A chaotic system based fragile watermarking scheme for image tamper detection

In the past few years, various fragile watermarking techniques have been proposed for image authentication and tamper detection. In this paper, a novel chaos based watermarking scheme for image authentication and tamper detection is proposed. Tamper localization and detection accuracy are two important aspects of the authentication watermarking schemes. Our scheme can detect any modification made to the image and can also indicate the specific locations that have been modified. To improve the security of the proposed scheme two chaotic maps are employed. Since chaotic maps are sensitive to initial values, the corresponding position relation between pixels in the watermarked image and the watermark get disturbed, which helps the watermarking scheme to withstand counterfeiting attacks. Initial values of the chaotic maps are used as secret keys in our scheme. The effectiveness of the proposed scheme is checked through a series of attacks. Experimental results demonstrate that the proposed scheme is not only secure but also achieves superior tamper detection and localization accuracy under different attacks. For instance in copy-and-paste attack and collage attack. (C) 2011 Elsevier GmbH. All rights reserved.