Consensus Mechanisms

// Simplified Proof of Work simulation
// Miners must find a number (nonce) that makes the hash start with zeros

function simpleHash(data) {
    // Simplified hash (not real SHA-256)
    let hash = 5381;
    for (let i = 0; i < data.length; i++) {
        hash = ((hash << 5) + hash) + data.charCodeAt(i);
        hash = hash & hash; // Convert to 32-bit integer
    }
    return Math.abs(hash).toString(16).padStart(8, "0");
}

function mineBlock(data, difficulty) {
    let nonce = 0;
    const target = "0".repeat(difficulty); // Hash must start with this many zeros

    console.log(`Mining block with difficulty ${difficulty}...`);

    while (true) {
        const hash = simpleHash(data + nonce);
        if (hash.startsWith(target)) {
            console.log(`✓ Block mined! Nonce: ${nonce}, Hash: ${hash}`);
            return { nonce, hash };
        }
        nonce++;
    }
}

// Mine a block (difficulty 2 = hash must start with "00")
const result = mineBlock("Alice→Bob:1BTC", 2);
console.log("Attempts needed:", result.nonce);
console.log("This is why mining takes energy — it's trial and error!");