Patent ID: 6282290
Filing Date: 2001-08-28
Classification: G06F

Abstract:
In a system comprising at least one processing unit adapted to receive a first communicated signal and derive a cryptographic key therefrom with improved computational efficiency by computation of a modular exponentiation of the form b.sup.e mod n based on said first signal, an apparatus comprises:means for dividing said modular exponentiation into at least first and second portions respectively having reduced modulus values p and q which are each smaller than an original modulus value n of said modular exponentiation, and a respective reduced base value b.sub.I which is smaller than an original base value b;means for factoring each said portion of said modular exponentiation into respective pluralities of smaller modular exponentiations using precalculated exponent values;means for multiplying said respective pluralities of smaller modular exponentiations together to provide respective first level intermediate products, said multiplying means being optimized for squaring operations;means for combining said intermediate products into a final modular exponentiation product, and means using the final modular exponentiation product as a cryptographic key.