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. 12, 2016
Filed:
Dec. 20, 2011
Sachihiro Ichikawa, Tokyo, JP;
Nori Matsuda, Tokyo, JP;
Tadakazu Yamanaka, Tokyo, JP;
Katsuyuki Takashima, Tokyo, JP;
Sachihiro Ichikawa, Tokyo, JP;
Nori Matsuda, Tokyo, JP;
Tadakazu Yamanaka, Tokyo, JP;
Katsuyuki Takashima, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
An invalidation scheme of a secret key is implemented, which is usable for a functional encryption scheme. In a cryptographic processing systememploying an encryption scheme with which if attribute information and key information set in encrypted data do not correspond to attribute information and key information set in a secret key, the encrypted data cannot be decrypted using the secret key, an encrypted data management deviceis provided, which carries out a relay between a user terminalcarrying out encryption and decryption of data and an encrypted data storage devicestoring encrypted data. The encrypted data management devicedetermines whether or not a user whose secret key is invalid is included in users having attribute information set in the encrypted data acquired from the encrypted data storage device, and sets a different value as key information in the encrypted data based on the determination result. Then, the encrypted data management devicesends the encrypted data in which the key information is set to the user terminal