Executable instructions designed to provide faster cryptographic processing, fixed-timing memory access, and dedicated memory usage are implementable on an x86 CPU utilizing XMM registers. The instructions can be utilized to implement cryptographic processing in accordance with the Advanced Encryption Standard (AES). To encrypt, a single instruction performs nonlinear transformation, rotation, and linear transformation. Another single instruction used during encryption performs nonlinear transformation and rotation. New instructions also are implemented to perform decryption. The instructions implemented to perform decryption perform the mathematical inverse functions of their counterparts used for encryption.