An Incentive Security Model to Provide Fairness for Peer-to-Peer Networks

Peer-to-Peer networks are designed to rely on the resources of their own users. Therefore, resource management plays an important role in P2P protocols. Early P2P networks did not use proper mechanisms to manage fairness. However, after seeing difficulties and rise of freeloaders in networks like Gnutella, the importance of providing fairness for users have become apparent. In this paper, we propose an incentive-based security model which leads to a network infrastructure that lightens the work of Seeders and makes Leechers to contribute more. This method is able to prevent betrayals in Leecher-to-Leecher transactions and helps Seeders to be treated more fairly. This is what other incentive methods such as Bittorrent are incapable of doing. Additionally, by getting help from cryptography and combining it with our method, it is also possible to achieve secure channels, immune to spying, next to a fair network. This is the first protocol designed for P2P networks which has separated Leechers and Seeders without the need to a central server. The simulation results clearly show how our proposed approach can overcome free-riding issue. In addition, our findings revealed that our approach is able to provide an appropriate level of fairness for the users and can decrease the download time.

I. Introduction

A Peer-to-Peer (P2P) network is a distributed solution which uses the resources of its own users. In these networks, each node uses the resources of other users and also has the capability to provide resources for other nodes [1] , [2] . These networks have many applications, including file sharing, distributed processing and messages passing to other nodes which can cause many security problems [3] , [4] . P2P networks are highly dependent on resources of their own users [5] . Therefore, the infrastructure of a P2P network should encourage users for contributions as well as using the resources of other members. The behavior of using resources of others without giving anything in return is called free-riding [6] . As a consequence, free-riders cause slower download times for contributing peers. Thus, it is an essential need for a P2P network to guarantee fair bandwidth allocation, where a peer receives bandwidth equal to what it contributes. Accordingly, the system will be able to guarantee a certain level of performance for contributing peers.