Side Channel Cube Attack Improvement and Application to Cryptographic Algorithm

The complexity of the pre-processing phase of the cubic attack grows exponentially with the number of output bit algebras, and the difficulty of finding an effective cube set increases. In this paper, the algorithm of preprocessing stage in cubic attack is improved. In the cube set search, from random search to target search, a new target search optimization algorithm is designed to optimize the computational complexity of the preprocessing stage. In turn, the offline phase time complexity is significantly reduced. The improved cubic attack combined with the side-channel method is applied to the MIBS block cipher algorithm. The algorithm characteristics of MIBS are analyzed from the perspective of side-channel attack. The leak location is selected in the third round, and the overdetermined linear equations from initial key and output bit are established, which can directly recover 33bit key. Then the 6bit key can be recovered by quadric-detecting. The amount of plaintext required is 2(21.64), time complexity is 2(25). This result is greatly improved compared with the existing results, the number of keys recovered is increased, and the time complexity of the online phase is reduced.