The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 2008
Filed:
Jul. 13, 2004
Kenji Mukaida, Kawasaki, JP;
Masahiko Takenaka, Kawasaki, JP;
Naoya Torii, Kawasaki, JP;
Shoichi Masui, Kawasaki, JP;
Kenji Mukaida, Kawasaki, JP;
Masahiko Takenaka, Kawasaki, JP;
Naoya Torii, Kawasaki, JP;
Shoichi Masui, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An arithmetic device for Montgomery modular multiplication which quickly calculates a parameter ND, the parameter ND satisfying R×R−N×ND=1 for an integer N and a radix R that is coprime to and greater than N, with a large number of effective lower bits. The device comprises an ND generator, a multiplication-accumulation (MAC) operator, and a sum data store. The ND generator produces effective lower bits of ND 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 an odd positive integer N. The MAC operator multiplies the produced k-bit ND value by N and adds the resulting product to S. The sum data store stores the variable S, which is updated with the output of the MAC operator, with its bits shifted right by k bits, for use by the ND generator in the subsequent clock cycle.