dre-ip

An implementation of the DRE-ip voting protocol as per the paper by Shahandashti and Hao.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Overview

This crate provides an implementation of the DRE-ip voting protocol. It is generic over a suitable group via the DreipGroup trait; an implementation is provided for the NIST P-256 elliptic curve via the default p256_impl feature.

The core interface consists of the Election, Ballot, and Vote structs. An Election is parameterised by a DreipGroup implementation and holds the global election data: generators and keys. It provides methods to create ballots and votes.

A Ballot represents a yes vote for exactly one candidate across a set of candidates, using the parallel-systems method of multiple candidate encoding (see section 6 of the paper). It contains multiple Votes, each of which represents a single yes or no vote for a single candidate.

Example Usage

fn example() {
    let mut rng = rand::thread_rng();

    // Create an election.
    let election = Election::<NistP256>::new(
        &[b"Hello, World!"],
        &mut rng
    );

    // Create a ballot.
    const BALLOT_ID: &str = "1234";
    let ballot = election.create_ballot(
        &mut rng,
        BALLOT_ID,
        "Alice",
        vec!["Bob", "Eve"]
    ).expect("This can only fail if there are non-unique candidate IDs.");

    // Verify the ballot.
    assert!(ballot.verify(&election, BALLOT_ID));

    // Inspect the contents.
    println!("Alice Z value: {:?}", ballot.votes.get("Alice").unwrap().Z);
}