opn.vote: A Publicly Verifiable Blockchain-Based eVoting System

opn.vote is a publicly verifiable e-voting system that mitigates the single point of failure in traditional bulletin board architectures by moving critical processes to a public blockchain. Using Ethereum's Account Abstraction, it lets voters cast and re-cast ballots without wallets or cryptocurrency. The protocol combines Schnorr blind signatures with ElGamal encryption to ensure anonymity and auditability.  
opn.vote pilots in Germany’s Abstimmung21 referendum in September 2025, aiming to shift 50% of votes online while reducing per-vote transaction costs from €2 to under €0.01. Compared to MACI, Ethereum’s leading voting system, it achieves approximately two times lower on-chain costs.