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. 06, 2010
Filed:
Sep. 05, 2003
Masato Yamamichi, Kadoma, JP;
Natsume Matsuzaki, Mino, JP;
Toshihisa Abe, Izumisano, JP;
Toshihisa Nakano, Neyagawa, JP;
Masaya Miyazaki, Ikeda, JP;
Masato Yamamichi, Kadoma, JP;
Natsume Matsuzaki, Mino, JP;
Toshihisa Abe, Izumisano, JP;
Toshihisa Nakano, Neyagawa, JP;
Masaya Miyazaki, Ikeda, JP;
Panasonic Corporation, Osaka, JP;
Abstract
Disclosed is a digital work protection system enabling a content distributor to flexibly define usage patterns of content permitted for users. The system is composed of a recording device and a playback device. The recording device acquires a digital work, range information showing a permission range within which the digital work is permitted to be used, and a subrange key for each subrange, generates an encryption key using all the acquired subrange keys, encrypts the digital work based on the encryption key to generate encryption information, and writes the encryption information and the range information to a recording medium. The playback device reads the range information and the encrypted information from the recording medium, acquires a subrange key for each subrange, generates a decryption key using all the acquired subrange keys, decrypts the encrypted information based on the decryption key to generate a digital work, and plays the digital work.