A new 2D hyperchaotic model-based encryption strategy for multiple images via pixel fusion

Abstract In view of the intrinsic characteristics of chaotic system, it can be widely applied in image encryption. Considering the common issues of insufficient chaotic performance and discontinuous range of control parameters in current chaotic systems, a hybrid chaotic model with the characteristics of simple and easy to design is devised to address these challenges. Through phase portraits, bifurcation diagrams, and the analysis of Lyapunov exponent spectrum, it is demonstrated that the proposed system can exhibit robust traversal performance. To meet the demands of digital image encryption, an effective encryption strategy for multi-image based on this model is proposed, which can accommodate the varying image sizes and types simultaneously. In the given strategy, the pixels are merged from multiple images at first, and then the keys can be derived with SHA-512. By the application of discrete wavelet transform, the information can be embedded from the plaintext images, which can ensure the robust resistance to data loss while facilitating the shared transmission of plaintext information. Finally, by leveraging the developed chaotic system, a three-dimensional cross-plane scrambling and diffusion algorithm is introduced to enhance the effectiveness of encryption scheme.