorithm.And the result suggests that module standardization,separating keys from algorithm,diffusion and confusion,uniformity and randomicity should be treated as basic design rules of modern block cipher.And these rules should be the jumping-off point of modern block cipher design.