Classifying Privacy and Verifiability Requirements for Electronic Voting

Voter privacy and verifiability are fundamental security concepts for electronic voting. Existing literature on electronic voting provides many definitions and interpretations of these concepts, both informal and formal. While the informal definitions are often vague and imprecise, the formal definitions tend to be very complex and restricted in their scope as they are usually tailored for specific scenarios. Moreover, some of the existing interpretations are contradictory. This paper provides informal, yet precise definitions of anonymity, receipt-freeness and coercion-resistance and identifies different levels of individual and universal verifiability. The overarching goal of this paper is to investigate which levels are conceivable for implementing these requirements in e-voting systems for elections of different significance (for instance political elections vs. elections in associations).