A chaotic fragile watermarking algorithm for image authentication

Fragile watermarking techniques for digital content have been studied in the past few years. Fragile watermarks are used to determine if a piece of watermarked digital content has been tampered, and distinguish tampered areas from non-tampered areas without referring to the original digital content. In this paper, a novel fragile watermarking scheme for image authentication is presented. Giving the initial value of the chaotic mapping, the fragile watermark is obtained by iterating several times of the chaotic mapping. The watermark is then inserted into the two least significant bit (LSB) planes of the host image. The proposed scheme can localize the tampers on the watermarked image by using to the high sensitivity on initial value of the chaotic mapping. Moreover, no host image is needed in watermark extraction. Our simulation results show the effectiveness, sensitivity and localization of tamper-proofing of this algorithm.