Smart Contract Demo on Arbitrum Sepolia

A simple smart contract demonstration deployed on Arbitrum Sepolia testnet.

Project Overview

This project contains a simple smart contract that is deployed on the Arbitrum Sepolia testnet.

Explore Smart Contracts

See the various deployments on https://sepolia.arbiscan.io/ Creator Wallet Address: 0xdb4Bf427b1546c462EF83620e2d2AaF8c781c5eB

Contracts

• 0xd4fe0aDEf0a62398b629Da0620E079F0D487bBd2
• 0x7675DA30Bcc226DFC4bbCE43bCAA441C88934d73
• 0x82b7896234Dcc5A4256657D1A9efa5879D8e5Ff6

View contracts at (https://sepolia.arbiscan.io/address/0x82b7896234Dcc5A4256657D1A9efa5879D8e5Ff6)[https://sepolia.arbiscan.io/address/0x82b7896234Dcc5A4256657D1A9efa5879D8e5Ff6]

Authentication Contracts

• 0x86475277CE05B5E217E695FA585468219905F864

Features

• HelloWorld smart contract with message storage and update functionality
• Deployment scripts for Arbitrum Sepolia
• Update scripts to modify the message in the deployed contract
• Balance checking utility

Prerequisites

• Node.js v18.20.4 (recommended, managed via nvm)
• npm or yarn
• An Ethereum wallet with some Arbitrum Sepolia testnet ETH

Setup

1. Clone this repository
2. Install dependencies:

   npm install
   

3. Create a .env file based on .env.example with your own API URL and private key:

   API_URL = "YOUR_ALCHEMY_API_URL"
   PRIVATE_KEY = "YOUR_WALLET_PRIVATE_KEY"
   

   Note: Never commit your actual .env file to version control!

Usage

Deploy the Contract

./run-hardhat.sh run scripts/deploy.js --network arbitrumSepolia

Update the Contract Message

./update-contract.sh <CONTRACT_ADDRESS> "Your new message"

Check Wallet Balance

./run-hardhat.sh run scripts/check-balance.js --network arbitrumSepolia

MetaMask Authentication for Smart Contracts on Arbitrum Sepolia

Users are able to sign up and authenticate with MetaMask on Arbitrum Sepolia. The project includes:

1. Enhanced Smart Contract

AuthenticatedHelloWorld.sol extends the original HelloWorld contract with:

• User registration with usernames
• MetaMask signature-based authentication
• Nonce system to prevent replay attacks
• Events for tracking authentication activities

2. Deployment Tools

• scripts/deploy-authenticated.js: Hardhat deployment script for the new contract
• deploy-authenticated.sh: Bash script to easily deploy the contract to Arbitrum Sepolia

3. Web Application

See the /web directory for a complete web application with funcctionality to:

• Connect with MetaMask
• Register with a username
• Authenticate using cryptographic signatures
• Update and view the contract message
• Transaction history tracking

The web/README.md file has instructions to spin up local instance of webui for interacting with authentication smart contract

How to Use MetaMask Authentication

1. Deploy the Contract

   ./deploy-authenticated.sh

   This will deploy the AuthenticatedHelloWorld contract to Arbitrum Sepolia and provide you with the contract address.

2. Update the Web App

   ./update-web-contract-address.sh YOUR_CONTRACT_ADDRESS

   This will update the web application with your deployed contract address.

3. Serve the Web Application

   cd web
   npm install
   npm start

   Then open http://localhost:3000 in your browser to interact with your contract.

4. Authenticate with MetaMask

   • Connect your MetaMask wallet to the application
   • Register with a username
   • Authenticate by signing a message with your wallet
   • Update the contract message and perform other actions

This implementation provides a secure, blockchain-based authentication system that leverages the cryptographic capabilities of MetaMask without requiring users to share their private keys or pay for gas on every login (only registration and initial authentication require gas).

Security Notes

• Always use a dedicated development wallet with minimal funds for testing
• Never use your main wallet's private key in development environments
• Keep your .env file secure and never commit it to version control

License

MIT