Privacy by Design in Federated Identity Management

Federated Identity Management (FIM), while solving important scalability, security and privacy problems of remote entity authentication, introduces new privacy risks. By virtue of sharing identities with many systems, the improved data quality of subjects may increase the possibilities of linking private data sets, moreover, new opportunities for user profiling are being introduced. However, FIM models to mitigate these risks have been proposed. In this paper we elaborate privacy by design requirements for this class of systems, transpose them into specific architectural requirements, and evaluate a number of FIM models with respect to these requirements. The contributions of this paper are a catalog of privacy-related architectural requirements, joining up legal, business and system architecture viewpoints, and the demonstration of concrete FIM models showing how the requirements can be implemented in practice.