Firmware-based trusted platform module for arm® trustzone implementations

TL;DR: Firmware-Based Trusted Platform Modules (fTPMs) as discussed by the authors enable secure code execution without the use of dedicated security processor hardware or silicon without requiring hardware modifications to existing devices.

Abstract: A "Firmware-Based TPM" or "fTPM" ensures that secure code execution is isolated to prevent a wide variety of potential security breaches. Unlike a conventional hardware based Trusted Platform Module (TPM), isolation is achieved without the use of dedicated security processor hardware or silicon. In general, the fTPM is first instantiated in a pre-OS boot environment by reading the fTPM from system firmware or firmware accessible memory or storage and placed into read-only protected memory of the device. Once instantiated, the fTPM enables execution isolation for ensuring secure code execution. More specifically, the fTPM is placed into protected read-only memory to enable the device to use hardware such as the ARM® architecture's TrustZone™ extensions and security primitives (or similar processor architectures), and thus the devices based on such architectures, to provide secure execution isolation within a "firmware-based TPM" without requiring hardware modifications to existing devices.