FPGA-based RO PUF with low overhead and high stability

Ring oscillator physical unclonable functions (RO PUF) promise cheap, efficient, and secure identification and authentication of the chip. However, RO PUF typically has high hardware overhead, and it is difficult to guarantee its stability due to the complex operating environment. In this Letter, the programmable delay lines were utilised to configure the ring oscillator to improve the performance of PUF on FPGA. The proposed structure generates a 16-bit reliable PUF response using only two slices. Experimental results show that the proposed PUF has low hardware overhead, and multiple measurements under a wide range of operating environments demonstrate that it is highly stable.