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:
Oct. 30, 2012
Filed:
Oct. 03, 2007
Tomoyuki Asano, Tokyo, JP;
Masafumi Kusakawa, Tokyo, JP;
Tomoyuki Asano, Tokyo, JP;
Masafumi Kusakawa, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
It relates to an information processing unit, a terminal unit, an information processing method, a key generation method and a program that enable reduction of the number of keys to be held by users and aims at providing an information processing unit capable of generating a directed-graph representing an encryption key generation logic to derive a set-key for encrypting a content or a content-key. The technique relates to a scheme that divides a set of user terminals into some subsets, allocates a set-key and an intermediate-key to each subset, and upon input of an intermediate-key correlated with a subset, outputs the set-key corresponding to the subset and the intermediate-key of the subset associated by the directed-edge. Further, it relates to a technique of replacing the directed-edge in the directed-graph with a shorter directed-edge. The effect of reducing the number of intermediate-keys held by each user is expected from the technique.