How Password Hashing Works: bcrypt, Argon2, and What Your App Should Use

How Password Hashing Works

MD5 and SHA-1 are not password hashing algorithms. Here is how bcrypt, scrypt, and Argon2 actually work and which to use in 2025.

This guide covers the key concepts, practical steps, and common mistakes to avoid when addressing this aspect of password security.

Best practices

• Use a dedicated password manager for all credentials
• Enable multi-factor authentication wherever supported
• Use unique passwords for every account
• Regularly audit accounts for breached credentials
• Generate passwords with a cryptographically random generator like PassGeni

How PassGeni helps

PassGeni addresses this challenge directly through its AI-seeded generation engine. Passwords are created client-side using JavaScript's crypto.getRandomValues() API — no data ever leaves your browser.

The Password DNA Score provides a 7-point quality audit so you know exactly how strong each generated password is before you use it.