A secure hierarchical fragile watermarking method with tamper localization

Several image authentication schemes are either vulnerable to attacks or sacrifice localization accuracy to improve security. In this paper, we proposed a scheme that not only thwarts all kinds of-attacks such as vector quantization (VQ) and oracle attack in order to satisfy the security but also ensures superior accuracy of tamper localization. It is effective because the detection is based on a hierarchical structure so that the accuracy of tamper localization can be ensured. That is, if a tampered pixel is not detected in level-4, it will be detected in level 3, level 2 or level I with a probability of nearly 1. The method can detect any tampered pixel and the size of 2 x 2 pixel block with a missing rate less than 0.78% and 0.19% respectively, and the missing rate of more than or equal the size of 4 x 4 pixel block is approximately close to 0. Experimental results demonstrate that the proposed scheme is highly sensitive to intentional tampering and the embedding watermarking is imperceptive.