Information delivery system, delivery center device, user terminal device and information delivery method

摘要

A user terminal device specifies presence or absence of additional recording in issuing a content request, and in the case of additional recording, the device transmits medium information and encrypted information of pre-recorded contents to a delivery center. When receiving a content additional recording request from the device, the delivery center decrypts once encrypted contents to be additionally recorded with the corresponding-content keys. The encrypted key information is decrypted by the medium information from the device to decrypt content keys of the pre-recorded contents and re-encrypts encrypted contents to be additionally recorded to deliver the re-encrypted contents to the device. When receiving contents for additional recording, the device records the received contents so as to be related to the pre-recorded contents, on a recording medium.

主权项

1. An information delivery system, comprising:
a user terminal device configured to record content on a first recording medium with medium information of a medium-specific identifier written thereon or to record content on a second recording medium that is different from the first recording medium in a state where the first recording medium is loaded; and a delivery center device which delivers requested content from a plurality of items of content to the user terminal device, wherein the delivery center device comprises:
a management apparatus which manages a plurality of encrypted contents obtained by encrypting the plurality of items of content by means of different content keys used for the encryption, wherein the plurality of encrypted contents are stored in a first storage unit, the content keys are stored in a second storage unit, and the plurality of encrypted contents are managed separately from the content keys by the management apparatus;an encryption processor that when a request for content is made from the user terminal device, receives the medium information from the user terminal device, retrieves encrypted content and a content key which corresponds to the requested content from the management apparatus and encrypts the content key by using the medium information, thereby generating encrypted key information; anda delivery apparatus which delivers the encrypted key information together with or separately from the encrypted content to the user terminal device,wherein when the request for content includes an instruction for recording additional content, the encryption processor retrieves the encrypted content and the content key which corresponds to the requested content from the management apparatus, decrypts the encrypted content, receives an encrypted key associated with content pre-recorded at the user terminal device and the medium information from the user terminal device, decrypts the encrypted key received from the user terminal device on the basis of the medium information, and re-encrypts the decrypted content using the decrypted key, andwherein the delivery apparatus delivers the re-encrypted content to the user terminal device when the instruction for recording additional content is made, and the user terminal device comprises:
a notification apparatus that, when a request for the content is made to the delivery center device, reads out the medium information from the first recording medium and transmits the medium information together with the request; anda recording processor which records the encrypted content and the encrypted key information that are received from the delivery center device on the first recording medium or the second recording medium,wherein when a request for recording additional content is made to the delivery center device, the notification apparatus transmits an instruction that the requested content is to be additionally recorded to pre-recorded content that has been previously received and the encrypted key associated with the pre-recorded content together with the request, andwherein the recording processor records there-encrypted content received from the delivery center device on the first recording medium with the pre-recorded content recorded thereon in such a manner that the re-encrypted content follows the pre-recorded content.