New attacks against reduced Rijndael‐160

Xiaoli Dong, Yongzhuang Wei
2021 IET Information Security  
The first 9-round meet-in-the-middle (MITM) attack and improved 8-round impossible differential (ID) attacks on Rijndael-160 are studied here. For the first 9-round MITM attack, a new effective attack path is explored by using the generalised δ-set and the generalised multiset, which are based on the property that the difference branch number of MixColumns is 5. With this attack path, a 5-round MITM distinguisher with a technique of the truncated differential characteristic is proposed, and
more » ... the attack on 9-round Rijndael-160 is performed. For the improved 8-round ID attacks, to take advantage of the key-schedule weaknesses for Rijndael-160 under key sizes of 160 and 256 bits, some new attack paths are found. With these attack paths, the 5-round IDs are proposed based on the property of MixColumns above, and then the attacks on the 8-round Rijndael-160 under key sizes of 160 and 256 bits are performed. When compared with the currently known attacks, the proposed attacks have lower data, time, and memory complexities.
doi:10.1049/ise2.12038 fatcat:ml25e3nox5gbph4xgq32ma4qfu