Print-Scan Resilient Watermarking for UAV Registration QR Codes in Intelligent Transportation Systems

To enhance the security of intelligent transportation systems (ITS) incorporating civil unmanned aerial vehicles (UAVs), this study addresses the vulnerabilities of physical copying and tampering with real-name registration QR codes used for UAV identity authentication. We propose a semi-fragile digital watermarking algorithm specifically tailored for print-scan scenarios in ITS environments. By analyzing the statistical characteristics of discrete cosine transform (DCT) coefficients after QR code printing and scanning, a mid-frequency coefficient energy enhancement module is designed. Combined with Logistic encryption and a DCT-domain watermark embedding strategy, the method achieves robustness against initial print-scan operations while maintaining sensitivity to secondary copying attempts. Experimental results demonstrate that, while preserving visual quality, the proposed algorithm effectively distinguishes between original prints and photocopy attacks, achieving a tampering detection accuracy of 100%, and exhibits resilience against common image processing operations such as Gaussian noise addition. This research provides a deployable and ITS-compatible anti-counterfeiting solution for UAV real-name registration systems, offering significant practical value and broad application prospects in secure transportation infrastructure.