Cryptanalysis of some AES Candidate Algorithms

Decorrelated Fast Cipher(DFC),LOKI97 and MAGENTA are candidates for the Advanced Encryption Standard(AES). In this paper we analyze their security respectively. Since cryptographic properties of the confusion permutation of DFC are weak, its security depends on its subkey addition completely. It seems that LOKI97 is not stronger than LOKI89 and LOKI91. Because of characteristics of the round function, LOKI97 is susceptible to linear cryptanalysis for some keys. MAGENTA is a Feistel cipher with only 6 rounds and its key schedule is very simple. Based on these limitations, we present a chosen plaintext attack against it using 264 chosen plaintexts. In conclusion, we do not think DFC, LOKI97 and MAGENTA are qualified candidates for the AES.