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:
Apr. 03, 2012
Filed:
Feb. 05, 2008
Masafumi Kusakawa, Tokyo, JP;
Tomoyuki Asano, Kanagawa, JP;
Masafumi Kusakawa, Tokyo, JP;
Tomoyuki Asano, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A terminal device improved with a digraph generation method in a key distribution method of various types of broadcast encryption systems is provided. The terminal device includes an acquiring unit for acquiring information related to a set, which is selected from a plurality of sets representing a combination of a plurality of terminal devices, and which represents some or all of the plurality of terminal devices; an extracting unit for extracting the set contained in the information and to which it belongs; and a digraph generation unit for generating a directional branch for generating a key corresponding to the extracted set in a predetermined digraph formed by a plurality of directional branches.