Silicon photonic physical unclonable function based on waveguide array embedded with phase shifters

Silicon photonic physical unclonable function (PUF) stands out as a promising hardware security primitive, offering the advantages of CMOS compatibility and a compact chip-scale footprint compared to other optical PUFs. It harnesses inherent fabrication variations arising during mass production to generate unique digital keys. In this paper, we experimentally demonstrate a silicon photonic PUF using an 8-channel waveguide array with embedded phase shifters, enabling the active generation of challenge-response pairs. Through testing six device copies fabricated on the same wafer, we achieve a false acceptance rate of 4.06 × 10^-21. Both challenge generation and response detection can be performed on-chip, leading to a stand-alone PUF on the silicon photonic platform.