A New Result of Impossible Differential Attacks on 7-Round AES-192

This paper concentrates on the impossible-differential attacks on reduced-round versions of the Rijndael cipher following the framework of the attacks by Biham-Keller and Cheon et al. One method is presented for impossible differential cryptanalysis of 7-round AES-192 combined with classing subsets and exploiting weaknesses in their key schedule. This attack requires about 278chosen plaintexts, demands 2129 words of memory, and performs 2155 7-round AES-192 encryptions, which update the best known impossible differential attacks on reduced AES. Compared with the available results, this cryptanalysis costs fewer chosen-plaintexts and lower computing complexity.