[tbb-bugs] #32861 [Applications/Tor Browser]: "Fingerprint.js PRO" successfully fingerprints Tor Browser

[Tor Bug Tracker & Wiki]

#32861: "Fingerprint.js PRO" successfully fingerprints Tor Browser
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 Reporter:  printerman22              |          Owner:  tbb-team
     Type:  defect                    |         Status:  new
 Priority:  Medium                    |      Milestone:
Component:  Applications/Tor Browser  |        Version:
 Severity:  Normal                    |     Resolution:
 Keywords:  tbb-fingerprinting        |  Actual Points:
Parent ID:                            |         Points:
 Reviewer:                            |        Sponsor:
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Comment (by tom):

 My experience:

 {{{
 First Load:  FzSw1dVTRpxk42FjoO9L

 Showed 5 previous visits.

 [New Identity]

 ID:  FzSw1dVTRpxk42FjoO9L

 Showed 6 previous visits (5 plus my last one.)

 [Resize Window]

 [New Identity]

 ID:  3NoTPDBQoIdFazthz1Aq

 No Visit History
 }}}

 My *guess* is that because we spoof your screen size to be the browser
 dimensions, which resizing changes, it is assigning a new Id based on that
 dimension (along with a new other things that are non-unique for Tor
 Browser users.)

 The open question to me however is if their script was smarter and
 realized that they can't use the screen dimension as a uniqueness test and
 instead consider it as variable would they be able to fingerprint people
 uniquely? Or well?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/32861#comment:5>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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