| 摘要 |
A created document or file 40 is associated with originator preferences 42 indicating the usage rules associated with the new document or file. The preferences are stored in a remote database 50 together with an indication of the content of the file, for example a digest of the file 44. When a user receives the file and requests to process it in some way, the form of the requested processing is sent to the database 64 together with a digest 62 of the received file and a user identifier. If the digest 62 matches or is close to a digest in the database, the associated preferences are checked and the requested processing is permitted only if the request is consistent with the preferences 66-70. The preferences may relate to saving, copying, or retransmitting the data. The originator or creator may be notified of any processing operations that are carried out. In another embodiment the preferences may be associated with the file some time after creation. |
