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:
Sep. 18, 2007
Filed:
Apr. 10, 2001
Osamu Shibata, Osaka, JP;
Taihei Yugawa, Nara, JP;
Tsutomu Sekibe, Osaka, JP;
Yoshiyuki Saito, Osaka, JP;
Toshihiko Otake, Hyogo, JP;
Osamu Shibata, Osaka, JP;
Taihei Yugawa, Nara, JP;
Tsutomu Sekibe, Osaka, JP;
Yoshiyuki Saito, Osaka, JP;
Toshihiko Otake, Hyogo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A decryption device includes: an internal-key storage section for storing an internal-key; a content-key storage section for storing a content-key; a determination section for determining whether or not a value of the content-key storage section in its initial state and a current value of the content-key storage section are different; and an operation section, the operation section including a first decrypting section which, when an encrypted content-key is input to the operation section, decrypts the encrypted content-key using the internal-key so as to obtain a content-key and stores the content-key in the content-key storage section, and a second decrypting section which, when an encrypted content is input to the operation section and the determination section determines that the value of the content-key storage section in its initial state and the current value of the content-key storage section are different, decrypts the encrypted content using the current value of the content-key storage section as a content-key so as to obtain a first output data and outputs the first output data to outside of the decryption device.