Reversible and Reconfigurable Optical Physical Unclonable Functions with Elastic Liquid Crystal Scatterers

In high-throughput network security applications, physical unclonable functions (PUFs) employing fixed mapping mechanisms are vulnerable to machine learning attacks. Reconfigurable PUFs can improve security by altering their mapping states, but often face constraints of limited reconfigurability, irreversible controllability, or high hardware overhead. Here, reversible and reconfigurable optical PUFs, 2RO-PUFs, were developed by two-beam manipulation of photothermal-sensitive scatterers with a precisely controllable phase transition. Experimental results verify that the programmed scatters and resultant speckle patterns exhibit deterministic and repeatable reconfigurability while maintaining cryptographic robustness. As demonstrated in a novel Internet of Things framework, the introduction of optically controlled speckle formation into PUFs frameworks enhances cryptographic security and flexibility while alleviating storage and computational overhead.