US Patent 8417693 Enforcing native access control to indexed documents

Techniques are provided for processing a search request. One or more indexed levels of access control list information are stored in a search index for each document identified in the search index. An interim result set is generated by matching the one or more indexed levels of access control list information associated with each said document to one or more security groups associated with the search request. A final result set is generated from the interim result set by performing impersonation.