The Secure File-sharing System Based On P2P In Collaborative Design

With the development of modern information technology,information exchange and file sharing at any time,any place are badly required by more and more people. In recent years,the P2P technology gradually becomes the most popular network transmission technology.Nowadays,P2P has been widely used in many aspects just like file-sharing,CSCW,scientific computing,search engines,instant messaging, online games and so on.Especially in the area of file-sharing,P2P has quit different concept from traditional download methods.The more people download,the faster the download.And it gets obvious advantages when the download files are large.So P2P has more and more fans.A lot of file sharing software based on P2P have become indispensable tools in our lives.But so far many are still used to share audios,videos,pictures and so on, seldom used in high security working environment.Collaborative design,as the combination of the technologies of CAD and CSCW,can fully utilize the remote resources,shorten products' made-time effectively,and reduce products' designing cost,then the file-sharing based on P2P applied to the collaborative environment is inevitable.In this paper,the author designes and develops a security file-sharing system based on P2P for the collaborative environment.It comprehensively analyzes the principle and characteristics of P2P.Introduced the well-known open-source P2P protocol - BT protocol,the advantages of BT protocol and its working principle.It also analyzes the security of the SSL protocol,and how to use SSL to encrypt the TCP transmission.Finally it designed and implemented a more secure file sharing system based on P2P,and uses SSL protocol to encrypt the key transmission channels. Not only improve the confidentiality of the sharing files and data integrity,but also identity the authentication who wants to get the sharing files.So it solve part of the security problems in collaborative environment.At the same time,the system has been obviously inherited the advantages from P2P like robustness,efficiency,load balancing.In this paper,the innovative characteristics of the point are summed up in the following two aspects:1) In the circumstances of collaborative design,to use a new download mode which combins the BT and the traditional FTP download advantages.Improve the efficiency of download.2) Both use BT protocol and SSL protocol.The system uses SSL protocol to encrypt the key channels of the BT transmission in order to enhance the security of file-sharing and improve anti-offensive.