Physical Anti-copying Semi-robust Random Watermarking for QR Code

Abstract

AbstractRecently, QR code has been applied in anti-counterfeiting scenarios, where a unique QR code is attached for a specific item. However, such a QR code-based anti-counterfeiting solution cannot resolve the physical illegal copying issue. The genuine QR code can be physically replicated by scanning and printing. In this work, we propose a physical anti-copying semi-robust randomly watermarking system for QR code. Specifically, the authentic and counterfeit channels a QR code experiences are investigated first. By exploiting the distortion characteristics between two channels, we devise a randomly watermark embedding system, where the watermark bit is embedded via modulating the relationship between two carefully selected transformed coefficients. Finally, to obtain a valid and recognizable binary QR code image, a random binarization procedure is applied, and the regions originally belonging to the white module are erased. The final resultant watermark appears as white-dot pattern resides the black module of QR code, which is robust to the authentic print-scan but fragile to the physically illegal copying. Experimental results demonstrate the effectiveness of the proposed watermarking system. This work makes the first step towards exploring semi-robust watermarking for combating physically illegal copying.KeywordsQR codeSemi-robust watermarkPhysical anti-copying