Version: v2.x

Command-line interface

MACI provides a command-line interface that allows for effective deployment and testing. Applications that build on top of MACI, such as clr.fund, implement their own web UIs.

Note that all the example commands default to a local Ethereum testnet at http://localhost:8545, and use the Ethereum private key 0xc87509a1c067bbde78beb793e6fa76530b6382a4c0241e5e4a9ec0a0f44dc0d3. Do not send any real funds to the address generated by this key.

For testing purposes, you can run:

# in maci/contracts
pnpm run hardhat

Note that you will need a hardhat.config file in your current directory to be able to run the cli.

info

If you are looking to use MACI's cli to deploy the smart contracts, we recommend you instead use the smart contract tasks for a better experience. Please refer to the deployment section for more information.

Subcommands

For a full list of MACI CLI's commands, please run the following:

maci-cli --help

For detailed information about each command please run:

maci-cli <command> --help

Command	Description
`create`	Deploy the contracts
`deployVkRegistry`	Deploy a new VkRegistry contract
`setVerifyingKeys`	Set the verifying keys
`deployPoll`	Deploy a new poll
`checkVerifyingKeys`	Check that the verifying keys in the contract match the local ones
`genMaciPubKey`	Generate a new MACI public key
`genMaciKeyPair`	Generate a new MACI key pair
`show`	Show the deployed contract addresses
`publish`	Publish a new message to a MACI Poll contract
`mergeMessages`	Merge the message accumulator queue
`mergeSignups`	Merge the signups accumulator queue
`timeTravel`	Fast-forward the time (only works for local hardhat testing)
`extractVkToFile`	Extract verification keys (vKey) from zKey files
`signup`	Sign up to a MACI contract
`isRegisteredUser`	Checks if user is registered with public key
`fundWallet`	Fund a wallet with Ether
`verify`	Verify the results of a poll on-chain
`genProofs`	Generate the proofs for a poll
`proveOnChain`	Prove the results of a poll on chain

Public and private key format

MACI uses private keys in the BabyJub field for operations which occur within zk-SNARKs, such as decrypting messages or signing commands. As MACI is deployed on Ethereum, we seek to avoid confusing BabyJub private keys with Ethereum private keys. To that end, users should pass serialized formats of public and private keys to this CLI. We use maci-domainobj's PrivKey.serialize and PubKey.serialize functions to do so.

Examples of serialized public and private keys:

Public key: macipk.946c756cb8588f7169d37e23a98b92051359d64321cf7372a75757b5e9d5590d
Private key: macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c

### Generate MACI keys

You can generate MACI keys using the following cli utility.

node build/ts/index.js genMaciKeyPair

Example output:

[✓] Public key: macipk.946c756cb8588f7169d37e23a98b92051359d64321cf7372a75757b5e9d5590d
[✓] Private key: macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c

If you already have a MACI private key in serialized form, you can generate its corresponding public key using the following command:

node build/ts/index.js genMaciPubKey -sk macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c

Example output:

[✓] Public key: macipk.946c756cb8588f7169d37e23a98b92051359d64321cf7372a75757b5e9d5590d

Coordinator: Deploy VkRegistry

This command deploys an instance of a VkRegistry contract. Multiple MACI contracts can refer to the same VkRegistry as long as they are all owned (via Ownable.sol) by the same account.

Example usage:

node build/ts/index.js deployVkRegistry

Example output:

[✓] VkRegistry deployed at: 0x6b5A4751307F6751E265c194244552A9995B6B3D

Coordinator: Set verifying keys

Note that the filename of the .zkey files must follow this format:

ProcessMessages_<STATE_TREE_DEPTH>-<MSG_TREE_DEPTH>-<MSG_SUBTREE_DEPTH>-<VOTE_OPTION_TREE_DEPTH>_test.<CONTRIBUTION_NUM>.zkey
TallyVotes_<STATE_TREE_DEPTH>-<INT_STATE_TREE_DEPTH>-<VOTE_OPTION_TREE_DEPTH>>_test.<CONTRIBUTION_NUM>>.zkey

Example usage:

node build/ts/index.js setVerifyingKeys \
    -s 10 -i 1 -m 2 -v 2 -b 1 \
    -p ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    -t ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey \

Example output:

[i] Setting verifying keys...
[i] Transaction hash: 0x6b5b2959ba5161497d5499a0f9d9c69f773cd5f9b82f80a79253797b066863e3
[✓] Verifying keys set successfully

Coordinator: Create MACI instance

Example usage:

node build/ts/index.js create -s 10

Example output:

[✓] MACI deployed at:  0xB08CEd0f34940a3E576Cf023b287f9Db2f306a1f

Coordinator: Deploy poll

Example usage:

node ./build/ts/index.js deployPoll \
    -pk macipk.946c756cb8588f7169d37e23a98b92051359d64321cf7372a75757b5e9d5590d \
    -t 300 -i 1 -m 2 -b 1 -v 2

Example output:

[i] Poll ID: 0
[i] Poll contract: 0xB6389Da0285c7B1FC0ba352F5A1D5fb1A492a786
[i] Message processor contract: 0xE0bF6021e023a197DBb3fABE64efA880E13D3f4b
[i] Tally contract: 0x3f21BC64076e7c9ed8695d053DCCBE6D8d5E6f43
[i] Subsidy contract: 0xb848ef765E289762e9BE66a38006DDc4D23AeF24

Example usage:

node ./build/ts/index.js signup \
    -p macipk.182a49caec452e9966f5fef65363c3c795bf8cda482cae8289a4684c0f5bcb7b

Example output:

[i] Transaction hash: 0x4c7c9f65187fcf6e243804b75555bda48cbae4c317bb312f1b9f95ac4b7697b1
[✓] State index: 1

User: publish message

Example usage:

node build/ts/index.js publish \
    -p macipk.182a49caec452e9966f5fef65363c3c795bf8cda482cae8289a4684c0f5bcb7b \
    -sk macisk.569cf25e35654046ecd9f176d9e6e47115d767fabfe0e97a206dd62e7a3a8546 \
    -i 1 -v 0 -w 9 -n 1 -o 0

Example output:

[i] Transaction hash: 0xa2ab91c821bf7fa73fedcf19a5371a0f0866ae0747d22f82f1685afca0e5db49
[i] Ephemeral private key: macisk.2631d585e46f059e4909ab35172451542ed7723a1ace120fcf49d68e27f935b0

Coordinator: Time travel (Testing only)

Example usage:

node build/ts/index.js timeTravel -s 300

Example output:

[✓] Fast-forwarded 300 seconds

Coordinator: merge state tree

Example usage:

node build/ts/index.js mergeSignups -o 0

Example output:

[i] Merging state subroots 1 / 1
[i] Transaction hash: 0xd7e7312f70831ec05bb23f23f506ef37d6ce0c2056c1b72f7bb989653d1c8a42
[✓] Executed mergeMaciStateAqSubRoots(); gas used: 720061
[✓] All state subtrees have been merged.
[i] Merging subroots to a main state root...
[i] Transaction hash: 0xb5e98d328b066d91e1b7aa35775fe624be446b540a00bcb4b27a02477636b569
[✓] Executed mergeStateAq(); gas used: 1004720

Coordinator: merge message tree

Example usage:

node build/ts/index.js mergeMessages -o 0

Example output:

[i] Merging message subroots 1 / 1
[✓] Executed mergeMessageAqSubRoots(); gas used: 602448
[i] Transaction hash: 0xdf9d11c6b35fcccff82dafa3aa15f760e3f7694a72b07007fbdb359d44df0bea
[✓] All message subtrees have been merged.
[i] Merging subroots to a main message root...
[✓] Executed mergeMessageAq(); gas used: 173346
[i] Transaction hash: 0x1f18ec08fd14db90a0d1d02d1ed27c0bfd3bc138701e812c4c3382572fc4d151
[✓] The message tree has been merged.

Coordinator: generate Maci state offchain

Example usage to generate the state locally from the smart contracts events:

node build/ts/index.js genLocalState \
    --poll-id 0 \
    --output localState.json \
    --privkey macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c \
    --blocks-per-batch 50

Example output:

[i] Fetching logs from 0 till 228 and generating the offline maci state
[✓] The state has been written to localState.json

Coordinator: generate proofs

Example usage:

C++ witness parameters

node build/ts/index.js genProofs -x 0x89962fa216d39fCcaaC11e1e462340d80ab6Cf4D \
    -sk macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c \
    -o 0 \
    -t tally.json \
    -f proofs \
    -r ~/rapidsnark/build/prover \
    -wp ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test_cpp/ProcessMessages_10-2-1-2_test \
    -wt ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test_cpp/TallyVotes_10-1-2_test \
    -zp ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    -zt ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey \

WASM Parameters

node build/ts/index.js genProofs \
    -sk macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c \
    -o 0 \
    -t tally.json \
    -f proofs \
    -zp ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    -zt ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey \
    -tw ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test_js/TallyVotes_10-1-2_test.wasm \
    -pw ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test_js/ProcessMessages_10-2-1-2_test.wasm \
    -w true \

Non Quadratic Voting

node build/ts/index.js genProofs \
    -sk macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c \
    -o 0 \
    -t tally.json \
    -f proofs \
    -zp ./zkeys/ProcessMessagesNonQv_10-2-1-2_test/ProcessMessagesNonQv_10-2-1-2_test.0.zkey \
    -zt ./zkeys/TallyVotesNonQv_10-1-2_test/TallyVotesNonQv_10-1-2_test.0.zkey \
    -tw ./zkeys/TallyVotesNonQv_10-1-2_test/TallyVotesNonQv_10-1-2_test_js/TallyVotesNonQv_10-1-2_test.wasm \
    -pw ./zkeys/ProcessMessagesNonQv_10-2-1-2_test/ProcessMessagesNonQv_10-2-1-2_test_js/ProcessMessagesNonQv_10-2-1-2_test.wasm \
    -w true \
    -uq false

Example output:

[i] starting to fetch logs from block 0
[i] Generating proofs of message processing...
[i] Progress: 1 / 1
[i] gen processMessage proof took 17.322 seconds

[i] Generating proofs of vote tallying...
[i] Progress: 1 / 1
[✓] The tally commitment is correct
[i] gen tally proof took 4.951 seconds

Coordinator: generate proofs using a local state file

Example usage to generate the proofs locally from the local state file created with genLocalState:

C++ witness parameters

node build/ts/index.js genProofs \
    --privkey macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c \
    --poll-id 0 \
    --rapidsnark ~/rapidsnark/build/prover \
    --process-witnessgen ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test_cpp/ProcessMessages_10-2-1-2_test \
    --tally-witnessgen ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test_cpp/TallyVotes_10-1-2_test \
    --process-zkey /zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    --tally-zkey ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey \
    --tally-file tally.json \
    --output proofs/ \
    --state-file localState.json

WASM Params

node build/ts/index.js genProofs \
    --privkey macisk.08a06aef74c7f6a6f73704e30677418731bc738500f4e6c63dbfe41af8d6719c \
    --poll-id 0 \
    --process-zkey ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    --tally-zkey ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey \
    --tally-file tally.json \
    --output proofs/ \
    --state-file localState.json \
    -tw ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test_js/TallyVotes_10-1-2_test.wasm \
    -pw ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test_js/ProcessMessages_10-2-1-2_test.wasm \
    -w true

Example output:

[i] Generating proofs of message processing...
[i] Progress: 1 / 1
[i] gen processMessage proof took 17.053 seconds

[i] Generating proofs of vote tallying...
[i] Progress: 1 / 1
[✓] The tally commitment is correct
[i] gen tally proof took 4.746 seconds

Coordinator: prove on chain

Example usage:

node build/ts/index.js proveOnChain \
    -o 0 \
    -f proofs/

Example output:

[i] Submitting proofs of message processing...
[i] Transaction hash: 0xa8acf67d6520ceaf5eef8acbf4cda7f5c2657122e2a72a092b9f4503282d70b9
[i] Progress: 1 / 1
[✓] All message processing proofs have been submitted.
[i] Submitting proofs of vote tallying...
[i] Progress: 1 / 1
[i] Transaction hash: 0x691687ab6fb504919859901f297cdb7d8c4d736756d2d4edf345d721bb82365b
[✓] All vote tallying proofs have been submitted.

Anyone: verify tally

Example usage:

node build/ts/index.js verify \
    -o 0 \
    -t tally.json

Example output:

[i] on-chain tally commitment: 83601b7979c13506317b58e859950e9e92e1e6d326810d89332cc13909833ec
[✓] The on-chain tally commitment matches.
[i] The on-chain tally matches the off-chain tally.

Demonstration

Scenario:

Alice votes for Party A
Alice changes her key
Eve tries to bribe Alice to change her vote to Party B
Alice submits an invalid vote for Party B
The coordinator processes the votes, computes, and verifies the final tally
The expected result is: Party A has some votes and Party B has 0 votes.

Implication: Alice's invalid vote was not counted, and Eve had no way to tell.

Examples of serialized public and private keys:

Coordinator:
Public key: macipk.281830024fb6d21a4c73a89a7139aff61fbbddad731ef2dc2db9516171fd390e
Private key: macisk.bf92af7614b07e2ba19dce65bb7fef2b93d83b84da2cf2e3af690104fbc52511

Alice:
Public key: macipk.1cac8e4e5b54d7dcce4aa06e71d8b9f324458756e7a9368383d005592719512a
Private key: macisk.63e796e4e5d18a5fcf4ccef1e74e83b807a165d6727bb89201782240458f7420

Coordinator: Deploy VkRegistry

node build/ts/index.js deployVkRegistry

Output:

[✓] VkRegistry deployed at: 0x7607Cfe2fA0d62F725537e55d83C693Cc3C76EF2

Coordinator: Set verifying keys

node build/ts/index.js setVerifyingKeys \
    --state-tree-depth 10 \
    --int-state-tree-depth 1 \
    --msg-tree-depth 2 \
    --vote-option-tree-depth 2 \
    --msg-batch-depth 1 \
    --process-messages-zkey ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    --tally-votes-zkey ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey

Output:

[i] Setting verifying keys...
[i] Transaction hash: 0xbd5d06935537fb59903c27b9bdb19a41d422f75e1dfd6eb61f028bf3a7b82c76
[✓] Verifying keys set successfully

Coordinator: Create MACI instance

node build/ts/index.js create -s 10

Output:

[✓] MACI deployed at:  0xC131D3eeD9D6D410A7bfc200d81b9795f1bb5ed6

Coordinator: Deploy poll

node ./build/ts/index.js deployPoll \
    -pk macipk.281830024fb6d21a4c73a89a7139aff61fbbddad731ef2dc2db9516171fd390e \
    -t 1000 -i 1 -m 2 -b 1 -v 2

Output:

[i] Poll ID: 0
[i] Poll contract: 0x2c3Adf2852788662148038511aD80962aaf631D7
[i] Message processor contract: 0xd3C3C6530fE4073292D6EAfdEAdEeAbf1A3DC19B
[i] Tally contract: 0x06c1939F6cBb68D42333F140CAE815cc36D341b0
[i] Subsidy contract: 0xCB74254716c96B07c812c73A5945e68aa1de4569

node ./build/ts/index.js signup \
    --pubkey macipk.1cac8e4e5b54d7dcce4aa06e71d8b9f324458756e7a9368383d005592719512a

Output:

[i] Transaction hash: 0x7ab4c2d23686049432d19bb64c8ee4e8776fff134d971dcf27e1f513b4fdb97f
[✓] State index: 1

Alice: votes for Party A (option index 0)

node build/ts/index.js publish \
    --pubkey macipk.1cac8e4e5b54d7dcce4aa06e71d8b9f324458756e7a9368383d005592719512a \
    --privkey macisk.63e796e4e5d18a5fcf4ccef1e74e83b807a165d6727bb89201782240458f7420 \
    --state-index 1 \
    --vote-option-index 0 \
    --new-vote-weight 9 \
    --nonce 1 \
    --poll-id 0

Output:

[i] Transaction hash: 0x60936cfb0b25c8618d3cb8d0f5497106d5f6e3776f3212932975442d874eddbd
[i] Ephemeral private key: macisk.103b8c4c98700d06f47522892032fce54bd03cd197cee495ede3802730409910

Alice: submits an invalid vote for Party B (option index 1) with different public key

node build/ts/index.js publish \
    --pubkey macipk.1cac8e4e5b54d7dcce4aa06e71d8b9f324458756e7a9368383d005592719512a \
    --privkey macisk.63e796e4e5d18a5fcf4ccef1e74e83b807a165d6727bb89201782240458f7420 \
    --state-index 1 \
    --vote-option-index 1 \
    --new-vote-weight 9 \
    --nonce 2 \
    --poll-id 0

Output:

[i] Transaction hash: 0x73f74b13d276cd311ce5421a145debc71e97e48abc8be2f9a0a548b26f7920f9
[i] Ephemeral private key: macisk.1e490d67477b4c5f08806973fca2bea81e723c60deba6bdeacab56f7a4bd867b

Coordinator: Time Travel

node build/ts/index.js timeTravel -s 1000

Output:

[✓] Fast-forwarded 1000 seconds

Coordinator: merge state tree

node build/ts/index.js mergeSignups --poll-id 0

Output:

[i] Merging state subroots 1 / 1
[i] Transaction hash: 0xd01932e8dfad251f9b0d288290ac17f12bc449ea859a6921f63edf6b4b06f4c9
[✓] Executed mergeMaciStateAqSubRoots(); gas used: 720061
[✓] All state subtrees have been merged.
[i] Merging subroots to a main state root...
[i] Transaction hash: 0x25f60a9b5a24d11b87c41d8a4f681e3fd895b3bdf78ea86755b9800005662ce6
[✓] Executed mergeStateAq(); gas used: 1004720

Coordinator: merge message tree

node build/ts/index.js mergeMessages --poll-id 0

Output:

[i] Merging message subroots 1 / 1
[✓] Executed mergeMessageAqSubRoots(); gas used: 600520
[i] Transaction hash: 0xac0e8a01277db1b6282f8fb3763a8a4aeeebb3e12a41dd0dee9fc2804a4c9e81
[✓] All message subtrees have been merged.
[i] Merging subroots to a main message root...
[✓] Executed mergeMessageAq(); gas used: 173346
[i] Transaction hash: 0x472f0fd515c7cd2a02c430189e4ee92a6843bd6b19807484ce454cb7dab0e931
[✓] The message tree has been merged.

Coordinator: generate proofs

node build/ts/index.js genProofs \
    --privkey macisk.bf92af7614b07e2ba19dce65bb7fef2b93d83b84da2cf2e3af690104fbc52511 \
    --poll-id 0 \
    --process-zkey ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test.0.zkey \
    --tally-zkey ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test.0.zkey \
    --tally-file tally.json \
    --output proofs/ \
    -tw ./zkeys/TallyVotes_10-1-2_test/TallyVotes_10-1-2_test_js/TallyVotes_10-1-2_test.wasm \
    -pw ./zkeys/ProcessMessages_10-2-1-2_test/ProcessMessages_10-2-1-2_test_js/ProcessMessages_10-2-1-2_test.wasm \
    -w true

Output:

[i] Generating proofs of message processing...
[i] Progress: 1 / 1
[i] gen processMessage proof took 16.644 seconds

[i] Generating proofs of vote tallying...
[i] Progress: 1 / 1
[✓] The tally commitment is correct
[i] gen tally proof took 4.809 seconds

Coordinator: prove on chain

node build/ts/index.js proveOnChain \
    --poll-id 0 \
    --proof-dir proofs/

Output:

[i] Submitting proofs of message processing...
[i] Transaction hash: 0x9c3280af80de2436f9a886e4cd94218e01fe35ea3d3e671aad97b5aa5d6108ed
[i] Progress: 1 / 1
[✓] All message processing proofs have been submitted.
[i] Submitting proofs of vote tallying...
[i] Progress: 1 / 1
[i] Transaction hash: 0x3e82ae3ad04215d4f357455ab5a610eba082796d2abc698aad91b046d16b9350
[✓] All vote tallying proofs have been submitted.

Anyone: verify

node build/ts/index.js verify \
    --poll-id 0 \
    --tally-file tally.json

Output:

[i] on-chain tally commitment: 1ed004ac21a5397a512cbe749e7110934a434837f4818265043fd2e2e9cbec91
[✓] The on-chain tally commitment matches.

Subcommands​

Public and private key format​

Coordinator: Deploy VkRegistry​

Coordinator: Set verifying keys​

Coordinator: Create MACI instance​

Coordinator: Deploy poll​

User: sign up​

User: publish message​

Coordinator: Time travel (Testing only)​

Coordinator: merge state tree​

Coordinator: merge message tree​

Coordinator: generate Maci state offchain​

Coordinator: generate proofs​

Coordinator: generate proofs using a local state file​

Coordinator: prove on chain​

Anyone: verify tally​

Demonstration​

Scenario:​

Examples of serialized public and private keys:​

Coordinator: Deploy VkRegistry​

Coordinator: Set verifying keys​

Coordinator: Create MACI instance​

Coordinator: Deploy poll​

Alice: sign up​

Alice: votes for Party A (option index 0)​

Alice: submits an invalid vote for Party B (option index 1) with different public key​

Coordinator: Time Travel​

Coordinator: merge state tree​

Coordinator: merge message tree​

Coordinator: generate proofs​

Coordinator: prove on chain​

Anyone: verify​

Subcommands

Public and private key format

Coordinator: Deploy VkRegistry

Coordinator: Set verifying keys

Coordinator: Create MACI instance

Coordinator: Deploy poll

User: sign up

User: publish message

Coordinator: Time travel (Testing only)

Coordinator: merge state tree

Coordinator: merge message tree

Coordinator: generate Maci state offchain

Coordinator: generate proofs

Coordinator: generate proofs using a local state file

Coordinator: prove on chain

Anyone: verify tally

Demonstration

Scenario:

Examples of serialized public and private keys:

Coordinator: Deploy VkRegistry

Coordinator: Set verifying keys

Coordinator: Create MACI instance

Coordinator: Deploy poll

Alice: sign up

Alice: votes for Party A (option index 0)

Alice: submits an invalid vote for Party B (option index 1) with different public key

Coordinator: Time Travel

Coordinator: merge state tree

Coordinator: merge message tree

Coordinator: generate proofs

Coordinator: prove on chain

Anyone: verify