Aranha, Diego F.Battagliola, MicheleRoy, LawrenceVolkamer, MelanieDuenas-Cid, DavidRønne, Peter B.Ryan, Peter Y ABudurushi, JurlindKulyk, OksanaRodriguez Pérez, AdriàSpycher-Krivonosova, IuliiaKirsten, MichaelDebant, AlexandreGoodman, Nicole2024-12-132024-12-132023978-3-88579-741-81617-5468https://dl.gi.de/handle/20.500.12116/45440Coercion resistance is one of the most challenging security properties to achieve when designing an e-voting protocol. The JCJ voting scheme, proposed in 2005 by Juels, Catalano and Jakobsson, is one of the first voting systems where coercion-resistance was rigorously defined and achieved, making JCJ the benchmark for coercion-resistant protocols. Recently, the coercion-resistance definition proposed in JCJ has been disputed and improved by Cortier, Gaudry, and Yang. They identified a major problem, related to leakage of the number of discarded votes by revoting; and proposed CHide, a new protocol that solves the issue and satisfies a stronger security notion. In this work we present an improved version of CHide, with complexity O(n log(n)) instead of O(n^2) in the number n of received ballots, that relies on sorting encrypted ballots to make the tallying phase faster. The asymptotic complexity of our protocol is competitive with other state-of-the-art coercion-resistant voting protocols satisfying the stronger notion for coercion resistance.enE-VotingCoercion-Resistance10.18420/e-vote-id2023_03