Physically unclonable function using RTN-induced delay fluctuation in ring oscillators

This paper proposes RTN-PUF, a novel PUF that utilizes random telegraph noise (RTN) of transistors as the physical uniqueness of individual devices. Our proposed RTN-PUF generates a response from a pair of ring oscillators (ROs) by comparing the numbers of frequency changes, which depend on the time constants of RTN. Due to the log-uniform distribution of the time constants, our RTN-PUF provides more stable responses than the existing manufacturing-variation-based PUFs. The numerical experiments show that the RTN-PUF reduces false negative errors by about 60 times compared to the conventional RO-based PUF. This facilitates to implement PUF into security purposes.