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. 22, 2008
Filed:
Apr. 17, 2002
Takumi Okaue, Tokyo, JP;
Takumi Okaue, Tokyo, JP;
Sony Corporation, , JP;
Abstract
A data processing apparatus extracts a root key by decrypting an enabling key block. The data processing apparatus then produces a content key on the basis of a random number and encrypts the content key using the root key. Furthermore, the data processing apparatus encrypts an ID of the data processing apparatus using the produced content key thereby producing a storage key. The data processing apparatus then produces encrypted content by encrypting a content using the storage key. Furthermore, the data processing apparatus stores the encrypted content together with the data produced by encrypting the content by the root key into a removable storage medium. The content, stored into the removable storage medium in the above-described manner, can be played back only by a specific limited device.