Finite-State-Machine inspired Hardware Watermark using Spin-Orbit Torque operated MTJ

The globalization of the Integrated Circuits (ICs) supply chain has increased threats from untrusted entities involved in the process. Various threats, such as the insertion of hardware Trojans, counterfeiting, cloning, overproduction, etc., have emerged as a potential challenge in the ICs supply chain. Several mechanisms are widely used to ensure hardware security, like logic locking, watermarking, split manufacturing, etc. In this work, we propose a different approach to designing a Finite State Machine (FSM) inspired hardware-based watermarks using the unique physical characteristic of spin-orbit torque-based Magnetic Tunnel Junction (MTJ). Watermarks are helpful to authenticate proof of ownership and are a widely acclaimed strategy against the counterfeiting of chips. We discuss the design strategy involved in detail, the strategy to use the VLSI CAD tool to harness the unique ability of MTJ, such as non-volatility and dependence on an external magnetic field for guiding the information through a specific sequence of states in an FSM. Furthermore, the performance prospects are analyzed using Monte-Carlo simulations, and security aspects are described to ensure a more robust and practical application.