  The Quantum Diamond Microscope (QDM) is an instrument with a demonstrated
capability to image electrical current in integrated circuits (ICs), which
shows promise for detection of hardware Trojans. The anomalous current activity
caused by hardware Trojans manifests through a magnetic field side channel that
can be imaged with the QDM, potentially allowing for detection and localization
of the effects of tampering. This paper seeks to identify the capabilities of
the QDM for hardware Trojan detection through the analysis of previous QDM work
as well as QDM physical limits and potential Trojan behaviors. QDM metrics of
interest are identified, such as spatial resolution, sensitivity,
time-to-result, and field-of-view. Rare event detection on an FPGA is
demonstrated with the QDM. The concept of operations is identified for QDM
utilization at different steps of IC development, noting necessary
considerations and limiting factors for use at different development stages.
Finally, the effects of hardware Trojans on IC current activity are estimated
and compared to QDM sensitivities to project QDM detection potential for ICs of
varying process sizes.
