Research On Security Mechanism Of Image Transmission Based On Space Communication Protocol

With the rapid development of aerospace technology,the existing space communication protocol has been unable to meet the security needs of space network.Due to the high openness of space wireless links,a large number of valuable satellite image data are vulnerable to malicious attacks by illegal elements in the transmission process,which will cause damage to national interests.Therefore,based on the image data compression protocol and the AOS(Advanced Orbiting Systems)space data link protocol,this paper designs the security mechanism scheme of the protocol and implements the image security transmission system for the security of image transmission in spatial network.Firstly,this paper analyzes the causes of security threats in space networks and studies the security mechanisms required for space networks.Moreover,this paper analyzes the space communication protocol group organized by the Consultative Committee for Space Data System,and studies the image data compression protocol and the AOS space data link protocol.Secondly,according to the analysis of the security risks of the image data compression protocol,this paper studies the basic theory of cellular automata,and proposes an encryption mechanism based on the image data compression protocol.Then,the encryption algorithm and the data unit format are designed for the encryption mechanism based on reversible cellular automata.And the proposed encryption algorithm is analyzed and tested.Then,according to the protocol vulnerability analysis results,the three cellular automata models of triggering,coupling and compounding are studied,and an encryption algorithm based on hybrid cellular automata is designed.Through the combination of the authentication mechanism and anti-replay mechanism,this paper proposes a security mechanism scheme for the AOS space data link protocol,designes the frame format of the security mechanism and verifies the security of the encryption algorithm.Finally,according to the security mechanism scheme of the image data compression protocol and the AOS space data link protocol,this paper proposes a solution scheme of image security transmission,and designs an image security transmission system by simulating the form of spatial data transmission.This system can be composed of three parts: the sending end,the relay server and the receiving end.The sending end implements the protection and transmission of the image.The relay server is responsible for link setup and data forwarding.And the receiving end has the function of the data receiving and verifying.Theoretical analysis and experimental results show that the security mechanism scheme proposed in this paper satisfies the requirements of space network security,and the novel reversible cellular automata encryption algorithm and the hybrid cellular automata encryption algorithm have high security.Moreover,the proposed image security transmission system has good performance,which can normally complete the image transmission tasks,and also can resist replay,eavesdropping,tampering and forgery attacks to enhance the image transmission security.