Peer-to-Peer (P2P) systems allow all peers to communicate and share resources with equal responsibility thereby eliminating the need for central authorities. These networks have gained wide popularity in providing services ranging from file sharing to distributed computing applications. In P2P networks the peers can join or leave the system dynamically and so the network topology changes due to this behavior. These features of a P2P make it vulnerable to different types of attacks. Trust and Reputation models can be used to minimize the impact of such threats. This paper proposes a trust model to identify malicious nodes in a P2P network. The main aim of the paper is to deploy a trust model for determining the trust value of peers with the notion of avoiding malicious ones. In this paper the global trust of a base peer is computed by only those set of peers that are reliable to the base peer. This can greatly help to reduce the computation and communication overhead associated with other trust and reputation based models where all the interacted peers have to respond to compute the global trust of the base peer. The proposed model takes the responsibility to detect malicious nodes and eliminates them from the system.

1. Lin Wang. 2006. Attacks against Peer to Peer Networksand Countermeasures. Seminar on Network Security,TKK T-110.
2. Audun Jøsang, Roslan Ismail and Colin Boyd, "A Survey of Trust and Reputation Systems for Online Service Provision". Journal Decision Support Systems, 2007, Vol 43, Issue 2, pp 618-644.
3. Xiaoliang Wang,Lincong Yang,Xingming Sun,Jinsong Han,Wei Liang and Lihong Huang, "Survey of Anonymity and Authentication in P2P Networks". Information Technology Journal, 2010, 9:1165-1171.
4. Natalia Stakhanova,Sergio Ferreri, Johnny S. Wong and Ying Cai,2006. A Reputation based Trust Management in Peer to Peer Network. Proceedings of ISCA,pp 510-515.
5. Selpk. A. A. , Uzun,E. and Pariente, A. , 2004. Reputation-Based Trust Management System for P2P Networks. IEEE International Symposium on Cluster Computing and Grid,pp 251-258.
6. Kim,Y. , Mazzocchi, D. and Tsudik,G. 2003. Admission Control in Peer Groups . Second IEEE International Symposium on Network Computing and Applications,pp 131.
7. Huu Tran, Michael Hitchens, Vijay Varadharajan and Paul Watters 2005. A Trust based Access Control Framework for P2P File-Sharing. Proceedings of Annual Hawaii International Conference on System Sciences,pp 302c.
8. Park, J. S. , An, G. and Chandra, D. 2007. Trusted P2P computing environments with role based access control. Information Security, IET Volume 1, Issue 1,pp 27-35.
9. Gaspary, L. P. , Barcellos,M. P. , Detsch, A. and Antunes, R. S. , " Flexible Security in Peer to Peer Applications: Enabling new opportunities beyond File sharing", International Journal of Computer and Telecommunications Networking, 2007,Vol 51.
10. A. Gupta, D. Malhotra and L. K. Awasthi, 2008. NeighborTrust: A trust based scheme for countering Distributed Denial of Service attacks in P2P Networks. Proceedings of 16 th IEEE International Conference on Networks, pp 1-6.
11. Loubna Mekouar, 2010. Reputation Based Trust Management in Peer to Peer File Sharing Systems. Thesis Report. University of Waterloo.
12. Moalla, S. , Hamdi, S. and Defude, B. , 2010. A New Trust Management Model in P2P Systems. Proceedings of International Conference on Signal Image Technology and Internet Based Systems,pp 241-246.
13. Sepandar ,D. Kamvar, Mario, T. Schlosser and Hector Garcia-Molina, 2003. The Eigen Trust Algorithm for Reputation Management in Peer to Peer Networks. Proceedings of International Conference on World Wide Web, pp 640-651.
14. L. Xiong and L. Liu,2004. PeerTrust:Supporting Reputation Based Trust for Peer to Peer Electronic Communities. IEEE Transactions on Knowledge and Data Engineering, Vol 16,pp 843-857.
15. Chen, X. Zhao, L. Tang, J. Hu, and Z. Chen, 2007. CuboidTrust: A Global Reputation based Trust Model in Peer to Peer Networks. Autonomic and Trusted Computing, Lecture Notes in Computer Science, Vol 4610, pp 203-215.
16. W. Wang, G. Zeng and L. Yuan, 2006. Ant-Based Reputation Evidence Distribution in P2P Networks. Proceedings of International Conference on Grid and Cooperative Computing, pp 129-132.
17. Debora Donato, Stefano Leonardi and Mario Paniccia, 2008. Combining Transitive Trust and Negative Opinion for better Reputation Management. Workshop on Social Network Mining and Analysis.
18. Han Yu, Zhiqi Shen, Chunyan Miao, C. Leung and D. Niyato, 2010. A Survey of trust and reputation management in wireless communications. Proceedings of the IEEE, 98(10):1755-1772.
19. Chun-Ling Cheng, Xiao-Long Xu and Bing-Zhen Gao, "MEtrust: A Mutual Evaluation Based Trust Model for P2P Networks". International Journal of Automation and Computing, 2012, V9 (1):63-71.
20. Y. Wang, Y. Tao, P. Yu and F. Xu, 2007. A Trust Evolution Model for P2P Networks. International Conference in Autonomic and Trusted Computing, pp 216-225.
21. F. Yu,H. Zhang, F. Yan and S. Gao,2006. An Improved Global Trust Value Computing Method in P2P System. Autonomic and Trusted Computing, Lecture Notes in Computer Science, Vol 4158, pp 258-267.
22. Chunqi Tian, Baijian Yang, "R2Trust - a reputation and risk based trust management framework for large –scale, fully decentralized overlay networks". Journal Future Generation Computer Systems, 2011, Vol 27, Issue 8, pp 1135-1141.

Peer To Peer Reputation Trust Ddos Attack.