Revised Unified Impossible Differential Cryptanalysis of ARIA

Abstract

Abstract-Unified Impossible Differential (UID) cryptanalysis is a systematic method to find impossible differentials for block ciphers and there are large amount of cryptanalysis results coming out by using it. ARIA is a Korean block cipher expecting no impossible differential chains on four or more rounds. In this paper, we apply UID to ARIA and 89136 four rounds impossible differential chains are found. With the optimization of the conflict searching algorithms, UID gets better results compared with former cryptanalysis results. Moreover, we conclude that no impossible differential chains with number of rounds larger than four can be found by the UID method.