I was asked recently if the BDC search results (when indexed by the search) can be controlled by an access list. The answer is that yes, the Security trimmer is the SharePoint feature to accomplish this. In fact any search result can be trimmed, so if you wanted to index some website that used custom permissions (i.e. a content access account that has full rights to a website) but you didn’t want to show that information to say public users of your site, this same security trimmer functionally can be used.
The important things to note are:
- The security trimmer is attached to a crawl rule
- The security trimmer is a class that implements the ISecurityTrimmer interface, the registration process defines the full assembly name, as such it must be loaded into the GAC.
- After the security trimmer is registered, you will need to recreate the content source and perform a full crawl
- Performance might be an issue, since every search result will be access checked, if your looking for insight on how to approach this refer to this MSDN article