| 摘要 |
A content distribution device carries out distribution services of contents whose copyright protection is required via a communication line, to a user terminal device that enables to record contents to an information storage medium in which medium information is written, when receiving a content distribution request from the user terminal device, distributes a content list, and receives content selection information. At that moment, the content distribution device acquires the medium information from the user terminal device, sends this medium information to an encoded content key issuing device and receives an encoded content key based on the medium information concerned, and encodes contents by this encoded content key and distributes them to the user terminal device as distribution request source. The encoded content key is to be distributed at every viewing and/or listening request from the user terminal device, and when viewing and/or listening valid period expires, key distribution is stopped. |
