Comment on the TEE for the secure booting. It would be better to have below references.
- Arm¡¯s TrustZone technology offers an efficient, system-wide approach to security with hardware-enforced isolation built into the CPU.
- MultiZone Security is the first trusted execution environment for RISC-V created by Hex Five Security.
- The AMD Platform Security Processor (PSP), officially known as AMD Secure Technology, is a trusted execution environment subsystem incorporated into AMD microprocessors.
- Apple uses a dedicated processor called SEP (Secure Enclave Processor) for features like data protection, Touch ID, and Face ID. The SEP is responsible for handling keys and other information such as biometrics that is sensitive enough to not be handled by the application processor.
- Google also has a similar solution called Titan M, an external chip available on some Android Pixel devices to implement a TEE and handle features like secure boot, lock screen protection, disk encryption, etc.
For small embedded devices, it is more feasible to design a secure boot scheme based on TPM.