Towards everlasting privacy and efficient coercion resistance in remote electronic voting

Grontas, P. and Pagourtzis, A. and Zacharakis, A. and Zhang, B. (2019) Towards everlasting privacy and efficient coercion resistance in remote electronic voting. In: FC 2018 International Workshops, VOTING 18 : International Conference on Financial Cryptography and Data Security. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) . Springer Verlag, Cham, pp. 210-231. ISBN 9783662588192

Abstract

In this work, we propose a first version of an e-voting scheme that achieves end-to-end verifiability, everlasting privacy and efficient coercion resistance in the JCJ setting. Everlasting privacy is achieved assuming an anonymous channel, without resorting to dedicated channels between the election authorities to exchange private data. In addition, the proposed scheme achieves coercion resistance under standard JCJ assumptions. As a core building block of our scheme, we also propose a new primitive called publicly auditable conditional blind signature (PACBS), where a client receives a token from the signing server after interaction; the token is a valid signature only if a certain condition holds and the validity of the signature can only be checked by a designated verifier. We utilize this primitive to blindly mark votes under coercion in an auditable manner.