A method of interpreting an authorization token is described herein. The service can receive an authorization token from a client device, and validate a signature of the authorization token. The service can identify an allowed function value associated at least part of an entitlement representation contained in a body of the authorization token. The service can convert the allowed function value to an allowed function bitmask that includes bits at a plurality of bit positions that are set to values indicating whether the subscriber element has attributes associated with each of the plurality of bit positions on a predefined attribute list. The service can determine whether the allowed function bitmask indicates that the subscriber element has one or more qualifying attributes that entitle a user of the client device to access the service.