Abstract

The advancement of blockchain technology introduces the new concept of electronic voting systems (e-voting) that are fully anonymous, transparent, trustless, and decentralized. The limitation of blockchain-based e-voting systems is the need for initial setup to verify and validate eligible voters. This initial setup requires human intervention, which curbs the full potential and exploitation of blockchain technology. Identity authentication is crucial in voting systems to ensure the eligibility of the voters and the validity of the results. This paper proposes a hybrid approach using ZK-SNARK for identity authentication systems in blockchain-based e-voting. The proposed hybrid approach aims to maintain the benefit of blockchain technology while guaranteeing the eligibility of voters. Both on-chain and off-chain identity authentication modules are designed and developed to balance the trade-off of centralized and decentralized nature for the blockchain-based e-voting systems. The affordability of the proposed system is essential in justifying the approach's feasibility and usability. Voting systems are expected to host thousands to millions of voters, and the cost is one major consideration. The proposed system is deployed in the Ethereum blockchain network, including its sidechain and Layer 2, i.e., Avalanche, Arbitrum One, and Polygon. The gas fee required for the smart contract deployment in Ethereum is USD12.5, while the lowest gas fee is in the Polygon blockchain network for USD0.02.