Secure semi-fragilewatermarking for image authentication

This paper proposes a secure semi-fragile authentication watermarking algorithm for natural images by embedding two complementary watermarks for content change analysis. Two authenticator watermarks are generated and embedded in different regions of the images: one for detecting malicious modifications and the other for estimating the degree of the changes. The proposed scheme is able to distinguish common content-preserving changes from malicious content-changing modifications. Simulations on real images demonstrate the effectiveness of the authentication watermarking scheme.