Security and Intelligent Information Systems [electronic resource] : International Joint Conferences, SIIS 2011, Warsaw, Poland, June 13-14, 2011, Revised Selected Papers / edited by Pascal Bouvry, Mieczysław A. Kłopotek, Franck Leprévost, Małgorzata Marciniak, Agnieszka Mykowiecka, Henryk Rybiński.