Patent ID: 7461115
Filing Date: 2008-12-02
Classification: G06F

Abstract:
1. A method, implemented in a device supporting elliptical curve cryptography, of performing a modular multiplication of two elements X(t) and Y(t), of GF(2 m ), where m is a field degree, comprising: performing a polynomial multiplication in a number of iterations to produce an intermediate result, wherein the number of iterations is determined, at least in part, according to the field degree m and digit size d, wherein the digit size d is at least two bits and corresponds to a number of bits examined in each of the iterations; storing the intermediate result in the device; determining if the field degree is less than a predetermined amount; performing a reduction operation on the intermediate result to provide an output element P(t) of GF(2 performing an additional shift operation on the intermediate result prior to supplying the intermediate result for the reduction operation in response to determining that the field degree is less than the predetermined amount; and using the output element in an elliptical curve cryptography application.