A method, including factoring an order of a multiplicative group of a Galois Field to produce a first integer factor p and a second integer factor q, wherein the multiplicative group includes (2m−1) elements, m a non-negative integer, so that 2m−1=pq. The method further includes receiving an element x of the Galois Field expressible as α(qi+j), where α is a primitive element of the group, i is a first non-negative integer less than p, and j is a second integer less than q. An inverse or a logarithm of the element x is calculated as a function of qi and j.