1. A method comprising: receiving input data of a Galois field GF(2 k ); mapping the input data to a composite Galois field GF(2 nm ), where k=nm; inputting the mapped input data to an Advanced Encryption Standard round function; performing two or more iterations of the Advanced Encryption Standard round function in the composite Galois field GF(2 nm ); receiving output data of a last of the two or more iterations of the Advanced Encryption Standard round function; and mapping the output data to the Galois field GF(2 k ).