Section: New Software and Platforms

Belenios

Participants : Pierrick Gaudry, Stéphane Glondu [contact] .

In collaboration with the Cassis team, we develop an open-source private and verifiable electronic voting protocol, named Belenios . Our system is an evolution of an existing system, Helios, developed by Ben Adida, and used e.g., by UCL and the IACR association in real elections. The main differences with Helios are the following ones:

• In Helios, the ballot box publishes the encrypted ballots together with their corresponding voters. This raises a privacy issue in the sense that whether someone voted or not shall not necessarily be publicized on the web. Publishing this information is in particular forbidden by CNIL's recommendation. Belenios no longer publishes voters' identities, still guaranteeing correctness of the tally.

• Helios is verifiable except that one has to trust that the ballot box will not add ballots. The addition of ballots is particularly hard to detect as soon as the list of voters is not public. We have therefore introduced an additional authority that provides credentials that the ballot box can verify but not forge [18] , [23] .

This new version has been implemented by Stéphane Glondu (http://belenios.gforge.inria.fr/ ). The first public release has been done in January 2014. In the last public release (April 2014), Belenios still uses a major component of the Helios system, the booth. Since then, the booth has been reimplemented but is not yet part of a public release. This development version of Belenios has been used in December 2014 for selecting photos of LORIA's calendar (187 persons voted for 0 to 6 pictures, within a set of 52 choices).