Running the Race: A Swiss Voting Story

On the 29th of March 2019 the Swiss Federal Chancellery launched a review of the procedures surrounding e-voting after numerous flaws were discovered in the Scytl-Swiss Post system sVote. On the 5th of July 2021 an independent examination of the revised Swiss Post system began, with some cantons planning to launch new trials with this system. We summarize and reflect on our experience with the examination of the cryptographic protocol so far and muse over the future. We find that the protocol specification considerably improved over the last 3 years, both through changes in the protocol itself and through clarifications of missing elements in its specification. The clarifications also shed a new light on shortcomings of the protocol, in terms of both verifiability and privacy, including in the latest version of the system, which remains incompletely specified. We believe that these findings illustrate virtues of the examination requirements set by the Swiss Federal Chancellery: problems can be fixed before deployment rather than being exploited by malicious parties during an election. They also illustrate the tremendous challenges of creating a secure Internet voting system, and the long road ahead.