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:
Aug. 11, 2009
Filed:
May. 17, 2002
Kouichi Tanimoto, Yokohama, JP;
Shinji Itoh, Yokohama, JP;
Kunihiko Miyazaki, Yokohama, JP;
Narihiro Omoto, Toda, JP;
Katsuko Nishioka, Tokyo, JP;
Kouichi Tanimoto, Yokohama, JP;
Shinji Itoh, Yokohama, JP;
Kunihiko Miyazaki, Yokohama, JP;
Narihiro Omoto, Toda, JP;
Katsuko Nishioka, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method of managing digital signature includes the steps of preparing a signature log file storing signature log entry information, generating a new digital signature for a transmission message by reflecting, in the new digital signature, signature log entry information registered to the signature log file in the past; generating signature log entry information associated with the new digital signature and registering the signature log entry information to the signature log file; and preparing a user search file in addition to the signature log file; registering, to the user search file, user identifier information indicating a transmission destination of the transmitted digital signature and a transmission source of the received digital signature, with a correspondence established between the information, the user identifier information, and each signature log entry information in the signature log file.