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:
Nov. 17, 2015
Filed:
Sep. 24, 2008
Hirohisa Hotta, Kawasaki, JP;
Akihiko Yushiya, Tokyo, JP;
Hirohisa Hotta, Kawasaki, JP;
Akihiko Yushiya, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
This invention makes the number of cycles required for AES encryption or decryption by hardware smaller than before by reducing the difference among the summation of the signal processing time for each sub-block transformations in each clock cycle period. To do this, an encryption/decryption circuit includes a first AddRoundKey Transformation module, a second AddRoundKey Transformation module, a ShiftRows Transformation module, a SubBytes Transformation module, a MixColumns Transformation module, and a data holding unit, wherein in a cycle of encryption, the first AddRoundKey Transformation module and the second AddRoundKey Transformation module are executed using different Round Keys.