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:
Nov. 10, 2009
Filed:
Apr. 06, 2001
Osamu Shibata, Moriguchi, JP;
Tsutomu Sekibe, Hirakata, JP;
Osamu Shibata, Moriguchi, JP;
Tsutomu Sekibe, Hirakata, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A copyright protection system comprises an encryption device and a decryption device. Cryptographic communication is performed between the encryption device and the decryption device using a contents key. The encryption device includes a contents storage section for storing contents, a first contents key generation section for generating the contents key based on a second decryption limitation obtained by updating a first decryption limitation, and a first encryption section for encrypting the contents using the contents key and outputting the encrypted contents. The decryption device includes a second contents key generation section for generating the contents key from the second decryption limitation, and a first decryption section for decrypting the encrypted contents using the contents key generated by the second contents key generation section.