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. 05, 2014
Filed:
Apr. 16, 2009
Shinichi Matsukawa, Tokyo, JP;
Akihiro Kasahara, Chiba, JP;
Hiroshi Suu, Chigasaki, JP;
Akira Miura, Sagamihara, JP;
Shinichi Matsukawa, Tokyo, JP;
Akihiro Kasahara, Chiba, JP;
Hiroshi Suu, Chigasaki, JP;
Akira Miura, Sagamihara, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
To exclude any unauthorized device from a system and thereby prevent illegal use of content data, a memory cardstores a service key Ksrv for encrypting content key data Kc in a hidden area. The memory cardstores answer data Ato be obtained when question data Q is fed to a host function F possessed by an authorized host device, with encryption applied to the answer data Aby the service key Ksrv. When the question data Q is provided to the host device, answer data Ais obtained based on the question data Q and the host function F. A comparison unitjudges match or mismatch of the answer data Aand the answer data A. When they match, the memory carddecrypts the content key data Kc encrypted by the service key Ksrv and sends it to the host device