How Secure Are RISC-V Chips? - Semiconductor Engineering

Abstract

The security of RISC-V chips is highly dependent on implementation quality and specific architecture extensions rather than being monolithic, posing unique verification and trust challenges due to its open and customizable nature. The ecosystem must focus heavily on establishing standardized hardware security features, such as robust roots of trust and sophisticated memory protection mechanisms, to manage risks associated with supply chain dispersal and design fragmentation. Ensuring widespread adoption requires rigorous application of formal verification methodologies and defined security profiles to achieve parity with established proprietary architectures in sensitive applications.

Report

Key Highlights

• Implementation Dependency: Unlike proprietary architectures where security features are standardized, RISC-V security is highly variable and depends entirely on the quality and robustness of the specific core implemented by the vendor.
• Customization Risk: The key strength of RISC-V—extensibility—is also a primary security concern, as custom instruction set extensions can introduce vulnerabilities or significantly complicate formal verification efforts.
• Hardware Root of Trust (HRoT): Establishing a standardized, verifiable, and secure HRoT across the diverse RISC-V implementation landscape is critical but challenging for ensuring boot integrity and establishing trust.
• Supply Chain Scrutiny: The open-source nature requires heightened scrutiny regarding the integrity of IP blocks used, necessitating methods to detect hardware Trojans and ensure a trustworthy digital supply chain.

Technical Details

• Physical Memory Protection (PMP): PMP is a fundamental security mechanism in RISC-V, used extensively to define access rights, isolate trusted execution environments, and segment critical memory regions from less privileged code.
• Privilege Levels: The RISC-V standard utilizes three main privilege modes (Machine Mode - M, Supervisor Mode - S, and User Mode - U) to enforce strong separation and control access to sensitive resources and registers.
• Security Extensions: Specific standard or custom extensions (e.g., cryptographic instruction sets, scalar cryptography extensions, or secure enclaves) must be integrated and verified to handle secure key management and high-speed cryptographic operations.
• Formal Verification Methods: Due to the complexity introduced by custom instructions, rigorous formal methods are necessary to mathematically prove the correctness and absence of security flaws (like Spectre or Meltdown vulnerabilities) at the register-transfer level (RTL).

Implications

• Market Adoption: The confidence in RISC-V security will directly dictate its adoption rate in sensitive markets such as automotive (ISO 26262), defense, and industrial control systems, which require the highest levels of functional safety and security assurance.
• Ecosystem Fragmentation: If security implementations remain too fragmented, it risks creating a complex compliance landscape, potentially hindering software portability and increasing integration costs for security-conscious developers.
• Verification Tooling Demand: The industry requires the rapid development of sophisticated, automated verification and security analysis tools specifically designed to handle the variable and modular nature of RISC-V core designs.
• Transparency as a Strength: The open ISA offers an inherent security benefit—the ability to fully audit the core—which provides greater assurance than proprietary ISAs, provided the necessary audit infrastructure and expertise are developed within the ecosystem.