Hitachi, Ltd.

Mizuhiro Sakai

Kazuo Takaragi

Ryoichi Sasaki

Kunihiko Miyazaki

Tsutomu Matsumoto

Seiichi Susaki

Mitsuru Iwamura

Toshiyuki Moritsu

Taiki Sakata

Mamoru Ozaki

Mashiho Kawamura

According to the invention, techniques for authenticating that a digitally signed document is genuine. Specific embodiments according to the present invention can determine whether a digital signature was generated by a digital signature generator, or if the digital signature was generated by a third party posing as the digital signature generator. Specific embodiments can provide independent verification of digital signer identity based upon prior signed messages, time/date stamps, and the like. Techniques according to the present invention can be embodied in methods, apparatus, computer software and systems.

Digital signing method

An electronic tax declaration system includes an input unit that receives financial information data to be declared; a data conversion unit that converts the received financial information data according to specifications of declaration data; a declaration data generation unit that adds a digital signature to the converted financial information data for generating declaration data and stores it into a storage; a declaration transmission unit that sends the declaration data to a regulator handling a tax; a declaration result reception unit that receives a declaration result of the declaration data from the regulator and stores it into the storage associated with the declaration data; and a loan application unit that creates loan application data by extracting the declaration data and the associated declaration result from the storage and adding a digital signature to them and sends the created loan application data to an external unit.

Tax declaration system

Growing community of inventors

Omiya, Japan

Mizuhiro Sakai