Towards Improving the Efficacy of Code-Based Verification in Internet Voting

Abstract

End-to-end verifiable Internet voting enables a high level of election integrity. Cast-as-intended verification, in particular, allows voters to verify that their vote has been correctly cast, even in the presence of malicious voting devices. One cast-as-intended verification approach is code-based verification, used since 2015 in legally-binding Swiss elections. We evaluated the Swiss paper-based polling sheet and voting interface, focusing on how well it supported voters in verifying their votes. We uncovered several potential issues related to manipulation detection. We improved the paper-based polling sheet and voting interface accordingly. Then, we carried out a between-subjects lab study with 128 participants to compare the original and improved sheet and interface wrt. usability and its effectiveness in supporting manipulation detection. Our improvements significantly enhanced detection. Our study delivered insights into participants' somewhat ineffectual reactions to detected anomalies, i.e. starting over again and trying to cast the same vote again, or calling the telephone number provided by the interface. This problem is likely to manifest in any verifiable voting system and thus needs to be addressed as future work.

Towards Verifiable Remote Voting with Paper Assurance

“…Also note that the usability of even the simplest cast-asintended verification mechanisms is questionable, with practical failure rates shown for both code voting [43] and the checking of plaintext printouts [10,20,22,41].…”

German Voters’ Attitudes Towards Voting Online with a Verifiable System

“…the steps to verify are more integrated in vote casting than it is is the case e.g. in Helios [4]; it has been used in Switzerland for actual elections, and past research has improved its usability and has shown that it is usable [17]. Furthermore, we were interested the effect of different interventions explaining in a more or less alarming way that it is important to carefully take all the steps described in the received voting material.…”

“…Furthermore, we were interested the effect of different interventions explaining in a more or less alarming way that it is important to carefully take all the steps described in the received voting material. This last research question is motivated by the fact that past research has concluded that it is important to motivate voters to verify as well as to explain the importance for the overall security of the system [17]. In particular, we are interested whether such interventions have a negative impact on trust.…”

“…This sheet provides the website address voters can use to cast their votes, instructions, and one or more codes to verify the correct processing of their vote. In this work, we use a variant based on a voting system used in Swiss elections [31], with the polling sheet and user interface modifications developed by Kulyk et al [17]. While there also exist improvements from [22], we decided to go for the Kulyk et al [17] because it was evaluated with respect to more attack types than the proposal by Marky et al [22].…”

“…The polling sheet of [17,22,31] provides three types of codes: check, confirmation and finalization code. In order to cast their vote, the voter first has to identify themselves by entering their password, which is provided on the polling sheet.…”