Every Vote Counts: Ensuring Integrity in Large-Scale Electronic Voting

This paper presents a new End-to-End (E2E) verifiable e-voting protocol for large-scale elections, called Direct Recording Electronic with Integrity (DRE-i). In contrast to all other E2E verifiable voting schemes, ours does not involve any Tallying Authorities (TAs). The design of DRE-i is based on the hypothesis that existing E2E voting protocols’ universal dependence on TAs is a key obstacle to their practical deployment. In DRE-i, the need for TAs is removed by applying novel encryption techniques such that after the election multiplying the ciphertexts together will cancel out random factors and permit anyone to verify the tally. We describe how to apply the DRE-i protocol to enforce the tallying integrity of a DRE-based election held at a set of supervised polling stations. Each DRE machine directly records votes just as the existing practice in the realworld DRE deployment. But unlike the ordinary DRE machines, in DRE-i the machine must publish additional audit data to allow public verification of the tally. If the machine attempts to cheat by altering either votes or audit data, then the public verification of the tallying integrity will fail. To improve system reliability, we further present a fail-safe mechanism to allow graceful recovery from the effect of missing or corrupted ballots in a publicly verifiable and privacy-preserving manner. Finally, we compare DRE-i with previous related voting schemes and show several improvements in security, efficiency and usability. This highlights the promising potential of a new category of voting systems that are E2E verifiable and TA-free. We call this new category “self-enforcing electronic voting”.