Design And Implement Of C/S Instant Message System Based On Winsock

With the rapid development of communication and the growing popularity of Internet,instant messaging is increasingly become an integral part of people's daily life. It is promoted by its own characteristics to be a portal of the personal information and applications,instant messaging,as one of Internet applications,will play a very important role in the future.Instant messaging system had been widely used after released,either as a tool for online- chatting in daily life, or as an communications platform in enterprises. Almost all the popular instant messaging systems have to access to the Internet. Besides,they can not guarantee the security of information,which prevents the real-time communication further used in enterprises and schools.Based on the study of Internet,encryption,database,and Winsock,this issue proposes a new design and implementation of instant messaging system,which applies to LAN and can secure transmission of information. It integrates three-layer C/S model and P2P model, and designs functional modules according to requirements.The paper analysis communication procedures of main modules,and come up with an implementation,which is combined with ADO technology,multi-threaded technology and DES encryption. The system has functions of login,text communications,file transfer,user-information management, and ensures the security of information.Finally,the paper conducts a test on function and performance of system. The result of test shows that,the system has normal functions and good performance,achieves the requirements of instant and security.