Password Complexity: A strong password is one of the most basic and important cyber security measures. Here's an example of how to generate a strong password using Node.js:

const generate password = (length = 12) => { const charset = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_+-='; let password = ''; for (let i = 0, n = charset.length; i < length; i++) { password += charset.charAt(Math.floor(Math.random() * n)); } return password; }

const password = generate password(); console.log(password);

In this example, we're using a random character set to generate a password that's 12 characters long. You can adjust the length and character set to meet your specific needs.

1. Two-Factor Authentication: Two-factor authentication (2FA) adds an extra layer of security to your accounts. Here's an example of how to implement 2FA using the speakeasy library in Node.js:

const speakeasy = require('speakeasy');

const secret = speakeasy.generateSecret({ length: 20, name: 'My App' });

const token = speakeasy.totp({ secret: secret.base32, encoding: 'base32' });

console.log(Secret: ${secret.base32}); console.log(Token: ${token});

In this example, we're using the speakeasy library to generate a secret key and a time-based one-time password (TOTP) token. The secret key is stored securely and the user is prompted to enter the TOTP token along with their password to access their account.

1. Data Encryption: Data encryption can help protect sensitive information from being intercepted or stolen. Here's an example of how to encrypt data using the crypto module in Node.js:

   const crypto = require('crypto'); const algorithm = 'aes-256-cbc'; const password = 'mysecretpassword'; const salt = crypto.randomBytes(16); const key = crypto.scryptSync(password, salt, 32); const iv = crypto.randomBytes(16); const cipher = crypto.createCipheriv(algorithm, key, iv); let encrypted = cipher.update('My secret message', 'utf8', 'hex'); encrypted += cipher.final('hex'); console.log(`Encrypted message: ${encrypted}`); const decipher = crypto.createDecipheriv(algorithm, key, iv); let decrypted = decipher.update(encrypted, 'hex', 'utf8'); decrypted += decipher.final('utf8'); console.log(`Decrypted message: ${decrypted}`);

In this example, we're using the crypto module to encrypt a message using the AES-256-CBC algorithm with a randomly generated salt and initialization vector (IV). The encrypted message is then decrypted using the same key, salt, and IV.

1. Input Validation: Input validation can help prevent attacks like SQL injection and cross-site scripting (XSS). Here's an example of how to use the joi library to validate user input in a Node.js app:

const Joi = require('joi');

const schema = Joi.object({ username: Joi.string() .alphanum() .min(3) .max(30) .required(), email: Joi.string() .email() .required(), password: Joi.string() .pattern(new RegExp('^[a-zA-Z0-9]{3,30}$')) .required() });

const user = { username: 'aman', email: 'user@example.com',