Coercion-Resistant Internet Voting with Everlasting Privacy

The cryptographic voting protocol presented in this paper offers public verifiability, everlasting privacy, and coercion-resistance simultaneously. Voters are authenticated anonymously based on perfectly hiding commitments and zero-knowledge proofs. Their vote and participation secrecy is therefore protected independently of computational intractability assumptions or trusted authorities. Coercion-resistance is achieved based on a new mechanism for deniable vote updating. To evade coercion by submitting a final secret vote update, the voter needs not to remember the history of all precedent votes. The protocol uses two types of mix networks to guarantee that vote updating cannot be detected by the coercer. The input sizes and running times of the mix networks are quadratic with respect to the number of submitted ballots.