Security and Privacy in Mobile Information and Communication Systems : Third International ICST Conference, MOBISEC 2011, Aalborg, Denmark, May 17-19, 2011, Revised Selected Papers - Ramjee Prasad, Károly Farkas, Andreas U. Schmidt, Antonio Lioy, Giovanni Russello, Flaminia L. Luccio ((Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering))