A hybrid authenticated image encryption scheme using elliptic curves for enhanced security

The rapid evolution of digital technology has heightened concerns about the security of multimedia communication across vulnerable platforms. In response to this challenge, our research introduces a comprehensive encryption and authentication framework tailored for both grayscale and color images. Central to our approach is the incorporation of the Elliptic Curve Diffie–Hellman (ECDH) key exchange method, complemented by the Fibonacci matrix and enhanced modified logistic maps. Furthermore, we present an asymmetric variant of the Affine-Hill cipher, designed specifically for block-based image encryption to ensure superior cipher image quality. A pivotal aspect of our methodology is the generation of a self-invertible key matrix and a shift Fibonacci matrix derived from the ECDH session key. This matrix, combined with two distinct one Dimensional (1D) modified logistic maps, efficiently scramble the original image pixel positions. To enhance the scheme's security, a novel authentication mechanism is incorporated, integrating a digital signature with the cipher image. Our Python 3-based implementation showcases the resilience of the proposed framework against a spectrum of attacks, as evidenced by rigorous evaluations of parameters such as correlation, entropy, variance, execution time, and key space. Through comparative analysis with recent encryption methodologies, we highlight that our approach is effective, robust and secure.