| With the gradual realization of the global service of Beidou satellite navigation system,Beidou's unique short message communication function has been widely used in various industries,and the security requirements for its communication transmission are also getting higher and higher.When the data is transmitted in the short message system,it is in plain text and no security encryption is used.In the case that the basic information such as the transmission standards and transmission formats of the Beidou satellite navigation system are publicly released,security problems such as user data leakage and tampering may occur during the transmission of the message data.Therefore,in order to ensure the secure transmission of the short message transmission system,it is necessary to perform security encryption operation on the message data transmitted by the Beidou short message.In view of the above problems,this paper combines the security cryptosystem with the Beidou short message transmission.Based on the transmission characteristics of the short message system and the data format and meaning of the message communication protocol,this paper proposes the use of symmetric encryption algorithm and chaotic encryption algorithm.A scheme for encrypting data of a content portion of a message in a message communication application protocol.In order to achieve the safe transmission of Beidou short messages.Aiming at the user location information frequently transmitted in the short message application,the message content location information transmission protocol is designed based on the content part of the message,which realizes the security and standard communication of the user location data.At the same time,the common symmetric encryption algorithm and chaotic mapping algorithm are compared and analyzed,which lays a foundation for encrypting the content of the message.Based on the above research and encryption scheme,this paper uses Logistic chaotic map encryption algorithm to encrypt short message data.By analyzing its key space,it is found that the key space of the algorithm is small,so it can not effectively resist the exhaustive attack.For this case,an improved Logistic algorithm based on coupled chaotic system is proposed.Short message data is encrypted using an improved encryption algorithm.The proposed algorithm performs exhaustive attacks,sequence randomness,correlation and differential performance analysis to verify the security of the improved Logistic chaotic mapping algorithm and the feasibility of the algorithm in short message system.At the same time,the AES encryption algorithm is used to encrypt the short message data of Beidou.It is found that the key expansion algorithm in AES cryptosystem can not effectively resist plaintext attacks such as Square attack,and the key expansion structure reduces the avalanche performance.In this paper,an improved AES encryption algorithm based on two-dimensional chaotic map TD-ERCS is proposed.The cryptographic key of the improved encryption algorithm is dynamically generated by the two-dimensional chaotic map TD-ERCS iteration,and the improved algorithm key space is enhanced while the algorithm is resistant to selective plaintext.Attack ability.The improved algorithm's anti-Square attack ability and anti-exhaustive attack ability are analyzed,and the security of the improved algorithm to encrypt short message information is verified.Finally,the two encryption methods proposed in this paper are applied in the Beidou short message communication system,and a Beidou short message security communication test platform is built.The platform forwards and forwards the content of the message in the encrypted Beidou short message communication application protocol.Through the statistical analysis of the packet loss rate and transmission delay of the message transmission system after adding the encryption algorithm,the feasibility of the encryption algorithm in the Beidou short message communication system is verified. |
PDF Full Text Request