A Comparison of Authentication Protocols for Unified Client Applications

OAuth, LDAP, forward authentication, and proxy authentication are protocols that allow a service to use a third party for user authentication. We compare these protocols on a variety of aspects, concluding that OAuth offers the greatest end-user convenience, forward and proxy authentication are the easiest to implement for the client application, and LDAP puts restrictions on how to identify the end-users. We then demonstrate a single data structure that can be used to store a client application in all four protocols, overcoming their disparate ways of functioning.