Accelerating higher-order masking of AES using composite field and SIMD

This paper introduces an efficient technique to speed up the higher-order masking scheme of the advanced encryption standard (AES), in which the S-box computation is based on the composite field, using Intel´s Supplemental Streaming SIMD Extensions 3 (SSSE 3) instruction set. Different side-channel attack (SCA) countermeasures are combined to mitigate more than one type of SCA. The proposed technique solves the problem of higher-order masking´s negative impact on performance and removes the need for lookup tables by applying parallel processing at the data level using single instruction multiple data (SIMD) technology. We implemented the technique on a Linux machine with an Intel processor that supports SSSE3 instructions. The technique performed nine times faster than the second order masking scheme and was seven times faster than the third order masking scheme reported in the literature. The results that we achieved through applying SIMD technology make our proposed technique practical and attractive.