Two-level security approach combining watermarking and encryption for securing critical colored images

With the widespread of the Internet and the rapid growth of technologies, several challenges face data hiding process. Although watermarking is widely used to hide/embed critical data into a cover image, the watermarked image may be attacked/hacked and the embedded data may be extracted or damaged. This paper presents an efficient two-level security approach to protect colored watermark images. In the first level, the color image is embedded into a grayscale image using a multi-level Discrete Wavelet Transform (DWT), Singular Value Decomposition (SVD), and wavelet fusion. In the second level, an additional encryption process on the watermarked image is done by using two-dimensional logistic chaotic map in a case and Advanced Encryption Standard (AES) in another case. The proposed scheme is evaluated by using several images and different hacks on the transmitted image. The experimental results show that the proposed scheme is efficient and can face many attacks such as Gaussian, Blur, Wrap, and Cropping. In addition, the extracted watermarks are recognized even when the marked images suffered from attacks.