http://dl.gi.de/handle/20.500.12116/18207 2026-07-21T13:39:35Z 2026-07-21T13:39:35Z Spycher, Oliver Koenig, Reto Haenni, Rolf Schläpfer, Michael http://dl.gi.de/handle/20.500.12116/18229 2018-11-14T10:53:13Z 2012-01-01T00:00:00Z

Achieving meaningful efficiency in coercion-resistant, verifiable Internet voting Spycher, Oliver; Koenig, Reto; Haenni, Rolf; Schläpfer, Michael Kripp, Manuel J.; Volkamer, Melanie; Grimm, Rüdiger In traditional voting schemes with paper, pens, and ballot-boxes, appropriate procedures are put in place to reassure voters that the result of the tally is correct. Considering that in Internet voting errors or fraud will generally scale over a much greater fraction of votes, the demand to get strong reassurances as well, seems more than justified. With the ambition of offering a maximum degree of transparency, so-called verifiable schemes have been proposed. By publishing the relevant information, each voter may verify that her vote is included in the final tally and that accepted votes have been cast using proper voting material. Remarkably, this can be done while guaranteeing the secrecy of the ballot at the same time. On the negative side, high transparency will generally make it easier for voters to reveal how they voted, e.g., to a coercer. In this paper we propose an Internet voting protocol that is verifiable and simultateously makes it practically impossible for vote buyers or coercers to elicit the voters' behaviour. We compare its efficiency with existing work under equal degrees of coercion-resistance using an appropriate measure (δ). The contribution of our scheme lies in its efficiency during the most critical phases of the voting procedure, i.e., vote casting and tallying. Moreover, during these phases, efficiency is insensitive to the desired degree of coercion-resistance.

2012-01-01T00:00:00Z Puigallí Allepuz, Jordi Guasch Castelló, Sandra http://dl.gi.de/handle/20.500.12116/18225 2018-11-14T10:53:13Z 2012-01-01T00:00:00Z

Cast-as-intended verification in Norway Puigallí Allepuz, Jordi; Guasch Castelló, Sandra Kripp, Manuel J.; Volkamer, Melanie; Grimm, Rüdiger The Norwegian Ministry started an initiative to implement Internetvoting trials during the municipal elections in 2011. One of the security requirements of the chosen e-voting system to not to put any trust in the voting client: a malicious application controlling the voting client should not be able to modify the voting options selected by the voter without being detected. This paper describes the voter verification return-code scheme that was implemented for this project. Furthermore, this paper explains the implementation details of the final solution and the workflow of the system during the different election phases. The aim of this paper is to provide a general overview of the cast-as-intended scheme implemented in eValg2011.

2012-01-01T00:00:00Z Dossogne, Jérôme Lafitte, Frédéric Markowitch, Olivier http://dl.gi.de/handle/20.500.12116/18230 2018-11-14T10:53:14Z 2012-01-01T00:00:00Z

Coercion-freeness in e-voting via multi-party designated verifier schemes Dossogne, Jérôme; Lafitte, Frédéric; Markowitch, Olivier Kripp, Manuel J.; Volkamer, Melanie; Grimm, Rüdiger In this paper we present how multi-party designated verifier signatures can be used as generic solution to provide coercion-freeness in electronic voting schemes. We illustrate the concept of multi-party designated verifier signatures with an enhanced version of Ghodosi and Pieprzyk [GP06]'s threshold signature scheme. The proposed scheme is efficient, secure, allows distributed computations of the signature on the ballot receipt, and can be parameterized to set a threshold on the number of required signers. The security of the designated verifier property is evaluated using the simulation paradigm [Gol00] based on the security analysis of [GHKR08]. Unlike previously provable schemes, ours is ideal, i.e. the bit-length of each secret key share is bounded by the bit-length of the RSA modulus.

2012-01-01T00:00:00Z Olembo, M. Maina Kahlert, Anna Neumann, Stephan Volkamer, Melanie http://dl.gi.de/handle/20.500.12116/18228 2018-11-14T10:53:13Z 2012-01-01T00:00:00Z

Partial verifiability in POLYAS for the GI elections Olembo, M. Maina; Kahlert, Anna; Neumann, Stephan; Volkamer, Melanie Kripp, Manuel J.; Volkamer, Melanie; Grimm, Rüdiger 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.

2012-01-01T00:00:00Z