Receipt-Free Electronic Voting from zk-SNARK

In 2016, Locher and Haenni (Locher and Haenni, 2016) proposed an e-voting scheme that offers verifiability, everlasting vote privacy, and computational receipt-freeness, as well as an informal discussion of how the scheme achieves such properties. We advance this line of work by proposing a new cryptographic scheme that provably satisfies those properties as well as everlasting participation privacy and efficient tallying. Receipt-freeness relies on deniable vote updating and verifiable null ballot posting, generated from public knowledge stored on the bulletin board. The everlasting vote and participation privacy properties directly result from the hash-based commitment scheme and efficient zero-knowledge proofs (SNARKs). Finally, we provide mathematical proofs for all the properties, including a new game-based definition of participation privacy.