Multiplexed optical encryption using Bessel–Gaussian speckle patterns in the Fresnel domain for secure and high-capacity data storage

Abstract The security and capacity of optical encryption systems critically depend on the unpredictability of encryption keys and the ability to multiplex multiple images efficiently. Conventional digitally generated keys often suffer from limited randomness and predictability, exposing systems to cryptographic attacks and limiting storage density. In this work, we propose speckle patterns generated from the Bessel–Gaussian (BG) beams as physically unclonable functions to serve as robust and inherently random encryption keys. These speckle patterns produced by scattering of BG beams through a ground glass plate, are unique, unclonable, and highly sensitive to input parameters. To demonstrate their effectiveness, the BG speckle physically unclonable functions substantially improve encryption robustness, with successful decryption observed only under exact key and propagation parameters, yielding high peak signal-to-noise ratio and low mean square error. The findings highlight the novelty and potential of BG speckle physically unclonable functions for applications in secure image transmission, Internet of things data protection, high-capacity optical storage, and communication security.