| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To contribute to the safety assurance of shared data when a key leaks from terminal equipment owned by a group member, and to reduce a processing load when disclosing the shared data. <P>SOLUTION: A group member terminal 1 includes: a terminal registration means for generating a common share from a key for a common share and a master share unique to a self-terminal, and for transmitting the common share and a self-terminal identifier to a storage server 2, and for making a registration request; a data storage means for encrypting the shared data by a common key encryption system by using an encryption key, and for generating an encryption key share from the encryption key and the master share, and for transmitting the encryption data, the encryption key share and the self-terminal identifier to the storage server 2, and for making a storage request; and a data referring means for acquiring the encryption data and the encryption key share for itself from the storage server 2, and restores the encryption key by using the encryption key share and the master share, and for decrypting encryption data acquired from the storage server 2 by using the encryption key. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
