Contactless module extends secure payment via NFC

STMicroelectronics offers a compact contactless module with boosted NFC technology, which extends secure payment to wearables.

According to STMicroelectronics, the ST53G system-in-package (SiP) combines the company’s expertise in near field communication (NFC) and secure-transaction chips.

As consumers become comfortable with making secure transactions using smart devices, traditional card manufacturers want to extend their offers into contactless wearable products for payments, ticketing, and access control. These can be difficult to implement within size and cost constraints, which are beyond that offered by conventionally separate NFC-radio and security chips, which demand extra space and complicate design. In addition, wearable form factors reduce the options to small antennae that can restrict communication performance.

ST’s ST53G SiP overcomes these barriers by combining a miniaturised and enhanced NFC radio with a secure banking chip in one compact 4.0 x 4.0mm module. The company claims that its proprietary boostedNFC technology allows wearables with small antennae to deliver a great user experience when interacting with card readers over typical contactless distances.

The all-in-one module helps card manufacturers to quickly introduce functional and attractive wearables that can range from fashion items to one-time devices like event wristbands. ST offers a development ecosystem, including radio-tuning tools and pre-defined antenna configurations. The ST53G meets all relevant card-industry standards, including EMVCo compliance, ISO/IEC-14443 NFC card emulation, and MIFARE ticketing specifications.

The ST53G completes ST’s range of SoCs and can host ready-to-use STPay smartcard operating systems and optional VISA/Mastercard/JCB-certified banking applications pre-loaded on the secure microcontroller.

Making secure transactions possible on wearables broadens consumer access to convenient, frictionless banking and ticketing. ST is working with customers to develop ST53G-based products and support.

The secure banking chip contained in the ST53G leverages ST’s ST31G480 secure microcontroller for high-performance smartcard applications, which is based on the Arm SC000 SecurCore processor. It features a secure architecture with a NESCRYPT co-processor for public-key cryptography and hardware accelerators for algorithms like AES and triple-DES. Anti-tamper protection includes an active shield, environmental monitoring, a serial number for each die, and built in protection against other attacks. These features complement software-based security running on the SC000 core to protect users’ credentials.

The contactless IC is the STS3922 RF booster, which uses active-load modulation (ALM) to maximise transaction range and omni-directional radio performance in card-emulation mode. This enables wearable devices to be easy to use, with equal or better device-to-reader positioning tolerance than conventional contactless smartcards, even though a smaller antenna is used. Using ST53G reduces device cost, as small antennae can be etched onto the PCB at almost zero additional cost, points out ST. In some cases, a challenging metallic case can itself be used as part of the RF antenna.

In addition, automatic power and gain control, configurable sensitivity, and configurable signal/reader-field phase difference ensure consistent communication over all ranges while enhancing interoperability with different types of readers and terminals including various types of transportation ticketing systems. The STS3922 has inherently low power consumption, and a dedicated secure-microcontroller wake-up output allows the ST53G SiP to maximise battery life by powering down when not in use.

The ST31G480 secure element is EMVCo and Common Criteria certified, and the STS3922 is ISO/IEC 14443 and EMVCo Level 1 compliant, ensuring full interoperability with existing payment and ticketing infrastructures.

In addition to radio-tuning tools, ST also provides software development kits (SDKs) for implementing card services on wearable-device architectures, as well as reference design, expansion boards, and pre-certification services to help simplify development and accelerate time to market.

Engineering samples of the ST53G SiP in the WFBGA64 package are available now. Full production is scheduled to start in Q1 2018.

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