Partial Verifiability in POLYAS for the GI Elections

We discuss the use of POLYAS, an Internet voting system, in GI (German Society for Computer Scientists (Gesellschaft für Informatik e.V.)) elections before 2010, in 2010 and 2011, as well as in the future. We briefly describe how the system was extended in 2010 to provide partial verifiability and how the integrity of the GI election result was verified in the 2010 and 2011 elections. Information necessary for partial verifiability has so far only been made available to a small group of researchers. In the future it would be ideal to make such information available to the general public, or to GI members, in order to increase the level of verifiability. We highlight legal considerations accompanying these possibilities, including publishing more details about the election results, the requirement for secret elections, avoiding vote buying, and how to handle complaints. Motivated by legal constraints, we propose further improvements to the POLYAS system. Finally, we generalize our findings for any partially-verifiable Internet voting system.