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:
Mar. 17, 2009
Filed:
Apr. 04, 2001
Ryuji Ishiguro, Tokyo, JP;
Yoshitomo Osawa, Kanagawa, JP;
Tateo Oishi, Saitama, JP;
Tomoyuki Asano, Kanagawa, JP;
Atsushi Mitsuzawa, Tokyo, JP;
Ryuji Ishiguro, Tokyo, JP;
Yoshitomo Osawa, Kanagawa, JP;
Tateo Oishi, Saitama, JP;
Tomoyuki Asano, Kanagawa, JP;
Atsushi Mitsuzawa, Tokyo, JP;
Sony Corporation, , JP;
Abstract
An enabling key block (EKB) used in an encrypted key distributing tree structure is generated by forming a simplified 2-branch or multi-branch type tree with a terminal node or leaf which is capable of decrypting on the basis of a key corresponding to a node or a leaf of the Simplified tree. Further, the EKB includes a tag for indicating a position of an encrypted key in the tree. The tag not only discriminates position but also stores data for judging the presence of encrypted key data within the EKB. As such, a considerable reduction in data quantity is realized, and the decrypting process in a device is also simplified.