Multilevel and Flexible Physical Unclonable Functions for High‐End Leather Products or Packaging

Counterfeit and substandard high-end leather products have inflicted substantial economic damage worldwide and have tarnished the reputation of the leather industry as a whole. Due to the limited security level, current anti-counterfeiting measures are often vulnerable to attacks. Physically unclonable function (PUF) is regarded as the pinnacle of protection against counterfeiting. Leather, with a distinctive micro-nano porous structure and random creasing patterns, serves as an ideal substrate for optical PUF. Here, a flexible and durable leather-based optical PUF device is introduced that incorporates leather and fluorescent perovskite quantum dots. The fluorescence intensity distributed along the texture of leather offers parametric support for challenge-response pairs. Combined with a self-defined fluorescence pattern, the hierarchical authentication of optical PUF is realized. In conclusion, this innovation offers a desired opportunity for achieving high-security anti-counterfeiting and information traceability.