Instant Messaging System Based On Hybrid Encryption Design And Implementation

With the With the development of computer and network technology,network communication has become an indispensable part in the information society today,which has an increasing influence on our lives.All kinds of tailor-made network communication technologies for the Internet are produced one after another.Because of the difference of the needs of each corporation,the designs of existing instant messaging system for corporations differ from each other.Meanwhile,due to the particularity of the Party and government organizations,it's an urging need to fulfill safe and fast instant messaging communication among them.Therefore,in the context of enterprises and institutions,this paper designs and implements a hybrid encrypted instant messaging system in order to help enterprises improve operational efficiency,reduce communication costs,offer the staff a safer,more convenient method to communicate.This paper analyzes the current development status of instant messaging software,sum up the shortcomings and advantages of several representative software,and emphatically analyzes its safety performance design.In terms of its shortcomings in security,taking the current internal demand for communication among employees into account,this paper combines key agreement and message encryption perfectly to achieve complementary design with the principles of safety and convenience,making use of the separate advantages of the current most representative symmetric and asymmetric encryption algorithms(AES & ECC).In addition,a "sharing" idea is manipulated to enhance the rate of file encryption transmission,and ultimately this enterprise-class section of a hybrid encryption instant messaging system is designed and implemented.The main work is as follows:(1)The session key was generated safety and quickly.Designing and implementing authentication protocol for communication.Based on the improved Needham-Schroeder protocol,the companion of server and client is used to verify identity and negotiate key agreement.Firstly,this protocol solves the problem of role assignment of the server and the client.The server in this protocol implementation is mainly responsible for the verification of client identity and the key management,and the client is in coordination with the server to verify the peer communication entities.Secondly,the technical problem of the symmetric encryption key generation is solved so that the key is able to be generated efficiently and exchanged safely.(2)Combining design realized by AES and ECC system of hybrid encryption algorithm.The main idea is to combine the separate advantages of the existing symmetric encryption algorithms AES,public-key encryption algorithm ECC,and Hash algorithm,to achieve a set of encryption mechanism corresponding to the application features of enterprises and institutions,which effectively reduces the message transmission risk.The symmetric encryption algorithm AES and public-key encryption algorithm ECC are combined to solve the multiple key technical problems of sole encryption mode easily cracked,low encryption efficiency,lack of standard to manage the key,so as to achieve efficiency and safety during the file transfer process.(3)Based on mixed system mode of C/S and P2 P,which overcomes the weakness of inefficient and hard maintenance in C/S mode,and low security in P2 P mode,with the help of boost portable C++ multithreading library,by socket programming the entire system achieves the basic functions of instant messaging software,including user login and registration,buddy list maintenance,server information management,message sending,file and folder transfer,and so on.Finally,according to their specific operating environment and functional requirements,separate functional parts of this system and the overall performance have been tested to improve the design of this system.