移动自组织网络(MANETs)中,移动节点具有匿名性和高度自治的特点;并且由于缺乏对与之交互的节点的可信程度的知识,节点需应对交互过程中可能出现的威胁.另外,网络拓扑结构的改变或无线冲突的发生都可能导致作为信任值评估证据的样本空间不一定完整和可靠,使得现有的信任评估模型不太适用.提出了一种基于置信度的MANETs环境下的主观信任管理模型(CFSTrust),用于量化和评估节点的可信程度;给出了模型的数学表述和实现方法.运用模糊似然度和置信度对信任管理问题进行了建模,给出信任的评价机制,并提出了推荐信任关系的推导规则,构造了一个完整的主观信任管理模型.分析及仿真实验结果表明,CFSTrust模型较已有的基于证据理论的信任评估模型(TrustNet)更为有效,并为MANETs环境中的信任管理研究提供了一个有价值的新思路.
In mobile Ad-hoc networks (MANETs), due to their anonymous and self-organization nature mobile nodes have to manage the risks involved in the transactions without prior knowledge about each other's reputation. The sample space of evidence may be not integrative or reliable because of the change of network topology or the occurrence of wireless collision, so the existing trust evaluation models can't be applied. To solve the problem of trust evaluation and establish the trust relationship between nodes, CFSTrust, a subjective trust management model, is proposed to quantify and evaluate the trustworthiness of nodes. Its mathematical description and implementation are also given. The fuzzy-similarity and certainty-factor are used to model the issues of trust management. The evaluation of subjective trust is discussed, the derivation rules of recommendation trust relationships in MANETs are presented and a subjective trust management model is provided. Theoretical analyses and experimental results show the model is more effective compared with the trust model based on evidence-evaluation (TrustNet). The formal model proposed provides a new valuable way for MANETs environments.