Frequently Asked Questions
Glossary
What is a Root of Trust?
A Root of Trust (RoT) is the foundational security component within a computing system. It is a highly specialized, isolated piece of hardware that is implicitly trusted to always behave exactly as expected. Because it serves as the ultimate anchor for security, everything else in the system relies on it to verify what is safe.
Key functions of a Root of Trust:
- Secure Boot: It ensures that the operating system and firmware have not been tampered with before allowing the device to turn on.
- Cryptographic Operations: It safely generates, stores and uses encryption keys utilising the OpenTitan Big Number accelerator – a security hardened RISC-V like programmable coprocessor for asymmetric cryptographic algorithms.
- Identity Verification: It proves to networks and other devices that the hardware is authentic.
Note: lowRISC stewards OpenTitan, which is the world’s first commercial grade open-source silicon Root of Trust.
What is a secure enclave?
While a Root of Trust acts as a system’s foundational anchor (especially during boot-up), a secure enclave acts as a locked vault during everyday operation.
A secure enclave is a deeply isolated region within an SoC’s memory and execution space. It is designed to process highly sensitive information—such as biometric data (like fingerprints or FaceID), passwords, or digital wallets—completely separated from the main operating system.
Even if a hacker or malware fully compromises the main device, they cannot look inside the secure enclave or extract the data being processed there.
Note: lowRISC’s COSMIC project ultimately aims to produce a design based on OpenTitan and a CVA6-CHERI core that is a secure enclave.
What is a Hardware Security Module?
A Hardware Security Module (HSM) is a dedicated, highly tamper-resistant physical computing device or subsystem engineered specifically to protect and manage digital keys and perform cryptographic operations.
While secure enclaves and roots of trust are typically built into a system-on-a-chip, traditional HSMs are often standalone appliances, plug-in cards, or external USB devices used by enterprises. However, in modern silicon design, embedded HSMs are increasingly bringing these robust capabilities directly onto the microchip.
Key features of an HSM:
- Tamper-Resistance: They are physically designed to self-destruct or erase their data if someone tries to pry them open or tamper with them.
- Dedicated Processing: They handle heavy cryptographic workloads (like encrypting databases or processing financial transactions) without relying on the main computer’s CPU.
- High Assurance: They undergo rigorous third-party certifications (like FIPS 140) to prove their security to governments and financial institutions.
What is a Trusted Platform Module?
A TPM, or Trusted Platform Module, is a specific type of hardware-based Root of Trust that follows a strict international standard (ISO/IEC 11889) set by the Trusted Computing Group.
Typically found as a dedicated microchip on a computer’s motherboard or integrated directly into modern CPUs, a TPM is designed to secure hardware through integrated cryptographic keys. If you have ever been prompted that your PC requires “TPM 2.0” to upgrade to a modern operating system like Windows 11, this is the chip they are referring to.
Key functions of a TPM:
- Platform Integrity: It measures and records the software environment during the boot process to ensure the system hasn’t been altered by malware or unauthorized users.
- Hardware-Bound Keys: It generates cryptographic keys that cannot easily be moved or copied off the physical chip, ensuring the device cannot be easily impersonated.
- Disk Encryption: It works in tandem with full-disk encryption software (like BitLocker) to ensure the hard drive cannot be read if it is stolen and plugged into a different computer.
Note: That the OpenTitan design can act as a TPM.