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. 15, 2006
Filed:
Apr. 06, 2001
Tomoyuki Asano, Kanagawa, JP;
Yoshitomo Osawa, Kanagawa, JP;
Ryuji Ishiguro, Tokyo, JP;
Atsushi Mitsuzawa, Tokyo, JP;
Tateo Oishi, Saitama, JP;
Ryuta Taki, Kanagawa, JP;
Tomoyuki Asano, Kanagawa, JP;
Yoshitomo Osawa, Kanagawa, JP;
Ryuji Ishiguro, Tokyo, JP;
Atsushi Mitsuzawa, Tokyo, JP;
Tateo Oishi, Saitama, JP;
Ryuta Taki, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
When a player cannot play back data because a master key held by the player has a generation older than the generation of a master key having been used for recording the data, or when a recorder cannot record data because a master key held by the recorder has a generation older than the generation of a master key necessary for recording to a recording medium, the user is prompted to renew the master key for acquisition of the necessary master key, thereby enabling the data playback or data recording. The renewed master key is distributed in such a form that can be processed by a specific device via a transmission medium such as a recording medium, network, IC card, telephone line, for example, via a tree-structured distribution system.