“Silicon photonic physical unclonable function,” by PhD student Brian Grubel and his team, Bryan Bosworth, Mike Kossey, Hongcheng Sun, and faculty members Amy Foster, Brint Cooper, and Mark Foster, was recently selected as an “Editor’s Pick,” by Optics Express (Vol. 25, No. 11 – 29 May 2017), a well-regarded, impactful journal that publishes original research of interest to the photonics community. “Editor’s Picks serve to highlight articles with excellent scientific quality and are representative of the work taking place in a specific field,” according to the journal’s Editorial Office.
The article describes a new type of silicon photonic “physical key” that stores private, random information within its physical structure, cannot be copied or duplicated and is not invertible. Brian’s work is based on ultrafast and nonlinear interactions within an integrated silicon photonic cavity roughly 30 microns in diameter. Such a cavity can imprint a unique signature on an incident optical wave while producing a highly complex and unpredictable yet deterministic response waveform that serves as the unique “fingerprint” of the cavity. Binary sequences extracted from such waveforms are unpredictable, robust, and entropically secure and are thus able to meet requirements for use in private key storage systems and various authentication applications while adding very little cost, space, or weight to the host system.