Bitcoin | Brain Wallet Generator
// Step 1: Hash passphrase with SHA-256 to get 32-byte private key const encoder = new TextEncoder(); const data = encoder.encode(passphrase); const hashBuffer = await crypto.subtle.digest('SHA-256', data); const privateKeyBytes = new Uint8Array(hashBuffer);
A brain wallet is a Bitcoin private key derived from a passphrase (memorable sentence) via a hash function. If someone guesses your passphrase, they steal your funds — so it's high-risk unless the passphrase has very high entropy. Feature Specification | Component | Description | |-----------|-------------| | Input | User-provided passphrase (e.g., "correct horse battery staple" ) | | Processing | Hash passphrase with SHA-256 → produce 256-bit private key | | Output | Bitcoin private key (WIF format) + corresponding public address | | Security | Runs client-side only (no server logging) | Reference Implementation (JavaScript/HTML) <!DOCTYPE html> <html> <head> <title>Bitcoin Brain Wallet Generator</title> <meta charset="UTF-8"> </head> <body> <h2>⚠️ Brain Wallet Generator (use at your own risk)</h2> <p>Enter a strong, high-entropy passphrase:</p> <textarea id="passphrase" rows="3" cols="50" placeholder="Your secret sentence..."></textarea> <br><br> <button onclick="generateWallet()">Generate Wallet</button> <br><br> <div id="output"></div> <script src="https://cdn.jsdelivr.net/npm/bitcoinjs-lib@6.1.0/dist/bitcoinjs-lib.js"></script> <script src="https://cdn.jsdelivr.net/npm/bip39@3.0.4/index.min.js"></script> <script> async function generateWallet() const passphrase = document.getElementById('passphrase').value; if (!passphrase.trim()) alert("Please enter a passphrase"); return; bitcoin brain wallet generator