Gray-box software integrity checking via side-channels

Abstract

Enforcing software integrity is a challenge in embedded systems which cannot employ modern protection mechanisms. In this paper, we explore feasibility of software integrity checking from measuring passive electromagnetic emissions of FPGA-implemented SoCs. We show that clock-cycle-accurate side-channel models can be built by utilizing gray-box analysis and regression techniques. The generality and effectiveness of our methods are shown by three different SoCs, profiled and tested on different chips of the same model. Our technique is non-invasive, and does not interrupt normal execution or change hardware/software configuration of the target device, making it particularly attractive for already-deployed systems.