A contract-based event-driven model for cooperative environments: the case of collaborative security

Assistant Supervisor: Dott.ssa Giorgia Lodi ii iii to my family and my long-time and more recent friends iv Acknowledgements I believe that one's results heavily depend on the context he lives daily. Looking back to my life and to the goals I've accomplished, I consider myself very lucky to have been surrounded by persons that have always given me the required serenity and the right boost to go ahead with my aspirations despite the usual big and small troubles that one has often to face. At this regard, I'd like to thank with all my heart my mother and my father for having supported me in all these years, in spite of the several changes I've made about my future directions. And I can't forget to thank all my friends in Terni and surroundings, from the high school ones to the others that I've met over time, for their loud company and strong understanding. A special thank goes to Roberto Baldoni and Giorgia Lodi for having introduced and guided me through the nice experience of getting involved in a European project and for the help they've given me in the writing of my thesis. I'd like also to thank Stefano, Luca and Silvia for their contribution to my work.