Anti-Counterfeiting for Polymer Banknotes Based on Polymer Substrate Fingerprinting

Polymer banknotes are the trend for printed currency and have been adopted by more than fifty countries worldwide. However, over past years, quantity of polymer counterfeits has increasing, so quality counterfeits. This shows that initial advantage bringing a new technology to fight against counterfeiting is reducing. To maintain one step ahead counterfeiters, we propose novel anti-counterfeiting technique called Substrate Fingerprinting (PSF). Our built based on observation opacity coating, critical during production notes, stochastic manufacturing process, leaving uneven thickness in coating layer random dispersion impurities from ink. The imperfections result translucent patterns when banknote back-lit light source. We show these can be reliably captured commodity negative-film scanner processed into compact fingerprint uniquely identify each banknote. Using an extensive dataset 6,200 sample images collected 340 UK banknotes, our method authenticate robust rough daily handling banknotes. Furthermore, extracted fingerprints contain around 900 bits entropy, which makes it extremely scalable every note circulated globally. As compared with previous or existing mechanisms distinctive advantage: ensures even extreme case counterfeiters procured same printing equipment ink as used legitimate government, remains infeasible because difficulty replicate process.