A Spintronics Memory PUF for Resilience Against Cloning Counterfeit

With the widespread use of electronic devices in embedding or processing sensitive information, new hardware security primitives have emerged to improve the shortcomings of traditional secure data storage. One of these solutions, the physically unclonable function (PUF), which is widely used for authentication and cryptography applications, extracts the unique and unclonable value from the circuit physical properties. However, a cloning attack on memory-based PUF has been demonstrated from the circuit back-side tampering, questioning its unclonable property and opening counterfeiting vulnerability in an untrusted supply chain. Spin transfer torque-magnetic random-access memory (STT-MRAM) is a promising technology due to its nonvolatility, scalability, and CMOS compatibility, therefore envisioned to be used in many embedded secure devices. In this paper, we reveal the vulnerability of existing STT-MRAM PUF solutions to back-side attacks by modeling different levels of tampering and their impact at electrical and logical levels. We propose a tamper resilient methodology for the STT-MRAM PUF design based on its switching properties. The resilience of the proposed solution to different levels of tampering and a 100% detection are confirmed with simulation results.