K.: The untapped potential of trusted execution environments on mobile devices

Nearly every smartphone, and even some feature phones, today contains a hardware-based trusted execution environment (TEE). Smartphones with TEEs first appeared almost a decade ago, but their use has been limited – application developers have not had the means to make use of TEEs to improve the security (and usability) of their applications. In this article, we discuss why TEEs are so widely deployed in mobile devices, and what kind of capabilities they support. We then describe Nokia Research Center’s On-board Credentials (ObC) system which opens up the device TEE to application developers and some example applications that make use of ObC. We conclude by briefly outlining recent developments in standardizing TEE functionality.