A user-centric federated single sign-on system

Current identity management systems are not concerned with user privacy. Users must assume that identity providers and service providers will ensure their privacy, which is not always the case. This paper proposes an extension of the existing federated single sign-on (FSSO) systems that adopts the beneficial properties of the user-centric identity management (UCIM) model. This new identity management system allows the users to control and enforce their privacy requirements while still retaining the convenience of single sign-on over a federation of service providers. Colored Petri Nets are used to formally model the new identity management system to provide assurance that the privacy goals are achieved. To our knowledge, Colored Petri Nets have not been used to model privacy in identity management systems before.