Linear cryptanalysis on second round simplified AES

Abstract

Linear attack, at the first, introduced for DES encryption system, by Matsui. That cryptanalysis was based on linear approximation of nonlinear S-boxes of algorithm. Then this kind of attack deployed for other kinds of block ciphers. This paper describes linear attack on second round SAES. By using this cryptanalysis, it is possible to attack on full round of SAES algorithm. Undoubtly, one of important results of this cryptanalysis is that, it is possible to better understanding linear attack on Rijndael