Belenios with Cast-as-Intended: Towards a Usable Interface

In this work we consider Belenios-CaI, a protocol offering a cast-as-intended mechanism and building upon Belenios, a voting system used in about 7000 elections to date. We modify the design of Belenios-Cai from the user perspective without changing its core cryptographic mechanism. The goal is to increase its usability by letting the voter simply check whether two symbols are equal or different. We conducted a user-study among 165 participants in a research center to evaluate the usability of our implementation of Belenios-CaI. Since the cast-as-intended mechanism assumes that voters make some random choices, we also evaluate whether the choices made by voters are sufficiently “random” to provide verifiability and whether it could affect their privacy. The study shows that, for our population, Belenios-CaI is considered as usable with the random choices of the voters seeming sufficient for verifiability and privacy.

In International Joint Conference on Electronic Voting