Voting machine on RISC Zero

A simple voting machine built on the RISC Zero platform.

This example is for educational purposes only. Not for use in actual elections.

Overview

A voting machine is a state machine with three operations:

• Initialize, which officials use to configure the machine;
• Submit ballot, which voters use to submit their ballot;
• Freeze, which reveals the current vote count & puts the machine into a state where it no longer accepts ballots.

Every time the voting machine updates its state it prints a "receipt" that commits it to that state. At the end of the election, officials can publish the full list of receipts and voters can check to ensure theirs is included. In this way, voters can confirm that their vote was counted.

Running the tests

Follow the examples guide to install dependencies and check out the correct version of the example.

Then, run the example with:

RUST_LOG=info cargo test --release -- --nocapture

[2022-03-29T18:13:44Z INFO  test::tests] initial commit: Ok(InitializeVotingMachineCommit { polls_open: true, voter_bitfield: 0, state: c3e42245ffdff31c980d63b232de1414ca2461a08c6efccca2af96737ef4d068 })
[2022-03-29T18:13:44Z INFO  test::tests] ballot 1: Ballot { voter: 0, vote_yes: false }
[2022-03-29T18:13:44Z INFO  test::tests] ballot 1 commit: Ok(SubmitBallotCommit { old_state: c3e42245ffdff31c980d63b232de1414ca2461a08c6efccca2af96737ef4d068, new_state: d05796eb3a889d209cc6e6e6a1429bbd9d218df2b58146a51be1fcafc3164042, polls_open: true, voter_bitfield: 1, voter: 0, vote_counted: true })
[2022-03-29T18:13:44Z INFO  test::tests] ballot 2: Ballot { voter: 1, vote_yes: true }
[2022-03-29T18:13:44Z INFO  test::tests] ballot 2 commit: Ok(SubmitBallotCommit { old_state: d05796eb3a889d209cc6e6e6a1429bbd9d218df2b58146a51be1fcafc3164042, new_state: cf922f404db827ea91f8c423c0621c677b464641fe0b6c6a7aeeb755fa19758b, polls_open: true, voter_bitfield: 3, voter: 1, vote_counted: true })
[2022-03-29T18:13:44Z INFO  test::tests] ballot 3: Ballot { voter: 2, vote_yes: true }
[2022-03-29T18:13:44Z INFO  test::tests] ballot 3 commit: Ok(SubmitBallotCommit { old_state: cf922f404db827ea91f8c423c0621c677b464641fe0b6c6a7aeeb755fa19758b, new_state: 3d5bc2f4e701d3184e5f2874d144b020bbfb3dd4a605509f703d82bd5daad5f2, polls_open: true, voter_bitfield: 7, voter: 2, vote_counted: true })
[2022-03-29T18:13:44Z INFO  test::tests] ballot 4: Ballot { voter: 1, vote_yes: false }
[2022-03-29T18:13:44Z INFO  test::tests] ballot 4 commit: Ok(SubmitBallotCommit { old_state: 3d5bc2f4e701d3184e5f2874d144b020bbfb3dd4a605509f703d82bd5daad5f2, new_state: 3d5bc2f4e701d3184e5f2874d144b020bbfb3dd4a605509f703d82bd5daad5f2, polls_open: true, voter_bitfield: 7, voter: 1, vote_counted: false })
[2022-03-29T18:13:44Z INFO  test::tests] ballot 5: Ballot { voter: 3, vote_yes: false }
[2022-03-29T18:13:44Z INFO  test::tests] ballot 5 commit: Ok(SubmitBallotCommit { old_state: 3d5bc2f4e701d3184e5f2874d144b020bbfb3dd4a605509f703d82bd5daad5f2, new_state: 560897b3110f28db5855b27a713d0bb98300526ced5c5786398d8710e55f5ab7, polls_open: true, voter_bitfield: 15, voter: 3, vote_counted: true })
[2022-03-29T18:13:44Z INFO  test::tests] freeze commit: Ok(FreezeVotingMachineCommit { old_state: 560897b3110f28db5855b27a713d0bb98300526ced5c5786398d8710e55f5ab7, new_state: 9aad1eebf324176d836beec9af1f09812915408082c48895f6271e06943ec116, polls_open: false, voter_bitfield: 15, count: 2 })
[2022-03-29T18:13:44Z INFO  test::tests] ballot 6: Ballot { voter: 4, vote_yes: true }
[2022-03-29T18:13:44Z INFO  test::tests] ballot 6 commit: Ok(SubmitBallotCommit { old_state: 9aad1eebf324176d836beec9af1f09812915408082c48895f6271e06943ec116, new_state: 9aad1eebf324176d836beec9af1f09812915408082c48895f6271e06943ec116, polls_open: false, voter_bitfield: 15, voter: 4, vote_counted: false })
[2022-03-29T18:13:44Z INFO  test::tests] Final vote count: 2
...