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:
Dec. 09, 2014
Filed:
Jan. 30, 2012
Hideo Shimizu, Kanagawa, JP;
Yuichi Komano, Kanagawa, JP;
Koichi Fujisaki, Kanagawa, JP;
Shinichi Kawamura, Tokyo, JP;
Hideo Shimizu, Kanagawa, JP;
Yuichi Komano, Kanagawa, JP;
Koichi Fujisaki, Kanagawa, JP;
Shinichi Kawamura, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
According to one embodiment, a first shift amount calculation unit counts the number of continuous zeros from a less significant bit toward a more significant bit of an intermediate result of a computation of Montgomery multiplication result z and calculates a first shift amount. A second shift amount calculation unit counts the number of continuous zeros from a less significant bit toward a more significant bit of redundant-binary-represented integer x and calculates a second shift amount. An addition/subtraction unit calculates the intermediate result by adding/subtracting, with respect to the intermediate result which has been bit-shifted by the first shift amount, the integer p, and the integer y which has been bit-shifted by the second shift amount. An output unit outputs, as the Montgomery multiplication result z, the intermediate result when the sum of the first shift amounts is equal to the number of bits of the integer p.