A low power and compact physical unclonable function based on the cascode current mirrors

In this paper, we present a novel on-chip physical unclonable function (PUF) based on the cascode current mirrors. It exploits the process variation of a single transistor as the load of the current mirror to generate a reliable digital signature for the chip. By employing a cascode NMOS transistor in the current-mode PUF architecture, the proposed PUF greatly boosts the output impedance. As a result, the tiny mismatch current can be amplified to a large output voltage swing. In addition, the area overhead per bit is only two minimum-sized NMOS transistors: one for the load of the current mirror, the other one for the selecting switch. Moreover, the proposed PUF design is validated by our extensive post-layout simulation using UMC 65nm CMOS technology, with a power consumption per bit as low as 0.13μW. The average area for each response bit extracted from the design layout is 5.47μm2.