Minitee-a lightweight trustzone-assisted TEE for real-time systems

Abstract

While trusted execution environments (TEEs) provide industry standard security and isolation, TEE requests through secure monitor calls (SMCs) attribute to large time overhead and weakened temporal predictability. Moreover, as current available TEE solutions are designed for Linux and/or Android initially, it will encounter many constraints (e.g., driver libraries incompatible, large memory footprint, etc.) when integrating with low-end Real-Time Operating Systems, RTOSs. In this paper, we present MiniTEE to understand, evaluate and discuss the benefits and limitations when integrating TrustZone-assisted TEEs with RTOSs. We demonstrate how MiniTEE can be adequately exploited for meeting the real-time needs, while presenting a low performance overhead to the rich OSs (i.e., low-end RTOSs).