Multiple RGB images encryption algorithm based on elliptic curve, improved Diffie Hellman protocol

For the asymmetric key, the Diffie Hellman Key (DHK) protocol is very efficient, but sometimes it is vulnerable against brute force attacks if the parameters are not chosen carefully. Our study aims to improve the asymmetric key scheme based on the elliptic curve cryptosystem (ECC). The sender and receiver agree on an elliptic curve based on the DHK sharing technique, but generator G is kept secret, and we generate its hash value, which is shared publicly. The authorized members can recover G using the hash value. By keeping G secret, the key protocol becomes much more robust than existing ones. Further, the proposed scheme will be applied to multiple RGB images. In this novel public key algorithm, 4D chaotic sequences are used for the diffusion of image pixels. The pixels’ values are used for permutations of images rather than the chaotic sequences, strengthening the scheme against chosen/known plain text attacks. The simulation and the security analysis of the proposed algorithm show efficiency, potential to endure the varied attacks, and prospects for real-world application.