Andrew Poulos
7/23/2014 10:39:00 PM
On 24/07/2014 4:43 AM, Eli the Bearded wrote:
> In comp.lang.javascript, Andrew Poulos <ap_prog@hotmail.com> wrote:
>> If you "know" the canvas element already and the canvas is "filled"
>> using js why can't you just send the js to the server?
>
> Let's use an analogy. The "canvas" is a sheet of paper (hardware), drawn
> on by a pen (hardware) in the user's hand (software). The "javascript"
> is the directions for what to do.
>
> If you just send the directions back, they look a whole lot like what
> they did when they were first sent out.
>
> If the user follows the directions to write some text on the sheet of
> paper and then sends a photo of the results back, that's a lot closer
> to the canvas fingerprinting scenario. The results in our example show
> pen choice, paper choice, handwriting choice, etc.
>
> In the real canvas fingerprint, the image itself is not sent to the
> site, only some information (a "fingerprint") of the image. But it still
> relies detecting on software and hardware variations in following
> directions exactly. In this case the directions are specifically
> selected to be likely to produce variations, things like blending
> colored text on top of other colored text.
Ah I think I get it now - there'll be more information than just what
can be generated with js.
Andrew Poulos