Information Security Theory and Practice. Security, Privacy and Trust in Computing Systems and Ambient Intelligent Ecosystems 6th IFIP WG 11.2 International Workshop, WISTP 2012, Egham, UK, June 20-22, 2012. Proceedings - Askoxylakis, Ioannis; Pöhls, Henrich C.; Posegga, Joachim (Springer Berlin Heidelberg, 2012)