TzPy: Python Runtime for Edge Code Deployment on TrustZone

As edge devices continue to improve in performance, their role is expanding in real-world environments such as smart factories and smart homes, where executing server-provided code on edge devices is essential for real-time processing and operational flexibility. However, edge code deployment introduces several security challenges, including the exposure of sensitive data and operations to runtime attacks, the absence of remote attestation mechanisms to validate code integrity and execution correctness, and insufficient access control for sensitive peripherals. Existing solutions address only a subset of these challenges and therefore fail to provide comprehensive security guarantees for edge devices. In this paper, we present TzPy, a Python runtime designed for secure edge code deployment on ARM TrustZone. TzPy enables the execution of Python code entirely within the secure world. In addition, we design a remote attestation mechanism that verifies both the static integrity of deployed Python code and its runtime control flow through control-flow tracing. Furthermore, TzPy enforces a manifest-driven, fine-grained peripheral access control mechanism to prevent unauthorised or unintended access to sensitive devices. We evaluate TzPy on a Raspberry Pi 3B+ using a smart farm workload and a blinky application, and the results show an end-to-end overhead of 13.4%.