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:
Jan. 28, 2014
Filed:
Sep. 20, 2010
Masahiko Takenaka, Kawasaki, JP;
Kouichi Itoh, Kawasaki, JP;
Masahiko Takenaka, Kawasaki, JP;
Kouichi Itoh, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
stores, in, key d' obtained by subtracting random number 2r held infrom key d held in. When an operation starts, the values '−C' and '−C' are calculated respectively, and the resultant values are stored in a multiplication table memorytogether with value “C”. In a first operation cycle,selects and outputs an intermediate valueheld in an in-operation data register, and thereby makes a modular-multiplication operation circuitperform squaring. In the second operation cycle,selects and outputs one of three values held inin accordance with the combination of key bit value d′and random number bit value r, and thereby makes the modular-multiplication operation circuitperform multiplication. Thereby, a cryptographic processing device that requires a short operation time period, small circuit scale, and has sufficient security can be realized.