A novel chirp-based 2D hyperchaotic map for enhanced image encryption

Abstract

Abstract This paper presents a novel image encryption algorithm based on a newly proposed two-dimensional hyperchaotic map derived from the chirp signal. Performance evaluations of the proposed map include bifurcation analysis, phase portrait visualization, sensitivity to initial conditions, Lyapunov exponent calculations, entropy measurements, and NIST tests. These evaluations confirm the map’s strong randomness and broad chaotic behavior. The proposed encryption algorithm utilizes the high sensitivity to initial conditions and wide chaotic range of the hyperchaotic map to enhance security. The algorithm achieves a high degree of confusion and diffusion through bit-level manipulation, chaotic permutation, and randomized row-column diffusion processes. As a result, it can effectively encrypt images of any size, whether color or grayscale. Comprehensive security evaluations, such as key analysis, histogram analysis, Shannon entropy analysis, correlation analysis, differential analysis, and robustness analysis, confirm the algorithm’s resilience against a wide range of cryptographic attacks. Thus, the proposed algorithm offers a promising solution for secure image transmission.