Zhexiong Wei

Security Enhancements for Mobile Ad Hoc Networks With Trust Management Using Uncertain Reasoning

The distinctive features of mobile ad hoc networks (MANETs), including dynamic topology and open wireless medium, may lead to MANETs suffering from many security vulnerabilities. In this paper, using recent advances in uncertain reasoning that originated from the artificial intelligence community, we propose a unified trust management scheme that enhances the security in MANETs. In the proposed trust management scheme, the trust model has two components: trust from direct observation and trust from indirect observation. With direct observation from an observer node, the trust value is derived using Bayesian inference, which is a type of uncertain reasoning when the full probability model can be defined. On the other hand, with indirect observation, which is also called secondhand information that is obtained from neighbor nodes of the observer node, the trust value is derived using the Dempster-Shafer theory (DST), which is another type of uncertain reasoning when the proposition of interest can be derived by an indirect method. By combining these two components in the trust model, we can obtain more accurate trust values of the observed nodes in MANETs. We then evaluate our scheme under the scenario of MANET routing. Extensive simulation results show the effectiveness of the proposed scheme. Specifically, throughput and packet delivery ratio (PDR) can be improved significantly with slightly increased average end-to-end delay and overhead of messages.

Cooperative Spectrum Sensing with Trust Assistance for Cognitive Radio Vehicular Ad hoc Networks

As Vehicular Ad hoc Networks (VANETs) attract a lot of research attention, VANETs with Cognitive Radio (CR-VANETs) are also studied as supplement and enhancement of VANETs, which are used to solve the issues of spectrum shortage in VANETs. With this CR technology, VANETs can satisfy more bandwidth demanding for amounts of applications based on communication between vehicles. Cooperative spectrum sensing is naturally suitable for CR-VANETs due to its autonomous characteristic. Cooperative spectrum sensing opens a door for malicious attacks in spectrum sensing. It assumes that every vehicle in the network is always honest and benign. However, the security attacks exist in all kinds of networks. Thus, solving this security issue becomes critical for CR-VANETs, which are using cooperative spectrum sensing. In this paper, a distributed cooperative spectrum sensing scheme is proposed to solve the security issue in CR-VANETs. In this scheme, a weighted consensus-based spectrum sensing algorithm with trust assistance is used to protect the spectrum sensing process in a hostile CR-VANET. The effectiveness of the proposed scheme is validated by extensive simulations.

Trust based security enhancements for vehicular ad hocnetworks

Vehicular Ad hoc Networks (VANETs) have been becoming a popular research topic in both academia and industry due to the demanding requirements of safe and efficient transportation systems. The security of VANETs is a significant issue for the implementation of most types of useful applications based on VANETs. In this paper, a trust-based framework is proposed to solve the security issue in VANETs. The trus-based mechanism can provide a second protection for VANETs to defense the inside attackers, which are hard to be thwarted by cryptographic techniques. The proposed scheme establishes trust with direct interactions and recommendations. The DempsterShafer Theory is used to tackle the uncertainty of thirdparty recommendations in order to obtain accurate trust values. The effectiveness of the proposed scheme is validated by simulations.

A token-based connectivity update scheme for unmanned aerial vehicle ad hoc networks

Code division multiple access mobile ad hoc networks (CDMA-MANETs) are envisioned to be the next-generation networking architecture for networking military platforms in a battlefield. In this paper we consider a CDMA ad hoc network consisting of multiple unmanned aerial vehicles (UAVs). We propose a token-based connectivity update scheme to solve the code collision problem in assigning code channels as well as the network link update problem for the CDMA UAV ad hoc network. Our proposed scheme uses a token message, which continuously circulates around the network in a non-predetermined order, to conduct assignment of code channels for each UAV. By using the broadcast properties of the wireless communication media, our proposed scheme is able to discover new or lost neighbors almost in real time. Moreover, the proposed token-based connectivity update scheme implements spatial reuse of code channels, which is mandatory in large-scale ad hoc networks due to the limited size of the CDMA code set. We then derive a theoretical result for approximating the connectivity update latency, which is further verified through computer simulations.

Security enhancement for mobile ad hoc networks routing with OLSRv2

Some features of Mobile Ad hoc Networks (MANETs), including dynamic membership, topology, and open wireless medium, introduce a variety of security risks. Malicious nodes can drop or modify packets that are received from other nodes. These malicious activities may seriously affect the availability of services in MANETs. Therefore, secure routing in MANETs has emerged as an important MANET research area. In this paper, we propose a scheme that enhances the security of Optimal Link State Routing version 2 (OLSRv2) in MANETs based on trust. In the proposed scheme, more accurate trust can be obtained by considering different types of packets and other important factors that may cause dropping packets in friendly nodes, such as buffer overflows and unreliable wireless connections. Simulation results are presented to demonstrate the effectiveness of the proposed scheme.

Cross-Layer Security Management Framework for Mobile Tactical Networks

Mobile tactical networks (MTNs) require agile operation, robustness, strong security protection, and high efficiency in order to fulfill their missions in contested environments. Research has shown that the classical layered protocol architecture has limitations and many cross-layer security techniques have been proposed in order to address these requirements. Most cross-layer techniques focus on a specific solution. A general framework is needed in order to support future diversified security applications. In this paper, we propose a cross-layer security management (CLSM) framework for MTNs, which provides a platform for developing various security services in MTNs. CLSM formalizes several functional blocks and control flows among these blocks, which include a local layer security-related attribute classification module, a security information retrieval engine, a security metric evaluation engine, a security knowledge repository, a shared security metric store, and a security related services module. We describe how CLSM can improve security performance in MTNs through two examples: intrusion detection and agile routing.

Securing cognitive radio vehicular Ad hoc networks with trusted lightweight cloud computing

Vehicular Ad hoc NETworks (VANETs) as the basic infrastructure can facilitate applications and services of connected vehicles (CVs). Cognitive radio (CR) technology is an effective supplement and enhancement for VANETs. It can reduce the impact of deficiency of spectrum resource in VANETs. Although CR-VANETs can utilize the unused licensed spectrum effectively, the distributed nature of CR-VANETs may open a door for different attacks, such as spectrum sensing data falsification attack. In this paper, we propose a joint RSU and vehicle-based light-weighted cloud for CR-VANETs. Based on this cloud computing model, we propose a new service named Spectrum Sensing as a Service (SSaaS), which can perform a cooperative spectrum sensing in CR-VANETs with cloud computing assistance to secure the spectrum sensing procedure. As a result, a reliable service can be obtained in CR-VANETs. Simulation results show that the cloud computing in CR-VANETs can effectively reduce latency and improve the security of CR-VANETs.

A trust based framework for both spectrum sensing and data transmission in CR-MANETs

Distributed cooperative spectrum sensing is an effective and feasible approach to detect primary users in Cognitive Radio Mobile Ad Hoc NETworks (CR-MANETs). However, due to the dynamic and interdependent characteristics of this approach, malicious attackers can interrupt the normal spectrum sensing more easily in open environments by spectrum sensing data falsification attacks. Meanwhile, attackers can perform traditional attacks to data transmission in MANETs. Towards these complicated situations in CR-MANETs, we study a new type of attack named joint dynamic spectrum sensing and data transmission attack in this paper. We propose a trust based framework to protect both distributed cooperative spectrum sensing and data transmission. For protection of distributed cooperative spectrum sensing, a weighted-average consensus algorithm with trust is applied to degrade the impact of malicious secondary users. At the same time, data transmission in a network formed by secondary users can be protected by trust with direct and indirect observations. Simulation results show the effectiveness and performance of the proposed framework under different experimental scenarios.