Minimizing a Smartphone’s TCB for Security-Critical Programs with Exclusively-Used, Physically-Isolated, Statically-Partitioned Hardware

Zhihao Yao, Seyed Mohammadjavad Seyed Talebi, Mingyi Chen, Ardalan Amiri Sani, Thomas Anderson

Project

• We present a split-trust hardware design composed of statically-partitioned, physically-isolated trust domains. We introduce a few simple, formally-verified hardware components to enable a program to gain provably exclusive and simultaneous access to both computation and I/O on a temporary basis. To manage this hardware, we present OctopOS, an OS composed of mutually distrustful subsystems. We present a prototype of this machine (hardware and OS) on a CPU-FPGA board and show that it incurs a small hardware cost compared to modern smartphone SoCs.