| 摘要 |
<P>PROBLEM TO BE SOLVED: To prompt document management even for created duplicates of documents. <P>SOLUTION: A server 10, when receiving data from a PC 12, stores the document data and a client ID of the PC 12. The server 10 sends a duplicate of the document data to an accessing PC 14. The PC 14 saves the duplicate of the document data received from the server 10. The server 10 periodically acquires the document data stored in the server 10, extracts digital watermark data to periodically determine whether or not the document data body of the document data has expired, and if confirming expiration, erases the document data and outputs an image representing the erasure due to the expiration to the PC 12 and PC 14. <P>COPYRIGHT: (C)2007,JPO&INPIT |
