利用P2P覆盖网络(P2P overlay networks)进行资源组织是当前研究的热点,如何保证资源获取的可靠性是研究人员面临的一个主要问题.利用节点的动态自组织属性,基于节点物理位置的拓扑构造可以提高P2P网络的性能,但没有关注P2P网络中恶意节点的问题;基于偏好的拓扑构造可以有效地提高资源共享和搜索的效率,但没有考虑节点实际提供服务的能力和节点行为的可靠性.提出了一个基于信任机制的自组织资源拓扑构造方案,利用Bayesian方法根据节点的行为来评估节点的信任度.通过节点间基于信任关系的链路更新,构造出新的自组织拓扑结构.仿真实验表明,该拓扑结构不仅有利于节点发现资源的效率,提高整个P2P网络的交互性能,还能使节点聚集在服务能力较强的可信节点周围,保证资源选取的可靠性.
Utilizing peer-to-peer (P2P) overlay networks to organize resources is a hot topic recently. How to assure the dependability of the resource selection in the overlay is a crucial problem. In overlay networks, self-organization is handled through protocols for node arrival and departure. Topology revolution based on physical location can improve the performance of P2P networks, but it ignores the problem of malicious nodes in the networks, which will greatly affect the resource providing ability of the whole P2P network; while topology revolution based on interest could improve the efficiency of resource sharing and searching in the networks, but it ignores the actual ability of resource providing and the reliability of nodes as well. In this paper a trust mechanism-based self-organization resource topology is developed and Bayesian method is used to evaluate the trust value of nodes based on their behavior. By updating the trust-based connection between each node, a novel self-organization topology is built on the top of the physical topology. Simulation experiments show that the proposed model not only increases the resource find ratio, but also improves the interaction performance of the entire network. In addition, this kind of model can cluster nodes near the trustworthy ones in the networks which have stronger ability of resource providing, and assure the reliability of resource sharing and selection.