Image encryption based on 2D-CPHM hyperchaotic map using cross-plane grouping permutation and cipher diffusion
摘要
With emerging technologies such as medical cloud services and remote consultations, unauthorized access to patient information may pose serious security threats. We propose a safeguarded and efficient image encryption technique utilizing a permutation-diffusion framework to address information security requirements and facilitate low-latency transmission for the services above. We propose an innovative two-dimensional hyperchaotic map termed 2D-CPHM, which is constructed by embedding a nonlinear bounded cosine and sine function externally and a polynomial with nonlinear exponential terms internally into the Hénon map. Compared to existing 2D hyperchaotic maps, this map demonstrates enhanced chaotic characteristics, evidenced by high Lyapunov exponents, a wide chaotic range, and a uniform phase trajectory distribution. We propose a method that combines a cross-plane grouping strategy with the Inside-Out shuffling algorithm. This approach effectively disrupts the correlation of adjacent pixels through a single-step permutation. To address the traditional Hill cipher’s dependence on an invertible key matrix during the diffusion phase and its limitations in encrypting uniform background images, a variation of the Fibonacci sequence exhibiting chaotic properties is employed to produce the key matrix elements, requiring only the (1, 1) element is selected from the ring