Intelligo ut Confido: Understanding, Trust and User Experience in Verifiable Receipt-Free E-Voting (long version)

TL;DR

The paper tackles the problem of receipt-free verifiability in e-voting by evaluating the Selene protocol’s receipt-free mechanism through a large-scale user study. It introduces a novel voting-trust questionnaire and a game-based design to measure voters’ understanding of receipt-free features and its impact on trust, using 300 UK participants via Prolific. The results show low user experience and trust, but a positive link between understanding and trust, highlighting the importance of clear explanations and usable interfaces for verifiable voting systems. The study yields practical recommendations to improve understandability, usability, and education around receipt-free mechanisms, and outlines avenues for future research, including cross-country replication and more interactive trust validation.

Abstract

Voting protocols seek to provide integrity and vote privacy in elections. To achieve integrity, procedures have been proposed allowing voters to verify their vote - however this impacts both the user experience and privacy. Especially, vote verification can lead to vote-buying or coercion, if an attacker can obtain documentation, i.e. a receipt, of the cast vote. Thus, some voting protocols go further and provide mechanisms to prevent such receipts. To be effective, this so-called receipt-freeness depends on voters being able to understand and use these mechanisms. In this paper, we present a study with 300 participants which aims to evaluate the voters' experience of the receipt-freeness procedures in the e-voting protocol Selene in the context of vote-buying. This actually constitutes the first user study dealing with vote-buying in e-voting. While the usability and trust factors were rated low in the experiments, we found a positive correlation between trust and understanding.