Why Johnny Checks but Doesn't Alert: Reporting as the Missing Step in Verifiable Internet Voting

End-to-end verifiable Internet voting promises that voters can remotely check whether their ballot was recorded correctly and that all ballots were tallied as cast. However, in order to achieve an adequate level of security, voters actually need to perform the first check. Our research focuses on the cast-then-audit approach for this check. We use related work to improve this approach in particular by providing a step-by-step guide. We conducted a deceptive online user study (N = 437) to compare our improved system with a baseline version from an actual election. We also measured the usability and participants confidence in using such systems. Our findings show that participants from the improved system perform significantly better than the baseline w.r.t. manipulation detecting and reporting capabilities. Furthermore, we show that it is important to distinguish between detection and reporting to understand how to further increase the overall security.