Browser Fingerprinting & Password Security

TL;DR

Browsers can be uniquely identified (fingerprinted) even without cookies. This information, combined with browser-stored passwords, creates a security risk. We’ll cover how fingerprints work and practical steps to protect your data.

What is Browser Fingerprinting?

Browser fingerprinting is a technique websites use to identify and track you based on details about your browser and computer setup. Unlike cookies, it doesn’t rely on you accepting tracking. It works by collecting information like:

• Your browser version
• Operating system
• Installed fonts
• Plugins
• Screen resolution
• Language settings

Taken together, this creates a unique ‘fingerprint’ that can be used to identify you across different websites. It’s harder to block than cookies.

Why is it a problem with passwords?

Most browsers offer to save your passwords. If a website is compromised and uses browser fingerprinting, attackers could potentially use the fingerprint to link saved password data to you specifically. Even if they don’t have your master password (if you use one), knowing which websites you used and having access to the stored credentials is a major risk.

How to Protect Yourself

1. Use a Password Manager: This is the most important step. A good password manager generates strong, unique passwords for each site and stores them securely. It also helps protect against phishing attacks.
   • Popular options include 1Password, LastPass, Bitwarden, and KeePass (open-source).
2. Enable Multi-Factor Authentication (MFA): Wherever possible, turn on MFA. This adds an extra layer of security beyond just your password.
3. Browser Privacy Extensions: Install extensions designed to reduce browser fingerprinting.
   • Privacy Badger: Automatically learns to block trackers and fingerprinting attempts.
   • uBlock Origin: A powerful ad blocker that also blocks many tracking scripts.
   • CanvasBlocker (Firefox): Specifically targets canvas fingerprinting, a common technique.
4. Regularly Clear Browser Data: Clearing your browsing history, cookies, and cache can help reduce the amount of information available for fingerprinting.
   • In Chrome: Ctrl+Shift+Delete (or Cmd+Shift+Delete on Mac). Select ‘All time’ as the time range.
   • In Firefox: Ctrl+Shift+Delete (or Cmd+Shift+Delete on Mac). Select ‘Everything’.
5. Use a Privacy-Focused Browser: Consider using a browser designed with privacy in mind.
   • Brave Browser: Blocks trackers and fingerprinting by default.
   • Tor Browser: Provides strong anonymity but can be slower.
6. Disable Unnecessary Plugins: Remove any browser plugins you don’t actively use, as they can contribute to your fingerprint.
   • In Chrome: Type chrome://plugins in the address bar and disable unwanted plugins.
   • In Firefox: Type about:addons in the address bar and manage your extensions/plugins.
7. Keep Your Browser Updated: Updates often include security patches that can help protect against fingerprinting techniques.
8. Be Careful What You Install: Some software installs browser extensions or modifies browser settings without your knowledge, increasing your fingerprintability.

Checking Your Fingerprint

You can use websites to see how unique your browser fingerprint is:

• Panopticlick: https://panopticlick.eff.org/
• BrowserLeaks: https://browserleaks.com/fingerprinting

These sites will show you the information websites can use to identify your browser.