Hitachi, Ltd.

Narihiro Omoto

Kunihiko Miyazaki

Shinji Itoh

Kouichi Tanimoto

Hiroshi Yoshiura

Yoshiharu Bessho

Katsuko Nishioka

Toshikazu Takigawa

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.

Method of managing digital signature, apparatus for processing digital signature, and a computer readable medium for recording program of managing digital signature

The invention provides a method for verification having a structure that reflects reliability of a signature history properly for a hysteresis signature used for verification based on the signature history, and provides a method for arbitration and an arbitrator apparatus that solve a dispute on correctness of a signature based on the method for verification. Furthermore, the invention provides a method for managing history that mitigates the signature history management burden on a signer. Reliability is set on a signature forming record that is a component of a signature history, reliability of the signature history is calculated based on the set reliability, and the calculated reliability is output as reliability of a verification result. The invention provides a method for verification having a structure that reflects the reliability of a signature history properly and a method for arbitration and an arbitrator apparatus that solve a dispute on correctness of a signature. Furthermore, providing a signature history storage service apparatus mitigates the signature history storage burden on a signer.

Method for verifying a digital signature

An electronic mall system is constituted of an ASP electronic mall and an ASP registration DB. Applications available for selection are represented as icons and a common execution screen is generated. The icons are linked with the ASP registration DB. The accounts are settled with each user and each ASP by measuring the application utilization time of the user and collating it with the ASP registration DB. A high-performance infrastructure environment is provided to support ASPs.

Electronic mail system

A reliably safe storage system is provided which makes provable the status of a file stored in a storage server at a time specified by a user and creates evidence information that will be effective in future. In response to a file status fixing request from the user over a network, a storage server generates file fixing guarantee data, including data publicized by a publication server, and saves the generated data with the file associated with the generated data.

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Toda, Japan

Narihiro Omoto