STORAGE METHOD, ACQUISITION METHOD, CREATION METHOD, STORAGE DEVICE, ACQUISITION DEVICE, CREATION DEVICE, STORAGE PROGRAM, ACQUISITION PROGRAM, AND CREATION PROGRAM

摘要

PROBLEM TO BE SOLVED: To efficiently enhance security in a shared storage area.SOLUTION: An information processing device 100 has a group key Gk unique to a group G to which the information processing device 100 belongs. A directory D of a database 101 can be used by a specific group G. The directory D stores a directory key Dk unique to the directory D that can generate a data key dk which is to be used for encrypting and decrypting data d in the directory D by combining with a group key Gk unique to an available group G. For storing data d in the directory D, if the information processing device 100 has the group key Gk unique to the specific group G, the information processing device 100 generates the data key dk by combining the group key Gk and the directory key Dk, and encrypts data d.