Random oscillation characteristics of single transistor-based oscillator and its application to a physical unclonable function

Abstract

Based on a single-transistor latch (STL) phenomenon, the oscillation characteristics of the single transistor based-oscillator operation by storing and releasing charges in the floating body are confirmed. The variation of oscillation characteristics according to process variation between devices, which is not intended but inevitably occurred in the identical fabrication process as one batch, is investigated. By quantitatively evaluating the uniformity, uniqueness, and reliability of oscillation characteristics measured in a number of transistors, application to physical unclonable function (PUF) is proposed. Additionally, functions for improving security level in the face of a hacking attempt is proposed by temporarily or permanently deleting the encryption key. The PUF based on a single transistor can significantly reduce power consumption, area, and cost compared to the PUF based on a conventional ring oscillator, making it more commensurate with the security of internet-of-things (IoT) devices.