How Open Source instruction set architectures are transforming security
Many people know that Open Source software can improve security by using large communities to identify and fix weaknesses. However, people often forget about its capacity to develop hardware-based security solutions.
Open Source hardware security is poised for a transformative revolution, spearheaded by advancements in instruction set architectures (ISA) extensions. These innovations pave the way for a future where software-based malware and attack exploits are rendered ineffective, as enhanced hardware safeguards can deny malicious software the necessary permissions to execute.
Open Source is revitalizing long-standing hardware security practices
While hardware security remains back-of-mind for many (ok, most) IT teams, experts are well aware of hardware-based encryption that protects data on drives and networks, as well as standards like Trusted Platform Modules (TPM) and Secure Boot that protect devices at bootup. Over time, ISAs like x86 and Arm have been adding security extensions to protect Intel-based machines and portable devices, respectively.
While the ISA space has long been dominated by x86 and Arm, recent free and Open Source entrants are transforming the field. Released in 2015, the Open Source RISC-V ISA continues to garner interest for its flexibility and extensibility. RISC-V’s rapid rise in adoption is very much a function of its collaborative Open Source community.
Looking at even more recent developments in the ISA space, Capability Hardware Enhanced RISC Instructions (CHERI) is a fully Open Source project pioneering a new hardware security strategy: controlling memory access with hardware-enforced bounds and permissions while retaining compatibility with existing software. Led by the University of Cambridge and SRI International the team has developed CHERI variants of several ISAs, including CHERI Arm and CHERI RISC-V.
The project utilizes the CheriBSD OS, which adapts Open Source FreeBSD to support software compartmentalization, memory safeguards, and additional security protections enabled by CHERI ISAs. The Morello platform from Arm—the most advanced CHERI prototype to date—pairs CheriBSD with a high-performance core to provide the clearest demonstration yet of CHERI’s tremendous potential as a hardware-based security solution. The Morello platform offers a development board for research and prototyping, including a completely memory-safe desktop environment and application stack.
Partners of the Open Source CHERI project include contributors like Google and Microsoft, making it clear that big tech is invested in the potential of this approach to hardware-based security.
Shielding the digital fortress: Memory safety
Exploits that attack memory vulnerabilities have led to high-profile incidents. While some new system and application software is being written in other languages to avoid C/C++ memory vulnerabilities, rewriting the millions of lines of code in existing apps isn’t a realistic option.
The Open Source CHERI ISAs are exciting because they offer a simpler solution: make software immune to memory exploits and many software vulnerabilities by recompiling to target memory-safe hardware. In 2020, three security engineers from the Microsoft Security Response Center, Nicolas Joly, Saif ElSherei, and Saar Amar, published a security analysis of CHERI ISA titled “Security Analysis of CHERI ISA” that found with work and some reasonable functions “the number of deterministically mitigated vulnerabilities would be at least 67%.”
Open Source hardware and software: Synergy for unparalleled security
The fusion of Open Source hardware and software, exemplified by groundbreaking projects like CHERI and the FreeBSD-derived CheriBSD, underscores a pivotal shift toward bolstering application security. Capability-based security at the hardware level not only fortifies defenses against common vulnerabilities but also paves the way for a new era of robust, trustworthy computing environments. As Open Source hardware and software progressively merge with capability security, these elements play a crucial role in advancing the security landscape, promoting resilience, and enabling developers to build applications that effectively withstand evolving cyber threats. This intersection is not merely a technological evolution but a transformative journey toward a more secure and resilient digital future.
Photo by Kieran Wood on Unsplash
