基于信誉和评价的p2p网络信任模型分析.docx

节点的全局信誉值·································································································· 34
本章小结················································································································ 36
第六章信任模型的仿真及实验分析················································································· 37
仿真的实验目的······································································································ 37
仿真的实验环境及参数设置···················································································· 37
仿真及实验结果分析······························································································ 37
不同规模的恶意节点下 SDR 比较 37
不同初始值下的 SDR 的比较 38
信任衰减下的 SDR 比较 38
节点协同***下的 SDR 比较 39
本章小结················································································································ 39
第七章总结与展望·········································································································· 40
本文的工作············································································································· 40
下一步工作·············································································································· 40
第一章 绪论
研究背景及意义
在早期的计算机网络时代,基于 C/S(Client/Server)网络已经成为人们平常生活中主流的网络应用方式,其服务器已经成为了整个计算机网络应用的核心。在 C/S 模式下,服务器终端功能比较强大,有着极为丰富的数据类资源和非常大的网络带宽,它可以同时为许多个用户提供较高质量的网络服务。而其客户端用户仅是作为访问网络的一个终端,不能为其它的用户提供相应的系列服务。伴随着 C/S 网络应用技术的快速发展,C/S 服务器的性能瓶颈问题也带来了不少突出问题,这些问题的存在极大的限制了服务端系统资源的充分利用,并且越来越无法满足日益快速增长的分布式应用服务需求。基于 C/S 网络应用的缺点和不足,P2P(Peer-to-Peer)网络的应用应运而生。P2P 网络也称之为点对点网络或对等网络,其每个节点在网络系统中既担当资源的提供者又担当系统资源的请求者,并且它的每个节点的地位相等,没有主次之分。P2P 网络与 C/S 网络的一个最大不同之处在于:在 P2P 网络中,系统的资源信息是以对称的双向传输和交换在节点之间进行传播发送的,每一个节点的功能都是一样的,这就去除了传统的 C/S 模式由于服务器负载过重和扩展性过差等带来的难题。P2P 网络为我们仿真了一种相似于人类社会中人与人之间交流的网络环境,在这个网络中任何个体都可以随时加入到这个网络,也可以随时离开网络,行动很自由,并且他们也可以在网络中获取他们所需要的资源信息,也可以为其他人提供所需的资源信息。
正是基于这个优点,P2P 网络已经逐渐成为人们平常生活的主要网络应用方式。然而 P2P 网络系统的缺点和不足也伴随着现有系统深入的应用而逐渐被暴