Everyone talks about how evil browser fingerprinting is, and it is, but I don’t get why people are only blaming the companies doing it and not putting equal blame on browsers for letting it happen.
Go to Am I Unique and look at the kind of data browsers let JavaScript access unconditionally with no user prompting. Here’s a selection of ridiculous ones that pretty much no website needs:
- Your operating system (Isn’t the whole damn point of the internet that it’s platform independent?)
- Your CPU architecture (JS runs on the most virtual of virtual environments why the hell does it need to know what processor you have?)
- Your JS interpreter’s version and build ID
- List of plugins you have installed
- List of extensions you have installed
- Your accelerometer and gyroscope (so any website can figure out what you’re doing by analyzing how you move your phone, i.e. running vs walking vs driving vs standing still)
- Your magnetic field sensor AKA the phone’s compass (so websites can figure out which direction you’re facing)
- Your proximity sensor
- Your keyboard layout
- How your mouse moves every moment it’s in the webpage window, including how far you scroll, what bit of text you hovered on or selected, both left and right clicks, etc.
- Everything you type on your keyboard when the window is active. You don’t need to be typing into a text box or anything, you can set a general event listener for keystrokes like you can for the mouse.
If you’re wondering how sensors are used to fingerprint you, I think it has to do with manufacturing imperfections that skew their readings in unique ways for each device, but websites could just as easily straight up record those sensors without you knowing. It’s not a lot of data all things considered so you likely wouldn’t notice.
Also, canvas and webGL rendering differences are each more than enough to 100% identify your browser instance. Not a bit of effort put into making their results more consistent I guess.
All of these are accessible to any website by default. Actually, there’s not even a way to turn most of these off. WHY?! All of these are niche features that only a tiny fraction of websites need. Browser companies know that fingerprinting is a problem and have done nothing about it. Not even Firefox.
Why is the web, where you’re by far the most likely to execute malicious code, not built on zero trust policies? Let me allow the functionality I need on a per site basis.
Fuck everything about modern websites.
Pretty much none of the information is necessary to ever render a site properly.
OS and CPU architecture? Ireelevant to whether you are sending a JPG or PNG background. Nearly irrelevant to whether you are using a vertical or horizontal screen (and browsers adverstise that info separately anyway, it’s even part of CSS media queries).
Accelerometer and gyroscope? The only reason that could ever be needed for rendering is if the user is moving so incredibly fast that red pixels in their screen would become green due to shifting. And in any time between 2025 and 2999, if you have someone moving that fast, you have worse problems than the site not rendering adequately.
Keyboard layout? If the rendering of a site depends on whether I’m pulsing “g” vs “j” while it loads, then that’s quite stupid anyway because that boldly assumes the app focus is on the page.
Proximity sensor? Again: absolutely useless unless rendering environment moving at incredibly superhigh speed (at which the sensor might be reading data wrong anyway).
That’s incorrect. Different sites have different needs and the devs can’t pre-program which of the billion sites need what.