#0055 How Do Passwords Really Work?

Intro

Passwords are the keys to our digital lives, granting access to everything from social media and banking to work emails and online shopping. But have you ever wondered what happens when you enter your password? How does the system verify it’s really you? Let’s break down how passwords actually work and why strong passwords matter.

The Basics of Password Authentication

When you create an account, the website or application stores your password—but not in plain text. Instead, it undergoes a process called hashing. Hashing converts your password into a unique string of characters using a cryptographic algorithm. The key aspect of hashing is that it’s a one-way function: once a password is hashed, it cannot be reversed back into its original form.

For example, if you set your password as MySecurePass123, a hashing algorithm might convert it into something like this:
5f4dcc3b5aa765d61d8327deb882cf99

When you log in, the system hashes the password you enter and checks if it matches the stored hash. If they match, access is granted; if not, access is denied.

Why Hashing Matters

If websites stored passwords in plain text, a data breach would expose every user's credentials. Hashing protects against this by ensuring that even if the database is compromised, attackers can’t immediately read passwords.
However, not all hashing algorithms are equally secure. Older algorithms like MD5 and SHA-1 are vulnerable to attacks. Secure systems use stronger algorithms like bcrypt, Argon2, or PBKDF2, which add extra layers of protection, making it harder for hackers to crack passwords using brute-force attacks.

The Role of Salting

To further enhance security, modern systems use salting—adding a unique, random value to each password before hashing it. This prevents attackers from using precomputed tables (rainbow tables) to reverse-engineer passwords. For example, if two users have the same password, salting ensures their stored hashes are different. Without salting, identical passwords would result in identical hashes, making attacks easier.

How Hackers Try to Crack Passwords

Hackers have several methods to break passwords, including:

1. Brute Force Attacks – Trying every possible password combination until they find the right one.
2. Dictionary Attacks – Using lists of commonly used passwords (like 123456 or password) to guess users’ credentials.
3. Credential Stuffing – Using leaked passwords from previous breaches to access other accounts, assuming people reuse passwords.
4. Phishing – Tricking users into revealing their passwords through fake websites or emails.

How to Protect Your Passwords

1. Use a Strong Password – A mix of uppercase, lowercase, numbers, and special characters makes passwords harder to guess.
2. Enable Multi-Factor Authentication (MFA) – Adds an extra layer of security beyond just the password.
3. Use a Password Manager – Helps generate and store complex passwords securely.
4. Avoid Reusing Passwords – If one account is compromised, unique passwords prevent hackers from accessing others.
5. Regularly Update Passwords – Especially after a security breach or if you suspect a compromise.

The Future of Password Security

While passwords remain the standard for authentication, new technologies are emerging, such as biometric authentication (fingerprints, facial recognition), passkeys, and hardware security keys. These methods offer increased security and convenience by reducing reliance on traditional passwords. In the meantime, understanding how passwords work and practicing good security habits can go a long way in protecting your digital identity.