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:
Jul. 24, 2007
Filed:
Sep. 05, 2002
Yoshinori Honda, Yokohama, JP;
Yoshinobu Tanigawa, Kawasaki, JP;
Koji Kikuchi, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In using log lists of chain signatures to assure validity of an original, work of opening log lists to the public is reduced. A first signature servergenerates a first chain signature to an original as an object of assurance, adds the generated first chain signature to a first log list, associating the first chain signature with the original, and sends a first certificate of custody including the first chain signature, to the sender of the original. Further, the first signature serversends an arbitrary first chain signature in the log list to a second signature server, to receive a second certificate of custody. On the other hand, the second signature servergenerates a second chain signature to the first chain signature received from the first signature server, adds the second chain signature to a second log list, associating the second chain signature with the first chain signature, and sends a second certificate of custody including the second chain signature, to the sender of the first chain signature. Further, the second signature serversends an arbitrary second chain signature in the second log list to a public server