Paper-based electronic voting

In this thesis, we present two paper-based electronic voting systems Prêt-à-Voter and Demos. We describe these in the same systematic way with new examples. Furthermore, we implement RSA cryptosystem in Prêt-à-Voter. Then, we propose an informal analysis of what is required both in practice and in the technical part of Prêt-à-Voter. We present randomized partial checking during mix-net and emphasize issues surrounding this component based on Pfitzmann attack and duplicate a vote attack. We discuss the size of a ciphertext in Prêt-à-Voter and explain the difficulty of proving permutation and randomness in the system. Finally, we discuss the concept of privacy based on the privacy game and illustrate with attacks how the privacy can be broken in both Prêt-à-Voter and Demos. For a general analysis of these two voting systems this thesis should be read together with the thesis of Anna Vederhus