Achieving secure mobile transactions for wearables

ST's development ecosystem helps product designers integrate support for payment, ticketing, digital access and loyalty-card applications within wearable form factors, using the device's main MCU with a hardware secure element providing strong protection against malicious attacks.

The ecosystem provides everything developers need to start building their applications on a host such as an STM32 MCU, choosing from proven secure-element devices in ST's portfolio, and adding optional NFC antenna-booster technology by ams, a leading provider of high-performance analog ICs and sensors. The ams technology allows the use of ultra-small NFC antennas, which are suitable for wearables and has already been used successfully in the mobile-payment reference design co-developed and announced by ST and ams in early 2015.

"Hardware-secured payments can make wearables even more attractive to a broader range of end users, helping both the wearables and the mobile-payments markets grow quickly to their full potential," said Laurent Degauque, Secure MCU Division Marketing Director, STMicroelectronics. "Our ecosystem provides everything needed to achieve full hardware and software integration, helping bring new products to market quickly and ensuring the highest levels of security leveraging our proven secure-element ICs."

The new ecosystem provides a choice of expansion boards containing either ST's ST31 secure MCU or the ST54 System-in-Package (SiP) comprising a secure MCU and an NFC controller, a removable NFC antenna and a complete set of software building blocks. An ST31-based design is suitable for VIP banking applications such as smart bands that support credit-card functionality, while the ST54 can support OEM NFC-payment devices.

Both expansion boards offer the widely available Arduino connector and are compatible with the STM32 Nucleo MCU-development environment, as well as the wide range of X-Nucleo boards that simplify adding functionality such as a Bluetooth module or fingerprint recognition. Both devices meet NFC standards, and have EMVCo (Europay, Mastercard, Visa) and CC-EAL5+ (Common Criteria Level 5+) security certifications.

The software blocks included with the Software Development Kit (SDK) provide everything needed to manage the secure element, maintain BLE connectivity, I²C, SPI, and USB connections and handle control, configuration and firmware updates of the NFC controller. A BLE Application Program Interface (API) is also provided that uses the STM32 BLE software stack to enable connection of an e-wallet application on a remote device, such as a smartphone, to the secure payment application.

In addition, the kit includes an NFC stack optimised to ensure real-time performance and make best use of MCU resources including minimising RAM and Flash footprint. The stack is provided as an executable code for STM32 MCUs featuring the ARMCortex-M cores, giving developers a choice of devices across a broad range of performance, price, package options, features and power consumption.

All of the devices supported by the SDK are in full production and readily available through ST sales channels, or from ams in the case of the antenna-booster ICs.