Verifiable Remote Paper Voting

An implementation of a verifiable remote-voting protocol with paper assurance. Protocol by Xavier Boyen, Kristian Gjøsteen, Thomas Haines, Eleanor McMurtry, and Vanessa Teague.

This code is for academic purposes ONLY. DO NOT USE IT IN PRACTICE.

To build and run, there is a makefile make (or run cargo build --release --all --all-targets).

k-out-of-n threshold ElGamal encryption is done with Cryptid using Pedersen secret sharing and Curve25519 (Ristretto subgroup).

Building & Running

Run via Docker

If you'd like to use Docker, there is a Dockerfile provided for the voter interface. (TODO: Dockerfiles for the other stuff?)

1. Run docker build -t papervote . to build the image.
2. Run docker run -it --name voter papervote to run the image, and make your selections.
3. Run the following commands to copy the printable PDF output:
   1. docker cp voter:/usr/src/app/paper1.pdf .
   2. docker cp voter:/usr/src/app/paper2.pdf .

Building

1. Install rustup with the nightly toolchain using the installation script here: download link. Don't use a package manager to do this!
   1. You'll need to select the custom installation settings to set it to use nightly. Otherwise, you can run rustup install nightly to install the right toolchain, then rustup default nightly to set it as your default.
2. Run make.
   1. You may need to install libssl-dev and pkg-config depending on the operating system.

Running

As a voter: Run target/release/voter. It will generate two files: paper1.pdf and paper2.pdf. Print both. Fold paper1.pdf so it hides the data, and fold paper2.pdf so it shows the data. Place both in an envelope and mail it. Note: if debug_mode = true in ~/.config/papervote/papervote.toml, then this will also produce a file raw.txt that can be piped into the receiving binary for ease of testing.

Verifying: Run target/release/verify and enter the voter ID to check for that voter ID's presence. Run target/release/verify all to run the global verifier, checking that all the proofs are valid and the facts on the WBB have been correctly checked.

As the WBB: Run target/release/wbb. To change the port it listens on, use export ROCKET_PORT=xxxx.

As a trustee: For the leader (who organises the other trustees), run target/release/trustee leader <id> <addr1> <addr2> ... where the addresses are those of the follower, and id ranges from 1 to n. The other trustees should run target/release/trustee follower <id> <port> where the port is that which you would like to listen on, matching the address the leader uses. The IDs should be such that there is one of each from 1 to n.

Receiving votes: Run target/release/trustee receive <leader address> to receive a vote interactively. Votes are encoded in base-36 in the order they appear on the ballot, starting from 0. For example, a ballot reading Alice: 2 Bob: 3 Eve: 1 would be encoded as 120; this is the encoding that must be entered when prompted for a vote.