A highly stable R-Diode-based physical unclonable function

This paper describes a new silicon physical unclonable function (PUF) using R-Diode sensors that can be fabricated on a standard CMOS process. Our proposed design is built using R-Diode sensors, differential amplifier, a comparator, voting mechanism and diffusion algorithm circuit. Multiple identical R-Diode sensors are fabricated on the same chip. Due to manufacturing process variations, each sensor produces slightly different bias values that can be compared in order to create a digital identification (ID) for the chip. Diffusion algorithm circuit ensures further that the proposed PUF is able to effectively identify a population of ICs. We also improve the stability of our design with respect to temporary environmental variations like temperature and supply voltage with the introduction of differential amplifier and voting mechanism. The R-Diode-based PUF is fabricated in 0.18μm CMOS technology. Experimental results show that the proposed PUF has a good output statistical characteristic of uniform distribution and a high stability of 96.2% with respect to temperature variation from -40 C to 100 C, and supply voltage variation from 1.7V to 1.9V.