MASARYK UNIVERSITY
FACULTY OF INFORMATICS
Operating systems for privacy
and anonymity: a survey
BACHELOR'S THESIS
Andrej Hulina
Brno, Fall 2020
MASARYK UNIVERSITY
FACULTY OF INFORMATICS
Operating systems for privacy
and anonymity: a survey
BACHELOR'S THESIS
Andrej Hulina
Brno, Fall 2020
This is where a copy of the official signed thesis assignment and a copy of the
Statement ofan Author is located in the printed version of the document.
Declaration
Hereby I declare that this paper is my original authorial work, which
I have worked out on my own. A l l sources, references, and literature
used or excerpted during elaboration of this work are properly cited
and listed in complete reference to the due source.
Andrej Hulina
Advisor: RNDr. Lukáš Němec
i
Acknowledgements
I would like to thank my advisor RNDr. Lukáš Němec for his help,
patience and suggestions, and also my family and friends for their
support during my entire studies.
ii
Abstract
The present thesis is set to explore the operating systems focused on
the user's privacy and anonymity. The first part of the thesis describes
such properties of operating systems, on which operating system
they should be built, which anonymous network should be used, and
which features they should contain. Furthermore, the thesis includes
a brief description of nine operating systems with such focus. Three
of them, Whonix, Tails OS, and Kodachi Linux, are described in detail
in the next part. A l l three systems are tested for everyday use, such
as searching the Internet, sending messages via instant messenger,
and sending emails. The systems are compared in the last part of the
thesis.
iii
Keywords
operating system, anonymity, privacy, security, Tor, users, Whonix,
Tails, Kodachi
iv
Contents
Introduction 1
1 Properties of the operating systems for privacy and anonymity 2
1.1 Tor anonymity network 3
1.1.1 The Tor Browser 3
1.1.2 OnionShare 4
1.1.3 Tor stream isolation 4
1.2 Features 4
1.2.1 App Armor 5
1.2.2 Keystroke Anonymization 5
1.2.3 Metadata cleaning 5
2 A survey of operating systems for privacy and anonymity 6
2.1 Tails OS 6
2.2 Whonix 6
2.3 Kodachi Linux 7
2.4 Parrot OS 7
2.5 Subgraph OS 8
2.6 IprediaOS 8
2.7 M O F O Linux 8
2.8 Heads OS 9
2.9 Robolinux 9
3 Whonix 10
3.1 Whonix-Gateway 11
3.2 Whonix-Workstation 12
3.3 Features 14
3.4 Tests 15
4 Tails OS 16
4.1 Encrypted Persistent Storage 17
4.2 Applications 18
4.3 Features 19
4.4 Tests 20
5 Kodachi Linux 22
v
5.1 Applications
5.2 Features
5.3 Tests
6 Comparison
7 Conclusion
Bibliography
List of Tables
6.1 Overall properties
6.2 Features 28
6.3 Applications 29
List of Figures
1.1 How Tor works 3
3.1 Lynis in Whonix 16
4.1 Lynis in Tails 21
5.1 Lynis in Kodachi 26
viii
Introduction
Gone are the days when everyone thought people were private on
the Internet. The internet users should already know that nobody is
100 percent protected against the companies trying to gain as much
information about every user as possible [1]. Every visited website
collects some data about the users. Almost all the free applications
and websites have the same rule. When the user does not pay he
becomes the product. Most websites contain advertisements, trackers,
and people are being tracked on almost every website [2].
People who care about humans' inalienable rights to privacy and
freedom of expression try to help others defeat all methods of internet
surveillance and censorship, which corporations, internet service
providers, and governments use [3]. They try to create all types of
software to keep privacy and stay anonymous on the Internet. Globally,
there are many different applications with such intent. However, even
the best application can not ensure the highest anonymity and privacy
if installed on a flawed operating system that can not be trusted. That
is why it is also necessary to have an operating system designed to
increase users' anonymity and privacy on the Internet [4].
The thesis focuses on operating systems that take users' anonymity
and privacy as the primary goal, even at the cost of lower usability or
slower connection. In the first chapter, the properties of such operating
systems are described. Part of the chapter is devoted to Tor, the
most common anonymity network. Proper operating systems with
such intent should come with several features, which increase all the
abilities. Few commonly used features increasing security, anonymity,
and privacy are also mentioned and briefly described.
In the next chapter, nine operating systems for anonymity and
privacy are briefly introduced. Three of them, Whonix, Tails OS, and
Kodachi Linux, are described in detail. A l l three systems are tested
for every day user activities and tested with Lynis, a testing security
tool that provides a health scan of the system to support compliance
and system hardening [5]. The sixth chapter compares the overall
properties, features, and applications of these three operating systems.
1
1 Properties of the operating systems for privacy
and anonymity
There are many operating systems globally, but only some focus on privacy
and anonymity. They are not created by the enormous companies,
but by people who often only want to help others, even without any
ambitions for profit. That is why the developers use the cornerstone
on which the entire operating system is built, the Linux distributions
like Debian that are free and open-source. However, these Linux distributions
come with versatility and usability as their primary goals.
For this reason, operating systems with such scope are heavily modified
to emphasize security, anonymity, and privacy over all else.
In the digital world, there is no single way to protect a system from
all types of attacks successfully. That is why many operating systems
use defense in depth. Defense in depth means that a series of security
mechanisms are layered to protect the system's data. If one layer fails,
another immediately steps up to thwart an attack. [6]
Operating systems for anonymity and privacy should be easy to
run and easy to destroy, as the system can get compromised by a
simple mistake that the users make on the Internet. When the system
is compromised, it is necessary to destroy it and use a new clean
version. The easiest way to create such an operating system is a live
system. The live operating system can be booted on to USB, C D , or
SD card, from where it always launches as a new, untouched system.
After the system shuts down, everything is wiped out, leaving no
trace, which solves the compromised system's problem. However, this
type of operating system is not persistent.
Another way how can be such an operating system designed is a
virtual machine. The operating system running as a virtual machine
can be easily installed and run as a persistent system. Such an operating
system should provide full hardware isolation, so the hardware
and host OS are protected when the system is compromised. When
it happens, the virtual machine can be destroyed by one click and
installed again [7].
2
i. PROPERTIES OF THE OPERATING SYSTEMS FOR PRIVACY A N D ANONYMITY
1.1 Tor anonymity network
For the highest anonymity and privacy, operating systems are using
anonymity networks. The most common is the Tor network. Tor stands
for The Onion Router and is often used as a building block for creating
new tools or operating systems focused on privacy and anonymity.
Commonly, only connections through the Tor network are available in
such operating systems to ensure the highest anonymity. Tor is a traffic
analysis resistance tool. It does not prevent data collection. However,
it makes it so that whatever data is collected cant be meaningfully
deciphered and utilize for whatever purpose by anyone.
The Tor software is an open network designed to give all of its
users the same identity. Tor hides the user's location by relaying the
traffic through three random places globally and encrypting the traffic
with a triple layer of encryption to ensure nobody can follow the Tor
circuit back to its origin [8, 9,10].
Figure 1.1: How Tor works
1.1.1 The Tor Browser
The easiest way to access the Tor network is the Tor Browser, a modified
Mozilla Firefox version. The Tor Browser works like a regular browser,
but besides, it is optimized for anonymity, and all the browsing data
are encrypted. A l l traffic from the browser is routed through the Tor
3
i. PROPERTIES OF THE OPERATING SYSTEMS FOR PRIVACY A N D ANONYMITY
network. Every visited website is isolated, which is a protection against
the follow by advertisements and third-party trackers, which allows
the users even to increase the security. The browser also automatically
clears the browsing history and cookies when it shuts down.
Tor browser has three security levels. The default level is Standard,
which does not disable any website features. The middle-way, Safer
level disables the most common dangerous website features. O n all
the non-HTTPS websites, it also disables Javascript. The Safest security
level allows only website features that are required for basic services
and static websites. Images, media, and scripts are affected. It also
disables Javascript on all websites [11,12].
1.1.2 OnionShare
OnionShare is an open-source tool that allows sharing files of any size
over the Tor network anonymously and securely. The users need to
drag and drop files into the OnionShare and start sharing, which will
generate an unguessable address. This address needs to be sent to the
receiver, who does not need OnionShare to download the file. The file
can be downloaded by opening the address in the Tor browser [13].
1.1.3 Tor stream isolation
Stream isolation creates a new circuit and isolates the stream as much
as possible, which prevents attacks on the users' anonymity. Before
the stream isolation implementation, it was very likely that multiple
streams would select the same circuit, which could lead to a
combination of unrelated transmissions and compromising users'
anonymity [14].
1.2 Features
Anonymity, security, and privacy are complex problems with many
issues beyond the IP address masking necessary for users' privacy
protection. Every operating system includes many different features.
However, some of them should be part of every operating system as
another security and anonymity layer.
4
l . PROPERTIES OF THE OPERATING SYSTEMS FOR PRIVACY A N D ANONYMITY
1.2.1 AppArmor
AppArmor is a Linux kernel security module whose functionality
allows the system administrator to use per-program profiles (AppArmor
profiles), designed to restrict specific high-risk applications from
unintentionally releasing information on the Internet. Profiles restrict
which system recourses applications can access. The most common are
capabilities for network access and raw socket access and permissions
for reading, writing, and executing files on specific paths. For some
applications like Tor, some profiles are enforced by default [15].
1.2.2 Keystroke Anonymization
The newest keystroke biometric algorithms can uniquely fingerprint
users based on soft biometric characteristics like typing speed, error
frequency, length of pauses in typing, and many others [16]. These
algorithms generate a primary pattern for users, which are compared
in the future. Every user produces keystrokes as specific as signature
or handwriting. However, typing styles can differ depending on
the user's energy or mood situation. Adversaries might likely have
samples of keystroke fingerprinting from everyday users' online activities,
which can be compared with "anonymous" samples. It is a
privacy risk, and users who care about their privacy should not type
straight into browsers with enabled Javascript. Recommended is using
an offline text editor for writing and copying the text into the web
interface. Operating systems might come with some specific Keystroke
Anonymization Tool [17,18].
1.2.3 Metadata cleaning
Metadata is data about data. Almost every file contains metadata, and
it should be cleaned for privacy. One file can be embedded information
like the users and computer name, date and time of the creation and
last update, location, and many others. If the operating system for
anonymity and privacy does not provide any metadata cleaning, it
should at least come with an additional feature, which allows the
users to clean all metadata from the files [19].
5
2 A survey of operating systems for privacy
and anonymity
In this section, nine operating systems focused on anonymity, and
privacy will be briefly introduced.
2.1 Tails OS
Its name is a shortcut for The Amnesiac Incognito Live System. Tails
is a portable Debian-based OS focused on preserving privacy and
anonymity designed to run with full functionality from a DVD or USB
thumb drive and can also run in the virtual machine.
The whole system runs independently from the other operating
system and does not write anything to the hard disk. It runs only
from the computer's memory, so it leaves no trace on the computer.
When the system shuts down, it deletes memory with all files unless
explicitly asked not to do so.
Tails uses Tor as its default networking application to protect users'
privacy online. The system blocks all the applications attempting to
access the Internet directly without Tor [20].
2.2 Whonix
Whonix is an open-source operating system focused on anonymity,
privacy, and security while connected to the web. Based on securityhardened
Debian derivative calls Kicksecure, Tor, and the principle
of protection by isolation.
The system consists of two virtual machines, the Whonix-Gateway
and the Whonix-Workstation, installed on a user-provided host operating
system and connected through an isolated network. Both have
their own IPs, which make it impossible to track activity back to its
original user. The Whonix-Workstation runs applications on a completely
isolated network and can only talk to the Whonix-Gateway. The
Whonix-Gateway runs as Tor processes and acts as a gateway. It means
that only connections through the Tor are permitted. This security
6
2. A SURVEY OF OPERATING SYSTEMS FOR PRIVACY A N D ANONYMITY
by isolation configuration averts many malware threats, misbehaving
applications, and users' error [21].
2.3 Kodachi Linux
Kodachi Linux is a live operating system based on Debian that can
boot from a DVD, USB stick, or SD card. The entire OS is functional
from the host's temporary memory R A M . The system cleans up after
itself, so no trace is left behind once it is shut down. Users can install it
on any PC, but this is not recommended as it will save all the settings
on the hard drive.
Kodachi provides full anonymity and privacy. When the operating
system starts, it automatically starts V P N and TOR network service.
A l l traffic runs through a V P N , after that through the Tor network
with DNS encryption. Free V P N is part of the pre-configured toolset.
The system has its browser based on the Tor Browser, from which
some problematic Tor modules have been cut off. It also offers I2P,
GNUNET, and a custom V P N [22].
2.4 Parrot OS
Parrot OS is a privacy-hardened GNU/Linux distribution based on
Debian, which comes in two major versions: Parrot OS Home and
Parrot OS Security. It can be dual-booted with other operating systems
or run on Docker or Virtual Box.
Parrot Home is a lightweight and always updated system designed
for daily use. It is focused on regular users who care about their privacy
but do not need special security tools. It includes Tor Browser, Firefox
with preset extension HTTPS Everywhere, and other programs to
increase users' privacy and anonymity. The system comes with Anon
Surf, which routes all the traffic and packets through Tor.
Parrot Security is made for professional use, and it comes as a complete
all-in-one environment for cloud pen testing, computer forensics,
reverse engineering, hacking, cryptography, privacy, and anonymity.
This version also has pre-installed security and anonymity tools like
Tor, I2P, or Anonsurf [23].
7
2. A SURVEY OF OPERATING SYSTEMS FOR PRIVACY A N D ANONYMITY
2.5 Subgraph OS
Subgraph OS is a lightweight Debian-based distribution that uses the
Gnome desktop environment. Although it looks like a modern OS, it
is still in the Alpha version. The system is designed to be difficult to
attack. It is accomplished by the proactive, ongoing focus on security
and attack resistance and also by the kernel hardened with Grsecurity
the best set of Linux kernel security enhancements available.
The applications run in sandbox environments, known as Oz,
unique to this OS. Oz is designed to isolate applications from each
other and the rest of the system. Access to system resources is only
granted to applications that need them. For example, the PDF viewer
and the image viewer do not have access to any network interface
in the sandbox they are configured to run in. The communication
of applications is restricted so that they use the Tor network exclusively.
Applications should connect through the Tor network via the
Metaproxy application [24].
2.6 IprediaOS
IprediaOS is a Fedora-based privacy-oriented operating system, which
can be run in live mode or installed to the users' hard drive. It uses
the I2P anonymizing network instead of the Tor network. I2P does
not act as Tor, so not as a gateway to the standard Internet. Because
of this, the system cannot browse regular websites, only i2p websites.
Anonymous email, bit torrent, and IRC clients, which provide an
anonymous internet experience, are pre-installed. IprediaOS is no
longer maintained [25].
2.7 MOFO Linux
M O F O Linux is an Ubuntu-based operating system focused on providing
users with a complete toolset for roaming around the Internet
safely with absolute freedom. The toolset includes OpenV P N , I2P,
Softether, Freenet, Tor, Tor Browser, and other tools that provide an
anonymous and secure connection to the Internet. Internet history
and usage tracks are destroyed on every shutdown. This OS is de-
8
2. A SURVEY OF OPERATING SYSTEMS FOR PRIVACY A N D ANONYMITY
signed for easy usage on every computer type. The system has no
documentation.
It contains office, multimedia, and internet applications enabling
web browsing, productivity, and entertainment. It can run directly
from a C D or USB, but the users can install it on H D D or SSD. It might
also run in a virtual machine [26].
2.8 Heads OS
Heads is a free and open-source Linux distro born to answer Tails since
Tails uses systemd as an init system and contains non-free software.
By default, Heads offers Openbox as its graphical window manager.
The system uses a hardened Linux kernel with grsecurity. Grsecurity
helps to protect the system against zero-day1
attacks and other known
attacks on the Linux kernel.
A l l Internet traffic is always routed through the Tor network, but
with an option to turn it off. The Tor protocol is designed to encrypt
the traffic so that users are anonymized on the Internet. Web sites and
services will not know from where the traffic comes [28].
2.9 Robolinux
Robolinux is a Debian-based operating system that can be installed on
a hard drive, bootable media, or a virtual machine. The system loads
with no logs V P N calls Private Internet Access, which is charged. The
users can add other privacy tools like Tor, I2P, Bleachbit, Enigmail,
and the JonDo browser.
Robolinux is unique with its integration between Windows and
Linux, on which it places a heavy emphasis. Every Robolinux version
runs regular Windows programs flawlessly and natively inside its
desktop, which increases the speed with which the users operate
with a computer. Besides, the system is not affected by any Microsoft
Windows viruses and malware. Also, it runs many times faster than
any other Windows OS [29].
1. Zero-day attack is an attack exploiting vulnerabilities of the software that have
not been disclosed publicly [27].
9
3 Whonix
Whonix is an open-source operating system focusing on security
anonymity, and privacy The system is being up to this day regularly
updated, and currently, 15.0.1.5.4 is the newest version released on
December 1, 2020.
Whonix is based on Kick Serure, a security-hardened derivative
of Debian. To make the system as secure as possible, Kick Secure uses
the kernel hardening settings standards, recommended by the Kernel
Self Protection Project known as the KSPP The project covers, among
other things, active detection of attack attempts or removal of entire
classes of bugs [30].
To ensure online anonymity, Whonix is built on Tor, which it uses
as a default anonymization network. All the rerouting and encryption
functions of Tor are applied to all applications that need a network connection.
A l l connections, applications, and traffic are forced through
Tor. Otherwise, they are blocked. Since all the Tor traffic is going
through several servers worldwide before it reaches the destination,
it is almost impossible to connect the Whonix users to their internet
activity [31].
For the best security, Whonix comes with isolation. It runs as two
virtual machines, Whonix-Gateway, and Whonix-Workstation, isolated
but connected through an isolated network. Currently, few options
for Whonix virtualization and hardware configuration, which significantly
affect Whonix's usability and security, are available.
The most common configuration consists of two virtual machines
installed on a single host system. Virtual machines can be installed in
VirtualBox V M , Qubes OS, or Linux K V M . Both of them run on the host
hardware but can not interact with the host OS. They are completely
isolated. Any dangerous malware, unwanted connections, or any other
threats can not leave Whonix. Neither the applications nor websites
can read any information about the host hardware. For example, if a
virus were to bypass the Tor browser, it would just end up inside a
virtual machine and not in the host machine. A virtual machine can
be easily destroyed and recreated. It gives the users the advantage
of this OS's protection features without rebooting or installing a new
operating system.
10
3. W H O N I X
Whonix-Gateway and Whonix-Workstation can also be physically
isolated on two separate host systems. The Whonix-Gateway can run
on its physical device run either directly on the hardware or inside a
virtual machine. The latter is recommended. The Whonix-Workstation
should always run in a Virtual Machine. If both software is installed
directly on physical devices, it does not provide any protection against
hardware fingerprints. It is also difficult to install and recommended
only for advanced users [32].
3.1 Whonix-Gateway
Whonix-Gateway is software designed to run Tor processes and act
as a gateway for the other virtual machine. This virtual machine has
two virtual network interfaces. Through the first one is connected to
the Internet. It is getting a connection from the host and communicates
with Tor relays. The second one is connected to the virtual L A N ,
which runs entirely inside the host. It connects the Gateway with the
Workstation, usually, Whonix-Workstation.
Whonix-Gateway also supports the torification of other operating
systems, Microsoft Windows, Android, and other GNU/Linux. However,
using a default Whonix-Workstation is the most secure and most
comfortable way. Whonix-Custom-Workstation is recommended only
for advanced users [33].
Whonix-Gateway is not designed for regular users' activity. It creates
and prevents Tor connections, there should be no Internet activity,
and it should not be used as a distribution for Linux. It is necessary to
keep it always updated. Tools like Stop Tor, Reload Tor, and Restart
Tor GUI, which do precisely what their name says, are pre-installed
along with others like Nyx-Status Monitor for Tor, Anon connection
wizard, Tor Control Panel, Global Firewall Settings, Reload Firewall,
and others. Since Whonix is a Linux derivative, it also contains a Terminal
[34].
Nyx is a terminal monitor for Tor, which provides detailed realtime
information about the user's relay, such as relay detail, IP, connection
types, C P U and memory usage, bandwidth graphs, event logs,
interpreter, and much more.
11
3. W H O N I X
Tor Control Panel is a Tor controller, the quality and suitability
of which is not guaranteed by The Tor Project, from which it is independently
produced. It allows the users to check Tor status, stop, restart,
or configure Tor, showing the logs. It also comes with the utilities for
displaying Tor circuits and streams and setting a new identity, which
can only be done if the system is connected to the Tor network [35].
Anon connection wizard is an application that helps the users to
configure the Tor bridge or a proxy before connecting to Tor. The users
can connect directly to the Tor network, but some countries do not
allow them to use Tor, as it is illegal. These users need to configure Tor
bridges, which hide the fact that the system connects to Tor from the
internet service provider. As a next step, the users can also configure
a proxy. Bridge and proxy can be configured at the same time. The Tor
network can also be disabled. However, without the Tor network, the
users are not able to do any internet activity [36].
WhonixCheck is a bash script responsible for checking essential
system variables. It verifies if the operating system is up-to-date or if
IP forwarding is disabled on Whonix-Gateway. It also checks if networking
is configured correctly and notifies about the Tor network. In
addition to these, WhonixCheck provides many other checks. It runs
automatically after the first boot, but the users can start it also manually
[37].
The firewall features of Whonix-Gateway include stream isolation,
optional Tor relay, optional VPN-Firewall, and others. The firewall
should not be removed. Users can modify them using User Firewall
Settings or access the preset rule with the Global Firewall Settings.
Both are pre-installed [38].
Web Browser is not allowed to be run on the Gateway. Browsing
the Internet is not secure on the Gateway.
3.2 Whonix-Workstation
The second virtual machine calls Whonix-Workstation, is the one that
should be actively used by users. It runs applications, which should
all be launched only in the Workstation, not in the Gateway. Unlike
the Gateway, the Workstation is connected only to the internal virtual
L A N , which allows it to communicate only with the Gateway. It is
12
3- W H O N I X
isolated from the host system. All traffic coming from the Workstation
is forced to pass through the Tor network. Only IP addresses on the
internal L A N , which are the same in every installation of Whonix,
are available for the Workstation. No application, not even malware
with root privileges, can see the host's real IP address but only the
anonymized Whonix IP addresses. It makes IP address and DNS leaks
impossible, which reduces the users' risk of being tracked by anyone.
Applications can also not connect to the unsecured Internet and can
communicate only over the encrypted Tor network. Since the Workstation
is not connected to the network directly but to the pre-anonymized
Gateway's network, it is impossible to establish an Internet connection
on the Workstation when the Gateway is turned off, or Tor does not
work [39].
Whonix-Workstations comes with a few pre-installed and preconfigured
applications with safety in mind, making them ready for
use with minimal user input.
Since Whonix ensures anonymity and privacy by using Tor, the
Tor browser is the system's default and the only recommended web
browser. Tor Browser was already described in the section 1.1 at the
page 3, and Whonix modifies the regular Tor Browser Bundle just
slightly. It disables the Tor Circuit View function for security reasons
and Open Network Settings. Together with other small changes,
Whonix changes the default landing page of the browser.
For communication, Whonix comes with two open-source applications,
XChat, and qTox. The former one uses IRC and the latter one
Tox protocol [40].
As the default password manager, Whonix uses KeePassXC. The
system also has pre-installed applications like VLC, Xpdf, or Ristretto
Image Viewer. For cryptocurrency, Whonix offers two options, Monero
GUI for Monero and Electrum Wallet for Bitcoin. Few applications
like WhonixCheck, Firewall settings, or Terminal are also pre-installed
on the Workstation and work similarly to the Gateway applications.
For Keystroke Anonymization has Whonix pre-installed application
called Kloak, which intercepts the user's keyboard input before it
reaches the driver and randomizes it [41].
13
3. W H O N I X
3.3 Features
Some of the features, like Tor, were already described in the section 1.1
at the page 3. Whonix implements stream isolation and some preinstalled
applications like Tor Browser or HexChat are configured
to use different SocksPort, which means that every application with
dedicated SockPort takes a different path through the Tor network.
The system does not perform automatic metadata cleaning of files,
but the system comes bundled with MAT2, which can be used for manual
metadata cleaning. It is a shortcut for the Metadata Anonymization
toolkit, and it supports almost every standard file formats. MAT does
not delete the file with removable metadata. Instead, it creates a new
clean file with the .cleaned extension. It does not anonymize the files'
content, nor can it handle any custom metadata field, steganography,
or watermarking. It just removes metadata from the file. To ensure
the best anonymity, using file formats with no metadata is highly
recommended [42].
By default, Whonix runs in a persistent mode. However, since
version 15, Whonix can also be run as a live system. V M Live Mode
ensures that everything written to the virtual drive is forgotten after
the system is powered off. A virtual machine in live mode is not
amnestic by itself. Even though live mode writes everything to the
R A M , core dumps, swap files, malware, or other configuration can
bypass it. Therefore, it is highly recommended to configure a read-only
hard mode as a prevention against malware from remounting the hard
drive as read-write. In Host Live Mode runs the entire host operating
system in live mode, only available for the OS based on Debian. All the
writes are redirected to the R A M , which is massive prevention against
malware gaining persistence. Highly recommended is also a correct
implementation of a write protection switch [43].
Timekeeping is essential for security, anonymity, and privacy. Therefore
Whonix does not use the host's system clock and time synchronization
mechanism and leaves them untouched. It also disables most
time synchronization features from the virtualizers.
Whonix comes with a sdwdate, which is a security time synchronization.
Sdwdate sets the systems clock by communicating with Tor
onion webservers via end-to-end encrypted TCP.
14
3- W H O N I X
Whonix also uses Boot Clock Randomization, which randomly
moves the system clock between 0 and 180 seconds into the future or
past during boot. It improves anonymity and privacy by prevention
of time-based fingerprinting and linkability issues [44].
3.4 Tests
Whonix-Gateway should always be started first, and its first start
should be in persistent mode. It allows Tor Entry Guards for Tor. When
the Gateway is first launching, the Tor network has to be set up. After
the first launch, Whonix-Gateway can also run in a live mode. The
first boot of Whonix-Workstation is very similar to Whonix-Gateway,
except that the Tor network does not have to be set up. Both of the
machines have to be regularly updated.
Every system boot after the first boot up takes only a few minutes,
even though two virtual machines have to be started. The time mainly
depends on the host machine. The system runs smoothly, and it is
automatically connected to the Internet if the host is connected. Internet
connection is a bit slower, as everything is forced through the Tor
network. Tor browser is pre-installed, and no additional settings are
needed.
Web browsing is slower than at the host OS, but still fast enough.
It all depends on the internet service provider.
The first instant messenger, HexChat, includes all the IRC client
functions and has only one server, the secure version of the OFTC.
A l l other servers have been removed. HexChat launches quickly and
is simple to use. It allows one-on-one communication with private
messaging and file sharing.
Another instant messenger, qTox, is also simple to use. It uses the
Tox protocol to communicate with other users. Tox is a peer-to-peer
video-calling and instant-messaging protocol. Currently is Tox, the
only VoIP solution compatible with Tor. QTox also allows adding a
friend by the Tox ID, which is different for every user.
Whonix does not come with any mail application pre-installed,
but any application available on Debian can be installed.
15
Lynis security scan d e t a i l s :
Hardening i n d e x : 68
T e s t s performed : 255
P l u g i n s enabled : 2
Components:
- F i r e w a l l
- Malware scanner
[U]
[ ]
Scan mode:
Normal [V] F o r e n s i c s [ ] I n t e g r a t i o n [ ] Pentest [ ]
Lynis modules:
- Compliance s t a t u s
- S e c u r i t y a u d i t
- V u l n e r a b i l i t y scan
[?]
[V]
[V]
F i l e s :
- T e s t and debug i n f o r m a t i o n : / v a r / l o g / l y n i s . l o g
- Report data : /var/log/lynis-report.dat
Figure 3.1: Lynis in Whonix
4 Tails OS
The Amnestic Incognito Live System is an open-source and free securityhardened
operating system based on Debian, which aims to preserve
privacy and anonymity. Tails is being regularly updated, and the new
version is released almost every month. Currently, 4.14 is the newest
version released on December 15, 2020.
Debian has already integrated most kernel-level security features.
Tails kernel has only a few other security features implemented as the
base Debian kernel. Several kernel parameters like vsyscal = none,
mce = 0, slub_debug = FZP, and a few more have been passed to the
Tails boot command line and /proc/sys. These parameters increase
security against kernel exploits [45].
Like many other operating systems focused on anonymity and
privacy, Tails achieves its anonymity using Tor as its default networking
application. A l l outgoing and incoming connections are forced
to go through Tor, which encrypts and anonymizes online activity.
A l l pre-installed software is configured to make a connection only
16
4. TAILS OS
via Tor. When an application tries to make a direct connection to the
Internet, it is automatically blocked. It also blocks all non-anonymous
connections. A website without any encryption is not allowed either.
Tails comes with the Tor applications like Tor Browser, OnionShare,
and others already pre-installed. Tor Project also provides financial
support for Tails development [46].
Tails is designed to be a portable, live operating system. The operating
system can be installed on DVD, USB, or SD card from which
can quickly run. It can also run as a virtual machine but was initially
created to run as a live system, which is still recommended. It gives
the users the ability to run Tails on every computer and stay anonymous
even outside the home in a public place. It runs independently
of the host machine. Everything is uploaded only to the R A M , so it
does not leave any trace on the host SSD or H D D . When the system
shuts down, browser history, downloaded files, and everything that
has not been pre-installed are deleted, making it almost impossible to
track down the users. For the users, who would like to store some files
and settings, Tails comes with Encrypted Persistent Storage. Since the
system runs in a Live mode and always starts in the clean mode, Tails
is not recommended as a permanent operating system [47].
4.1 Encrypted Persistent Storage
Encrypted Persistent Storage allows users, which run Tails from the
USB Stick to store some data in the USB's free space to keep the data
persistent. A l l the stored data are encrypted by default, but not everything
can be stored. Users can configure the storage by using the tool
called Configure Persistent Volume, which can be found in Tails Tab
in the Applications list. The first step of persistent volume creation
is to set the password, which will be used to unlock the storage after
every boot. Tails will then create a persistent volume on the USB stick.
The USB stick must be at least 8 GB. After the persistent volume is
successfully created, the users can specify the features, which will be
stored in it.
When the configuration is finished, it is necessary to reboot the
system. Until the reboot, nothing will change. After it, Tails starts
with Welcome to Tails as usual, but now with to option to unlock the
17
4. TAILS OS
Encrypted Persistent Storage with the chosen password. All data of the
selected features of the Persistent Storage are automatically available.
Personal data can be stored in a directory called Persistent. When the
system is started without the unlocked storage, it starts without this
directory in the clean mode without any saved configuration. Not only
files, but the additional applications can be stored and are installed
every time Tails starts. Every pre-installed application in Tails is tested
for security, and the additional applications could be a security threat.
Network Connections, Browser Bookmarks, Printer Settings, and many
others can be stored in the Encrypted Persistent Storage.
It is highly recommended not to store any sensitive data in persistent
storage, as anyone can steal the USB stick and hack into the Tails
because the storage is visible to anyone who gains access to the USB
stick. It can even be opened in another operating system.
When one feature is turned off, data is no longer available but is still
stored in the Encrypted Persistent Storage. It is necessary to navigate
to I live I persistence/ TailsData" _" unlocked with nautilus command
execute with root rights and delete a specific folder of the feature.
To delete everything stored in the Persistent Storage, Tails also
comes with a Delete Persistent Volume tool. It is necessary to keep
the storage locked after the boot. Storage can not be deleted when
it is unlocked. Current data recovery techniques can recover files
even from a deleted Persistent Storage. It is a security threat, so it is
recommended to format the USB stick for a complete cleanup [48,49].
4.2 Applications
As a proper Operating system, Tails comes with the most necessary
applications already pre-installed. A l l the applications are tested for
security, and the system provides application isolation for some applications
with App Armor.
Tor Browser with HTTPS Everywhere, No Script, New identity, and
other features is the Tails' default browser. Besides, to protect the data
and the system from the attacks against Tor Browser, Tails confined
the Tor Browser with App Armor, which allows the Tor Browser to
write to and read-only from a limited number of folders [50].
18
4- TAILS OS
For communication, Tails includes Pidgin Instant Messenger. Pidgin
is an open-source chat program that allows users to connect to
multiple different chat networks and have more accounts connected
at once. Currently, for security reasons, only IRC and XMPP protocols
can be used in Tails. Pidgin contains a list of plug-ins. One of the
plug-ins is Off-The-Record Messaging, which provides encryption,
authentication, deniability, and perfect forward secrecy. It all allows
users to have a private conversation over instant messaging [51].
As a default email-client, Tails uses Thunderbird, which comes preinstalled.
Thunderbird has built-in support of OpenPGP and S/MIME,
which are encryption standards. Besides, in Tails, it is configured for
additional anonymity and privacy. Only secure protocols are allowed.
Insecure protocols are disabled. From the emails' header are removed
the information that could identify a Tails users. A l l the technologies
that could be used for trackings, like Javascript or cookies, are
disabled [52].
Same as Whonix, Tails uses KeePassXC as its default password
manager.
Additionally, all the applications available for Debian can be easily
installed on Tails.
4.3 Features
Tails comes with several features that support privacy and encryption.
Tails does not provide any data encryption, except Encrypted Persistent
Storage. However, Tails comes with GnuPG, an open implementation
of OpenPGP, and provides document encryption. Tails
also includes OpenPGP Applet, which allows manipulating text using
OpenPGP. It can use the passphrase encryption of OpenPGP to encrypt
text with a passphrase. Applet can also use OpenPGP's public key
encryption, allowing users to encrypt text and decrypt encrypted text.
Users can also sign text with OpenPGP and verify such a text. It is recommended
not to type any confidential text directly into the browser,
but encrypt the text written to a text application using OpenPGP
Applet and paste the encrypted text into the browser [53, 54].
The system comes with LUKS, which is the standard method for
encryption of Linux hard disk. VeraCrypt, another disk encryption
19
4. TAILS OS
tool, is also supported. Both LUKS and VeraCrypt are used to create
an encrypted partition, but VeraCrypt works not only on Linux but
also on Windows and macOS. It is recommended to encrypt all the
files for Tails and Linux with LUKS and files, which are supposed to
be shared across different operating systems with VeraCrypt [55].
Tails does not provide any metadata cleaning, but it comes with
MAT, which is similar to MAT2, and also contains PDF Redact Tools,
which is used to strip and redact metadata from the documents.
Tails does not do any keystroke anonymization, but Gnome's
screen keyboard can be used for protection against keyloggers.
4.4 Tests
Even though Tails can also run inside the virtual machine, it is created
to run as a live system from a USB stick, and that is how it is tested.
The system launches fast, the same as every standard operating
system, but it mostly depends on the host machine. Since the system
erases all the settings after it shuts, it must always be connected to
the Internet. It takes approximately one minute to start the Tor after
the network connection is established. Overall, it takes maximally
4 minutes till the system is ready for use.
The system is based on Debian, which is by itself a user-friendly
operating system, and Tails does not change anything. A l l the preinstalled
applications are wisely separated into blocks and all launch
without any delay.
The default browser, Tor browser, works without any complications.
Everything downloaded via Tor Browser must be saved to the
Tor Browser folder. The files have to be copied to this folder before
uploading them via Tor Browser.
Pidgin Instant Messenger comes with a user-friendly interface,
which allows users to start conversations quickly. It is translated almost
into ninety languages, so even people who do not speak English can
use it without any restrictions.
Mozilla Thunderbird, the mail application in Tails, is also straightforward
and easy to use. The users need to access their email, and
Thunderbird contains an assistant that guides the users to access it
20
4- TAILS O S
when starting. Thunderbird in Tails comes with many security utilities,
which were already described.
Lynis security scan details:
: 62 ############ ]
: 234
: 0
Components:
- F i r e w a l l [V]
- Malware scanner [X]
Scan mode:
Normal [V] Forensics [ ] I n t e g r a t i o n [ ] Pentest [ ]
Lynis modules:
- Compliance status [?]
- Security audit [V]
V u l n e r a b i l i t y scan [V]
Files:
- Test and debug information : /war/log/lynis.log
- Report data : /uar/log/lynis-report.dat
Figure 4.1: Lynis in Tails
21
5 Kodachi Linux
Kodachi Linux is a free operating system designed to be secure, anonymous,
and anti-forensic. The system is based on Xubuntu 18.04.5,
which is a Ubuntu derivative. The difference is that Ubuntu uses
Gnome as its desktop environment, but Xubuntu uses customized
Xfce. Hence the name, Ubuntu + Xfce. A n IT company calls Eagle
Eye Digital Solutions is developing it. The company is based in Oman
and focuses on preserving computer anonymity and privacy. There
are three ways to use Kodachi. The developer's first and most recommended
way is to boot up the Kodachi's ISO file using a virtual
machine inside the host machine. The developer recommends using
VMware. By default, the system runs in a live mode, ensuring that
all the memory is wiped down after every shutdown. However, the
system can also be installed inside the virtual machine, which will
allow the users to store the files. The second option is to have the ISO
file burned on a USB stick, DVD, or SD card and run it in live mode.
Even though everything is deleted when the system shuts down, some
files can also be saved across different sessions and do not have to wipe
completely. Kodachi offers to create persistent storage on USB, which
can be encrypted or unencrypted. The last option is to install Kodachi
on the hard drive of the host PC. Installation can be done from the
desktop of running Kodachi in a live mode, where are two installation
files available. One provides online installation and the second offline
installation. Both of the installations allow the users to install Kodachi
anytime. The offline installation installs all the packages, which are
verified with PGP, from an ISO file. The online installation installs everything
from the Internet. Another option for how to install Kodachi
on the hardware is to install it from the boot menu. The primary purpose
of Kodachi was to be an anti-forensic operating system. So with
the installation, it loses its main purpose, and it is not anti-forensic
anymore. It is only recommended to use it as a live system. However,
even installed Kodachi can be secured. It has to be installed as encrypted,
and the main OS has to be encrypted as well if it is installed
inside the virtual machine [22].
22
5. KODACHI LINUX
5.1 Applications
Even though Kodachi was created to be an anti-forensic and live system,
it can also be used daily A l l the applications like media players,
video and audio editing applications, image viewers, all Libre office
applications, text editors, and many others are pre-installed.
The default web browser is the Kodachi Browser, which is a standard
Firefox enhanced to perform better. The Kodachi browser comes
in three versions. The first is for people who care about privacy but
are not paranoid. It has several plug-ins, and when it launches, it
automatically uses the host V P N IP.
The second option, also called Loaded Kodachi Browser, is more
secure and has more plug-ins and configurations. After the launch, it
automatically connects through Tor and uses the Tor IP.
The third one, Kodachi Ghacks Browser, is the most secure. It is
similar to the previous one, but with advanced Ghacks scripting. Most
of the visited sites are broken and might look like a mess because
Javascript is disabled. The system also comes with Tor Browser and
Sphere Tor Browser, a secure browser protected with a password.
However, the users can also use the default Firefox, which is an unsafe
browser.
Kodachi comes with a few instant messengers pre-installed. Session
Messenger is the one most recommended by the developer because
of its high security. Nevertheless, users can choose from secure
messengers like Element, Signal, Wire, Pidgin, CoylM, or Bettegram.
The system does not automatically change the M A C address. It is
so because some network cards lose their connection when their M A C
address changes. Nevertheless, Kodachi comes with a tool to change
the M A C address manually. Kodachi does not provide any metadata
cleaning, but it comes with MAT, Metadata Anonymization Toolkit
like MAT2.
It is recommended to use multiple layers of encryption. That is why
Kodachi comes with more encryption utilities, VeraCrypt, ZuluCrypt,
and SiriKali. For the users who do not want to use V P N or Tor but
connect to the internet service providerdirectly, Kodachi comes with a
tool calls Noisy Crawler. Noisy Crawler generates HTTP/DNS traffic
noise that looks like more people are browsing the web from the
system. Internet service providerwould see queries of websites that
23
5. KODACHI LINUX
the users did not visit. Since the users do not use any V P N or Tor, the
destination IP is leaked. However, it makes the data less valuable for
extra obscurity and selling.
Kodachi includes two filesharing tools. The first one, OnionShare,
was already described in the section 1.1.2 at the page 4. The second
one, which does not rely on the Tor network, calls Syncthing. It runs
inside the web browser, so it automatically launches the web browser
with the Syncthing web page after the start. The system also comes
with KeePassXC and Password and Keys pre-installed. Both of the
applications are password managers.
On the desktop are shown information about CPU, disks, V P N ,
Tor, or Security score. Security score shows how the system is secure.
The system comes with a Security Evaluation tool, which helps the
users reach the maximum score of 100 [56, 57].
5.2 Features
Kodachi is pre-configured to use V P N , Tor, and DNScrypt to ensure
privacy and anonymity.
It also uses AppArmor for application security When the system
starts, Kodachi's VPN, which Kodachi's developer pays, automatically
starts. He does not want any user to misuse his V P N bandwidth by
downloading huge files like movies or torrent files, killing the VPN's
bandwidth. That is why the users can get banned from using it. The
banned users need to write an email to the developer and ask him for
an unban. To download any stuff without getting banned, the users
have to use another VPN. Kodachi comes with another free VPN, V P N
Gate, but it is recommended to use Kodachi's V P N , which is more
secure. Users can also use Mullvad, NordVPN, Proton, HideMe, or
other paid VPNs, which are pre-configured or set up their VPN, which
is simple in Kodachi.
The system allows users to stop the VPN. However, when the V P N
runs, the users can ensure that the traffic is forced through the V P N .
Kodachi comes with two scripts called Force Traffic via VPN, ensuring
that all the Internet traffic is blocked when the V P N connection is
lost. No packet is allowed to leave the machine when some of the
predefined attributes are changed. The first option checks only one
24
5. KODACHI LINUX
attribute, the IP. The second one also stops the connection when port,
interface, or protocol are changed. These scripts do not allow any
connections without a V P N , so the real IP will never leak.
Tor also starts automatically after the system's start. Tor can be
enabled even without the VPN, but it is not recommended. The users
can also torify the entire system, ensuring that no packet leaves the
system without entering the TOR network. The system can run only a
torified shell, without the whole system being torified. The users can
specify one exit node country from the predefined countries or let the
system randomly select the exit node country.
With V P N and Tor, Kodachi automatically launches DNScrypt,
which is secure and very fast. Another encrypted option is Tor DNS,
which is much slower but, on the other hand, much more secure
because it is decentralized. Even though DNScrypt is centralized, the
developer predefined several properly tested nodes in the config file.
One of the nodes is always randomly picked to prevent the IP leak.
Kodachi also allows other DNS providers like Open Nic, Mullvad, or
Nord DNS, and the users can also set up their DNS.
5.3 Tests
Kodachi can be used in more options. The live mode is the most
recommended, so tests are provided in Kodachi running in a virtual
machine as a live system.
The system can be used from the first start without any additional
settings. The virtual machine takes only a few minutes to start, it depends
on the host. Same as Whonix, Kodachi is automatically connected
to the Internet if the host is connected. VPN, Tor, and DNScrypt
start automatically but can be turned off or changed using predefined
scripts that handle each change with a single click.
Kodachi runs smoothly and takes only a few seconds to launch
every application. A l l applications are reasonably divided into tool
blocks like Web browsers, Tor tools, System apps, or Security apps.
All browsers start fast. The ones that work with Tor are slower than
those without Tor, but it all depends on the internet service provider. If
it is fast, then all the browsers in Kodachi are also fast enough. All three
versions of the default Kodachi Browser come with many security add-
25
5- KODACHI LINUX
ons and bookmarks with many websites for security check, DNS check,
or proxies, making the browsers even more user-friendly
By the developer, Session Messenger is the most recommended
messenger but currently does not work. A l l other seven messengers
launch pretty fast and are globally commonly used, which is why they
are pre-installed in Kodachi. It is needed to create an account to use
them, which is straightforward, as the messengers are user-friendly
and overall simple to use.
Mozilla Thunderbird is the only one mail application in Kodachi.
It is installed in default settings, but the users can easily add any
extensions like EnigMail, which adds OpenPGP authentication and
message encryption to Thunderbird. Thunderbird is globally used
and has a user-friendly interface, intuitive even for common users
with low IT skills.
Lynis security scan details:
Hardening index : 69 [tmmmmmt ]
Tests performed : 265
Plugins enabled : 2
Components:
- Firewall [V]
- Malware scanner [V]
Scan mode:
Normal [V] Forensies I ] Integration [ ] Pentest [ ]
Lynis modules:
- Compliance status [7]
- Security audit [V]
- V u l n e r a b i l i t y scan [V]
Files:
- Test and debug information : /var/log/lynis.log
- Report data : /var/log/lynis- report.dat
Figure 5.1: Lynis in Kodachi
26
6 Comparison
All three operating systems are designed for the same, anonymity and
privacy, but each achieves it differently
Table 6.1: Overall properties
Whonix Tails Kodachi
General
purpose
Persistent sys-
tem
Live system Live system
Based on Debian Debian XUbuntu
Default
Desktop
Xfce Gnome Xfce
Persistence Yes Yes, but it is
not recom-
mended
Yes, but it is
not recom-
mended
Live mode Yes Yes Yes
Lynis -
Hardening
Index
68 62 69
hline Documen-
tation
Extensive
wiki
Extensive doc-
umentation
on the website
Small documentation
on
the website
Usability User-friendly
interface and
easy to use for
everyone
User-friendly
interface and
easy to use for
everyone
User-friendly
interface, but
it is harder to
use for people
without
knowledge of
Linux
Whonix was created to run in a persistent mode and can also run
as a live system and has an isolated Workstation from the Gateway
for the best security. On the other site, Kodachi and Tails were created
to run as live systems, and they do not come with isolation. However,
27
6. COMPARISON
Kodachi can be installed, and in Tails, Encrypted Persistent Storage
allows users to store the files. None of this is recommended.
Whonix has an extensive wiki page where everything about this
system is described in detail. It contains complete manuals even for
more advanced settings. Tails also offers significant documentation
that helps users set up the Encrypted Persistent Storage, or create an
email account. However, Kodachi has only small documentation on
the main website, which only describes how the system works and
how users can increase its security.
All three systems come with a user-friendly interface, which helps
users to achieve the highest anonymity and privacy on the Internet.
However, Kodachi includes many more applications, and only with
small documentation, it can be hard to use for the users with a little
Linux knowledge. Whonix and Tails are straightforward, with not too
many applications and much better documentation.
Table 6.2: Features
Whonix Tails Kodachi
Tor starts
automatically
Yes Yes Yes
Built-in VPN No No Yes
Encrypted
DNS
Tor DNS Tor DNS DNScrypt, Tor
DNS
Stream
Isolation
Yes Yes No
AppArmor Yes Yes Yes
Keystroke
Anonymization
Yes No No
Some of the features have all the systems similar. Tor starts automatically
when the system connects to the Internet, and all the traffic
is forced through the Tor. Nevertheless, Kodachi also comes with another
anonymous network, I2P. The users can switch between Tor
and I2P, even though Tor is the recommended one. V P N is set up by
default only in Kodachi. However, Whonix and Tails both have small
documentation of how VPNs can be set up. Even though keyloggers
28
6. COMPARISON
are becoming still a more significant threat, only Whonix provides
Keystroke Anonymization. None of the systems require any other
settings and can be used straight after it launches.
Table 6.3: Applications
Whonix Tails Kodachi
Default
Browser
Tor Browser Tor Browser Kodachi
Browser
Pre-installed
Email client
None ThunderBird ThunderBird
Pre-installed
Instant
messenger
HexChat,
qTox
Pidgin Session and 7
other applica-
tions
Pre-installed
Cryptocur-
rency
wallet
Monero GUI
and Electrum
Electrum Electrum
Whonix and Tails come with a wide selection of pre-installed applications.
However, Kodachi comes with many more applications
than Whonix or Tails. It includes more than one application for almost
every application type, as the developer wants to satisfy everyone.
Not all the applications in Kodachi come with the best security.
29
7 Conclusion
The thesis aimed to provide a survey of the operating systems for
anonymity and privacy There is no single way to design such a system.
Every system can be built on different Linux distribution, use
a different anonymity network. It depends on the users what they
prefer. Some users might prefer anonymity and privacy over usability,
and others might need the system to be user-friendly and easy to use,
although it may not be as secure.
The most commonly used anonymity network is Tor, and several
operating systems are based on it. Some of the operating systems do
not use and do not recommend using any VPN. However, others come
with V P N built-in, as their developers believe it increases anonymity
and privacy.
Although there are many operating systems for anonymity and privacy,
as described in the second chapter, not all are regularly updated,
and some have not been updated for more than a year. However, three
in detail described operating systems are being regularly updated and
currently belong to the most used systems for such intent.
There is no one best operating system for everybody, whereas
every system is useful for different people and situations. Whonix is
designed to run mainly as a persistent system in a virtual machine. It
is simple to run this system. However, the host machine needs to be
started first, which might take some time. On the other hand, Tails and
Kodachi are designed to run as live systems. Tails from USB, C D , or
SD card, and Kodachi also in a virtual machine. Tails useful for people
who want to use operating system for anonymity and privacy in some
public place, as it boots fast and does not leave any traces on the
host machine. Kodachi works the same, although it launches slower
because it contains many more applications. Nevertheless, Kodachi
can also be installed on the hard disk and used as a persistent operating
system. From these three operating systems, Kodachi is the one with
the most possibilities of use but is also the hardest to use, as it has
many features and applications but almost no documentation.
30
Bibliography
1. GRITZALIS, Stefanos. Enhancing web privacy and anonymity
in the digital era. Information Management & Computer Security.
2004.
2. BORST, Karl Joseph; B R A U N D , Stephen. Website with activities
triggered by clickable ads. Google Patents, 2011. US Patent A p p .
12/893,430.
3. M E N D E L , Toby; PUDDEPHATT, Andrew; WAGNER, Ben;
HAWTIN, Dixie; TORRES, Natalia. Global survey on Internet
privacy andfreedom of expression. UNESCO, 2012.
4. KRAIJAK, Surapon; T U W A N U T , Panwit. A survey on internet
of things architecture, protocols, possible applications, security,
privacy, real-world implementation and future trends. In: 2025
IEEE 16th International Conference on Communication Technology
(ICCT). 2015, pp. 26-31.
5. G U N A W A N , Teddy Surya; LIM, Muhammad Kassim; ZULKURNAIN,
Nurul Fariza; KARTIWI, Mira. On the Review and Setup
of Security Audit Using Kali Linux. Indonesian Journal of Electrical
Engineering and Computer Science. 2018, vol. 11, no. 1, pp. 51-59.
6. KUIPERS, David; FABRO, Mark. Control systems cyber security: Defense
in depth strategies. 2006. Tech. rep. Idaho National Laboratory
(INL).
7. V O N HÄGEN, William. Through the Web, Darkly: Privacy,
Anonymity, and the Dark Web. Pittsburg: William Von Hägen, 2019.
ISBN 978-0-578-56194-3.
8. SYVERSON, Paul; DINGLEDINE, Roger; M A T H E W S O N , Nick.
Tor: The secondgeneration onion router. In: Usenix Security. 2004,
pp. 303-320.
9. H U A N G , Hsiao-Ying; BASHIR, Masooda. The onion router: Understanding
a privacy enhancing technology community. Proceedings
of the Association for Information Science and Technology.
2016, vol. 53, no. 1, pp. 1-10.
31
BIBLIOGRAPHY
10. Tor [online]. The Tor Project, 2014/2020 [visited on 2020-12-27].
Available from: https : //2019 . www . torproject. org/about/
overview.html.en.
11. JADOON, Abid Khan; IQBAL, Waseem; A M J A D , Muhammad
Faisal; A F Z A L , Hammad; B A N G A S H , Yawar Abbas. Forensic
analysis of Tor browser: a case study for privacy and anonymity
on the web. Forensic science international. 2019, vol. 299, pp. 59-73.
12. Tor Browser [online]. The Tor Project, 2014/2020 [visited on 2020-
12-27]. Available from: https : //tb-manual .torproject. org/
about/.
13. HASSAN, Nihad A ; HIJAZI, Rami. Online Anonymity. In: Digital
Privacy and Security Using Windows. Springer, 2017, pp. 123-194.
14. K I R A N , Kumar; C H A L K E , Saurabh S; U S M A N , Mohammad;
SHENOY, PraDeepa; V E N U G O P A L , KR. Anonymity and Performance
Analysis of Stream Isolation in Tor Network. In: 2019
10th International Conference on Computing, Communication and
Networking Technologies (ICCCNT). 2019, pp. 1-6.
15. GRUENBACHER, Andreas; ARNOLD, Seth. AppArmor Technical
Documentation. 2007.
16. KILLOURHY, Kevin S; M A X I O N , Roy A . Comparing anomalydetection
algorithms for keystroke dynamics. In: 2009IEEE/IFIP
International Conference on Dependable Systems & Networks. 2009,
pp. 125-134.
17. MIGDAL, Denis; ROSENBERGER, Christophe. Keystroke Dynamics
Anonymization System. In: ICETE (2). 2019, pp. 448-
455.
18. MONACO, John V; TAPPERT, Charles C. Obfuscating keystroke
time intervals to avoid identification and impersonation. arXiv
preprint arXiv:1609.07612. 2016.
19. Z E N G , Marcia Lei. Metadata. Neal-Schuman Publishers, Inc.,
2008.
20. Tails [online]. Tails, 2011/2020 [visited on 2020-12-01]. Available
from: https: //tails. bourn. org/index. en. html.
32
BIBLIOGRAPHY
21. Whonix [online]. Whonix, 2011/2020 [visited on 2020-11-01].
Available from: https: //www. whonix. org/wiki/Main_Page.
22. Kodachi [online]. Warith A l Maawali, 2013/2020 [visited on 2020-
12-15]. Available from: https : / /www . digi77 . com / linux -
kodachi/.
23. Parrot OS [online]. Parrot Security, 2013/2020 [visited on 2020-
10-20]. Available from: https : //www. parrotsec. org/.
24. Subgraph OS [online]. Subgraph, 2014/2020 [visited on 2020-10-
20]. Available from: https: //subgraph. com/.
25. Ipredia OS [online]. Ipredia, 2015/2020 [visited on 2020-10-20].
Available from: https: //www. ipredia. org/.
26. Mofolinux [online]. Mofolinux, 2015/2020 [visited on 2020-10-20].
Available from: https: //mofolinux. com.
27. BILGE, Leyla; DUMITRA§, Tudor. Before we knew it: an empirical
study of zero-day attacks in the real world. In: Proceedings of
the 2012 ACM conference on Computer and communications security.
2012, pp. 833-844.
28. Heads OS [online]. Heads, 2013/2020 [visited on 2020-10-20].
Available from: https: //heads. dyne. org/.
29. Robolinux [online]. John Martinson, 2013/2020 [visited on 2020-
10-20]. Available from: https : //robolinux. org/about .html.
30. KickSecure [online]. Whonix, 2013/2020 [visited on 2020-11-05].
Available from: https: //www. whonix. org/wiki/Kicksecure.
31. Whonix and Tor [online]. Whonix, 2013/2020 [visited on 2020-11-
06]. Available from: https : //www . whonix . org/wiki/Whonix_
and_Tor.
32. Whonix - Stream Isolation [online]. Whonix, 2013/2020 [visited on
2020-11-08]. Available from: https : //www. whonix . org/wiki/
Stream_Isolation.
33. Whonix - Other Operating Systems [online]. Whonix, 2013/2020
[visited on 2020-11-07]. Available from: https : //www. whonix.
org/wiki/0ther_0perating_Systems.
33
BIBLIOGRAPHY
34. Whonix - Gateway [online]. Whonix, 2013/2020 [visited on 2020-
11-07]. Available from: https://www.whonix.org/wiki/Whonix-
Gateway.
35. Whonix - Tor Controller [online]. Whonix, 2013/2020 [visited on
2020-11-07]. Available from: https : //www. whonix . org/wiki/
Tor_Controller#Arm.
36. Whonix - Anon Connection Wizard [online]. Whonix, 2013/2020
[visited on 2020-11-07]. Available from: https : //www. whonix.
org/wiki/Anon_Connection_Wizard.
37. Whonix - WhonixCheck [online]. Whonix, 2013/2020 [visited on
2020-11-07]. Available from: https : //www. whonix . org/wiki/
Whonixcheck.
38. Whonix - Gateway firewall [online]. Whonix, 2013/2020 [visited
on 2020-11-07]. Available from: https : //www. whonix. org/wiki/
Whonix-Gateway_Firewall.
39. Whonix - Workstation [online]. Whonix, 2013/2020 [visited on
2020-11-07]. Available from: https : //www. whonix . org/wiki/
Whonix-Workstation.
40. Whonix - Instant Messenger Chat [online]. Whonix, 2013/2020
[visited on 2020-11-06]. Available from: https : //www. whonix.
org/wiki/Chat.
41. Whonix - Software [online]. Whonix, 2013/2020 [visited on
2020-11-08]. Available from: https : //www. whonix . org/wiki/
Software.
42. VOISIN, Julien; G U Y E U X , Christophe; BAHI, Jacques M . The
metadata anonymization toolkit. arXiv preprint arXiv:1212.3648.
2012.
43. Whonix - Live Mode [online]. Whonix, 2013/2020 [visited on 2020-
11-06]. Available from: https : / /www . whonix . org/wiki/VM_
Live_Mode.
44. Whonix - Dev/TimeSync [online]. Whonix, 2013/2020 [visited on
2020-11-06]. Available from: https : //www. whonix . org/wiki/
Dev/TimeSync.
34
BIBLIOGRAPHY
45. Tails - Kernel hardening [online]. Tails, 2011/2020 [visited on 2020-
12-09]. Available from: https : //tails .bourn, org/contribute/
design/kernel_hardening/.
46. Tails - Tor [online]. Tails, 2011/2020 [visited on 2020-12-09]. Available
from: https : //tails . bourn . org/doc/about/tor/index .
en. html.
47. Tails - How it works [online]. Tails, 2011/2020 [visited on 2020-
12-09]. Available from: https: //tails .bourn, org/about/index.
en. html.
48. Tails - Persistence [online]. Tails, 2011/2020 [visited on 2020-12-
09]. Available from: https : //tails . bourn . org/contribute/
design/persistence/.
49. Tails - Encrypted Persistence Storage [online]. Tails, 2011/2020 [visited
on 2020-12-09]. Available from: https : //tails . bourn. org/
doc/f irst_steps/persistence/conf igure/index.en.html.
50. Tails - Tor Browser [online]. Tails, 2011/2020 [visited on 2020-12-
10]. Available from: https ://tails .boum.org/doc/anonymous_
internet/Tor_Browser/index.en.html.
51. Pidgin [online]. Pidgin, 2011/2020 [visited on 2020-12-10]. Available
from: https: //www. pidgin. im/.
52. Tails - Thunderbird [online]. Tails, 2011/2020 [visited on 2020-12-
11]. Available from: https ://tails .boum.org/doc/anonymous_
internet/thunderbird/index.en.html.
53. WINTER, Brenno de; M O L L A R D , Michael Fischer v. Gnu Privacy
Guard (GnuPG) Mini Howto. retrieved from the Internet:
http://www. gnupg. org/documentation/howtos. en. html, version 0.1.
2003, vol. 4.
54. Tails - OpenPGP Applet [online]. Tails, 2011/2020 [visited on
2020-12-11]. Available from: https : //tails . bourn . org/doc/
encryption_and_privacy/gpgapplet/index.en.html.
55. Tails - LUKS [online]. Tails, 2011/2020 [visited on 2020-12-12].
Available from: https : //tails . bourn . org/doc/encryption_
and_privacy/encrypted_volumes/index.en.html.
35
BIBLIOGRAPHY
56. Interview by the Russian OSINT and Linux Kodach 7.1 Walk through
- E16 [online]. Tech and Crypto Vibes, 2020-07-10 [visited on
2020-12-15]. Available from: https : //www.youtube. com/watch?
v=dVVqiuWxdjs&ab_channel=TechandCryptoVibes.
57. Linux Kodachi 4.0 security OS x Full walk around and how to install
it - E13 [online]. Tech and Crypto Vibes, 2018-10-05 [visited on
2020-12-16]. Available from: https : //www.youtube. com/watch?
v=tZiHljmN3WE&ab_channel=TechandCryptoVibes.
36