The API view of GSS-API does have significant value as well; since the abstract operations are well defined, the information that a mechanism gets from the application is well defined. Also, the set of assumptions the application is permitted to make is generally well defined. As a result, an application protocol that supports GSS-API or SASL is very likely to be usable with a new approach to authentication, including the authentication mechanism defined in this document, with no required modifications. In some cases, support for a new authentication mechanism has been added using plugin interfaces to applications without the application being modified at all. Even when modifications are required, they can often be limited to supporting a new naming and authorization model. For example, this work focuses on privacy; an application that assumes that it will always obtain an identifier for the client will need to be modified to support anonymity, unlinkability, or pseudonymity.