 In particular, calculation using a Galois field GF("k"2), where "k" is a Mersenne prime, allows the use of a transform sized to a power of 2; e.g.supports transform sizes up to 232.There is a trivial lower bound of Ω("n") for multiplying two "n"-bit numbers on a single processor; no matching algorithm (on conventional machines, that is on Turing equivalent machines) nor any sharper lower bound is known.