Increasing security without decreasing usability: A comparison of various verifiable voting systems

Electronic voting researchers advocate for verifiable voting schemes to maximise election integrity. In order to maximise vote secrecy, so-called code-voting approaches were proposed. Both verifiability and code voting require voters to expend additional effort during vote casting. Verifiability has been used in actual elections, but this is not the case for code voting due to usability concerns. There is little evidence from empirical studies attesting to its usability. Our main contribution is to extend an existing verifiable voting system (used for real world elections) with a code-voting approach to improve the system's security properties. We minimise voter effort as corresponding QR codes are scanned instead of requiring manual code entry. We conducted a user study to evaluate the general usability of this proposal as well as its manipulation-detection efficacy. In particular, we found that extending the considered verifiable voting systems with code-voting approaches to enhance vote secrecy is feasible because we could not observe a significant decrease in general usability while manipulation detection improved significantly.