共查询到20条相似文献,搜索用时 156 毫秒
1.
针对已有基于轻量云模型的节点信誉安全方案中存在的决策困难问题以及推荐节点的恶意行为识别问题,提出了优化的轻量云模型MLCM(Modified Light-weighted Cloud Model),并在此基础上设计实现一种新型的节点信誉安全方案.首先,在传统无线传感网信任管理信任值的处理方式的基础上,对节点的直接信任值和间接信任值进行综合处理后再利用云模型简化逆向云算子进行计算,以解决信任误判问题;其次,用云隶属度函数计算推荐信任值,在涉及推荐节点信任值计算时可以提高恶意节点识别的准确度.实验表明,该方案在克服传统的入侵容忍和敏感度之间矛盾问题的同时,还解决了攻击节点对单一节点发动攻击时造成的决策困难问题和恶意节点准确识别问题. 相似文献
2.
3.
4.
无线传感网(Wireless Sensor Network,WSN)因节点众多、通信开放、资源有限,且通常部署在无人值守区域,表现出明显的安全脆弱性。提出了基于具有能量高效特征巡查机制的WSN安全应对模式,设计出了一种融合信誉评估与巡查机制的WSN安全成簇算法:首先构建簇化层次式网络模型,基于节点的剩余能量和簇质心距离选取簇头节点,提升节点能量消耗的均衡性;并建立节点信誉评估模型,通过巡查机制随机检测节点的通信行为,基于节点行为对信息安全的威胁程度,利用指数函数计算并及时更新节点的信誉值,放大性地惩罚节点的异常行为,有助于节能和快速发现恶意节点。仿真测试结果表明,算法能够均衡传感器节点的能量消耗,在不明显缩短网络生命周期的情况下,对无线传感网中恶意节点具有较高的检测速率和97%的检测率。 相似文献
5.
恶意节点会影响SDN网络的稳定运行,因此,设计有效的恶意节点识别系统具有重要意义。针对SDN网络提出基于信誉机制的恶意节点识别系统。首先,通过设计控制中心模块、监控模块、响应模块和检测模块组建系统整体结构;然后,在云模型的基础上设计节点信誉机制,获取节点在SDN网络中的信任值,根据信任值识别恶意节点;最后,设计了信任更新机制,跟踪节点在不同时刻的信任值变化情况,提高对恶意节点的识别精度。实验结果表明,该系统具有较高的恶意节点识别精度和识别率。 相似文献
6.
基于时间窗反馈机制的动态P2P信任模型 总被引:5,自引:0,他引:5
现有的信任模型在识别不诚实反馈、惩罚恶意节点的策略性动态改变行为和激励机制等方面存在不足.为了解决这些问题,提出了一个基于时间窗的局部信任模型TW-Trust,统一考虑了信任、信誉与激励三者的内在关系,同时考虑了时间因素对信任计算的影响.使用直接信任、历史信誉、差别信誉、滥用信誉、相似度和激励效用6个参数来计算网络节点信任度,并通过反馈控制机制动态调节这些参数,提高了信任模型的动态适应能力.仿真实验结果表明,TW-Trust较已有模型能更好地处理恶意节点策略性动态变化行为和不诚实反馈对系统的攻击,能更好解决相似度计算中的稀疏性问题,在信任计算误差和事务失败率等性能指标上有较大提高. 相似文献
7.
8.
为了解决联邦学习过程中数据异质性导致模型性能下降的问题,考虑对联邦模型个性化,提出了一种新的基于相似度加速的自适应聚类联邦学习(ACFL)算法,基于客户端本地更新的几何特性和客户端联邦时的正向反馈实现自适应加速聚类,将客户端划分到不同任务簇,同簇中数据分布相似的客户端协同实现聚类联邦学习(CFL),从而提升模型性能。该算法不需要先验确定类簇数量和迭代划分客户端,在避免现有基于聚类的联邦算法计算成本过高、收敛速度慢等问题的同时保证了模型性能。在常用数据集上使用深度卷积神经网络验证了ACFL的有效性。结果表明,所提算法性能与聚类联邦学习算法相当,优于传统的迭代联邦聚类算法(IFCA),且具有更快的收敛速度。 相似文献
9.
针对流式数据的动态聚类问题,提出了一种基于变长滑动窗口和遗传算法相结合的流数据聚类算法.在给出微簇、变长滑动窗口模型和流数据项衰减函数等定义的基础上,给出了在线部分使用的基于变长滑动窗口进行微聚类的算法描述,进而结合遗传算法设计了离线部分采用的宏聚类算法.实验结果表明,算法不仅解决了传统聚类具有的初始中心敏感性问题,而且具有较小的内存开销和良好的聚类质量. 相似文献
10.
提出了一种基于信息熵的层次词聚类算法,并将该算法产生的词簇作为特征应用到中文组块分析模型中.词聚类算法基于信息熵的理论,利用中文组块语料库中的词及其组块标记作为基本信息,采用二元层次聚类的方法形成具有一定句法功能的词簇.在聚类过程中,设计了优化算法节省聚类时间.用词簇特征代替传统的词性特征应用到组块分析模型中,并引入名实体和仿词识别模块,在此基础上构建了基于最大熵马尔科夫模型的中文组块分析系统.实验表明,本文的算法提升了聚类效率,产生的词簇特征有效地改进了中文组块分析系统的性能. 相似文献
11.
12.
13.
Aiming at the problem that the wireless Mesh network (WMN) security routing mechanism was scarce and internal malicious nodes drop data packets during data transmission,a secure routing mechanism based on dynamic reputation (SRMDR) for wireless Mesh network was proposed.Firstly,the dynamic reputation mechanism was used to evaluate the node’s behavior,the node’s comprehensive reputation value was calculated according to the node’s direct reputation value and the recommended reputation value,and the node’s dynamic reputation value was calculated according to the node’s historical comprehensive reputation value and the current comprehensive reputation value.Then,the dynamic reputation was combined with the routing mechanism to establish secure routing paths,the nodes with a dynamic reputation value less than the threshold were determined to be malicious nodes,which were isolated during the routing process.Experimental results show that compared with HWMP and SHaRP,SRMDR has higher malicious node recognition rates,and SRMDR can effectively reduce packet loss rate and improve network throughput. 相似文献
14.
Mobile ad hoc network (MANET) is defined as the category of wireless network that is capable of operating without any fixed infrastructure. The main assumption considered in this network is that all nodes are trusted nodes but in real scenario, some nodes can be malicious node and therefore can perform selective dropping of data packets instead of forwarding the data packets to the destination node. These malicious nodes behave normally during route discovery phase and afterwards drop fractions of the data packets routed through them. Such type of attack is known as smart gray hole attack which is variation of sequence number based gray hole attack. In this paper, we have launched smart gray hole attack and proposed a new mechanism for mitigating the impact of smart gray hole attack. Mitigating Gray hole Attack Mechanism (MGAM) uses several special nodes called as G-IDS (gray hole-intrusion detection system) nodes which are deployed in MANETs for detecting and preventing smart gray hole attack. G-IDS nodes overhear the transmission of its neighbouring nodes and when it detects that the node is dropping the data packets which are greater than threshold value then it broadcast the ALERT message in the network notifying about the identity of malicious node. The identified malicious is then blocked from further its participation by dropping the request and reply packet. In order to validate the effectiveness of our proposed mechanism, NS-2.35 simulator is used. The simulation results show that the proposed mechanism performs slightly well as compared with the existing scheme under smart gray hole attack. 相似文献
15.
信任管理成为车载自组织网络(VANET)应用的重要问题。针对该问题提出一种基于角色和事件信任等级评价的信任模型,结合以往方法的直接信任和邻居节点推荐信任的基础上,引入节点角色和事件等级并分配相应权重,综合判定信息是否可信。信任值计算采用角色信任等级评价的方法,受评价节点信任等级的影响,在一定程度上降低恶意节点共谋攻击,恶意评价。仿真后证明,该方法在安全性能、过滤恶意节点、降低系统开销等几个方面有较好表现,进一步加强了VANET网络环境中对恶意节点和恶意信息的识别和过滤,更有效地进行信息传递。 相似文献
16.
摘要:传统的航空无线电协作频谱感知算法无法区分节点的性质(普通/恶意),而新的加权序贯检测(weighted sequential probability ratio test,WSPRT)算法虽然解决了这个问题,但在具有频谱感知数据篡改(spectrum sensing data falsification,SSDF)攻击节点的环境中,无法保持高的感知正确率。提出了一种改进型WSPRT 算法,在传统的 WSPRT 算法基础上改进了信誉度奖惩方案,增加了临近时间内感知稳定度的量化。从实验仿真结果看,改进后的算法不仅时间复杂度更低,而且能够有效地识别恶意节点,对于恶意用户的判定更准确。 相似文献
17.
18.
Mobile ad-hoc network (MANET) is a temporary network in which the main requirement for establishing the communication path among nodes is that the nodes should be cooperative. However, in the presence of malicious node, the MANET’s routing protocol such as AODV is vulnerable to different types of flooding attacks. The flooding attack can be continuous or selective. In the available literature, although many researchers have analyzed the network under continuous flooding attack but they have not focussed on selective flooding attack in which an attacker can sometimes behave as a normal and sometimes behave as a malicious. Most of the existing schemes use constant threshold value which lead to a false positive problem in the network. In order to address this issue, a new mechanism called as Mitigating Flooding Attack Mechanism is proposed which is based on a dynamic threshold value and consists of three phases. It makes use of several special nodes called as Flooding-Intrusion Detection System (F-IDS) that are deployed in MANETs in order to detect and prevent flooding attack. The F-IDS nodes are set in promiscuous in order to monitor the behaviour of the node. The simulation results show that the proposed mechanism improves network performance metrics in terms of PDR, throughput and reduces the routing overhead as well as normalized routing load. 相似文献
19.
针对无线传感器网络路由安全与可靠性的问题,提出了一种基于组合指标的安全路由算法.评估节点通过观测被评估节点的数据包转发行为,计算直接信任值,然后与第三节点推荐的信任值进行加权求和,得到一个综合信任值.为了提高信任的准确性,避免出现合谋攻击,对第三方推荐的信任值进行了信任相似度检测.通过对期望传输次数和信任值进行加权组合,形成一个用于选择下一跳节点的组合路由指标.最后,对所提出的算法进行了仿真验证.结果表明,所提出的算法能够有效地避免恶意节点的攻击,在传递率和总的传输次数方面明显优于其他算法. 相似文献