The Future of Identity in the Information Society : 4th IFIP WG 9.2, 9.6, 11.6, 11.7/FIDIS International Summer School, Brno, Czech Republic, September 1-7, 2008, Revised Selected Papers - Vashek Matyá., Simone Fischer-Hübner, Daniel Cvr.ek, Petr .venda ((IFIP Advances in Information and Communication Technology))