Detection of Layout-Level Trojans by Monitoring Substrate with Preexisting Built-in Sensors

The mass production of secure circuits demands nowadays new testing methods able to detect the possible existence of hardware Trojans, which might be even a slight layout alteration. This paper proposes a new method for the detection of Trojans by exploiting preexisting current sensors that are originally built in system's subcircuits as online-testing devices for detecting radiation- or laser-induced transient currents. In the proposed method, the sensor operates as an offline-testing mechanism to provide digital signatures of the subcircuit's substrate after injection of current pulses into MOSFET body terminals. Simulation results considering process variations demonstrate the effectiveness of the method on detecting gate- and layout-level Trojans.