Privacy and Identity Management for Life : 7th IFIP WG 9.2, 9.6/11.7, 11.4, 11.6 International Summer School, Trento, Italy, September 5-9, 2011, Revised Selected Papers - Jan Camenisch, Bruno Crispo, Simone Fischer-Hübner, Ronald Leenes, Giovanni Russello ((IFIP Advances in Information and Communication Technology))