Transitioning to a Javascript Voting Client for Remote Online Voting

Voters in remote electronic voting systems typically cast their votes from their own devices, such as PCs and smartphones. The software executed at their devices in charge of performing the ballot presentation, navigation and most of the cryptographic operations required to protect the integrity and privacy of the ballot, is referred to as the voting client. The first voting clients were developed as Java Applets. However, the use of this technology has become relegated in front of web technologies such as Javascript, which provide a better multi-platform user experience. This is the reason why in 2013 Scytl decided it was imperative to develop a voting client purely based on Javascript. This industrial paper shows the implementation experiences and lessons learned during the development and deployment of Javascript voting clients for our remote electronic voting systems. The paper is complemented with a performance study of 1) the main cryptographic primitives used in voting clients and 2) the voting casting process of one of the voting clients used in a real election.