A Research and Improvement Based on Rijndael Algorithm

S-box is the only non-linear operation of the AES algorithm, it directly determines the performance and security of the algorithm. For that S-box´s iterative output cycle is not more than 88, but has nine algebraic expressions as well as the efficiency of AES algorithm cannot meet the need of network storage, we proposed improved programs, and construct a new S-box. After the improvement, iterative output cycle is 256, and algebraic expression reached 254 items. The implementation efficiency of the algorithm has improved nearly 40%.