An Anonymous Distributed Electronic Voting System Using Zerocoin

Electronic voting systems have several necessarily requirements, such as anonymity that others cannot link voters with votes, the fairness that votes should not be leaked before the tally, and the accuracy that eligible voters’ votes should be counted correctly. There have been proposed various methods to realize the requirements. Some of them require anonymous communication paths as necessary elements to satisfy the anonymity requirement for a practical electronic voting system. Cruz et al. proposed an electronic voting system that does not need anonymous communication paths, using Bitcoin, a cryptographic currency, as a distributed database. However, Bitcoin is a system in which all data are disclosed, and anyone can check what exchanges a person of a certain ID (Bitcoin address) has done. It is possible to reveal which voter made what vote, and hence(anonymity is not satisfied. In this paper, we propose a method to solve the above problem by using Bitcoin mixing. We propose an electronic voting system using Zerocoin, a variant of Bitcoin, as a database, in which zero knowledge proof is used instead of blind signature for mixing.