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building on this previous post Can canvas hash be used to track me and ruin my anonymity?

I want to ask:

Is there any way a user can affect this canvas html hash generation, a way to make the hash change regularly? Could things like playing around with browser settings or cookie policies help? What good methods are there?

Or one step further: is there a method to globally disable the canvas hash generation?

A hash needs input. So if we know what parameters are included in the "input" data which are then hashed, we could play around with those input parameters, correct? Do you know where to find the input data list which flows into the canvas hash generation? timezone, system language, etc. those are inputs, and if you just change one single input, the resulting canvas hash should be totally different right? This is the function of a hash after all - to deliver random strings if input changes...

  • You could always disable javascript. Except (ironically) that probably makes you more trackable, and also is a big inconvenience. – Conor Mancone Oct 24 '19 at 20:44
  • No, i want JS active always. But is there a way to disable others reading from a Canvas surface? And do you have the input list for the canvas hash generation, which variables flow into it? i can imagine that the "browser" input component can be easily changed. if you change browser setttings, the browser "looks" different, right? i just want to know what settings are relevant , what to change? – johnsmiththelird Oct 24 '19 at 20:54
  • then tell me another solution: lets do the contrary: how would you be able to be one of many in the masses? how to have a canvas that many others probably have, too? – johnsmiththelird Oct 24 '19 at 21:07
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I think you've misunderstood what the canvas hash is. The "canvas" is a JS component that allows the browser to draw graphics.

The hash input is only a single thing, the binary data that makes up the image drawn by your graphics card.

Obviously, a number of things go into the generation of that image. There are multiple JS engines used by different browsers, which will affect the generation as well as the version of the engine (and of the code running on the engine). Additionally your graphics drivers, the GPU and/or CPU will all have an affect.

However, none of that (besides switching browsers) is easy to change on a regular basis.

The good news is that their are a limited amount of combinations of these things. I'd imagine something like the newest Chrome, on Windows with an Intel CPU and integrated GPU is likely to be the most common combination.

As was said in your previous question, that is only a single element of the fingerprint built up to uniquely identify you. This website gives you a good idea of how unique (or not) you are.

  • Not if the patterns drawn expose the fine details of specific antialiasing method applied by a variant of the driver... – curiousguy Oct 26 '19 at 1:47

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