| 摘要 |
A system allows a user to specify restriction categories for media provided by a content provider. The media can be rated, guaranteed, and marked with a digital watermark to verify that the media matches the restrictions placed by the user. This process may also be used by a content provider to verify the status of customer's accounts, restricting media to those customers whose accounts are paid. The system calculates a digest value of content provided by a content provider on a terminal of the content provider, and generates control information including the calculated digest value. The digest value included in the control information is compared with a digest value calculated on a terminal of the user. This comparison is used to control the reproduction of the content on the user's terminal. Content reproduction control is achieved by using the key information on the user's terminal to determining whether the control information is valid. If the digest values are identical, and the control information is determined to be valid based on the key information, the user will be able to reproduce the content.
|
