IoT boot integrity measuring and reporting

Abstract

The current era can be characterized by the massive reliance on computing platforms in almost all domains, such as manufacturing, defense, healthcare, government. However, with the increased productivity, flexibility, and effectiveness that computers provide, comes the vulnerability to cyber-attacks where software, or even firmware, gets subtly modified by a hacker. The integration of a Trusted Platform Module (TPM) opts to tackle this issue by aiding in the detection of unauthorized modifications so that devices get remediation as needed. Nonetheless, the use of a TPM is impractical for resource-constrained devices due to power, space and cost limitations. With the recent proliferation of miniaturized devices along with the push towards the Internet-of Things (IoT) there is a need for a lightweight and practical alternative to the TPM. This paper proposes a cost-effective solution that incorporates modest amounts of integrated roots-of-trust logic and supports attestation of the integrity of the device's boot-up state. Our solution leverages crypto-acceleration modules found on many microprocessor and microcontroller based IoT devices nowadays, and introduces little additional overhead. The basic concepts have been validated through implementation on an SoC with an FPGA and a hard microcontroller. We report the validation results and highlight the involved tradeoffs.