Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio

Secure and Privacy-Preserving Authentication Protocols for Wireless Mesh Networks

Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation wireless networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to service providers. As WMNs become an increasingly popular replacement technology for last-mile connectivity to the home networking, community and neighborhood networking, it is imperative to design efficient and secure communication protocols for these networks. However, several vulnerabilities exist in currently existing protocols for WMNs. These security loopholes can be exploited by potential attackers to launch attack on WMNs. The absence of a central point of administration makes securing WMNs even more challenging. The broadcast nature of transmission and the dependency on the intermediate nodes for multi-hop communications lead to several security vulnerabilities in WMNs. The attacks can be external as well as internal in nature. External attacks are launched by intruders who are not authorized users of the network. For example, an intruding node may eavesdrop on the packets and replay those packets at a later point of time to gain access to the network resources. On the other hand, the internal attacks are launched by the nodes that are part of the WMN. On example of such attack is an intermediate node dropping packets which it was supposed to forward. This chapter presents a comprehensive discussion on the current authentication and privacy protection schemes for WMN. In addition, it proposes a novel security protocol for node authentication and message confidentiality and an anonymization scheme for privacy protection of users in WMNs.Comment: 32 pages, 10 figures. The work is an extended version of the author's previous works submitted in CoRR: arXiv:1107.5538v1 and arXiv:1102.1226v

Efficient Security Protocols for Fast Handovers in Wireless Mesh Networks

Wireless mesh networks (WMNs) are gaining popularity as a flexible and inexpensive replacement for Ethernet-based infrastructures. As the use of mobile devices such as smart phones and tablets is becoming ubiquitous, mobile clients should be guaranteed uninterrupted connectivity and services as they move from one access point to another within a WMN or between networks. To that end, we propose a novel security framework that consists of a new architecture, trust models, and protocols to offer mobile clients seamless and fast handovers in WMNs. The framework provides a dynamic, flexible, resource-efficient, and secure platform for intra-network and inter-network handovers in order to support real-time mobile applications in WMNs. In particular, we propose solutions to the following problems: authentication, key management, and group key management. We propose (1) a suite of certificate-based authentication protocols that minimize the authentication delay during handovers from one access point to another within a network (intra-network authentication). (2) a suite of key distribution and authentication protocols that minimize the authentication delay during handovers from one network to another (inter-network authentication). (3) a new implementation of group key management at the data link layer in order to reduce the group key update latency from linear time (as currently done in IEEE 802.11 standards) to logarithmic time. This contributes towards minimizing the latency of the handover process for mobile members in a multicast or broadcast group

Secure Incentives to Cooperate for Wireless Networks

The operating principle of certain wireless networks makes essential the cooperation between the mobile nodes. However, if each node is an autonomous selfish entity, cooperation is not guaranteed and therefore we need to use incentive techniques. In this thesis, we study cooperation in three different types of networks: WiFi networks, Wireless Mesh Networks (WMNs), and Hybrid Ad-hoc networks. Cooperation has a different goal for each of these networks, we thus propose incentive mechanisms adapted to each case. In the first chapter of this thesis, we consider WiFi networks whose wide-scale adoption is impeded by two major hurdles: the lack of a seamless roaming scheme and the variable QoS experienced by the users. We devise a reputation-based solution that (i) allows a mobile node to connect to a foreign Wireless ISP in a secure way while preserving his anonymity and (ii) encourages the WISPs to cooperate, i.e., to provide the mobile clients with a good QoS. Cooperation appears here twofold: First, the mobile clients have to collaborate in order to build and maintain the reputation system and second, the use of this reputation system encourages the WISPs to cooperate. We show, by means of simulations, that our reputation model indeed encourages the WISPs to behave correctly and we analyze the robustness of our solution against various attacks. In the second chapter of the thesis, we consider Wireless Mesh Networks (WMNs), a new and promising paradigm that uses multi-hop communications to extend WiFi networks. Indeed, by connecting only one hot spot to the Internet and by deploying several Transit Access Points (TAPs), a WISP can extend its coverage and serve a large number of clients at a very low cost. We analyze the characteristics of WMNs and deduce three fundamental network operations that need to be secured: (i) the routing protocol, (ii) the detection of corrupt TAPs and (iii) the enforcement of a proper fairness metric in WMNs. We focus on the fairness problem and propose FAME, an adaptive max-min fair resource allocation mechanism for WMNs. FAME provides a fair, collision-free capacity use of the WMN and automatically adjusts to the traffic demand fluctuations of the mobile clients. We develop the foundations of the mechanism and demonstrate its efficiency by means of simulations. We also experimentally assess the utility of our solution when TAPs are equipped with directional antennas and distinct sending and receiving interfaces in the Magnets testbed deployed in Berlin. In the third and last chapter of this thesis, we consider Hybrid Ad-hoc networks, i.e., infrastructured networks that are extended using multi-hop communications. We propose a secure set of protocols to encourage the most fundamental operation in these networks, namely packet forwarding. This solution is based on a charging and rewarding system. We use "MAC layering" to reduce the space overhead in the packets and a stream cipher encryption mechanism to provide "implicit authentication" of the nodes involved in the communication. We analyze the robustness of our protocols against rational and malicious attacks. We show that the use of our solution makes cooperation rational for selfish nodes. We also show that our protocols thwart rational attacks and detect malicious attacks

Key Management Systems for Smart Grid Advanced Metering Infrastructure: A Survey

Smart Grids are evolving as the next generation power systems that involve changes in the traditional ways of generation, transmission and distribution of power. Advanced Metering Infrastructure (AMI) is one of the key components in smart grids. An AMI comprises of systems and networks, that collects and analyzes data received from smart meters. In addition, AMI also provides intelligent management of various power-related applications and services based on the data collected from smart meters. Thus, AMI plays a significant role in the smooth functioning of smart grids. AMI is a privileged target for security attacks as it is made up of systems that are highly vulnerable to such attacks. Providing security to AMI is necessary as adversaries can cause potential damage against infrastructures and privacy in smart grid. One of the most effective and challenging topic's identified, is the Key Management System (KMS), for sustaining the security concerns in AMI. Therefore, KMS seeks to be a promising research area for future development of AMI. This survey work highlights the key security issues of advanced metering infrastructures and focuses on how key management techniques can be utilized for safeguarding AMI. First of all, we explore the main features of advanced metering infrastructures and identify the relationship between smart grid and AMI. Then, we introduce the security issues and challenges of AMI. We also provide a classification of the existing works in literature that deal with secure key management system in AMI. Finally, we identify possible future research directions of KMS in AMI

Mobility management across converged IP-based heterogeneous access networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 8/2/2010.In order to satisfy customer demand for a high performance “global” mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged “all-IP” centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme

Media Processing in Video Conferences for Cooperating Over the Top and Operator Based Networks

Telecom operators have dominated the communication industry for a long time by providing services with guaranteed quality of service. Such services are provided by the operator at the cost of maintaining a high grade network. With the introduction of broadband and internet, many over the top (OTT) services have emerged. These services use the underlying operator networks as a mere bit pipe while all service intelligence resides in the application running on the client device. Introduction of OTT services has seen a good response from general users who are no longer bound to services provided by the network operator. This in turn has caused operators and telecom companies to loose the ownership of their customers. This thesis takes media processing in video conferencing as a case study to compare the two competing domains of operator networks and OTT networks. Both domains offer video conferencing to end users, but they follow different architectures. The study shows that OTT services can perform much better if they utilize support of the underlying network. This will also bring the user base back to the network operator. The proposal is to turn the competition into cooperation between both parties. Assessments are done from both technical as well as business perspectives to assert that such cooperative agreements are possible and should be experimented in real life

State of the art in Wireless Mesh Networks - delivrable L3.01 - RNRT project "Airnet"

This delivrable presents a state of the art on management related issues in Wireless Mesh Networks. We describe existant work focusing on the five functional domains of the management plane: fault management, configuration management, accounting, performance and security