What Is Encryption?

import crypto from 'node:crypto';

const algorithm = 'aes-256-gcm';
const key = crypto.randomBytes(32); // 256-bit key
const iv = crypto.randomBytes(12);  // 96-bit standard GCM IV

function encrypt(text) {
  const cipher = crypto.createCipheriv(algorithm, key, iv);
  let encrypted = cipher.update(text, 'utf8', 'hex');
  encrypted += cipher.final('hex');
  const tag = cipher.getAuthTag().toString('hex');
  return { encrypted, iv: iv.toString('hex'), tag };
}

function decrypt(encrypted, ivHex, tagHex) {
  const decipher = crypto.createDecipheriv(algorithm, key, Buffer.from(ivHex, 'hex'));
  decipher.setAuthTag(Buffer.from(tagHex, 'hex'));
  let decrypted = decipher.update(encrypted, 'hex', 'utf8');
  decrypted += decipher.final('utf8');
  return decrypted;
}

const secureData = encrypt("Confidential API Secret");
console.log("Ciphertext:", secureData.encrypted);
console.log("Decrypted:", decrypt(secureData.encrypted, secureData.iv, secureData.tag));