中文摘要：

针对困扰P2P文件共享系统的搭便车问题,构造了一种基于节点信度的激励模型.该模型中每个节点都是一个信度实体.引入信度收益函数使节点根据资源请求者的信度值分配资源,使信度收益最大化.并应用回溯算法求解信度收益最大化问题.引入信度衰减机制防止信度值＂通货膨胀＂且收到更好激励效果,该模型给出了节点信度的计算方法.针对当前激励机制评价标准的不足,补充了一个新的评价参数,即资源有效利用率.实验证明,该模型能够有效抑制P2P系统中的搭便车问题,提高了系统效率.

英文摘要：

In order to deal with free riding in P2P systems, an incentive model based on peer credit has been proposed. Each peer in this model is a credit entity. Through introducing reward method to the model, peers will allocate resources according to the credits of request peers to maximize their own credits. A backtracking algorithm has been suggested to solve the issue of maximizing credit rewards. To avoid inflation of the credit, attenuation method is introduced. The scheme on how to apply the credit model in hybrid P2P networks has also been presented in this work. The experimental results show that the model can effectively control free riding and improve efficiency of the system.