STMicroelectronics is working with AWS and Microsoft to help STM32U5 enable more secure IoT development

STMicroelectronics is strengthening its collaboration with Amazon (AWS) and Microsoft to expand the Internet of Things. On AWS, ST provides a reference that makes it easier and more secure to connect IoT (Internet of Things) devices (STM32U5) to the AWS cloud. At the same time, STMicroelectronics is working with Microsoft to strengthen the security of emerging IoT applications.

Partner with AWS

The collaboration between ST and AWS combines ST's STM32U5 ultra-low-power microcontroller (MCU), the FreeRTOS open source real-time operating system, and Arm's Trusted Firmware for Embedded Systems (TF-M). The reference implementation is implemented on ST's B-U585I-IOT02A Discovery Kit, which is used for IoT nodes equipped with STM32U5 MCUs and contains rich features including USB, Wi-Fi and Bluetooth Low Energy (BLE) connections and multiple sensors. The addition of the STSAFE-A110 security element can support a more complete protection mechanism and is pre-installed with IoT credentials, which helps to protect and simplify the connection between connected objects and the AWS cloud.

FreeRTOS has kernel optimizations for resource-constrained embedded systems and software libraries for connecting various types of IoT endpoints to the AWS cloud or other edge devices. AWS's long-term support (LTS) will be maintained for two years on FreeRTOS versions, providing developers with a stable platform to deploy and maintain their IoT devices.

The Arm TF-M firmware simplifies the protection of embedded systems, including secure boot, secure storage, encryption and authentication services, forming the basis of a trusted execution environment (TEE) on the device. Designed for the Arm v8-M architecture, TF-M can be easily integrated with TrustZone on the ST STM32U5 MCU, which uses the Arm Cortex-M33 core.

Targeting demanding IoT edge applications, STMicroelectronics' STM32U5 MCU leverages the advanced 160-MHz Cortex-M33 core with Arm TrustZone technology and Armv8-M mainline security extensions, up to 2 MB of on-chip flash memory, and excellent power-saving features. With hardware cryptographic accelerators, secure firmware installation and updates, and high resistance to physical attacks, the MCU has been certified by PSA Certified Level-3 and SESIP 3.

In addition, its extremely energy-efficient design simplifies application powering and extends battery life. Highlights include three different stop modes that maximize low-power capabilities, and ST also offers a low-power background autonomous mode that captures peripheral data even when the core is powered off.

ST will release a reference implementation based on STM32Cube tools and software in collaboration with AWS in the third quarter of this year, which will further simplify IoT design and integrate seamlessly with the rest of the STM32 ecosystem.

Collaboration with Microsoft

In a separate partnership, STMicro and Microsoft have collaborated to launch the Microsoft Azure IoT Cloud Reference. The reference design integrates ST's ultra-low-power STM32U5 MCU with Microsoft Azure RTOS and IoT middleware and Arm TF-M services for embedded systems. The project produces an Arm TF-M-based Azure IoT Cloud reference implementation that leverages the enhanced security features of the STM32U5 and the enhanced key storage of the STSAFE-A110 secure element.

IoT device developers face tremendous time-to-market pressures while also meeting the highest levels of security industry standards. Hopefully, ST and Microsoft’s efforts will accelerate embedded development by improving security as well as power efficiency and performance.

Microsoft Azure RTOS provides a comprehensive middleware package optimized for resource-constrained connected applications such as IoT edge and nodes. It combines the compact footprint of the ThreadX RTOS with memory management and connectivity services, including NetX Duo IPv4/IPv6 and TLS secure socket support.

Like ST’s collaboration with AWS, the Arm TF-M kit provides trusted services such as secure boot, secure storage, encryption and attestation. Designed for Arm Cortex-M processors, the TF-M kit can be easily integrated with ST’s STM32U5 MCU.

Other security features of the STM32U5 include physical attack protection and Arm’s TrustZone architecture, which provides additional isolation for safety-critical resources. The STSAFE-A110 EAL5+ certified secure element brings a personalized authentication scheme and service that automatically and securely connects connected objects to Microsoft Azure, alleviating the historical burden of IoT device manufacturers to protect confidential credentials during product manufacturing.

ST will release a reference implementation integration based on STM32Cube in collaboration with Microsoft in the third quarter of 2022, which will further simplify the security design of IoT devices.