OpenID and the Enterprise: A Model-Based Analysis of Single Sign-On Authentication

Single sign-on (SSO) protocols allow one person to use the same login credentials for several organizations. Enterprises face increasing competitive pressure to position themselves with regard to SSO, yet the ramifications of a move to SSO are not fully understood. In this paper we discuss OpenID, a relatively new SSO protocol that is gaining traction on the web. We apply enterprise application modelling techniques to OpenID in order to obtain well-founded decision aids for enterprises: we show how published modelling approaches can be used to analyse risks in OpenID, and show that these can identify security problems with common OpenID practice. Finally, we propose analysis principles that condense important general insights of authentication modelling.