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:
Aug. 26, 2014
Filed:
Jun. 08, 2011
Koichi Fujisaki, Kawasaki, JP;
Atsushi Shimbo, Tokyo, JP;
Koichi Fujisaki, Kawasaki, JP;
Atsushi Shimbo, Tokyo, JP;
Kabushiki Kaisha Toshiba, Minato-ku, Tokyo, JP;
Abstract
According to one embodiment, a cryptographic processing apparatus is provided with first to fifth units. The first unit mask-converts input data from first temporary mask into first fixed mask (an invariable value in a first linear operation). In an encryption, the third unit performs a nonlinear operation on the mask-converted data and outputs a first result masked with second fixed mask data (an invariable value in a second linear operation). The fourth unit performs the second linear operation and outputs a encryption result masked with second fixed mask data. In a decryption, the second unit performs the first linear operation on the mask-converted data and outputs a second result masked with the first fixed mask. The third unit performs the nonlinear operation and outputs a decryption result masked with the second fixed mask. In encryption/decryptions, the fifth unit converts the mask of the encryption/decryption results into second temporary mask.