A robust digital watermarking algorithm using DES and ECC in DCT domain for color images

Nowadays, Internet and multimedia is popularly growing fast and is being used in digital communication. With increase in demand, risks are also involved. Thus, digital watermarking is an absolute method to provide authentication and copyright protection to the digital media to protect it from illegal modification and redistribution. In this paper, we have proposed a robust watermarking algorithm using DES, ECC and DCT for color images. The original color image (watermark) and cover image has been separated into three independent color channels (red, green and blue) and their gray scale equivalents are used. Each individual gray scale equivalent of RGB components of original image has been encrypted using Data Encryption Standard (DES). The Henon map is used to generate three different round keys for DES with different initial parameters. After encrypting three different gray scale equivalents, the encrypted images are mapped to the points of elliptic curve. The mapped images so formed are embedded in different gray scale equivalents of RGB components of color image using DCT. The mapped images are hidden into the mid frequency of DCT blocks to avoid it from common attacks. The effectiveness and robustness of the algorithm is shown in the experiments.