A Novel Thyristor-Based Silicon Physical Unclonable Function

Abstract

This paper describes a new silicon physical unclonable function (PUF) using thyristor components that can be fabricated on a standard CMOS process. Our proposed design is built using thyristor-based sensors, time difference amplifier (TDA), time difference comparator, voting mechanism, and diffusion algorithm circuit. Multiple identical thyristor-based sensors are fabricated on the same chip. Due to the manufacturing process variations, each sensor produces two slightly different delay values that can be compared in order to create a digital identification for the chip. Diffusion algorithm circuit further ensures that the proposed PUF is able to effectively identify a population of integrated circuits. We also improve the stability of PUF design with respect to temporary environmental variations, such as temperature and supply voltage with the introduction of TDA and voting mechanism. The thyristor-based PUF is fabricated in a 0.18- $\mu \text{m}$ CMOS technology. Experimental results show that the PUF has a good output statistical characteristic of a uniform distribution and a high stability of 96.8% with respect to temperature variation from −40 °C to 100 °C, and supply voltage variation from 1.7 to 1.9 V.