异构无线网络中基于模糊集合的动态信任模型

针对异构无线网络融合带来的安全问题，提出了一个基于模糊集合的动态信任模型DTMBF。使用模糊隶属度标示了信任的主观不确定性，引入直接信任、推荐信任、推荐可信度和信任时间戳4个参量来计算网络的信任度，并通过信任反馈控制机制动态调节上述参量。直接信任和推荐信任反映了网络的历史服务情况，推荐可信度和信任时间戳则反映了信任反馈的可信性和时效性。仿真分析表明，该模型能准确有效地确定网络的信任度，有效地抑制了恶意用户的诋毁行为和合谋欺骗行为。

Dynamic trust model based on fuzzy set in heterogeneous wireless network

A dynamic trust model based on fuzzy set (DTMBF) was proposed to solve the new security challenges in heterogeneous wireless networks (HWNs). In the model, the fuzzy membership degree was used to show the subjectivity and indeterminacy of the trust. The trustworthiness evaluation incorporated direct trust, recommendation trust, reputation of recommenders and time stamp. These parameters were adjusted in time using trust feedback control mechanism. Direct and recommendation trust reflected how well the candidate network has fulfilled the service agreements in the past. Reputation of recommenders and time stamp were introduced to show the creditability and time efficiency of the trust feedback. The simulation results show the DTMBF model can accurately evaluate the trustworthiness of the network and effectively restrain the acts of slander and co-fraud.