Physical Realization of a Hyper Unclonable Function

TL;DR

This paper introduces a reconfigurable photonic structure called Hyper PUF that can reversibly change its physical configuration, enabling multiple secure keys within one device and enhancing cryptographic security against quantum attacks.

Contribution

It presents a novel all-optical, reversible reconfiguration method for photonic PUFs, allowing multiple unclonable functions in a single device, advancing security and application scope.

Findings

Reversible all-optical reconfiguration of photonic structures achieved.

Enables multiple co-existing unclonable functions within one device.

Enhances security with complex, information-rich keys.

Abstract

Disordered photonic structures are promising materials for the realization of physical unclonable functions (PUF), physical objects that can overcome the limitations of conventional digital security methods and that enable cryptographic protocols immune against attacks by future quantum computers. One PUF limitation, so far, has been that their physical configuration is either fixed or can only be permanently modified, and hence allowing only one token per device. We show that it is possible to overcome this limitation by creating a reconfigurable structure made by light-transformable polymers, in which the physical structure of the unclonable function itself can be reversibly reconfigured. We term this novel concept Hyper PUF or HPUF in that it allows a large number of physical unclonable functions to co-exist simultaneously within one and the same device. The physical transformation of the structure is done all-optically in a reversible and spatially controlled fashion. Our novel technology provides a massive enhancement in security generating more complex keys containing a larger amount of information. At the same time, it allows for new applications, for example serving multiple clients on a single encryption device and the practical implementation of quantum secure authentication of data.