Analysis and design of authentication watermarking
Chuhong Fei, Deepa Kundur, Raymond H. S. Kwong · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
This paper focuses on the use of nested lattice codes for effective analysis and design of semi-fragile watermarking schemes for content authentication applications. We provide a design framework for digital watermarking which is semi-fragile to any form of acceptable distortions, random or deterministic, such that both objectives of robustness and fragility can be effectively controlled and achieved. Robustness and fragility are characterized as two types of authentication errors. The encoder and decoder structures of semi-fragile schemes are derived and implemented using nested lattice codes to minimize these two types of errors. We then extend the framework to allow the legitimate and illegitimate distortions to be modelled as random noise. In addition, we investigate semi-fragile signature generation methods such that the signature is invariant to watermark embedding and legitimate distortion. A new approach, called MSB signature generation, is proposed which is shown to be more secure than the traditional dual subspace approach. Simulations of semi-fragile systems on real images are provided to demonstrate the effectiveness of nested lattice codes in achieving design objectives.