# secureblue

> security-focused desktop and server Linux operating system

**Wikidata**: [Q131841087](https://www.wikidata.org/wiki/Q131841087)  
**Source**: https://4ort.xyz/entity/secureblue

## Summary
Secureblue is a security-focused Linux distribution designed for desktop and server use. Inspired by GrapheneOS, it emphasizes hardening and sandboxing through the use of technologies like Hardened malloc, SELinux, and Flatpak. The operating system is open-source, licensed under the Apache Software License 2.0, and reached its first stable release in March 2024.

## Key Facts
- **Classification:** Secureblue is an instance of a Linux distribution and a security-focused operating system.
- **Inspiration:** The project is inspired by GrapheneOS, a privacy and security-focused mobile operating system.
- **License:** The software is released under the Apache Software License 2.0.
- **Core Technologies:** It utilizes Hardened malloc, bubblewrap, Flatpak, just, Homebrew, Security-Enhanced Linux (SELinux), Network Time Security (NTS), and DNS over TLS.
- **Components:** The distribution includes "Trivalent" as a notable component or part.
- **Initial Release:** Version 1.0.0 (stable) was released on March 21, 2024.
- **Latest Listed Release:** Version 3.1.1 (stable) was released on August 21, 2024.
- **Website:** The project maintains an official website at secureblue.github.io and a domain at secureblue.dev.
- **Repository:** The source code is hosted on GitHub under the username `secureblue`.

## FAQs
### Q: What type of operating system is Secureblue?
A: Secureblue is a Linux distribution focused on security for both desktop and server environments. It classifies itself as a free software community project.

### Q: What security features does Secureblue use?
A: The operating system employs a suite of security tools including Hardened malloc for memory allocation, Security-Enhanced Linux (SELinux), and bubblewrap for sandboxing. It also enforces secure communication via DNS over TLS and Network Time Security.

### Q: When was the first stable version of Secureblue released?
A: The first stable version, v1.0.0, was released on March 21, 2024.

### Q: Where can Secureblue be downloaded?
A: Secureblue can be downloaded from its official installation page at https://secureblue.dev/install.

## Why It Matters
Secureblue represents a growing trend in the Linux ecosystem to prioritize security hardening beyond standard distribution defaults, extending concepts popularized by mobile security projects like GrapheneOS to the desktop and server. By integrating Hardened malloc—a memory allocator designed to mitigate heap corruption vulnerabilities—along with mandatory access controls via SELinux, Secureblue aims to provide a robust defense against common exploitation techniques.

The project matters for users and administrators who require high assurance environments but prefer a Linux-based workflow. Its rapid release cycle in 2024 (progressing from v1.0.0 to v3.1.1 within five months) indicates active development and responsiveness to security needs. The inclusion of modern sandboxing technologies like Flatpak and bubblewrap suggests a focus on containerized application isolation, which is increasingly critical for limiting the blast radius of compromised applications. As cyber threats become more sophisticated, distributions like Secureblue provide a necessary option for users seeking "security-first" defaults without having to manually configure complex hardening scripts.

## Notable For
- **GrapheneOS Inspiration:** Bringing the hardening philosophies of the mobile OS GrapheneOS to the Linux desktop/server ecosystem.
- **Hardened Memory Allocation:** Integrating Hardened malloc to prevent heap-based memory corruption exploits.
- **Rapid Development Cycle:** Releasing multiple major stable versions (v1.0 to v3.1) within a five-month span in 2024.
- **Secure Networking:** Enforcing Network Time Security (NTS) and DNS over TLS to prevent network-level time shifting and DNS spoofing attacks.
- **Trivalent:** Developing and utilizing the "Trivalent" component as a notable part of its architecture.

## Body
### Core Architecture and Security
Secureblue is built as a Linux distribution that emphasizes rigorous security hardening. It is inspired by GrapheneOS and incorporates similar defensive technologies. The system relies on **Hardened malloc** for secure dynamic memory allocation and **Security-Enhanced Linux (SELinux)** for enforcing mandatory access control policies.

To further isolate applications and system processes, Secureblue utilizes **bubblewrap** and **Flatpak**, the latter of which is sourced from the verified Flathub repository. The system also integrates **just** (a command runner) and **Homebrew** for package management tasks. Network security is addressed through the implementation of **Network Time Security (NTS)** and **DNS over TLS**, ensuring encrypted and authenticated time synchronization and DNS resolution.

### Release History
The project has maintained an active release schedule throughout 2024, establishing a stable baseline and quickly iterating on its feature set.

*   **v1.0.0:** Released March 21, 2024 (First stable version).
*   **v1.0.1:** Released March 30, 2024.
*   **v1.0.2:** Released April 7, 2024.
*   **v1.1.0:** Released April 10, 2024.
*   **v2.0.0:** Released April 23, 2024.
*   **v2.1.0:** Released May 23, 2024.
*   **v2.2.0:** Released June 1, 2024.
*   **v3.0.0:** Released July 29, 2024.
*   **v3.1.0:** Released August 20, 2024.
*   **v3.1.1:** Released August 21, 2024.

### Project Resources
Secureblue operates as a free software community project under the **Apache Software License 2.0**. The code is copyrighted, and the source repository is available on GitHub. Users can access the official FAQ in English, and the project accepts donations via an official page. A distinct component associated with the project is **Trivalent**.

## References

1. [Release 1.0.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v1.0.0)
2. [Release 1.0.1. 2024](https://github.com/secureblue/secureblue/releases/tag/v1.0.1)
3. [Release 1.0.2. 2024](https://github.com/secureblue/secureblue/releases/tag/v1.0.2)
4. [Release 1.1.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v1.1.0)
5. [Release 2.0.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v2.0.0)
6. [Release 2.1.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v2.1.0)
7. [Release 2.2.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v2.2.0)
8. [Release 3.0.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.0.0)
9. [Release 3.1.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.1.0)
10. [Release 3.1.1. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.1.1)
11. [Release 3.1.2. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.1.2)
12. [Release 3.1.3. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.1.3)
13. [Release 3.2. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.2)
14. [Release 3.2.1. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.2.1)
15. [Release 3.3. 2024](https://github.com/secureblue/secureblue/releases/tag/v3.3)
16. [Release 4.0.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v4.0.0)
17. [Release 4.1.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v4.1.0)
18. [Release 4.2.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v4.2.0)
19. [Release 4.3.0. 2024](https://github.com/secureblue/secureblue/releases/tag/v4.3.0)
20. [Release 4.4.0. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.4.0)
21. [Release 4.4.1. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.4.1)
22. [Release 4.4.2. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.4.2)
23. [Release 4.5. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.5)
24. [Release 4.5.1. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.5.1)
25. [Release 4.6. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.6)
26. [Release 4.6.1. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.6.1)
27. [Release 4.7. 2025](https://github.com/secureblue/secureblue/releases/tag/v4.7)
28. [Release 4.8. 2026](https://github.com/secureblue/secureblue/releases/tag/v4.8)
29. [Release 4.8.1. 2026](https://github.com/secureblue/secureblue/releases/tag/v4.8.1)
30. [Release 4.8.2. 2026](https://github.com/secureblue/secureblue/releases/tag/v4.8.2)