Adaptive fragile watermark for image authentication with tampering localization

A fragile content-based image authentication scheme with location based on integer wavelet transform is presented. In this scheme, the digest of each block is coded by a chaotic sequence to form its watermark, which is embedded in another block which selected by an ergodic matrix of a hyperchaotic sequence. The encryption further strengthens the security. That all security parameters are user dependent 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 8times8 pixels.