Research On Image And Audio Encryption With Cluster Synchronization Of Two-layer Complex Networks

Internet multimedia information is closely related to the development of society,which includes text,image,audio,etc.Compared with text information,image and audio information can carry more information,and the expression of information is more vivid than text.However,when more information can be carried,image and audio files will be larger than text files,and more memory is needed.The traditional encryption algorithms are not suitable for the encryption of these information,such as RSA,DES,AES,and so on.Therefore,it is necessary to design an effective encryption scheme for these large amount of data,the complex network encryption based on a chaos system is an effective method to realize the encryption of a large amount of data.Chaotic system has high randomness and initial value sensitivity.Furthermore,complex network has high complexity.Combining these characteristics of chaotic systems and complex networks,we can use the complex dynamic network coupled by many chaotic systems to design various encryption schemes.In the previous encryption schemes using chaotic systems,most of them are based on the synchronization between two chaotic systems.Compared with the encryption scheme based on the synchronization of complex dynamic network,there are some disadvantages in the key space and encryption/decryption speed.Of course,there are also some encryption schemes designed by using the synchronization of single-layer or double-layer complex dynamic network,but the convergence of synchronization time and the clustering characteristics of the network in real life are not considered.Based on the above analysis,this paper designs an encryption scheme based on finite-time cluster synchronization of double-layer complex dynamic network,and the influence of external random disturbance are taken into consideration as well.The main research work of this paper can be given as follows:1.Based on the double-layer network structure,a scheme to realize finite time cluster synchronization of the double-layer complex dynamic network is proposed in this paper,and the influence of random disturbance is considered.In the synchronization scheme of two-layer complex network,each layer network is divided into two clusters,and the node dynamic systems in different clusters are different.With the design of some suitable controllers,the required synchronization time can be computable.Then,the feasibility of finite-time cluster synchronization in the proposed two-layer complex dynamic network is analyzed theoretically.2.An image information encryption scheme based on finite-time cluster synchronization of two-layer complex dynamic network is proposed in this paper.In the given image encryption scheme,symmetric encryption method and disposable encryption technology are adopted.The encryption process is mainly divided into three steps: scrambling,XOR operation and diffusion;the decryption process is divided into three steps: inverse scrambling,XOR operation and inverse diffusion,and chaotic systems are involved in each step.Finally,the numerical simulation is carried out,and the performance of the encryption system is analyzed from the key space,synchronization time,correlation,and information entropy.The simulation and theoretical analysis show that the scheme can realize the encryption/decryption of image information safely and efficiently.3.This paper proposes an audio information encryption scheme based on finitetime cluster synchronization of two-layer complex dynamic network.Similar to the image encryption scheme proposed in this paper,the audio encryption scheme also adopts symmetric encryption method and one-time encryption technology.The encryption process is mainly divided into two steps: time-domain scrambling and encryption function,and the decryption process is mainly divided into two steps:inverse time-domain scrambling and decryption function.Finally,we carried out numerical simulation,during the process of this simulation,we use different network topologies and chaotic systems from the image encryption scheme.In this encryption scheme,we adopt the finite-time control method,the synchronization time of the double-layer complex dynamic network is controllable and predictable.Therefore,compared with the synchronization of drive-response or feedback,the synchronization time of this encryption scheme is shorter,and it has greater advantages in timeliness.We also analyze the performance of the audio encryption system in detail from the aspects of key space,correlation,MSE and PSNR.The simulation and theoretical analysis show that the audio encryption/decryption scheme proposed in this paper can safely and efficiently implement the encryption/decryption of audio information.