| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently deliver trial content and content for purchasing, and improve security against an unauthorized copy or the like. <P>SOLUTION: Clients devices 10, 11, 12- are provided with content data and first management information which permits the trial use of the content data from a server 20 or a CD-ROM, and store the data and the information in HDDs. If the authorized use of the stored content data is desired, the client devices 10, 11, 12- transmit requests for the authorized use to the server 20, and receive second management information for permitting the authorized use of the content data from the server 20. Only by a client for which the authorized use is permitted, ordinary reproduction without restrictions on a reproduction function can be performed on the basis of the second management information. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
