An Advanced Encryption Standard (AES) key generation assist instruction is provided. The AES key generation assist instruction assists in generating round keys used to perform AES encryption and decryption operations. The AES key generation instruction operates independent of the size of the cipher key and performs key generation operations in parallel on four 32-bit words thereby increasing the speed at which the round keys are generated. This instruction is easy to use in software. Hardware implementation of this instruction removes potential threats of software (cache access based) side channel attacks on this part of the AES algorithm.