Paper 2026/1435 Original: eprint.iacr.org/2026/1435 ↗

FiltrumVote: Scalable, Verifiable, and Coercion-Resistant Internet Voting

Abstract

Internet voting can increase voter turnout and reduce operational costs; however, it also facilitates voter coercion. One compelling approach to address this issue is deniable vote updating, which allows voters to cast multiple ballots while counting only their final vote. Despite its intuitive appeal, achieving deniable vote updating together with verifiability and scalability has proven challenging. Therefore, we present FiltrumVote, a scalable, publicly verifiable, and coercion-resistant Internet voting system based on deniable vote updating. It has a quasi-linear cleansing phase, and it is built mainly from zero-knowledge proofs with standard $\Sigma-$protocol techniques. As a result, FiltrumVote is highly scalable: a standard computer takes less than 5 hours to prove all zero-knowledge proofs for one million votes.