一种无结构P2P网络中对抗Free-rider的新方法

Novel Method to Anti-free-rider on Unstructured P2P Networks

无结构P2P网络中普遍存在搭便车(freeriding)现象,从而严重威胁到P2P网络的性能(如公平性、容错性和扩展性)和广泛应用.本文提出一种新的分布式算法,通过对搭便车者(free-rider)的准确定位并采取的应对制约措施,来降低搭便车者对网络的危害.在本文算法中,每一个对等节点仅监控自己的邻居,判断其是否为搭便车者,进而对其采取限制或惩罚措施.和绝大多数现有的对抗搭便车者的方法不同,本文的算法既不需要一个用来维护系统全局信誉的安全基础结构,也不需要永久节点ID,每个节点只需存储来自邻居的消息(message)并维护一组邻居消息计数器,因此是高效、轻量级的.仿真结果表明本算法对抗free-riding的效能良好,对无结构P2P网络的吞吐量等有显著提高.

In P2P network,free riding is so prevalent that it is harmful or even seriously threatened to the normal P2P applications.A novel distributed algorithm to alleviate the impacts of free-riding is proposed,in which free-riders＇ location is mainly concerned.In the algorithm,each peer monitors its neighbors and reaches its own judgment that if the neighbor is a free-rider or not.Most of the existing methods fighting with free-riding require a permanent peer＇s ID or a mechanism to maintain a global reputation of each peers,but in our algorithm each node just store the message coming from its neighbours and a set of counters.Simulation experiments show that the algorithm is effective and efficient to combat free-riding in the unstructured P2P networks and its performance on throughput has significantly improved in compare with the existing solutions.