== Attack Description ==
Keystroke fingerprinting works by measuring how long keys are pressed
and the time between presses. Its very high accuracy poses a serious
threat to anonymous users.[1]
This tracking technology has been deployed by major advertisers (Google,
Facebook), banks and massive online courses. Its also happening at a
massive scale because just using a JS application (or SSH in interactive
mode) in presence of a network adversary that records all traffic allows
them to construct biometric models for virtually everyone (think Google
suggestions) even if the website does not record these biometric stats
itself.[2] They have this data from everyone's clearnet browsing and by
comparing this to data exiting the Tor network they will unmask users.
== Current Measures and Threat Model ==
While the Tor Browser team is aware of the problem and working on a
solution, current measures [6] are not enough. [4][5]
Security distros are designed to protect the user even if an end user
application is compromised and provide desfense in depth.
The goal is to protect users even in the event of an attacker taking
over an application running ina VM/Container.
This is valid for systems running in VMs or on bare metal.
== Existing Work on Countermeasures ==
As a countermeasure security researcher Paul Moore created a prototype
Chrome plugin known as KeyboardPrivacy. It works by caching keystrokes
and introducing a random delay before passing them on to a webpage.[3]
Unfortunately there is no source code available for the add-on and the
planned Firefox version has not surfaced so far. There are hints that
the author wants to create a closed hardware soltuion that implements
this which does not help our cause.
== Proposal for a System-wide Solution ==
A very much needed project would be to write a program that mimics the
functionality of the this add-on but on the display server / OS level.
Ideally the solution would be compatible with Wayland for the upcoming
transition in the near future.
[1]
http://arstechnica.com/security/2015/07/how-the-way-you-type-can-shatter-anonymity-even-on-tor/
[2]
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7358795
[3]
https://archive.is/vCvWb
[4]
https://www.lightbluetouchpaper.org/2015/07/30/double-bill-password-hashing-competition-keyboardprivacy/#comment-1288166
[5]
https://trac.torproject.org/projects/tor/ticket/16110
[6]
https://trac.torproject.org/projects/tor/ticket/1517
***
This feature request has been mirrored on each project's bugtrackers
respectively:
https://github.com/subgraph/subgraph-os-issues/issues/103
https://labs.riseup.net/code/issues/11257
https://github.com/QubesOS/qubes-issues/issues/1850
