Patent ID: 9177170
Filing Date: 2015-11-03
Classification: G06F

Abstract:
1. An information provision system comprising: a content encryption circuit which acquires content key generation conditions and content information from a copyright owner or a copyright manager of content, generates a content key on the basis of the content key generation conditions, and encrypts the content information using the content key to generate encrypted content; a content information copying circuit which attaches content identification information identifying the content information and access destination information to the encrypted content, writes the encrypted content to an information storage medium with the content identification information and the access destination information attached to the encrypted content to generate a copied information storage medium, the information storage medium comprising medium information including medium key information and a unique identifier of the information storage medium, acquires the medium information from the information storage medium, attaches the content identification information to the acquired medium information, and issues the medium information and the content identification information attached to the medium information; a content key encryption circuit which stores the content key generated by the content encryption circuit; and an encrypted content key distribution circuit which acquires the medium information and the content identification information attached to the medium information that are issued by the content information copying circuit, stores the acquired medium information and the content identification information attached to the medium information, wherein; the encrypted content key distribution circuit receives a content viewing request from a user terminal device to which the copied information storage medium is set, receives medium information and content identification information written in the copied information storage medium from the user terminal device, compares the received medium information with the stored medium information issued by the content information copying circuit and, when the received medium information matches the stored medium information, sends the matched medium information with the received content identification information to the content key encryption circuit, acquires an encrypted content key from the content key encryption circuit, and distributes the encrypted content key from the content key encryption circuit to the user terminal device via a communication line, the content key encryption circuit receives the matched medium information and the content identification information from the encrypted content key distribution circuit, acquires content key identified by the content identification information, and encrypts, the acquired content key with the received medium information or the received medium information and device unique information of the user terminal device presented from the user terminal device to generate the encrypted content key, and the user terminal device reads out the access destination information from the copied information storage medium in accordance with the content viewing request, accesses, based on the access destination information, the encrypted content key distribution circuit via the communication line, presents the medium information and the content identification information stored in the copied information storage medium or the medium information, the content identification information, and the device unique information to the encrypted content key distribution circuit, acquires the encrypted content key from the encrypted content key distribution circuit, decrypts the encrypted content key with the medium information, and decrypts the encrypted content stored in the copied information storage medium with the decrypted content key.