zkGames

zkGames is a platform that allows users to play zk (zero knowledge) games and mint an NFT as proof that they have won.

The project is currently on Harmony Mainnet and the frontend is hosted on Vercel.

zkGames has 3 games so far: Futoshiki, Skyscrapers and Sudoku.

zkGames Link:

https://zkgames.one/

zkGames Demo Video:

https://youtu.be/EpeK3WzmS8Y

Table of Contents

• Project Structure
  • circuits
  • contracts
  • zkgames-ui
• Zero Knowledge Structure
• Run Locally
  • Clone the Repository
  • Run circuits
  • Run contracts
  • Run zkgames-ui
• Steps to Add a New Game
• Some Images of the zkGames Application
  • Initial page
  • Futoshiki Game
  • Skyscrapers Game
  • Sudoku Game

Project Structure

The project has three main folders:

• circuits
• contracts
• zkgames-ui

circuits

The circuits folder contains all the circuits used in zkGames.

To learn more about the zkGames circuits, read the README file inside the circuits folder.

contracts

The contracts folder contains all the smart contracts used in zkGames.

To learn more about the zkGames smart contracts, read the README file inside the contracts folder.

zkgames-ui

The zkgames-ui folder contains the zkGames frontend.

To learn more about the zkGames frontend, read the README file in the zkgames-ui folder.

Zero Knowledge Structure

The following graphic shows the structure of the most important zero knowledge elements of the zkGames project.

├── circuits
│   ├── futoshiki
│   │   ├── futoshiki.circom
│   ├── skyscrapers
│   │   ├── skyscrapers.circom
│   ├── sudoku
│   │   ├── sudoku.circom
├── contracts
│   ├── contracts
│   │   ├── Futoshiki
│   │   │   ├── Futoshiki.sol
│   │   │   ├── verifier.sol
│   │   ├── Skyscrapers
│   │   │   ├── Skyscrapers.sol
│   │   │   ├── verifier.sol
│   │   ├── Sudoku
│   │   │   ├── Sudoku.sol
│   │   │   ├── verifier.sol
├── zkgames-ui
│   ├── public
│   │   ├── zkproof
│   │   │   ├── futoshiki
│   │   │   │   ├── futoshiki.wasm
│   │   │   │   ├── futoshiki_0001.zkey
│   │   │   ├── skyscrapers
│   │   │   │   ├── skyscrapers.wasm
│   │   │   │   ├── skyscrapers_0001.zkey
│   │   │   ├── sudoku
│   │   │   │   ├── sudoku.wasm
│   │   │   │   ├── sudoku_0001.zkey
│   ├── zkproof
│   │   ├── futoshiki
│   │   │   ├── snarkjsFutoshiki.js
│   │   ├── skyscrapers
│   │   │   ├── snarkjsSkyscrapers.js
│   │   ├── sudoku
│   │   │   ├── snarkjsSudoku.js
│   │   ├── snarkjsZkproof.js

Run Locally

Clone the Repository

git clone https://github.com/vplasencia/zkGames.git

Run circuits

To run cicuits, go inside the circuits folder:

cd circuits

Then, follow the intructions in the README file in the circuits folder.

Run contracts

To run contracts, go inside the contracts folder:

cd contracts

Then, follow the intructions in the README file in the contracts folder.

Run zkgames-ui

To run the frontend, go inside the zkgames-ui folder:

cd zkgames-ui

Then, follow the intructions in the README file in the zkgames-ui folder.

Steps to Add a New Game

Steps to follow to add a new game (in each step you can check how is done with the other games):

1. Create the required circom circuits:

• Inside the circuits folder, create a new folder and inside the new folder, create the necessary circom circuits.
• Compile the circuit and generate the wasm, zkey and verifier.sol files using the execute.sh file.

2. Create the necessary smart contracts:

• Inside the contracts/contracts folder, create a new folder with the necessary smart contracts. Add here the verifier.sol generated before using snarkjs.
• Change the solidity version to ^0.8.4 (it is the version used in the other smart contracts) and the contract name (to <gameName>Verifier) in verifier.sol.
• Test the functionalities of the new smart contracts in scripts/run.js.
• Update the contracts/scripts/deploy.js file and deploy smart contracts.

3. Create the user interface of the game:

• Inside zkgames-ui/components, add a new folder to create all the components needed to render the game.
• Add a new page inside zkgames-ui/pages to access the new game.
• Create the css of that page inside zkgames-ui/styles, called <GameName>.module.css.
• Add an image inside zkgames-ui/assets to represent the game (width: 700 pixels and height: 700 pixels).
• Inside zkgames-ui/public/zkproof add a new folder with the wasm and zkey elements generated before.
• Inside zkgames-ui/utils/abiFiles, add a new folder with the json abi file of the smart contract.
• In zkgames-ui/utils/contractaddress.json, add the new contract address.
• In zkgames-ui/zkproof, create a new folder and inside the new folder create a new file called snarkjs<NewGame>.js with the code to export the call data.
• In zkgames-ui/components/gameList.js add the game as follows:

 {
   nameGame: "<nameGame>",
   imageGame: nameGameImage,
   urlGame: "/<nameGame>",
 }

Some Images of the zkGames Application

Initial page

Futoshiki Game

Skyscrapers Game

Sudoku Game