maci v0.0.1

Minimal Anti-Collusion Infrastructure

Please refer to the implementation spec for technical details, and the original ethresear.ch post for a high-level view.

We welcome contributions to this project. Please join our Telegram group to discuss.

Local development and testing

Requirements

You should have Node 11.14.0 installed. Use nvm to install it.

TODO: Test this with Node 12 LTS.

You also need Solidity 0.5.16 installed in your PATH.

Get started

Clone this repository, install dependencies, and build the source code:

git clone git@github.com:barryWhiteHat/maci.git && \
npm i && \
npm run bootstrap && \
npm run build

Local development

This repository is organised as Lerna submodules. Each submodule contains its own unit tests.

• config: project-wide configuration files. Includes config files for both testing and production.
• crypto: low-level cryptographic operations.
• circuits: zk-SNARK circuits.
• contracts: Solidity contracts and deployment code.
• domainobjs: Classes which represent high-level domain objects particular to this project.
• core: Business logic functions for message processing and vote tallying.

Subdirectories which are not Lerna submodules are:

• docker: Docker files for testing and deployment.

Trusted setup

For development purposes, you can generate the proving and verifying keys for the zk-SNARK circuits, along with their Solidity verifier contracts as such:

cd circuits
npm run buildBatchUpdateStateTreeSnark
npm run buildQuadVoteTallySnark

Alternatively, you can save time by downloading the files from Dropbox:

cd circuits
npm run downloadAllSnarks

Testing

Unit tests

The following submodules contain unit tests: crypto, circuits, contracts, and domainobjs.

Except for the contracts submodule, run unit tests as such (the following example is for crypto):

cd crypto
npm run test

For the contracts unit tests, run the tests one by one. This prevents incorrect nonce errors.

First, start a Ganache instance in a separate terminal:

cd contracts
npm run ganache

In another terminal, run the tests individually:

cd contracts
npm run test-hasher
npm run test-maci
npm run ...

Deploying contracts to the local testnet

Assuming that you have a Ganache node set up and listening to the path configured in config/test.yaml:

cd contracts
npm run deploy

The addresses which the contracts have been deployed to will be saved in contracts/deployedAddresses.json.

TODO: when we develop the CLI, this command should also copy the deployed addresses to the CLI submodule.

Deploying contracts to an Ethereum testnet or the mainnet

First, set the private key you need to deploy the contracts. The account associated with the key should already have some ETH in it. Create this file in your home directory (e.g. /home/user/kovanPrivKey.json) and replace the value between the quote marks with the private key.

["0x................................................................"]

There is an existing kovan.yml file in the config submodule. We will use it as an example of deploying to the Kovan testnet.

cd contracts
NODE_ENV=kovan npm run deploy

If the deployment fails because of an error from the Ethereum node, change it in kovan.yml:

chain:
  url: "https://kovan.infura.io/v3/<your infura key>"