Defect dynamics in 2D van der Waals materials for hardware security

Abstract The accelerated progression of artificial intelligence and the Internet of Things has resulted in a substantial increase in demand for hardware-based security solutions, particularly for resource-constrained edge applications. Achieving the security mainly depends on the unpredictability of cryptographic keys, which are fundamentally generated by hardware security primitives, such as true random number generators (TRNGs) and physically unclonable functions (PUFs). However, these hardware security solutions currently rely on complementary metal-oxide-semiconductor processes, which are increasingly constrained by scaling limits and power inefficiencies. Two dimensional van der Waals (2D vdW) materials have been identified as a promising platform due to their atomic thickness, energy efficiency, and inherent stochastic behavior, which originates from defect dynamics processes. This review focuses on microscopic origins of randomness in 2D vdW materials, including electron trapping/detrapping and ion migration, that underlie phenomena such as random telegraph noise and variability in resistance switching. These stochastic phenomena are then exploited to implement TRNGs and PUFs. Recent research progress in the application of these hardware security primitives based on 2D vdW materials, including authentication, secure communications, image encryption, and privacy-preserving computing, is summarized. Challenges in this field and future research directions are also discussed.