Blockchain Electronic Voting Scheme Based on Fully Homomorphic Encryption

In digital voting systems, the combination of Fully Homomorphic Encryption (FHE) and blockchain technology guarantees the security and privacy of E-voting. The overall performance of existing schemes is constrained owing to the complex computation process of FHE algorithm, especially in terms of vote-counting efficiency and fairness. To address these issues, this paper proposes a Blockchain E-voting Scheme based on Fully Homomorphic Encryption (BCEVS-FHE). This scheme optimizes the Brakerski—Fan—Vercauteren (BFV) FHE algorithm by mitigating the impact of noise factor to reduce the computational overhead during encryption and decryption, thereby improving the vote-counting efficiency. The SM2 digital signature algorithm is used to sign ballot information generated by voters, ensuring that the voters could not deny their voting behavior and preventing identity impersonation and fraud. Furthermore, smart contracts are introduced to improve the weighting method used for vote tallying. Consequently, the unforgeability and non-tampering of voter weights are ensured, thereby guaranteeing the fairness and impartiality of the voting process. Finally, all transaction information is stored in the chain using a private blockchain, ensuring that the entire voting process is tamperproof and fully traceable. Experimental results show that BCEVS-FHE not only guarantees security attributes such as privacy, confidentiality, security, uniqueness, and verifiability but also excels in functional attributes such as fairness and mobility. Overall, BCEVS-FHE meets the security requirements of E-voting protocols and has high potential for practical applications, which is of significant research for the widespread application of digital voting systems.