Hitachi Solutions, Ltd.

Minoru Fujimoto

Makoto Aoyagi

Yoshiki Sameshima

A search system includes a storage device and a search server. The storage device stores an index database storing an index encrypted with an index key and the index key encrypted with a user key and associated with the encrypted index and stores a document database storing a document encrypted with a document key and the document key encrypted with the user key and associated with the encrypted document. The search server extracts a term for search from a requested search query, decrypts the encrypted index key with a user key which belongs to a user requesting the search query, encrypts the extracted term with the decrypted index key without storing the decrypted index key in a non-transitory storage device, searches the index database with the index encrypted using the encrypted first term, and sends a search result to a terminal.

Search system

An objective of the present invention is to ensure security of the file sharing function provided by cloud storages without significantly decreasing the convenience of cloud storages. The encryption key management program according to the present invention encrypts, using authentication information of a user, a group shared key shared in a user group and stores it as an encrypted group shared key. The encryption key management program, upon receiving a request from a user, sends the encrypted group shared key corresponding to the requesting user.

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Tokyo, Japan

Minoru Fujimoto