A fuzzy‐based trust model for flying ad hoc networks (FANETs)

The use of unmanned aerial vehicles has significantly increased for forming an ad hoc network owing to their ability to perform in exciting environment such as armed attacks, border surveillance, disaster management, rescue operation, and transportation. Such types of ad hoc networks are popularly known as flying ad hoc networks (FANETs). The FANET nodes have 2 prominent characteristics—collaboration and cooperation. Trust plays an important role in predicting the behavior of such nodes. Researchers have proposed various methods (direct and indirect) for calculation of the trust value of a given node in ad hoc networks, especially in mobile ad hoc networks and vehicular ad hoc networks. The major characteristic that differentiates a FANET from other ad hoc networks is the velocity of the node; as a result, there are frequent losses in connection and topology change. Therefore, the existing methods of trust calculation are not efficient and effective. In this paper, a fuzzy‐based novel trust model has been proposed to handle the behavioral uncertainty of FANET nodes. Nodes are classified using a multicriteria fuzzy classification method based on node's behavior and performance in the fuzzy and complex environment. Quality of service and social parameter (recommendation) are considered for evaluating the trust value of each node to segregate the selfish and malicious nodes. With the node classification, FANET nodes are rewarded or punished to transform node behavior into a trust value. Compared with the existing trust techniques, the simulation results show that the proposed model has better adaptability, accuracy, and performance in FANETs.     

A Risk-Aware Reputation-Based Trust Management in Wireless Sensor Networks

Wireless sensor networks (WSNs) are susceptible to many security threats and are specifically prone to physical node capture in which the adversary can easily launch the so-called insider attacks such as node compromise, bypassing the traditional security mechanisms based on cryptography primitives. So, the compromised nodes can be modified to misbehave and disrupt the entire network and can successfully perform the authentication process with their neighbors, which have no way to distinguish fraudulent nodes from trustworthy ones. Trust and reputation systems have been recently suggested as a powerful tools and an attractive complement to cryptography-based schemes in securing WSNs. They provide ability to detect and isolate both faulty and malicious nodes. Considerable research has been done on modeling and managing trust and reputation. However, trust topic issue in WSNs remains an open and challenging field. In this paper, we propose a Risk-aware Reputation-based Trust (RaRTrust) model for WSNs. Our novel framework uses both reputation and risk to evaluate trustworthiness of a sensor node. Risk evaluation is used to deal with the dramatic spoiling of nodes, which makes RaRTrust robust to on–off attack and differ from other trust models based only on reputation. This paper contributes to model the risk as opinion of short-term trustworthiness combining with traditional reputation evaluation to derive trustworthiness in WSNs.

     

Trust evaluation method for clustered wireless sensor networks based on cloud model

Trust Management has been proved to be an effective method to detect malicious nodes and ensure security in Wireless Sensor Networks (WSNs). While, most existing trust management methods are not good at dealing with uncertainty of trust relationship such as randomness, fuzziness in WSNs, which leads to inaccurate trust metric. In this paper, a trust evaluation method for clustered wireless sensor networks based on cloud model is proposed and evaluated, which implements the conversion between qualitative and quantitative of sensor nodes’ trust metrics in order to achieve better trust evaluation. Firstly, the method considers multi-factors including communication factor, message factor and energy factor and builds mathematical model for each trust factor to get factor trust cloud. Secondly, immediate trust cloud is calculated by assigning adjustive weights for each factor trust cloud and combining them. Thirdly, recommendation trust cloud and immediate trust cloud are synthesized according to time sensitive factor in order to get final trust cloud. Furthermore, the final trust cloud of sensor node is converted to trust grade by trust cloud decision-making. Verification Experiments manifest that the proposed method has feasibility and accuracy in the aspect of evaluating sensor nodes’ trust. Moreover, comparison experiments under different attacks show that our method is sensitive to multiple attacks, it outperforms other trust evaluation methods not only in the accuracy of detecting malicious nodes, but also in the tolerance of abnormal conditions.     

Self-Recommendation Mechanism in Trust Calculation Among Nodes in WSN

This paper proposes a node self-recommendation mechanism which is effective in trust calculation model in wireless sensor networks (WSNs). The mechanism has little practical sense to cable and wireless network among which nodes’ resources, especially energy, are almost unlimited; furthermore it may bring some security risk to networks on the contrary. But as to WSNs where nodes’ resources are strictly limited, a node can express its intension of participating communication to its neighbors by using the mechanism according to its current running state and predefined strategies. This mechanism is useful to save nodes’ energy, balance network load and prolong network lifetime ultimately. The paper focuses on self-recommendation value expression, calculation and synthesis method. Application method of the mechanism is also discussed. Simulation results show that using trust calculation model cooperatively with self-recommendation mechanism can protect low energy nodes effectively and balance energy consumption among adjacent nodes without weakening malicious node identification function of the trust model.

     

Trust-Aware Fuzzy Evaluation Method for Preventive Route Generation in Mobile Network

The existence of a non-cooperative or black hole node as an intermediate node in a mobile network can degrade the performance of the network and affects the trust of neighbor nodes. In this paper, a trust-aware routing protocol is defined for improving the routing reliability against black hole attacks. A new Trust aware and fuzzy regulated AODV (TFAODV) protocol is investigated in this work as an improvement over the existing AODV protocol. The session-driven evaluation of stability, communication-delay, and failure-ratio parameters are conducted for evaluating the trust of nodes. The fuzzy rules apply to these parameters for computing the degree of trust. This trust vector isolates the attack-suspected and trustful nodes. The proposed TFAODV protocol used the trustful mobile nodes as the intermediate path nodes. The proposed protocol has been experimented with in the NS2 simulation environment. The analytical results are obtained in terms of PDR ratio, Packet Communication, Loss rate parameters. The comparative results are derived against the AODV, Probabilistic AODV, PDS-AODV, PSAODV, and Juneja et al. protocols. The analysis is performed on different scenarios varied in terms of network density, degree of stability, and the number of attackers. The simulation results ensured the proposed TFAODV protocol has improved the PDR ratio and reduced the communication loss significantly against these state-of-art protocols.

     

Applying trust enhancements to reactive routing protocols in mobile ad hoc networks

Due to the characteristics of mobile ad hoc networks, such networks are more susceptible to the destruction of malicious attacks or denial of cooperation. It would be easy for an adversary or a malicious node to launch attacks on routing function, especially attacks on packet routing. In order to mitigate these hazards, we incorporate the concept of ‘trust’ into MANETs, and abstract a decentralized trust inference model. The core of this model is trust computation, which is divided into two parts: historical trust assessment and trust prediction. We can quantify a node’s historical trust based on its historical behaviors via introducing multiple trust attributes. The fuzzy AHP method based on entropy weights is used to calculate the weight of trust attributes. By making use of the obtained historical trust data sequence, we propose an improved dynamic grey-Markov chain prediction measure to effectively estimate node’s trust prediction. In order to verify the validity of our trust model, we propose a trust-enhanced unicast routing protocol and a trust-enhanced multicast routing protocol, respectively. Both of the two new protocols can provide a feasible approach to kick out the untrustworthy nodes and choose the optimal trusted routing path. Moreover, the new proposed data-driven route maintenance mechanisms can reduce the routing overhead. The persuasive experiments have been conducted to evaluate the effectiveness of the new proposed trust-enhanced routing protocols in the aspects of packets delivery ratio, end-to-end latency, malicious node detection and attack resistance.     

基于等级评价的VANET信任模型

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。     

Adaptive and dual data-communication trust scheme for clustered wireless sensor networks

In wireless sensor networks, trust management schemes are designed to preserve them against misbehavior of malicious sensor nodes. These schemes observe the behavior of nodes, check their conformity to what is expected, compute and assign them trust values, and avoid any interaction with untrustworthy nodes. In this paper, we introduce Adaptive and dual Data-Communication Trust scheme (ADCT) for clustered wireless sensor networks to effectively deal with untrustworthy nodes. Unlike prior works, we propose an adaptive trust function to assess the direct trust between nodes according to the application’s requirement in terms of trust severity. We also consider data trust to cope with untrustworthy nodes during the data collection despite their communication capabilities. Moreover, we use the duality data-communication trust to deal with untrustworthy recommendations when building cluster-member’s feedback at the cluster-head level. Theoretical analysis and simulation show that the trust mechanism presented in this paper provides a better cooperation with the same or even lower communication overhead compared to the latest trust management schemes proposed for clustered wireless sensor networks.     

Ad Hoc网络中一种基于救赎机制的信任模型

在Ad Hoc网络中,节点由于自私等恶意原因以及链路错误导致拒绝转发数据,需要采用适当的机制来提高网络的转发性能。提出一种Ad Hoc网络中的信任模型来激励节点间的协作,在此信任模型中,每个节点通过直接监控和其它节点的推荐监控信息共同完成对邻居节点的信任评价,并维护所有邻居节点的信任值,同时在信任值更新和重建中引入信任值衰退和信任救赎机制来体现模型的健壮性。实验表明该信任模型中的信任救赎机制能提高网络可用性,且该模型有效抑制了恶意节点的行为。     

基于信任度计算的三阈值控制Ad Hoc网络节点撤销机制

为解决在资源受限且拓扑结构多变的Ad Hoc网络中对节点状态的量化控制,提出一种准确计算节点信任度值、三阈值控制的节点撤销机制.基于投诉机制的阈值用于快速将可疑节点挂起;基于信任度计算的阈值用于最终将恶意节点撤销;基于预警的阈值用于防止恶意节点短期内发起对某合法节点的连续错误投诉.分析及仿真表明:所提方案避免根据投诉数目而撤销节点的武断性,三阈值的采用保证了对潜在恶意节点的快速反应、信任度可量化及准确撤销,且能防止恶意节点对合法节点合谋投诉而造成的误撤销.     

MANET 中基于信任的安全位置辅助路由模型

In view of the security weakness in resisting the active attacks by malicious nodes in mobile ad hoc networks, the trust metric is introduced to defend those attacks by loading a trust model on the previously proposed Distance Based LAR. The improved Secure Trust based Location Aided Routing algorithm utilizes direct trust and recommendation trust to prevent malicious nodes with low trust values from joining the forwarding. Simulation results reveal that ST LAR can resist attacks by malicious nodes effectively; furthermore, it also achieves better performance than DBLAR in terms of average end to end delay, packet delivery success ratio and throughput.     

基于简化云与K/N投票的选择性转发攻击检测方法

针对无线传感器网络中恶意节点产生的选择性转发攻击行为,该文提出一种有效的攻击检测方法。该方法将简化云模型引入信任评估中,结合改进的K/N投票算法确定目标节点的信任值,将目标节点信任值与信任阈值比较,进行选择性转发攻击节点的判定。仿真结果表明,当信任阈值为0.8时,经过5个时间段后,该方法能够有效地检测出网络中的选择性转发攻击节点,具有较高的检测率和较低的误检率。     

Trust prediction and trust-based source routing in mobile ad hoc networks

Mobile ad hoc networks (MANETs) are spontaneously deployed over a geographically limited area without well-established infrastructure. The networks work well only if the mobile nodes are trusty and behave cooperatively. Due to the openness in network topology and absence of a centralized administration in management, MANETs are very vulnerable to various attacks from malicious nodes. In order to reduce the hazards from such nodes and enhance the security of network, this paper presents a dynamic trust prediction model to evaluate the trustworthiness of nodes, which is based on the nodes’ historical behaviors, as well as the future behaviors via extended fuzzy logic rules prediction. We have also integrated the proposed trust predication model into the Source Routing Mechanism. Our novel on-demand trust-based unicast routing protocol for MANETs, termed as Trust-based Source Routing protocol (TSR), provides a flexible and feasible approach to choose the shortest route that meets the security requirement of data packets transmission. Extensive experiments have been conducted to evaluate the efficiency and effectiveness of the proposed mechanism in malicious node identification and attack resistance. The results show that TSR improves packet delivery ratio and reduces average end-to-end latency.     

Secure Access Control Guarding Against Internal Attacks in Distributed Networks

In this paper, we propose a secure and efficient trust scheme with Bayesian theory to detect whether a node is malicious or not. In order to improve the correctness of detecting behavior, we aim to consider the influence with respect to the internal attacks of compromised nodes as many as possible. Moreover, the information of malicious behaviors is collected by their neighboring nodes and fused by the foregoing hop nodes. And then, the trust value concerning some node is computed by its father node in a route. Moreover, the key exchange of a secure route is implemented by the modified Diffie–Hellman key agreement protocol to guard against man-in-the-middle attack. The simulation results show that, with the increase of trust ratio, the Bayesian theorem can make more credible judgment on whether the network nodes are secure than the Beta function and the efficient clustering scheme for group key management in the present of malicious nodes.     

An efficient weighted trust‐based malicious node detection scheme for wireless sensor networks

The aim of wireless sensor networks (WSNs) is to gather sensor data from a monitored environment. However, the collected or reported information might be falsified by faults or malicious nodes. Hence, identifying malicious nodes in an effective and timely manner is essential for the network to function properly and reliably. Maliciously behaving nodes are usually detected and isolated by reputation and trust‐based schemes before they can damage the network. In this paper, we propose an efficient weighted trust‐based malicious node detection (WT‐MND) scheme that can detect malicious nodes in a clustered WSN. The node behaviors are realistically treated by accounting for false‐positive and false‐negative instances. The simulation results confirm the timely identification and isolation of maliciously behaving nodes by the WT‐MND scheme. The effectiveness of the proposed scheme is afforded by the adaptive trust‐update process, which implicitly performs trust recovery of temporarily malfunctioning nodes and computes a different trust‐update factor for each node depending on its behavior. The proposed scheme is more effective and scalable than the related schemes in the literature, as evidenced by its higher detection ratio (DR) and lower misdetection ratio (MDR), which only slightly vary with the network's size. Moreover, the scheme sustains its efficient characteristics without significant power consumption overheads.     

链路守卫节点合作监测检测恶意合谋攻击

针对移动Ad Hoc网络环境中合谋节点的恶意丢包行为,将源节点及其传输链路上各守卫节点所检测的结果结合起来,设计一种通过守卫节点合作监测来检测发现恶意合谋攻击的方法.NS2上仿真实验结果表明,该方法能够有效应对合谋节点的恶意丢包行为,降低恶意路由出现的概率,提高网络的分组投递率.     

A Trust-Distortion Resistant Trust Management Scheme on Mobile Ad Hoc Networks

Trust management is a promising approach to conduct nodes’ transactions and establish management interactions in mobile ad hoc networks, in which collaboration between nodes is critical to achieve system goals. Lack of centralized management, severe resource constraints (e.g. computing power, energy, bandwidth), and important network dynamics (e.g. topology changes, node mobility, node failure, propagation channel conditions) make the trust management a challenging task in such a network. Mainly, trust management frameworks are prone to attacks trying to deceive nodes’ estimation on other nodes’ trustworthiness, referred to as trust-distortion attacks. In order to inhibit such attacks, we propose a Trust-distortion Resistant Trust Management Scheme (TRTMS) which provides nodes with an accurate estimation on other nodes’ behavior and enables them to handle different trust-distortion attacks in a multi-attack environment. Simulation results prove that TRTMS significantly outperforms the existing alternatives in the literature in presence of simultaneous and contradictory different trust-distortion attacks.     

Trust establishment in cooperative wireless relaying networks

In cooperative wireless networks, relay nodes are employed to improve the performance of the network in terms of throughput and reliability. However, the presence of malicious relay nodes in the network may severely degrade the performance of the system. When a relay node behaves maliciously, there exists a possibility that such a node refuses to cooperate when it is selected for cooperation or deliberately drops the received packets. Trust establishment is a mechanism to detect misbehaving nodes in a network. In this paper, we propose a trust establishment method for cooperative wireless networks by using Bayesian framework. In contrast with the previous schemes proposed in wireless networks, this approach takes the channel state information and the relay selection decisions into account to derive a pure trust value for each relay node. The proposed method can be applied to any cooperative system with a general relay selection policy whose decisions in each cooperative transmission are independent of the previous ones. Moreover, it does not impose additional communication overhead on the system as it uses the available information in relay selection procedure. Copyright © 2012 John Wiley & Sons, Ltd.     

Byzantine robust trust establishment for mobile ad hoc networks

In a mobile ad hoc network (MANET), the nodes act both as traffic sources and as relays that forward packets from other nodes along multi-hop routes to the destination. Such networks are suited to situations in which a wireless infrastructure is unavailable, infeasible, or prohibitively expensive. However, the lack of a secure, trusted infrastructure in such networks make secure and reliable packet delivery very challenging. A given node acting as a relay may exhibit Byzantine behavior with respect to packet forwarding, i.e., arbitrary, deviant behavior, which disrupts packet transmission in the network. For example, a Byzantine node may arbitrarily choose to drop or misroute a certain percentage of the packets that are passed to it for forwarding to the next hop. In earlier work, we proposed a trust establishment framework, called Hermes, which enables a given node to determine the “trustworthiness” of other nodes with respect to reliable packet delivery by combining first-hand trust information obtained independently of other nodes and second-hand trust information obtained via recommendations from other nodes. A deficiency of the Hermes scheme is that a node can fail to detect certain types of Byzantine behavior, such as packet misforwarding directed at a particular source node. In this paper, we propose new mechanisms to make Hermes robust to Byzantine behavior and introduce a punishment policy that discourages selfish node behavior. We present simulation results that demonstrate the effectiveness of the proposed scheme in a variety of scenarios involving Byzantine nodes that are malicious both with respect to packet forwarding and trust propagation.     

Adjacent Node based Energetic Association Factor Routing Protocol in Wireless Sensor Networks

Mobile Ad-Hoc Network (MANET) consist a numerous nodes and these nodes are structured with remote transceivers. These nodes forward the message with one another by getting to the typical channel. In MANET, security is the principle challenge to be analyzed. Due to the behaviour of malevolent nodes, the network security is weakened. Along these lines, the significant goal of this research is to enhance the network security by detecting the malevolent nodes. So, for the detection of malevolent node, an effective trust management method is presented in this paper. Improving the trust score the optimized fuzzy framework is proposed. For enhancing the execution of the fuzzy framework, the triangular membership function of the input parameters is improved with the Cat Swarm Optimization. After estimating the trust score for every node in the network, threshold depend decision module is processed for detecting the activity of malevolent nodes. Implementation results illustrate that the execution of the proposed model achieves maximum network lifetime and minimum energy consumption.