Hitachi, Ltd.

Kunihito Takeuchi

Kazuo Takaragi

Ryoichi Sasaki

Kunihiko Miyazaki

Tsutomu Matsumoto

Seiichi Susaki

Takeshi Matsuki

Mitsuru Iwamura

Takeshi Tsunoda

Hisanori Mishima

An object of the present invention is to provide a document data identity verifying technology which is capable of easily manage identity of data in a file generated from the original data. An apparatus includes: an I/O unitwhich receives document data in a first format from a creation source of the document data and receives the document data in the first format from the reception source of the document data or the document data converted into another format; a format management unitwhich converts the received document data in the first format into another format according to a preset conversion definition; an irreversible cipher management unitwhich generates an irreversible cipher on the received document data; and an irreversible cipher verification unitwhich verifies the irreversible cipher generated based on the document data in the first format received from the creation source or the document data converted into another format by the format management unitand an irreversible cipher generated based on the document data received from the reception source; wherein identity of the document data received from the creation source and the document data received from the reception source is validated according to the verification results.

Document data identity verifying apparatus

Digital signature generating method and digital signature verifying method

Growing community of inventors

Zushi, Japan

Kunihito Takeuchi