Enhancing robustness and security of medical images through composite watermarking method

With the expansion of IOTs and Wireless devices, data transmission has increased over the internet. Maintaining security during data transmission using invisible watermarks has become a focus and has captured the attention of numerous researchers. The three security necessities, privacy, integrity, and authenticity, call for close attention and remedial actions. In this respect, watermarking and cryptographic techniques are a probable way to handle the above-mentioned issues adequately. The paper presents a novel approach to watermarking using a combination of NSST, HD, and SVD transforms, which improves the robustness and security of the watermarked image. The method involves using a grayscale image as the watermark and embedding it in multiple cover images. The resulting images are transformed sequentially using NSST, HD, and SVD to obtain the final watermarked images. The authors also apply AES encryption to enhance security, which generates a hash subkey and authentication tag. The proposed methodology performs better than other watermarking techniques, with a maximum improvement of 47.81%. Overall, the proposed approach offers a more secure and robust solution for watermarking.