When typing on the keyboard the pattern of your input may be as unique as your fingerprint. Whonix uses a keyboard de-anonymization tool by default that hides your keyboard-strokes. This tool is called Kloak and is short for “Keystroke-level Online Anonymization Kernel”.

The purpose of this is to obfuscate the time interval between key press and release events, thus making it harder to identify your individual typing-pattern.

This article details the specifics of how your keyboard strokes may be used to identify a user https://www.whonix.org/wiki/Keystroke_Deanonymization

“Users can be uniquely fingerprinted based on:

  • Typing speed.
  • Exactly when each key is located and pressed (seek time), how long it is held down before release (hold time), and when the next key is pressed (flight time).
  • How long the breaks/pauses are in typing.
  • How many errors are made and the most common errors produced.
  • How errors are corrected during the drafting of material.
  • The type of local keyboard that is being used.
  • Whether they are likely right or left-handed.
  • Rapidity of letter sequencing indicating the user’s likely native language.
  • Keyboard Layout as the placement of the keys on the keyboard leads to different key seek times and typing mistakes.”

Kloak has a github repository at https://github.com/vmonaco/kloak which can be used to build a binary for your linux distribution.

To build on Debian install these tools:

sudo apt install devscripts

Clone the repository and build the code:

git clone git@github.com:vmonaco/kloak.git
cd kloak
sudo mk-build-deps --remove --install
make all

Test the build by starting as root. This is because it reads and writes to device files:

sudo ./kloak

If you want it to run as a service, do the following:

sudo mkdir /usr/local/bin/kloak
sudo cp kloak /usr/local/bin
sudo vi /etc/systemd/system/kloak.service

This is my configuration:

[Unit]
Description=kloak
After=network.target  

[Service]
Type=simple
Restart=always
ExecStart=/usr/local/bin/kloak

[Install]
WantedBy=multi-user.target

Reload the daemons and start the service:

systemctl daemon-reload

systemctl enable kloak.service

Created symlink ‘/etc/systemd/system/multi-user.target.wants/kloak.service’ → ‘/etc/systemd/system/kloak.service’.

systemctl start kloak.service

└─$ systemctl status kloak.service ● kloak.service - kloak Loaded: loaded (/etc/systemd/system/kloak.service; enabled; preset: disabled) Active: active (running) since Fri 2025-02-07 14:05:24 CET; 26s ago Invocation: 803e7700ed2f4ab1a8247300b6582081 Main PID: 3850758 (kloak) Tasks: 1 (limit: 14135) Memory: 1.3M (peak: 2.5M) CPU: 528ms CGroup: /system.slice/kloak.service └─3850758 /usr/local/bin/kloak

Feb 07 14:05:24 kali systemd[1]: Started kloak.service - kloak.