Abstract: Branch domain controllers (DCs) contain read only replicas of the data in a normal domain DC. This includes information about the groups a user belongs to so it can be used to determine authorization information. Password information, however, is desirably replicated to the branch DCs only for users and services (including machines) designated for that particular branch. Moreover, all write operations are desirably handled by hub DCs, the primary domain controller (PDC), or other DCs trusted by the corporate office. Rapid authentication and authorization in branch offices is supported using Kerberos sub-realms in which each branch office operates as a virtual realm. The Kerberos protocol employs different key version numbers to distinguish between the virtual realms of the head and branch key distribution centers (KDCs).

Abstract: Systems and related methods enable a web service to map a unique identifier received from a client to the client's user account in a directory service using an authentication protocol and thereby receive permission to access resources for the client in the service's domain or in a distant domain. When the unique identifier is a web service unique identifier (PUID), the PUID is changed to a user principal name (UPN) mappable to the client's user account object in the directory service.