Using Approximate Circuits Against Hardware Trojans

International audienceHardware Trojans (HTs) are malicious alterations in Integrated Circuits (ICs) that pose an important threat to safety-critical systems. Many techniques based on logic testing or side-channel analysis have been proposed in the literature aiming at detecting such malicious modifications in fabricated ICs. The detection of HTs is becoming more challenging with the shrinking of the technology and the impact of process variations. Therefore there is a need to neutralize the effect of HTs when the typical detection mechanism fails. In this work, we propose to tackle the effect of HTs by leveraging fault-tolerant techniques like Triple Modular Redundancy (TMR). More specifically, we propose to use an approximate TMR in order to neutralize the effects of HTs while saving area and increasing the complexity of inserting HTs. The efficiency of the proposed approach has been evaluated by using the ISCAS’85 benchmarks and stealthy ad-hoc HTs.