A chaos-based fragile watermarking method in spatial domain for image authentication

In this paper, a fragile watermarking method based on chaos map for image authentication is proposed. The watermark is a binary logo of the same size with the host image. Before embedding, the watermark is encrypted by XOR-ing it with a chaotic image. The chaotic image is generated by using Logistic Map. Next, the least significant bits (LSB) of pixels is used for embedding where the LSB´s of the host image are replaced by the encrypted watermark. Authentication is done by extracting the watermark from the watermarked image and then compare it with the original watermark. If found the extracted watermark fragile then it indicates that the image has been altered. Various typical attacks to the watermarked images are carried out to assess the performance of the proposed method. Experiment results show that the proposed method can detect image integrity due to the attacks. For increasing security, the chaos system give sensitivity aspect so that the method is secure from the exhaustive attack.