Je tiens à remercier: �Monsieur Yves Rouchaleau pour avoir accepté de présider mon jury de thèse, �Messieurs Simon Lacroix et El Mustapha Mouaddib pour leur travail de rapporteurs, �Madame Delphine Dufour, Messieurs David Filliat et Roland Siegwart pour avoir examiné ma thèse, �la DGA pour le

I would like to thank some people who were involved in the creation of this thesis: • Berry Schoenmakers of TU Eindhoven for introducing me to the topic of cryptographic voting protocols. • Evangelos Karatsiolis for his work in guiding me through the process of writing this thesis and his constant motivation. • Roberto Samarone Araujo for hours of discussing various protocols with Evengelos and me. • Warren D. Smith for providing with a preliminary version of his upcoming book »How Mathematics can Improve Democracy«. • Ute Günther and Christian Burgmann for their proof-reading. Nonetheless, any remaing errors shall be blamed on me. • Andrea Peter for her love and for cheering me up when I was down. • Last but not least my parents, Jacqueline Herrnkind and Hans Peter Klink – without their love and continuous support, this thesis would never have been written.