Microsoft® SQL Server™ OLAP Services imposes user security restrictions based on the access rights the user has been granted by the operating system. OLAP Services uses Security Support Provider Interface (SSPI) as the interface to Microsoft Windows NT® security for authentication, and supports the authentication scheme of NT LM Security Support Provider. Authentication occurs at the operating system level when a user logs on to a Windows NT domain. Access to OLAP Services requires the user to be a member of the same domain as the user account under which the server was installed, or to be a member of a trusted domain. A user is denied access if the user’s account cannot be authenticated against a trusted domain.