Overview of the Block Cipher

Since the introduction of the Data Encryption Standard (DES) in the mid-1970s, block cipher is a wildly used algorithm in modern society. Along with the deep cryptanalysis, drawbacks of block cipher such as DES have been found which means improvement of cryptology should be done to face the challenge. Some block cipher algorithms such as SM4 are proposed to strong security. This paper describes the basic block cipher algorithm, design theory and structure, and cryptanalysis according to recent trend of development.