Self-tallying e-voting with public traceability based on blockchain

In the post-epidemic era, the prevalence of remote collaborations in modern work environments highlight the importance of e-voting as a critical component in facilitating distributed decision-making. Most of the existing e-voting systems heavily rely on a centralized tally authority which requires a high degree of moral trust. However, this kind of architecture is insufficient for expected decentralization and verifiability in remote decision-making. A self-tallying e-voting system is more in line with our developed demands, nonetheless, it suffers adaptive and abortive issues inherently and as a result, fairness cannot be guaranteed. In this paper, we try to provide rational trust by building a blockchain-based self-tallying e-voting system with public traceability. We improve fairness and achieve a balance between privacy and accountability by taking advantage of a time-lock puzzle and traceable ring signature, in which the puzzle-solving time does not impose a real burden. We propose a concrete construction and prove that our protocol satisfies time-limited ballot secrecy, anonymity, exculpability, public traceability, self-tallying and fairness. We implement the prototype both on-chain and off-chain, and the results of time overhead of each phase demonstrate the practicability of our proposal.