An Efficient Blockchain-Based Self-Tallying Voting Protocol with Full-Anonymity

Abstract

Abstract As an electronic form of traditional voting, electronic voting is becoming more and more popular in today’s information society. Most of the existing electronic voting protocols need a trusted center to calculate the voting result, but the requirement of a trusted center is often unrealistic and prone to single point of failure. In this regard, the decentralized electronic voting protocols based on blockchain have been proposed. Unfortunately, most existing blockchain-based voting protocols fail to ensure anonymity, legitimacy, and correctness of counting. Besides, they do not satisfy robustness, i.e., the voting result cannot be counted in the event of voter abstention. To address the above challenges, we propose a novel blockchain-based self-tallying voting protocol, where the group signature and zero-knowledge proof are utilized in a way that the voter can securely distribute anonymous and unlinkable electronic ballots, thereby guaranteeing complete anonymity and legitimacy. Meanwhile, a novel signcryption algorithm is designed by combining distributed ElGamal encryption and Paillier encryption algorithms, which enhances the computational efficiency of voting results while supporting robustness. The security proof shows that our protocol ensures the confidentiality of ballots, complete anonymity, legitimacy, fairness, dispute-freeness and resistance against multi-voting. In addition, our protocol satisfies robustness, i.e., voting result can be correctly calculated and verified even if some voters abstain from voting. Finally, extensive experiments show that our protocol greatly reduces the computational cost and communication overhead, and is more practical than existing self-tallying voting protocols.