Identity Continuance in Single Sign-On with Authentication Server Failure

Single sign-on (SSO) is an identity management technique that provides users the ability to use multiple Web services with one set of credentials. However, when the authentication server is down or unavailable, users cannot access Web services, even if the services are operating normally. Therefore, enabling continuous use is important in single sign-on. In this paper, we present an identity continuance method for single sign-on. We explain four such continuance methods: Redundant SSO Auth Server method, Alias SSOID method, Multiple SSOID method, and SSOID Migration method. We consider these four methods from the viewpoint of continuity, security and efficiency. Moreover, we discuss the feasibility of each.