Research on ARM TrustZone

Abstract

ARM TrustZone [1] is a hardware-based security feature that can provide software with a high-privilege and isolated execution environment. Such isolation is ensured by hardware, which is usually considered as more trustworthy than software. Thus the execution environment is also known as trusted execution environment (TEE). TrustZone technology was proposed in 2002, but did not get widely used until 2009, when Apple released iPhone 5s. In iPhone 5s, Apple leveraged TrustZone to protect its Touch ID, which ensures that even if the iOS is fully compromised, the user's fingerprint data can still be safe. In 2017, Google made TEE a mandatory requirement on any Android devices with a fingerprint scanner. Nowadays, almost all mobile phones and tablets have TEE deployed. Meanwhile, ARM integrates TrustZone in ARM64 and ARMv8-M to support a broader range of platforms including servers and IoT devices.