Mozilla Firefox 67 will function a brand new anti-fingerprinting technique that protects towards sure window-size associated fingerprinting strategies.
Mozilla plans to combine the brand new function in Firefox 67 however delays might postpone the discharge. Firefox 67 will probably be launched on May 14, 2019 in line with the official release schedule.
The technique comes from experiments that the builders of the Tor browser performed and is a part of the Tor Uplift project that introduces enhancements within the Tor browser to Firefox (Tor browser relies on Firefox code).
Window dimensions, particularly in maximized state and when home windows are resized, could also be used for fingerprinting.
Fingerprinting refers to utilizing information supplied by the browser, e.g. robotically or by operating sure scripts, to profile customers. One of the appeals that fingerprinting has is that it doesn’t require entry to native storage and that some strategies work across browsers.
Maximized or fullscreen home windows present display width and peak data. Fullscreen reveals the precise display with and peak, a maximized window the width and peak minus toolbars.
Resized home windows alternatively reveal actual dimensions of the browser window, e.g. 1003×744.
Letterboxing protects higher towards window dimension associated fingerprinting strategies. It is a technique that rounds the content material view dynamically utilizing 128×100 pixel steps.
Letterboxing provides margins across the content material view of the window and calculates the margin dynamically to make sure that it’s utilized to resize eventualities as nicely (and never solely when a brand new window is created).
Setting this up in Firefox
The Firefox preference privacy.resistFingerprinting determines whether or not anti-fingerprinting is enabled in Firefox. Note that it could render some websites and providers unusable or much less useful.
- Make certain you run no less than Firefox 67 (examine about:help for the model. Note that this doesn’t seem to have landed in Firefox Nightly atm)
- Load about:config within the Firefox deal with bar.
- Confirm that you may be cautious.
- Search for privateness.resistFingerprinting.
- True: Fingerprinting safety is enabled together with Letterboxing (as of Firefox 67).
- False: Fingerprinting safety is disabled.
You can confirm that the safety is in place by visiting Browserleaks or some other web site that returns the display decision and viewport. Just change the window dimension a few occasions and reload the web page to search out out if it rounds the decision and viewport (it ought to return a a number of of 128×100 pixels).
You may discover the margins that Firefox makes use of when the function is enabled.
Now You: Have you enabled anti-fingerprinting in your browser?