Abstract: A method of performing a cryptographic process on data, the cryptographic process treating a quantity of the data as an element of a Galois field GF(?k), where k=rs, the method comprising: isomorphically mapping the element of the Galois field GF(?k) to an s-tuple of elements of a Galois field GF(??); and representing and processing each of the elements of the s-tuple of elements of the Galois field GF(??) in the form of one or more respective n-of-m codewords, where an n-of-m codeword comprises n 1-bits and m-n 0-bits, where m and n are predetermined positive integers and n is less than m.