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. 20, 2011
Filed:
Apr. 25, 2006
Kazuya Shimizu, Osaka, JP;
Tomoya Sato, Nara, JP;
Makoto Fujiwara, Kyoto, JP;
Kentaro Shiomi, Kyoto, JP;
Kazuya Shimizu, Osaka, JP;
Tomoya Sato, Nara, JP;
Makoto Fujiwara, Kyoto, JP;
Kentaro Shiomi, Kyoto, JP;
PANASONIC Corporation, Osaka, JP;
Abstract
In the case where a target device stores: m keys {Ka, . . . , Kam} (m is a natural number) in a manner that the Kai (i is a natural number satisfying 1≦i≦m) is encrypted with the Ka (i−1); and n keys {Kb, . . . , Kbn} (n is a natural number) in a manner that the Kbj (j is a natural number satisfying 1≦j≦n) is encrypted with the Kb (j−1), a confidential information processing unit is caused to perform a processing of re-encrypting the encrypted key Enc (Kai, Ka (i−1)), which has been encrypted with the Ka (i−1), by using the Kb (j−1) and outputting as an encrypted key Enc (Kai, Kb (j−1)).