ENCRYPTION UPDATE SYSTEM, ENCRYPTION UPDATE REQUEST DEVICE, ENCRYPTION UPDATE DEVICE, DECRYPTION DEVICE, ENCRYPTION UPDATE METHOD, AND COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a technique for performing encryption update without transmitting plain texts or decryption information to an administrator of a database storing encrypted data, while reducing a load on a device of a user requiring the encryption update.;SOLUTION: An encryption update request device 100 comprises: a pre-update key acquisition unit 101 which acquires pre-update key information; a key generation unit 102 which generates post-update key information; a pre-update decryption key encrypting unit 103 which generates pre-update decryption key encrypted data in which pre-update decryption key information included in the pre-update key information is encrypted by using the post-update key information; and an update request transmission unit 104 which transmits update request including the pre-update decryption key encrypted data and encryption update key information included in the post-update key information to an encryption update device 200. The encryption update device 200 comprises an encryption update unit 201 which generates post-update encrypted data in which information including encrypted data of an update request target and the pre-update decryption key encrypted data is encrypted by using the encryption update key information.;COPYRIGHT: (C)2014,JPO&INPIT