Smart Search: Filter documents for users with valid permissions (roles)

Hi,

I have a folder where I added a role "X" under "Properties -> Security". Role X has the permission to read all documents under this folder. Other permissions like Modify, Create,... are denied. The permissions on all documents of this folder are inherited from the folder itself.

I use smart search web parts to display documents from several folders. Among these documents are the documents of the described folder (with limited permissions for roles). In my smart search, however, all documents are shown, independent of user roles.

So my question is:

How do I filter documents to only show documents where the currently logged in user has the permissions (via their role) to read the documents?

Thanks, Roland