Paillier homomorphic cryptosystem with poker shuffling transformation based water marking method for the secured transmission of digital medical images

Digital watermarking is a technique that provides security and authentication for digital image transmission. In general, patient reports are stored in the form of a medical image. A medical image shared through the Internet can be easily modified by an unauthorized user. In order to overcome this risk, we have proposed a method, namely, Paillier homomorphic cryptosystem with poker shuffling transformation-based watermarking method for ensuring security for the digital medical images. In this paper, the watermarking process initially is done at an encrypted DWT-DCT domain. Paillier homomorphic cryptosystem is used for encrypting the original image. The watermark image is scrambled using poker shuffling transformation to generate the scrambled image. This is followed by the encryption of the scrambled image. The embedding process is used for generating an encrypted watermark image. The extraction process involves the decryption of encrypted watermark image for getting the original and the watermark image. The medical data is collected from the private hospitals. The experimental results have established the improvement in the robustness of our proposed watermarking system in an encrypted DWT-DCT domain apart from providing security for the digital image transmission.