LC-Physical Unclonable Function in Wireless 3D IC for Securing Internet of Things Devices

Abstract

The near-ubiquitous expansion of the Internet of Things (IoT) into more application domains has significantly improved the quality of life. However, the low-power, heterogeneous and resource-constrained nature of IoT devices makes incorporating security features extremely challenging. Conventional security measures, such as encryption, are infeasible for deployment under such constraints. 3D integrated circuits (3D ICs) include several heterogeneous layers in a stacked architecture in the chip layout and provide a promising paradigm for secure, heterogeneous 3D integration suitable for IoT devices. However, the disadvantage of 3D IC architectures is the interconnections between the layers, utilizing through-silicon vias (TSVs), which result in mechanical stress and create thermal management issues. A recent wireless 3D integration technique mitigates these issues by replacing TSVs and other inter-layer connections in 3D ICs with inductively coupled links (ICLs). Therefore, the resulting 3D IC architecture is cheap to manufacture and assemble, has a shorter design cycle, and is independent of the technology node. The coupling and information transmission between layers is through electromagnetic (EM) induction, making ICL 3D ICs vulnerable to EM probing side-channel attacks. This paper proposes a secure transmission method that uses the key generated by the process variation of the inductor coil in the ICL 3D IC to encrypt the information transmitted between the layers. Our proposed method protects against EM probe side-channel attacks since the attacker cannot decrypt the transmitted information without knowing the inherent process variation in the fabricated layers.