| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a content distribution system which can prevent an unauthorized act performed by a transmitter for transmitting content by masquerading as a receiver for receiving content. <P>SOLUTION: A content delivery system 1 is a system that sends and receives content between a transmission device 10 and a reception device 20. The transmission device 10 transmits a plurality of contents to which a digital watermark is embedded to the reception device 20, and the reception device 20 selects one of the plurality of contents. Here, the transmission device 10 cannot obtain information of a content which the reception device 20 has selected. As a result, the transmission device 10 can not perform an unauthorized act by masquerading as the reception device 20. When a content selected by the reception device 20 is illegally leaked, it is judged that the reception device 20 is a leak source. When a content other than the content selected by the reception device 20 is leaked, it can be judged that the transmission device 10 is a leak source. <P>COPYRIGHT: (C)2008,JPO&INPIT |
