andrejrakic / zokrates-demo

Zokrates (library for ZkSnarks on Ethereum blockchain) demo app to prove that two numbers are equal 7 (or any other number) without revealing numbers itself

Zokrates demo app

Running

make sure to install necessary dependencies

cd ./server && npm start

cd ./client && yarn start

About the app

Developed using Zokrates plugin for Remix IDE

1) Zok file

main.zok

 def main(private field firstNumber, private field secondNumber, field sum) -> (field):

    field result = if firstNumber + secondNumber == sum then 1 else 0 fi

    return result

2) Verifier smart contract

verifier.sol is available on Rinkeby test net at 0x600c3dC2568d97D85082bE1110f7a9dC52C2123C

Navigate to smart contract via Etherscan

3) Flow

Server on start compiles zok file, does a setup (creates a proving key and a verification key pair).

After User input data on client side and press Compute button, request to server is being send.

Server then does a computation and generates proof which sends back to client as a response.

Client then uses proof as an argument to call smart contract's verifyTx function and after a response from blockchain displays to User success or failed verification.

zokrates-demo's Issues

Separate the logic in React app for Web3

Put web 3 instancing and smart contract instancing into separate config folder and then include it in component

Server: Add unit tests and push .env file (it is safe)

env file contains only port, it is safe to push it to repo

Crate Web3 reconnecting mecahnism

Update README.md

Update README file to show how to start an app, explain the workflow and give additional context. Include contract and files from Remix IDE is must

Update main.yml file to support CI/CD for Express part

Add install job (npm ci working-directory ./server)
If possible create meaningful tests for server side and add it to github action

Alert API calls errors

Add .catch block to axios call i alert error instead of console.logging. To the existing .catch blocks (verifyTx call and isWeb3Connected call) add alert instead of console logging message.
Purpose of this is not to create handle errors mechanism thus this is just small demo app (so we don't need complete log, just UI indicator to end-user that something went wrong).

Add animation for failed validation

Red cross for example is fine

Handle bad requests to zokrates (e.g. empty string, letter instead number etc.)