改进的7轮AES-128的不可能差分攻击

Improved Impossible Differential Attack on 7-round AES-128

AES的不可能差分分析是AES众多分析方法中最为有效的方法之一.本文之前,AES-128的不可能差分攻击最好结果是由Mala等人在2010年提出的.他们构造了一个新的4轮不可能差分区分器并攻击了7轮AES-128,攻击需要106.22个选择明文,时间复杂度为110.22次AES加密,存储量为94.22个字节.在本文中,我们采用并行攻击技术和明文对早夭技术,运用基于快速排序原理的明文对筛选方法,对Mala等人的7轮AES-128的不可能差分攻击进行了改进,更为有效地排除错误的候选密钥,降低了时间复杂度和存储复杂度.我们的攻击需要106.22个选择明文,时间复杂度为108.62次加密,存储量为85.22字节,这个结果是目前为止最好的7轮AES-128的不可能差分攻击结果.

Impossible differential attack is one of the most efficient attacks on AES. Before this paper, the impossible differential attack on AES-128 proposed by Mala et al. in 2010 was known as the best. They constructed a new 4-round impossible differential distinguisher and attacked 7-round AES-128 with a data complexity of 106.22 chosen plaintexts, a time complexity of 110.22 encryptions and a memory complexity of 94.22 bytes. In this paper, we use parallel attack technique, plaintext pair early abort technique and the plaintext pair sieve method based on quicksort algorithm to improve the impossible attack on 7-round AES-128 given by Mala et al. Our method excludes the wrong candidate keys more effectively and decreases the time and memory complexity. Our attack requires 106.22 chosen plaintexts and 85.22 bytes of memory and performs 108.62 AES encryptions, which is the best result of impossible differential attack on 7-round AES-128 known so far.