Apollo: End-to-End Verifiable Voting Protocol Using Mixnet and Hidden Tweaks

Abstract

Fair conduct of elections is essential for the smooth existence of democratic societies. In order to response voting security concerns, security researchers have developed tamper-resistant and voter verifiable methods. These end-to-end voting schemes are unique because they give voters the option to both verify the voting scheme’s functionality and to check that their votes have been recorded after leaving the polling booth. Helios and $\mathrm{P{\hat{r}}et}$ á voter are the most usable voter verifiable, end-to-end voting schemes using mixnet. Helios is a web-based open-audit voting system utilizing mixnet and secure cryptographic primitives. It satisfies almost all the security properties like privacy, individual and universal verifiability, and mixnet integrity etc. However, the proof of mixnet integrity is complex to understand and costly in terms of computations that effects conducting large-scale elections. For a voter, it is rarely impossible to verify the correctness of election results without trusting on election administrator and the candidates for the correctness of election result. In this paper, we address this issue by presenting a simple and fast method for conducting end-to-end voting and allowing public verification of the correctness of the announced vote tallying results. Our method is based on existing Helios structure, we call it Apollo that facilitates a direct proof of mixnet integrity, and also satisfies all the security properties.