ETH Key Tool

A secure, offline-first Ethereum private key analysis and cryptographic utility tool.

🌐 Live Site: ethkeytool.com

Features

• Private Key Analysis: Derive public keys, addresses, and hashes from private keys
• Message Signing: Sign messages using Ethereum's standard signing format
• Keccak256 Calculator: Compute Keccak256 hashes for any text or hex data
• Offline Security: Works completely offline for maximum security
• EIP-55 Checksumming: Generates properly checksummed Ethereum addresses
• Input Validation: Real-time validation with clear error messages
• Copy-to-Clipboard: Easy copying of all generated values
• Modern UI: Clean, responsive interface with accessibility features

How It Works

The tool uses industry-standard cryptographic libraries to perform Ethereum key operations:

• Private Keys: 256-bit hex strings validated using secp256k1 curve parameters
• Public Keys: Derived using elliptic curve cryptography (secp256k1)
• Addresses: Generated from public key using Keccak256 hash with EIP-55 checksumming
• Signatures: Created using Ethereum's standard message signing format

Usage

Web Application

1. Visit ethkeytool.com
2. Private Key Analysis:
   • Enter a 64-character hex private key
   • Get the derived public key, Ethereum address, and Keccak256 hash
3. Message Signing:
   • First analyze a private key, then enter a message to sign
   • Get the signature in Ethereum's standard format
4. Hash Calculator:
   • Enter any text or hex data to compute its Keccak256 hash

Offline Usage

For maximum security when working with private keys:

1. Disconnect from the internet
2. Open the website (it works completely offline)
3. Use the tool without network connectivity
4. Clear browser data when finished

Security Features

• No Network Requests: All cryptographic operations happen locally in your browser
• No Data Storage: Private keys and sensitive data are never stored or transmitted
• Industry-Standard Libraries: Uses Noble cryptography libraries for security
• Input Validation: Real-time validation prevents invalid key usage
• Offline Indicator: Shows network status and offline functionality

Development

Prerequisites

• Node.js 18+ and pnpm
• Nix (recommended for reproducible builds)

Setup

git clone https://github.com/BriungRi/ethkeytool.git
cd ethkeytool

# Using nix-shell (recommended)
nix-shell --run "pnpm install"
nix-shell --run "pnpm dev"

# Or with direct pnpm
pnpm install
pnpm dev

Available Scripts

# Development
pnpm dev          # Start development server
pnpm build        # Build for production
pnpm preview      # Preview production build

# Testing
pnpm test         # Run test suite
pnpm test:ui      # Run tests with UI

# Code Quality
pnpm lint         # Run ESLint
pnpm format       # Format code with Prettier
pnpm type-check   # Run TypeScript checks

Project Structure

ethkeytool/
├── src/
│   ├── utils/
│   │   ├── ethereum.ts    # Ethereum cryptographic functions
│   │   └── offline.ts     # Network status and offline utilities
│   ├── App.tsx            # Main application component
│   ├── App.css            # Styles with glassmorphism design
│   └── main.tsx           # React entry point
├── public/
│   ├── index.html         # HTML template with SEO optimization
│   ├── manifest.json      # PWA manifest
│   └── legal/privacy pages
└── tests/
    └── App.test.tsx       # Comprehensive test suite

Security Considerations

⚠️ Important Security Notes:

• Never enter private keys on untrusted websites
• Always verify you're on the correct domain (ethkeytool.com)
• Use offline mode when working with valuable private keys
• Clear browser data after use on shared computers
• This tool is for educational and development purposes

Links

• Live Site: ethkeytool.com
• GitHub: BriungRi/ethkeytool
• Ethereum: ethereum.org
• Noble Crypto: Noble cryptography libraries

Made with ❤️ for the Ethereum community