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The bootloader is a critical part of a device's secure startup, and its interactions with firmware images require cryptographic operations. Instead of storing keys for authentication and encryption in the bootloader, one can harden the system by offloading the key storage and all cryptographic operations to a secure element. This paper analyzes the susceptibility of MCUboot used in conjunction with a secure element to voltage fault injection during firmware image verification. We designed and built a low-cost voltage fault injection tool using a Cortex-M7 MCU and an analog switch, which can achieve a timing resolution of 6.67 ns. We found vulnerable instructions in the glue code between the bootloader and the secure element library. By targeting these vulnerable instructions, we showed how an attacker could bypass a signature verification performed by a secure element by faulting a Nordic nRF52840 host MCU. While secure elements are still suited for securely storing keys and other sensitive data, a holistic approach is required to secure a device against fault injection. Otherwise, the threat of fault injection could diminish the benefits of secure bootloaders and secure elements.

Today's security solutions for IoT applications remain static in an ever-changing environment, making applications insecure and vulnerable to ever-growing cyber threats. The static solutions make credential life-cycle management difficult and lack proper protection of APIs. Overall, they weaken the security of not only the IoT devices but all components involved. A more dynamic approach to the security of IoT applications is required. IoThentix has developed a token-based approach to device authentication that not only allows IoT devices to access protected APIs according to state-of-the-art standards but also enables dynamic management of device credentials. As a result, it significantly improves the credential life-cycle management and the security of the entire IoT application.

Memory corruption is still the most used type of exploit in today’s malware landscape. Human error inevitably introduces memory vulnerabilities into software by using memory-unsafe languages like C and C++, affecting not only security but also safety, dependability, and even basic functionality of devices. The Rust language guarantees memory safety without a garbage collector, promises comparable performance to C/C++, and allows for gradual extension of existing codebases by using its foreign function interface. This report presents the risks of having memory vulnerabilities in embedded applications, what a switch to Rust looks like, how the development experiences differ between Rust and C/C++, and if there are significant differences in performance.

This research was funded by Renesas Electronics Europe GmbH., IoT is an increasingly tempting target for attackers due to its exponential growth. Besides pure software vulnerabilities (like weak or hardcoded passwords, insecure data transfer and storage), the OWASP IoT Top Ten lists hardware-related vulnerabilities such as the lack of physical hardening and the omission of a secure update mechanism. Mitigating these challenges requires additional hardware, as many of these devices are physically exposed and thus at a higher risk than conventional IT devices. More types of hardware solutions that implement the required functionality are entering the market; however, there are few to no performance comparisons. This lack further hinders the adoption of adequate solutions on a per-project basis. This white paper compares the performance of Renesas RX72N's on-chip security engine to secure elements that connect to the host MCU over a serial bus.