Privacy-protected Electronic Voting System Based on Blockchin and Trusted Execution Environment

Blockchain technology is more and more popular for its advantage of decentralization, transparency, and nonmodifiable. In an electronic voting system, voting can be fair and secure by blockchain technology without a trusted third party. In this paper, we propose an economical and efficient electronic voting system based on the Ethereum Smart Contract that can also protect voters' privacy. The privacy of voters and votes can be protected by blind signature and homomorphic encryption. More importantly, the encryption algorithm is implemented in the Trusted Execution Environment (TEE), which can effectively reduce the complex operations in the contract and make the cost of Gas as low as possible. In addition, we also evaluated the system's implementation cost and designed a proposal to better protect voters' privacy for board-scale elections.