Chaotic encryption algorithm for satellite images based on novel RNA coding

Threat to sensitive data and images during storage and transmission between Earth Observation Satellites and ground stations is increasing with the increasing number of satellites. We present an infinite dimensional chaotic encryption algorithm for satellite images of Earth Observation Satellite, which using by a novel RNA encoding method combined with layered bidirectional diffusion operations of pixels. Firstly, dynamic characteristics of the infinite dimensional chaotic system are introduced, including infinite dimensional properties of the system, phase diagrams, sequence charts, Lyapunov exponential results, and bifurcation diagrams. Secondly, a novel RNA encoding method is designed to dynamically encode image pixel values based on sequences generated by infinite dimensional chaotic system after processing. Meanwhile, multiple RNA operations are used to solve the possibility of being vulnerable to brute force attacks caused by fewer RNA coding rules. Thirdly, layer bidirectional diffusion operations are brought into the image encryption algorithm to complete pixels diffusion and achieve required security effects. Finally, the experimental simulation results on MATLAB platform verify effectiveness and practicability of the presented image encryption algorithm, such as key sensitivity, information entropy, efficiency, robustness against transmission errors and other indicators, which could provide bases for effectively resisting various attacks. The presented satellite image encryption algorithm is a safe method and could achieve universal and satellite-required security, as well as robustness against transmission errors. In addition, the secure key space is incomparable to other similar algorithms.