DATA UTILIZATION APPARATUS, ENCRYPTION DATA DISTRIBUTION SYSTEM, DATA UTILIZATION METHOD, ENCRYPTION DATA DISTRIBUTION METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a data utilization apparatus capable of appropriately operate key information following attribute information that may change with time.;SOLUTION: A data utilization apparatus includes: an encryption data control unit that transmits an encryption data request, receives attribute information, encryption data including a decryption condition, and identification information for the encryption data, outputs a decryption key acquisition request, and acquires a decryption key to decrypt the encryption data including the decryption condition; a key control unit that searches for a decryption key, outputs an effective decryption key in the case that the effective decryption key exists, transmits a key generation request in the case that no effective decryption key exists, and receives a decryption key to output the received decryption key; and an attribute control unit that searches for attribute information when having received an attribute information acquisition request, transmits effective attribute information in the case that the effective attribute information exists, and externally receives updated attribute information to transmit the received attribute information in the case that no effective attribute information exists.;COPYRIGHT: (C)2015,JPO&INPIT