Detecting Byzantine Attacks Without Clean Reference

We consider an amplify-and-forward relay network composed of a source, two relays, and a destination. In this network, the two relays are untrusted in the sense that they may perform Byzantine attacks by forwarding altered symbols to the destination. Note that every symbol received by the destination may be altered, and hence no clean reference observation is available to the destination. For this network, we identify a large family of Byzantine attacks that can be detected in the physical layer. We further investigate how the channel conditions impact the detection against this family of attacks. In particular, we prove that all Byzantine attacks in this family can be detected with asymptotically small miss detection and false alarm probabilities by using a sufficiently large number of channel observations \emph{if and only if} the network satisfies a non-manipulability condition. No pre-shared secret or secret transmission is needed for the detection of these attacks, demonstrating the value of this physical-layer security technique for counteracting Byzantine attacks.Comment: 16 pages, 7 figures, accepted to appear on IEEE Transactions on Information Forensics and Security, July 201

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 Routing in Wireless Mesh Networks

Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to the service providers. Unlike traditional Wi-Fi networks, with each access point (AP) connected to the wired network, in WMNs only a subset of the APs are required to be connected to the wired network. The APs that are connected to the wired network are called the Internet gateways (IGWs), while the APs that do not have wired connections are called the mesh routers (MRs). The MRs are connected to the IGWs using multi-hop communication. The IGWs provide access to conventional clients and interconnect ad hoc, sensor, cellular, and other networks to the Internet. However, most of the existing routing protocols for WMNs are extensions of protocols originally designed for mobile ad hoc networks (MANETs) and thus they perform sub-optimally. Moreover, most routing protocols for WMNs are designed without security issues in mind, where the nodes are all assumed to be honest. In practical deployment scenarios, this assumption does not hold. This chapter provides a comprehensive overview of security issues in WMNs and then particularly focuses on secure routing in these networks. First, it identifies security vulnerabilities in the medium access control (MAC) and the network layers. Various possibilities of compromising data confidentiality, data integrity, replay attacks and offline cryptanalysis are also discussed. Then various types of attacks in the MAC and the network layers are discussed. After enumerating the various types of attacks on the MAC and the network layer, the chapter briefly discusses on some of the preventive mechanisms for these attacks.Comment: 44 pages, 17 figures, 5 table

Esquemas de segurança contra ataques de poluição em codificação de rede sobre redes sem fios

Doutoramento em TelecomunicaçõesResumo em português não disponivelThe topic of this thesis is how to achieve e cient security against pollution attacks by exploiting the structure of network coding. There has recently been growing interest in using network coding techniques to increase the robustness and throughput of data networks, and reduce the delay in wireless networks, where a network coding-based scheme takes advantage of the additive nature of wireless signals by allowing two nodes to transmit simultaneously to the relay node. However, Network Coding (NC)-enabled wireless networks are susceptible to a severe security threat, known as data pollution attack, where a malicious node injects into the network polluted (i.e., corrupted) packets that prevent the destination nodes from decoding correctly. Due to recoding at the intermediate nodes, according to the core principle of NC, the polluted packets propagate quickly into other packets and corrupt bunches of legitimate packets leading to network resource waste. Hence, a lot of research e ort has been devoted to schemes against data pollution attacks. Homomorphic Message Authentication Code (MAC)-based schemes are a promising solution against data pollution attacks. However, most of them are susceptible to a new type of pollution attack, called tag pollution attack, where an adversary node randomly modi es tags appended to the end of the transmitted packets. Therefore, in this thesis, we rst propose a homomorphic message authentication code-based scheme, providing resistance against data pollution attacks and tag pollution attacks in XOR NC-enabled wireless networks. Moreover, we propose four homomorphic message authentication code-based schemes which provide resistance against data and tag pollution attacks in Random Linear Network Coding (RLNC). Our results show that our proposed schemes are more e cient compared to other competitive tag pollution immune schemes in terms of complexity, communication overhead and key storage overhead