Patent ID: 7403965
Filing Date: 2008-07-22
Classification: G06F

Abstract:
1. An encryption/decryption system for calculating effective lower bits of a parameter ND for Montgomery modular multiplication, the parameter ND satisfying R×R −1 −N×ND=1 for an integer N and a radix R that is coprime to and greater than N, the system comprising: an input-output device; an ND generator that produces effective lower bits of an ND value at a rate of k bits per clock cycle, with reference to lower k bits of a variable S, as well as to lower k bits of the integer N; a multiplication-accumulation (MAC) operator that multiplies the produced k-bit ND value by the integer N and adds the resulting product to the variable S; and a sum data store that stores the variable S, wherein the variable S is updated by the MAC operator, with bits thereof shifted right by k bits, for use by said ND generator in a subsequent clock cycle, wherein k is an integer larger than 1.