This project looks into a new side channel information that attackers can use to learn a computer chip design. This is important for advancing the science for understanding what vulnerabilities there are from this side channel. A new side-channel, which is called Terahertz-frequency (THz) backscattering, is the focus of this project. A computer system directly emanates virtually no THz-frequency signals. Instead, a THz signal is transmitted toward the desired part of the targeted system and is reflected back. The signal contains information about the activity in the targeted part of the system because the signal's reflection depends on the impedance of the material it reflects from, so the reflected signal is modulated by the switching state of any transistors that are in the target area (or connected to metal wires that are in the target area) of the incoming THz beam. The project will construct the first-ever measurement testbed for THz backscattering side-channels, use this testbed to evaluate the key properties of THz back-scattering from system boards, chip pins, and circuitry within a chip, and characterize the advantages and disadvantages of THz back-scattering for various use scenarios, e.g. as a "signature" of a specific chip, as a way of validating a chip's activity against a "known good" reference, as a potential threat (when used for side channel attacks), etc.
EAGER: Exploration of THz Backscattering as a Side-channel in Computer Systems