An Image Authentication Scheme with Localization and Recovery

A block-wise and content-based image authentication scheme with location and recovery is presented. In this scheme, the watermark of each block is an encrypted form of its content-feature, which is embeded in another block which selected by an ergodic matrix of a chaotic sequence. The randomicity of selected block can robust the VQ attack. The encryption further strengthens the security. That all security parameters are user dependent and can be computed at both ends individually based on Diffie-Hellman key exchange method makes the scheme not only robust against collage attack but also truly oblivious. The experiments demonstrate that the proposed scheme can detect and localize any tampering of size 8x8 pixels and above and can recover a 40% damaged image to an intelligible one.