1. A method of adding elements of a finite field F 2 m , where m is less than a predetermined number n, said method comprising the steps of: a) storing a first and a second element in a pair of registers, each of said pair of registers comprising said predetermined number of machine words; b) establishing an accumulator having said predetermined number of machine words; c) computing for each of said machine words in said accumulator the exclusive-or of the corresponding machine words representing each of said first and second elements.