Solving the discrete logarithm problem for packing candidate preferences

Abstract

Ranked elections are used in many places across the world, and a number of end-to-end verifiable voting systems have been proposed to handle these elections recently. One example is the vVote system designed for the Victorian State Election, Australia. In this system, many voters will give a full ranking of up to 38 candidates. The easiest way to do this is to ask each voter to reorder ciphertexts representing the different candidates, so that the ciphertext ordering represents the candidate ranking. But this requires sending 38 ciphertexts per voter through the mixnets, which will take a long time. In this paper, we explore how to "pack" multiple candidate preferences into a single cipherte..