Integrated photonic cryptographic key generator using low-power MEMS-on-PIC technology

To improve data security and authentication, we designed and fabricated a cryptographic key generator based on a photonic integrated circuit that converts a digital input key into a digital output key by means of a physical unclonable function (PUF). The PUF is realized by an imperfect multi-mode interferometer controlled by low-power micro-electromechanical system (MEMS) phase shifters. An analytical model was derived and used to prove the randomness of the generated digital keys, and the model was validated by measurements of a first proof-of-concept demonstrator. The demonstrator was fabricated using a silicon nitride photonic integrated circuit (PIC) platform and our recently developed MEMS-on-PIC technology.