Counterfeit consumer products, electronic components, and medicines generate heavy economic losses, pose a massive security risk, and endanger human lives on a daily basis. Combatting counterfeits requires incorporation of uncopiable or unclonable features in each and every product. By exploiting the inherent randomness of stochastic processes, an optical authentication system based on physical unclonable functions (PUFs) was developed. The system relies on placing unique tags-PUF-tags-on the individual products. The tags can be created using commercial printing and coating technologies using several combinations of carrier materials and taggant materials. The authentication system was found to be independent of how contrast was generated, and examples of PUF-tags based on scattering, absorption, and luminescence were made. A version of the authentication using the combination of scattering-based PUF-tags and a smartphone-based reader was validated on a sample size of 9720 unique codes. With zero false positives in 29 154 matches, an encoding capacity of 2.5 × 10120, and a low cost of manufacture, the scattering-based authentication system was found to have the potential to solve the problem of counterfeit products.
Keywords: anti-counterfeiting ink; anti-counterfeiting system; anti-counterfeiting tags; lanthanide luminescence; luminescent tags; optical authentication; physical unclonable functions.