AvecVoting: Anonymous and Verifiable E-voting with Untrustworthy Counters on Blockchain

E-voting plays a vital role in modern social life. However, traditional e-voting systems usually rely on a trusted third party and therefore non-verifiable and prone to a single point of failure. In recent years, many researchers have tried to turn to blockchain to eliminate the vulnerabilities of e-voting systems. However, blockchain-based e-voting brings new problems in protecting voters’ privacy and ballots’ confidentiality, and causes a great performance degradation. In this paper, we propose AvecVoting, an anonymous and verifiable blockchain-based e-voting scheme, providing both strong security and high performance. Specifically, we utilize threshold encryption and one-time ring signature to protect voters’ privacy and ballots’ confidentiality. Furthermore, to improve the performance, we introduce the concept "counter" to count the ballots. Through the carefully designed RandomSortition and reputation-based PayOff algorithms based on smart contracts, AvecVoting can achieve correct counting even when some counters are untrustworthy. Our security and performance analyses show that AvecVoting provides strong security such as anonymity, non-repeatability, confidentiality, verifiability, etc., and meanwhile overcome the performance issues caused by blockchain and provides good efficiency in both voting and counting stages.