Privacy and security are pressing concerns for all of us these days – not a day goes by that we aren’t bombarded with security news headlines about hacks, breaches and the increased storing and monitoring of sensitive personal information by governments and corporations.
Luckily, when it comes to security, Linux users are faring better than their Windows- or Mac- using counterparts. Linux offers inherent security advantages over proprietary operating systems due to the transparency of its open-source code and the constant, thorough review that this code undergoes by a vibrant global community. While transparent source code may at first seem like a privacy nightmare, it is actually the complete opposite. As a result of the “many eyes” that Linux has on its code at all times, security vulnerabilities are identified and remedied very rapidly. In contrast, with proprietary OSes like Windows or MacOS, source code is hidden from outsiders - in other words, users are dependent upon Microsoft or Apple to find, fix and disclose vulnerabilities. Linux is also a relatively unpopular target for malicious hackers due to its small user base.
While all Linux “distros” - or distributed versions of Linux software - are secure by design, certain distros go above and beyond when it comes to protecting users’ privacy and security. We’ve put together a list of our favorite exceptionally-secure Linux distros and spoken with some of their lead developers to find out first-hand what makes these distros so great. This article aims to help you evaluate your options and select the distro that best meets your individual needs.
Why Choose A Specialized Secure Linux Distro?
While moving from a proprietary OS to a regular Linux distro such as Ubuntu, Fedora or Debian can significantly boost your privacy online, there is also a wide selection of specialized Linux distros available for users with serious privacy needs such as pentesters and ethical hackers whose work requires that they conceal their identity online. All of these “secure Linux distros” have an intense focus on providing users with maximum security, privacy and anonymity online, and many of them incorporate Tor technologies and offer an impressive selection of hacking, pentesting and digital forensics tools. As you can imagine, these characteristics and resources are invaluable when assessing the security infrastructure of an organization or conducting a security audit.
Each distro offers a unique set of features and benefits designed to meet users’ varying requirements and priorities. However, these benefits come with some tradeoffs. The most popular operating systems and programs typically have the weakest privacy protections but also are compatible with the majority of websites and offer the most support. While certain secure Linux distros are relatively mainstream and user-friendly, others have a steep learning curve, especially for less tech-savvy users.
Our Top 7 Linux Distros for Security, Privacy and Anonymity
Qubes OS is an ideal choice for users looking to mitigate risk by compartmentalizing their digital life. A key feature of this operating system is the confinement of high-risk applications to separate virtual machines. Multiple virtual machines - or “Qubes” - are used to organize and separate systems around ‘work’, ‘personal’, ‘Internet’ and so on. These Qubes, which are conveniently color-coded to help users differentiate them, are highly secure and can offer privacy advocates peace of mind in an increasingly invasive digital environment. As a result of this compartmentalization, if you happen to download malware to your work machine, your personal files won’t be affected and vice versa.
Integration of various Qubes is provided by the Application Viewer, which creates an illusion for the user that all system applications execute natively on the desktop - when in reality they are hosted in isolation in separate Qubes. The Dom0 domain manager, which manages the virtuals disks of all other VMs, is isolated from the network to prevent attacks originating from an infected VM.
In a conversation with the LinuxSecurity editors, Qubes OS Community Manager Andrew David Wong elaborated, “Rather than attempting to fix all of the security bugs in software, Qubes assumes that all software is buggy and compartmentalizes it accordingly, so that when flaws are inevitably exploited, the damage is contained and the user's most valuable data is protected." Its “Security by Isolation” approach using containers - aka “Qubes” - eliminates the concern of compromised programs.
What Makes Qubes OS So Great:
- Its “Security by Isolation” approach using containers - aka “Qubes” - eliminates the concern of compromised programs.
- All of these Qubes are integrated into one common desktop environment and color-coded to help users stay organized.
- Sandboxing protects system components.
- Qubes OS offers full-disk encryption for maximum file protection.
Tails uses the Tor network, a network heralded for its privacy and anonymity benefits, to keep users safe online. All connections run through this network - concealing users’ location and other private information. Tails comes with a secure browser, a secure email client and other secure Internet tools. Tails is the most well-known privacy-focused distro, and a popular choice among less tech-savvy security enthusiasts.
A Tails Project contributor explains, “With Tails, anybody can turn any computer into a secure environment free from malware and capable of circumventing censorship.”
On top of the privacy and anti-censorship properties of Tor, Tails empowers users worldwide by developing and distributing an integrated and secure operating system that protects users from most surveillance and censorship threats by default. The distro provides a level of security that individual applications are unable to achieve because they ultimately depend on the safety of the underlying operating system.
What Makes Tails So Great:
- Its tight integration with the Tor network ensures anonymity online.
- The included web browser is pre-configured for maximum security and includes add-ons like NoScript, Ublock Origin, and HTTPS Everywhere.
- Users get access to Onion Circuits, a valuable tool that allows them to view how their PC traverses through the Tor network.
- Tails comes with the Aircrack-NG wireless network auditing tool.
- The OS is encrypted and designed to run with full functionality on a USB drive.
- The distro features a built-in Bitcoin wallet ideal for users looking to make secure cryptocurrency transactions.
Kali Linux is an industry standard pentesting distro. It is one of the most popular distros among pentesters, ethical hackers and security researchers worldwide and contains hundreds of tools.
A Kali Linux contributor provides some insight into the distro’s history and the benefits it offers users: “Named after a Hindu goddess, Kali has been around for a long time – but it’s still updated weekly, can be run in live mode or installed to a drive, and can also be used on ARM devices like Raspberry Pi.”
What Makes Kali Linux So Great?
- Kali Linux uses LUKS full-disk encryption to protect sensitive pentesting data from loss, tampering and theft.
- This flexible distro offers full customization with live-build.
- Users can automate and customize their Kali Linux installations over the network.
- “Forensics” mode makes this distro perfect for forensics work.
- There’s a Kaili Linux training suite available called Kali Linux Dojo, where users can learn how to customize their own Kali ISO and learn the basics of pentesting. All of these resources are available on Kali’s website, free of charge. Kali Linux also boasts a paid-for pentesting course that can be taken online, with a 24-hour certification exam. Once you pass this exam, you’re a qualified pentester!
Parrot OS can be seen as a fully-portable laboratory for a wide range of cyber security operations from pentesting to reverse engineering and digital forensics - but this Debian-based distro also includes everything you need to secure your data and develop your own software.
Parrot OS is frequently updated and provides users with a wide selection of hardening and sandboxing options. The distro’s tools are designed to be compatible with the majority of devices via containerization technologies such as Docker or Podman. Parrot OS is very lightweight and runs surprisingly fast on all machines - making it a great option for systems with old hardware or limited resources.
What Makes Parrot OS So Great?
- The distro provides pentesters and digital forensics experts with the best of both worlds - a state-of-the-art “laboratory” with a full suite of tools accompanied by standard privacy and security features.
- Applications that run on Parrot OS are fully sandboxed and protected.
- Parrot OS is fast, lightweight and compatible with most devices.
This popular pentesting distro hails from Arch Linux, and contains over 2,000 different hacking tools - allowing you to use whatever you need without having to download new tools. BlackArch Linux offers frequent updates, and can be run from a USB stick or CD or installed on your computer.
BlackArch Linux is similar to both Kali Linux and Parrot OS in that it can be burned to an ISO and run as a live system, but is unique in that it does not provide a desktop environment. However, this up-and-coming distro does offer a large selection of preconfigured Window Managers.
What Makes BlackArch Linux So Great?
- BlackArch Linux offers a large selection of hacking tools and preconfigured Window Managers.
- The distro provides an installer with the ability to build from source.
- Users can install tools either individually or in groups with the modular package feature.
Sometimes using a live OS can be inconvenient – you have to restart your machine each time you want to use it, which is tedious and time-consuming. By installing an OS on your HD; however, you run the risk of the OS being compromised. Whonix offers a solution to this predicament – it’s a virtual machine that works inside the free program Virtualbox and aims to provide security, privacy and anonymity on the Internet.
This Debian-based distro operates in two parts – the first part, known as the Gateway, routes all connections to the Tor network. The second part, referred to as the Workstation, runs user applications and can directly communicate only with the Gateway. The Workstation VM can only “see” IP addresses on the Internal LAN, which are identical in every Whonix installation. Therefore, user applications have no knowledge of the user’s real IP address, nor do they have access to any information about the physical hardware of the machine that the OS is running on. This split design allows the user to remain completely anonymous and mitigates the risk of DNS leaks, which reveal private information such as your web browsing history.
Whonix has recently added an amnesic live mode that “forgets” user’ activities - not leaving traces on disk. The distro is currently working to create a unified desktop experience. Whonix developer Patrick Schleizer explains, “Our upcoming Whonix-Host extends many of our usability and hardening features to the entire desktop.”
Whonix encourages users to provide feedback on their experience, and sincerely appreciates donations and contributions to support the project’s ongoing efforts.
What Makes Whonix So Great?
- Whonix comes with the Tor Browser and the Tox privacy instant messenger application - ensuring fully-anonymous web browsing and instant messaging.
- The OS employs an innovative Host/Guest design to conceal users’ identity behind the anonymous proxy and prevent IP and DNS leaks.
- The distro features pre-setup Mozilla Thunderbird PGP email.
- Linux Kernel Runtime Guard (LKRG), a kernel module that performs runtime integrity checking of the Linux kernel to detect security vulnerabilities and exploits, can be easily installed on Whonix.
Openwall GNU/*/Linux (Owl)
Openwall GNU/*/Linux (or Owl for short) is a small security-enhanced distro for servers with Linux and GNU software at its core, currently used only as a research model for what the basis of a secure distribution should look like. Owl is part of the Openwall Project, which currently offers a selection of active projects and services. Openwall was effectively founded in 1996 (but under its current name in 1999) by renowned Russian security developer Alexander Peslyak, better known as Solar Designer, who is famous for his research and publications on exploitation and computer security protection techniques.
To ensure maximum security, Owl combines several approaches to reduce the number and/or impact of vulnerabilities in its software components and the impact of flaws in third-party software that a user may install. The primary approach is proactive, thorough source code review for multiple classes of security vulnerabilities. Other key approaches are consistent application of the least privilege principle and introduction of privilege separation. Owl also used strong cryptography within its core components, unlike many other distros at the time, and includes security policy enforcement through proactive password checking, network address-based access control, and integrity checking, among other valuable capabilities.
A distinctive characteristic of Owl is that the distro has no user-accessible SUID binaries, yet is fully functional. Owl was also one of the first distros to offer container virtualization out of the box, using OpenVZ.
We’ve included Owl in this article despite the fact that the distro is currently on hold because of the important role that Owl has played in the open-source security community since its inception. That being said, new users should be cautious in selecting Owl and other distros no longer being developed unless they are viewing it as an educational opportunity or intend to borrow code and/or ideas from the project.
We believe there’s still room in the security community for another distro like Owl that can be used as a basis for building secure systems using tools originating from the Openwall Project including John the Ripper, Linux Kernel Runtime Guard, and several password hashing techniques.
What Makes Owl So Great?
- Owl provided compatibility with the majority of Linux/GNU distros at the time, and could be viewed as a solid base for building a system.
- The distro provided a complete-build environment capable of re-building an entire system with only one simple command - “make buildworld”.
- Proactive review of source code defends against multiple classes of security vulnerabilities.
- The distro consistently applies the least privilege principle and privilege separation.
- Owl’s central components are protected with strong cryptography.
- Security policies are enforced with proactive password checking, network address-based access control, integrity checking and other capabilities.
- Owl offers container virtualization out of the box.
- The distro is fully functional, despite having no user-accessible SUID binaries.
Read more about the concepts behind Openwall.
Thanks to Solar Designer for correcting several key issues with the Openwall GNU/*/Linux (Owl) section of an earlier version of this article.
The Bottom Line
It is apparent that Linux offers a wide variety of distro options for pentesters, software developers, security researchers and users with a heightened concern for their security and privacy online. Choosing the best Linux distro for your own privacy needs is a balancing act - each disto offers a different balance of privacy vs. convenience.
Based on your specific requirements and concerns, it is likely that one (or many!) of the distros profiled above could be a great fit for you - offering the tools and capabilities you are looking for in a distro as well as the peace-of-mind that your system is secure and your privacy is protected in this rapidly-evolving modern digital threat landscape.
Have additional questions? Leave a comment below and a security expert will be in touch with you shortly!
Stay tuned for our next feature article which will cover our top tips for securing your Linux system!