Password Strength Testing with zxcvbn: A Deep Dive into Modern Password Security

In 2024, password security will remain a critical aspect of digital security. . In this comprehensive guide, we’ll explore password security and focus on the powerful zxcvbn library for password strength testing.

Learn about password security

The evolution of password security

Password security has evolved significantly since the early days of computing. Initially, simple length and character requirements were considered sufficient. However, as computing power increased and attack methods became more sophisticated, these basic requirements proved insufficient.

Traditional password strength meters usually use simple rules:

• Minimum length requirement
• Uppercase and lowercase letters exist
• Numbers and special characters
• Basic dictionary word check

While these rules can help create passwords that look strong, they often lead to predictable patterns that are easier to crack than expected. For example, a password like “Password123!” meets most traditional requirements but is relatively weak due to its predictable pattern.

Modern password security challenges

Today’s password security faces several key challenges:

1. computing power: Modern GPUs can try billions of password combinations per second
2. Password reuse: Users often reuse passwords across multiple services
3. Data leakage: Massive leak exposes millions of passwords, helping attackers learn common patterns
4. social engineering: Attackers can collect personal information to guess passwords
5. predictable patterns: Users often follow a similar pattern when creating “complex” passwords

Introduction to zxcvbn

What is zxcvbn?

Developed by Dropbox, Zxcvbn is a password strength estimator that takes a realistic approach to keeping passwords safe. Unlike traditional password strength meters, zxcvbn:

• Analyze passwords based on pattern matching
• Consider common alternatives
• Check against multiple dictionaries
• Estimate actual cracking time based on different attack scenarios
• Provide detailed feedback for improvements

How zxcvbn works

Zxcvbn uses a number of sophisticated techniques to assess password strength:

1. pattern matching

   • Keyboard mode (e.g. “qwerty”)
   • Repeat characters
   • consecutive numbers or letters
   • Common password patterns

2. Dictionary check

   • English words
   • common name
   • Popular passwords
   • Common phrases
   • Wikipedia terminology

3. L33t speech analysis

   • Common character substitutions (e.g., “a” → “@”)
   • Many substitutions

4. spatial analysis

   • Keyboard layout mode
   • Common movements on the keyboard
   • Neighboring character relationships

Understand the score of zxcvbn

Zxcvbn provides scores from 0 to 4:

Implement password strength testing

Use zxcvbn in your application

Here’s how to implement zxcvbn in a modern TypeScript application:

import { zxcvbn, ZxcvbnResult } from '@zxcvbn-ts/core';
import * as commonPackage from '@zxcvbn-ts/language-common';
import * as englishPackage from '@zxcvbn-ts/language-en';

// Initialize with options
const options = {
  translations: englishPackage.translations,
  graphs: commonPackage.adjacencyGraphs,
  dictionary: {
    ...commonPackage.dictionary,
    ...englishPackage.dictionary,
  },
};

// Test a password
const password = "MyPassword123";
const result = zxcvbn(password);

console.log(result.score); // 0-4
console.log(result.crackTimesDisplay); // Human-readable crack times
console.log(result.feedback); // Suggestions for improvement

Understand the results

Zxcvbn provides detailed feedback on password strength:

1. Crack time

   • Speed-limited online attack (100/hour)
   • No rate limit for online attacks (10 times/second)
   • Slow hash offline attack (10k/sec)
   • Fast hash offline attack (10B/sec)

2. feedback

   • Warning messages about specific vulnerabilities
   • Improvement suggestions
   • pattern recognition

Password Security Best Practices

Create strong passwords

1. Length trumps complexity

   • Longer passwords are generally stronger than shorter, more complex passwords
   • Aim for at least 12 characters
   • Consider using a password

2. Avoid common patterns

   • Don’t use keyboard mode (qwerty, 12345)
   • Avoid simple character substitutions (a→@, i→1)
   • Do not use personal information

3. Use a unique password

   • Never reuse passwords across services
   • Consider using a password manager
   • Generate random passwords whenever possible

Enforce password policy

When enforcing password policies in applications:

1. Do

   • Intensity estimation using zxcvbn
   • Provide clear, actionable feedback
   • Encourage password managers
   • Enforce rate limiting
   • Use a secure hashing algorithm (such as bcrypt)

2. No

   • Enforce arbitrary complexity rules
   • Need to change password frequently
   • Block password managers
   • Store passwords in plain text
   • Unnecessarily restricting maximum password length

Advanced Password Security Considerations

Multi-factor authentication

While strong passwords are important, they should be part of a broader security strategy:

1. things you know (password)
2. what you have (phone, security key)
3. what are you (Biometrics)

Password storage

Correct password storage is crucial:

1. Use strong hashing

2. With salt

   • Every password is unique
   • sufficient length
   • Store with hash value

3. Enforce rate limiting

   • Prevent brute force attacks
   • Track failed attempts
   • Implement account lockout

The future of password security

emerging trends

1. Passwordless authentication

   • Network authentication
   • Biometric authentication
   • magic link

2. Artificial intelligence and machine learning

   • Advanced pattern recognition
   • behavioral biometrics
   • Adaptive authentication

3. Zero trust architecture

   • Continuous certification
   • Context-aware security
   • risk-based access control

in conclusion

Password security remains an important component of digital security. Despite the emergence of new authentication methods, passwords are likely to remain important for the foreseeable future. Using tools like zxcvbn can help create more secure applications by providing a true password strength assessment and actionable feedback. You can use our Password strength checker Use zxcvbn to test your password.

Remember, password security involves not just the password itself, but the entire authentication system. Implementing appropriate storage, using multi-factor authentication, and following security best practices are all key elements of a comprehensive security strategy.

Other resources

This blog post is part of our ongoing series on network security and development tools. take a look at our Password strength checker Use zxcvbn to test your password.