| 摘要 |
In a Digital Rights Management (DRM) system, an unencrypted index of the content of encrypted material is provided to a search engine in order to enable encrypted material to be included in a search. The index may be produced prior to encryption of the content, and may include e.g. keywords descriptive of the content and an indication of the location of the content. The index may be produced either by the content publisher or a third party DRM "bureau", which may also provide the search engine facility. The index may be protected by e.g. signatures to prevent tampering. |
