The Norwegian internet voting protocol

Abstract

The Norwegian government will run a trial of internet remote voting during the 2011 local government elections. A new cryptographic voting protocol will be used, where so-called return codes allow voters to verify that their ballots will be counted as cast. This paper discusses a slightly simplified version of the cryptographic protocol. The description and analysis of the simplified protocol contains most of the ideas and concepts used to build and analyse the full protocol. In particular, the simplified protocol uses the full protocol's novel method for generating the return codes. The security of the protocol relies on a novel hardness assumption similar to Decision Diffie-Hellman. While DDH is a claim that a random subgroup of a non-cyclic group is indistinguishable from the whole group, our assumption is related to the indistinguishability of certain special subgroups. We discuss this question in some detail. © 2012 Springer-Verlag.