Research On And Implementation Of Instant Messaging System Based On XMPP Protocol And Hybrid Encryption

With the rapid development of smart phones and mobile internet,mobile instant messaging software has gradually become a part of people's lives.Rich multimedia information makes people communicate with their relatives and friends more colorful anytime,anywhere.However,the privatization of commercial instant messaging software protocols has hindered the development of instant messaging,and developers are increasingly aware of the drawbacks of developing only by themselves.Therefore,the open source instant messaging protocol has been paid more and more attention.XMPP(Extensible Messageing and Presence Protocol)protocol has been favored by more and more developers.In view of the current situation of the blockade of instant messaging software protocols,combining with the open source XMPP protocol and hybrid encryption scheme,this paper designs a special hybrid encryption scheme for instant messaging system by improving the AES(Advanced Encryption Standard)and ECC(Elliptic Curves Cryptography)encryption algorithm based on the project of "Gaining Customers in Finance",and designs and develops an instant messaging system based on XMPP protocol.Firstly,this paper investigates the development status of instant messaging software and instant messaging protocol at home and abroad,and compares four commonly used instant messaging protocols,and chooses XMPP protocol which is open source,flexible and scalable.Then,this paper studies the overall architecture,address structure,message format and security mechanism of XMPP protocol in detail,and introduces Openfire open source server,Smack open source API based on XMPP protocol and Android operating system.Then,this paper analyses the functional and non-functional requirements of the IM system embedded in "Gaining Customers in Finance".Then it designs the overall architecture and network topology of the system,and designs the database,server and client in detail.On this basis,the original encryption algorithms of AES and ECC are studied,and their security defects are improved.At the same time,the key generation process is adjusted,and the hybrid encryption scheme and selective encryption are designed.Then this paper implements the instant messaging system,gives the corresponding class diagrams of each module,explains the important classes and methods,implements the hybrid encryption scheme,and then tests each module of the client,at the same time tests the function and performance of the hybrid encryption,and demonstrates its security.It is confirmed that the performance and security of the mixed encryption scheme designed in this paper are better than those of the single encryption algorithm.Finally,this paper summarizes the whole work,analyzes the shortcomings of the system,and looks forward to the development of instant messaging.