A secure fragile watermarking scheme for image authentication

A fragile watermarking scheme for secure image authentication is proposed. A scrambling encryption scheme is introduced to extend the security and increase the capacity of the fragile watermarking algorithm. The proposed algorithm not only possesses excellent tamper localization properties, but also demonstrates a new useful feature, called tamper discrimination. That is, it can indicate whether the modification made to the image is on the contents or the embedded watermark or both. If only the watermark is modified the verification algorithm will display isolated dots spread all over the image, not just the altered regions. Thus the authenticity of the image is assured, instead of being declared as a counterfeit. Experimental results are given to illustrate the effectiveness of our method.