| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a download device etc. for detecting the validity of a message received from a provider device or terminal equipment. <P>SOLUTION: The download device 11 generates a first authentication code according to a predetermined algorithm by using at least a part of content sales history received from a provider device 10 as a seed, holds a sales history with authentication code including the first authentication code and terminal equipment ID. When receiving a download request from terminal equipment 12, the download device 11 specifies from the held sales histories with authentication code, one sales history with authentication code by using a URI of a download source and the terminal equipment ID of the terminal equipment 12 which has made the download request, collates the first authentication code included in the specified sales history with authentication code with a second authentication code included in the URI of the download source, and transmits the requested content to the terminal equipment 12 only when collation succeeds. <P>COPYRIGHT: (C)2011,JPO&INPIT |
