Research Of Optical Image Encryption And Transmission Base On Optical Chaos

As one of the popular information dissemination forms,digital image is now widely used in various industries due to its intuitive,visual and vivid features.The digital media occupied a large proportion can be as the carrier of signal to transmit the daily information in politics,economy,education,etc.However,the level of security for digital media is relatively high in most some special fields,such as military,commercial,and national defense.If the information leakage happens,it would cause immeasurable losses.It is the needs of various industries and the release of national policies that have promoted the technology of the information security to become an attractive research area in recent years.Furthermore,the image encryption and secure transmission are important parts of key technologies in information security technology.The encrypted effect obtained by a good encryption algorithm can meet its development and application.Owing to the advantages of unpredictability,sensitive initial conditions,and pseudorandom,the chaos can be combined with the encryption algorithms,which can break through the traditional bottleneck of cryptographic encryption.Some image encryption algorithms based on chaotic mappings(such as logistic mapping,tent mapping,and hyperchaotic systems)have been implemented and published.However,comparing with traditional electrical chaos,the optical chaos has unique advantages such as high complexity,high bandwidth,and low loss,which makes it more suitable for image encryption,secure communication,and random number generation.With the study of the complex nonlinear dynamic behavior of different types of semiconductor lasers(SCLs)under different topological structures and external disturbance conditions,the nonlinear dynamics of SCL can be clearly analyzed and mastered,which is beneficial to its optimization and application in research.The advance in the study of chaotic dynamics of SCL and the need for high-speed data transmission recently will further promote the image encryption and transmission systems base on the optical chaos to replace traditional encryption and transmission methods.Therefore,combining high-quality chaotic output with image encryption and secure transmission of image information can achieve high-security image information interaction in medical,commercial,and academic research.So based on the chaotic signals with high complexity generated by SCL,this paper studies a new color image encryption algorithm,and realizes the transmission of encrypted information in a secure transmission system.The main contents of research are as follows:In order to increase the chaotic complexity of the output signals of the slave laser,the optical feedback is performed on the master laser(ML),and the external optical injection is performed on the driven laser(DL).And for the purpose of generating the optical chaos and achieving chaotic synchronization,the output of ML is injected into the SL1 and SL2 simultaneously.The SL1 and SL2 can generate high-complexity chaotic signals to be used as the chaotic carrier and keys to improve the security.In the results of simulation,the characteristics of output and the optical chaos,the parameter indicators of chaos synchronization and the communication performance are analyzed.By randomly selecting datas from the optical chaotic signals generated by the SL1(or SL2),the key and new chaotic sequence in the scrambling operation are constructed again.For the constructed chaotic sequence,we use the logical operation of Coulomb's law to construct and scramble the image encryption again to improve the security of simple scrambling based on Hilbert curve(HC).In addition,the logistic chaotic mapping and mathematical operations are used to complete the diffusion process of color image,which can optimize the color image encryption algorithm.Moreover,the numerical analysis and simulation are used to prove the security and feasibility of key space,key sensitivity,information entropy,histogram,pixel correlation,pixel change rate(NPCR),and uniform average change intensity(UACI).Finally,the chaos masking(CMS)technology is used to transmit the encrypted image information in a 10 km single mode fiber(SMF).The research content of this paper has theoretical and practical significance for the nonlinear dynamics and optical chaos of SCL in image encryption and confidential transmission.