Courtois et al. showed that AES could be presented as a large system of multivariate quadratic (MQ) equations and proposed the XSL algorithm as a dedicated method exploiting the MQ systems in 2002. However the XSL algorithm does not provide an efficient method for solving the MQ equations because of the limits of T′ method. In this paper, a new efficient modified XSL algorithm is presented to overcome the limits of XSL algorithm, based on T′ method, specialization and linearization.
Author's Name: Zhang, M., Liu, J., Wang, X., Zhao, L.