An Area and Energy-Efficient Spin-Driven Hardware Trojan for Pure Magnetic Logic Circuits

Today, new magnetic devices have found applications in the design of logic circuits due to their high speed, efficiency, non-volatility, and reduced energy consumption. For example, emerging logics such as m-Logic, mCell, and mGate, which are implemented using all-magnetic devices, exhibit significantly lower power consumption compared to CMOS circuits. Consequently, hardware Trojans designed for circuits based on magnetic devices have become critically important. This paper proposes a hardware Trojan based on Spin-Transfer Torque Magnetic Tunnel Junctions (STT-MTJ) with an external activator and discusses its integration into all-magnetic circuits. Our proposed Trojan is the first of its kind in the domain of all-magnetic circuits. In implementing this Trojan, minimal hardware resources have been utilized to ensure a compact area footprint. The activation of the proposed Trojan and its disruptive behavior are specifically designed to bypass logic lock-based security measures. Furthermore, HSPICE-based simulations were conducted to validate the correct operation and the destructive behavior of various circuits before and after Trojan activation.