A Comprehensive QR Code Protection and Recovery System Using Secure Encryption, Chromatic Multiplexing, and Wavelength-Based Decoding
Paola Noemi San Agustín Crescencio, Leobardo Hernández-González, Pedro Guevara López, Oswaldo Ulises Juarez-Sandoval, Jazmín Ramírez-Hernández, Eduardo Salvador Estevez-Encarnacion · Applied Sciences · 2025
QR codes (Quick Response) were originally developed by the automotive industry to enable rapid data exchange and have since evolved into versatile tools for commercial applications, such as linking to products or websites. However, the scope of their adoption has expanded into sensitive domains including financial, corporate, and governmental sectors. In order to address increasing security concerns, this work proposes a novel three-layer protection scheme. First, data confidentiality is ensured through encryption—in this study, symmetric AES (Advanced Encryption Standard) encryption is used as an example, though any encryption algorithm can be employed. Second, a multiplexing technique is employed to integrate two independent dichromatic QR codes into a single printed chromatic structure. Third, the recovery of each dichromatic code is achieved through the controlled incidence of specific wavelengths, not only providing improved channel separation but also functioning as a physical access control mechanism. This physical layer restricts unauthorized reading.