The Research And Design Of Image Encryption Algorithm Based On Multi-wings Hyper-chaotic Attractor

With the speedy development of communication technology and network technology,multimedia communication becomes the main transmission mode of Internet information.In the multimedia information,compared with voice and text messages,digital images are more vivid and contain abundant information.Therefore,digital images became a main way of transfer information,sharing information and daily communication.However,because of bulky data capacity,data redundancy and the characteristics of strong correlation among adjacent pixels,traditional encryption algorithms,such as MD5,IDEA and AES,are poorly suited to image encryption.Due to the development of the chaotic dynamics,it was found that the chaos systems,especially the hyperchaos systems,have excellent randomicity,ergodicity and sensitivity to initial conditions and system parameters,make its have superior characteristics of mixing and diffusion,fully meet the requirements of the cryptography and has natural ties with cryptography.As a result,image encryption algorithm based on chaotic system is more suitable image encryption.And the study of the chaotic image encryption has become more and more popular.First,this article introduces the research background and significance,introduces the research status of chaos and multi-wing chaos and analyzes the research status of chaotic image encryption at home and abroad.Then,the paper introduces the basic theory of the definition and main characteristics of chaos and image encryption technology.On this basis,we propose two image encryption algorithms based on multi-wings chaotic attractor.(1)Image encryption algorithm using pixel-level permutation and bit-level permutation based on multi-wings hyper-chaos system.First,we employ pixel-level permutation and bit-level permutation to permute original image by combining chaotic encryption and conventional encryption.In this way,we can change the pixel position and the pixel values.Then,a diffusion process is employed to enhance the security of encryption algorithm.(2)A novel color image encryption algorithm based on multi-wings hyper-chaos system and permutation-diffusion structure.First,the algorithm utilizes a block permutation which is realized by mixing red,green and blue components to strengthen the dependence of each component.In addition,block permutation can reduce time consumption.Then,the key streams generated by the hyper-chaotic system are exploited to diffuse the pixels and we make the three components affect each other again.And in the diffusion process,we can get two totally different encrypted images even though we change the last pixel because green component is diffused in reverse order.Finally,we realize two image encryption algorithms using Matlab,include the statistical properties,the sensitivity of the plain-text and the key,the key space and the information entropy.The simulation results and performance analysis demonstate that compared with other chaotic image encryption algorithms,our algorithm has better ability to resist statistical attack and differential attack,larger key space and the information entropy is closer to 8.