Silver-Octo-Waffle

This is a POC for anonymous-voting system inspired by the paper An efficient and effective Decentralized Anonymous Voting System. The contract is built on Near protocol. The generated ballot is signed by a ring signature to ensure anonimity and the ballot itself is ecrypted by applying unlinkable payments scheme proposed by Nicolas van Saberhagen.

Note : This is not a scalable system and the amount of gas required to decrypt a ballot is quite high.

Runtime or Compiler dependencies

1. rustc 1.62.1 and rustup 1.25.1 for smart contract
2. nodejs ^18.0.0
3. wasm-pack 0.10.3

Quick Start

1. Install docker and docker compose
2. Run docker-compose up in the project directory.

Manual Start

1. Install dependencies npm run deps-install
2. Deploy smart contract npm run deploy
3. Copy the contract name from contract/neardev/dev-account.env to frontend/.env as VITE_CONTRACT_NAME=${contractname}
4. Run npm start to start the frontend dev server.

Exploring The Code

1. The smart-contract code lives in the /contract folder. In blockchain apps the smart contract is the "backend" of your app.
2. The frontend code lives in the /frontend folder. /frontend/index.html is a great place to start exploring. Note that it loads in /frontend/index.tsx, this is your entrypoint to learn how the frontend connects to the NEAR blockchain.
3. Ring signature and code for generating keys are in /frontend/ring-sig/.
4. Run tests on contract: npm test:unit, this will run the unit tests.

Deploy

Every smart contract in NEAR has its [own associated account][NEAR accounts]. When you run npm run deploy, your smart contract gets deployed to the live NEAR TestNet with a temporary dev account. When you're ready to make it permanent, here's how:

Step 0: Install near-cli (optional)

near-cli is a command line interface (CLI) for interacting with the NEAR blockchain. It was installed to the local node_modules folder when you ran npm install, but for best ergonomics you may want to install it globally:

npm install --global near-cli

Or, if you'd rather use the locally-installed version, you can prefix all near commands with npx

Ensure that it's installed with near --version (or npx near --version)

Step 1: Create an account for the contract

Each account on NEAR can have at most one contract deployed to it. If you've already created an account such as your-name.testnet, you can deploy your contract to near-blank-project.your-name.testnet. Assuming you've already created an account on [NEAR Wallet], here's how to create near-blank-project.your-name.testnet:

1. Authorize NEAR CLI, following the commands it gives you:

   near login

2. Create a subaccount (replace YOUR-NAME below with your actual account name):

   near create-account near-blank-project.YOUR-NAME.testnet --masterAccount YOUR-NAME.testnet

Step 2: deploy the contract

Use the CLI to deploy the contract to TestNet with your account ID. Replace PATH_TO_WASM_FILE with the wasm that was generated in contract build directory.

near deploy --accountId near-blank-project.YOUR-NAME.testnet --wasmFile PATH_TO_WASM_FILE

Step 3: set contract name in your frontend code

Modify the line in src/config.js that sets the account name of the contract. Set it to the account id you used above.

const CONTRACT_NAME = process.env.CONTRACT_NAME || 'near-blank-project.YOUR-NAME.testnet'

Imporovement / Enhancements

1. Move the poll data to a decentralised database or ipfs rather than storing it in smart contract.
2. We can use Diffie-Hellman key exchange to create the shared public-private key pair instead of storing them in smart contract.
3. Decrypting a ballot right now takes up high amount of gas and thus large number of ballots cannot be decrypted in a single transaction. A better solution is to have a serverless function or a centralised backend that calls the smart contract in a loop to decrypt ballots rather than computing the voting result in a single smart contract call.