Hitachi, Ltd.

Kosuke Anzai

Yoshiaki Isobe

Natsuki Watanabe

Hisayoshi Sato

Kunihiko Miyazaki

Naoki Hayashi

Yoko Hashimoto

Daisuke Miyamoto

Katsuaki Nakahara

Suguru Iwasaki

Tomohisa Kumagai

A user attribute information provision system processes attribute information of users while preventing a leakage of attribute information. A provision apparatus: selects an apparatus group forming a communication path; generates information registration request in which information of a predetermined user is concealed in data recognizable only to a correspondent of the provision apparatus; and transmits the information registration request to an access destination solving apparatus via the apparatus groups. The access destination solving apparatus: stores the information of the user indicated by the information registration request and information of a correspondent provision apparatus; receives an inquiry request from an inquiry apparatus; and transfers the inquiry request by way of the correspondent provision apparatus as the user to the provision apparatus as the inquiry destination via the provision apparatuses in the communication path, thereby causing the provision apparatus to return the attribute information of the user to the inquiry apparatus.

Attribute information provision method and attribute information provision system

With a portal server, a request for information from a terminal of a second user that is an agent for a first user is received, and an encrypted data directed to a terminal of the first user, stored in an encrypted-data memory unit, is re-encrypted using a re-encryption key for the second user, stored in a first encryption-key memory unit, and is transmitted to the terminal of the second user, with the terminal of the second user, the re-encrypted data received is decrypted using an encryption key for the second user, stored in a second encryption-key memory unit, and time keys specified by the terminal of the first user, related to a time-period during which browsing of the information is permitted.

Method, information service system and program for information encryption/decryption

A data authenticity assurance method carried out by a management computer including: a first step of receiving the first data piece from the computer; a second step of selecting a plurality of second data pieces at predetermined intervals in chronological order from among the plurality of second data pieces held in the data holding part; a third step of performing an arithmetic operation for each of the hash values of the selected plurality of second data pieces; a fourth step of generating signature target data by combining the first data piece received from the computer with the hash values of the selected plurality of second data pieces; and a fifth step of generating a second data piece by assigning the digital signature to the signature target data by using the preset key, and holding the generated second data piece in chronological order sequentially in the data holding part.

Data authenticity assurance method, management computer, and storage medium

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Tokyo, Japan

Kosuke Anzai