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. 07, 1995
Filed:
Nov. 29, 1993
Hiroshi Matsumoto, Fujisawa, JP;
Kazuo Takaragi, Ebina, JP;
Seiichi Susaki, Yokohama, JP;
Hiroyuki Maezawa, Tama, JP;
Shinobu Koizumi, Sagamihara, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Chubu Software, Ltd., Aichi, JP;
Abstract
In a terminal which received an electronic document with at leastone digital signature, when a user changes the contents of the received electronic document, a new digital signature is produced by enciphering signature data by using a secret key of the user, the signature data including a hash total of the document of a new version, personal information of the user (signatory), and version management information necessary to restore an electronic document of a former version from the electronic document of the new version. The new digital signature and the new version electronic document version are transmitted together with the received digital signature to a next person on a document circulating route.