An Image Encryption Scheme Based on Hybrid Orbit of Hyper-chaotic Systems

This paper puts forward a novel image encryption scheme based on ordinary differential equation system. Firstly, a hyper-chaotic differential equation system is used to generate two hyper-chaotic orbit sequences. Introducing the idea of hybrid orbit, two orbits are mixed to generate a hybrid hyper-chaotic sequence which is used to be the initial chaotic key stream. Secondly, the final encryption key stream is generated through two rounds of diffusion operation which is related to the initial chaotic key stream and plain-image. Therefore, the algorithm’s key stream not only depends on the cipher keys but also depends on plain-image. Last but not least, the security and performance analysis have been performed, including key space analysis, histogram analysis, correlation analysis, information entropy analysis, peak signal-to-noise ratio analysis, key sensitivity analysis, differential analysis etc. All the experimental results show that the proposed image encryption scheme is secure and suitable for practical image and video encryption.