Low-power, lightweight and reliability-enhanced current starved inverter based RO PUFs

Ring oscillator (RO) based physical uncloanble function (PUF) is an emerging hardware security primitive but its response is susceptible to changes in operating conditions. Current solutions either incur large hardware overhead or require sophisticated RO selection algorithms to increase its reliability. This is the first paper that exploits the temperature invariant biasing of three different types of current staved inverter for the design of RO PUFs with high temperature stability. The reliability is further improved by a simple proximity detector circuit and the generation of internal challenges is made more secure by an irregular clocking scheme for linear feedback shift register. The results show that the proposed method increases the reliability of regular inverter based RO PUF by more than 12% with only less than 9% of hardware overhead.