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 - Ioannis Askoxylakis, Henrich C. Pöhls, Joachim Posegga ((Lecture Notes in Computer Science))