International Journal of Emerging Technology in Computer Science and Electronics ( IJETCSE)
Single Sign-Up (SSU) is a new authentication mechanism that enables a legal user with a single credential to be authenticated by multiple service providers in a distributed computer network. Recently, the researchers proposed a new SSU scheme and claimed its security by providing well-organized security arguments. However in this paper, the authors describe that their scheme is actually insecure as it fail to meet credential privacy and soundness of authentication. Specifically, they represent two impersonation severities.