Optical Physical Unclonable Function

An optical physical unclonable function is a hardware primitive that turns the microscopic irregularities of a material into a reproducible but unpredictable pattern of light. When a beam such as a laser or white light shines on a specially prepared surface—often a piece of polymer, glass, or semiconductor—the way the light scatters, interferes, and reflects depends on the exact arrangement of particles, voids, and defects that were introduced during manufacturing. By recording the resulting speckle pattern with a camera or photodetector array, one obtains a visual fingerprint that is practically impossible to duplicate because the underlying disorder cannot be precisely replicated.