2015 neuchȃtel’s cast-as-intended verification mechanism

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Colleges, School and Institutes


Cast-as-intended verification seeks to prove to a voter that their vote was cast according to their intent. In case ballot casting is made remotely through a voting client, one of the most important dangers a designer faces are malicious voting clients (e.g. infected by a malware), which may change the voter’s selections. A previous approach for achieving cast-as-intended verification in this setting uses the so-called Return Codes. These allow a voter to check whether their voting options were correctly received by the ballot server, while keeping these choices private. An essential ingredient of this approach is a mechanism that allows a voter to discard a vote that does not represent their intent. This is usually solved using multiple voting, namely, if the return codes received by the voter do not match their choices, they cast a new vote. However, what happens if voters are not allowed to cast more than one ballot (aka single vote casting)? In this paper we propose a simple ballot casting protocol, using return codes, for allowing a voter to verify votes in a single vote casting election. We do so without significantly impacting the number of operations in the client side. This voting protocol has been implemented in a binding election in the Swiss canton of Neuchˆatel in March 2015, and will be the canton’s new voting platform.


Original languageEnglish
Title of host publicationE-Voting and Identity
Subtitle of host publication5th International Conference, VoteID 2015, Bern, Switzerland, September 2-4, 2015, Proceedings
EditorsRolf Haenni, Reto E. Koenig, Douglas Wikström
Publication statusPublished - 13 Aug 2015
Event5th International Conference on E-Voting and Identity, VoteID 2015 - Bern, Switzerland
Duration: 2 Sep 20154 Sep 2015

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference5th International Conference on E-Voting and Identity, VoteID 2015


  • Binding election, Cast-asintended verifiability, Electronic voting protocols, Malicious voting client, Return codes