Hidehisa Nakayama

A survey of routing attacks in mobile ad hoc networks

Recently, mobile ad hoc networks became a hot research topic among researchers due to their flexibility and independence of network infrastructures, such as base stations. Due to unique characteristics, such as dynamic network topology, limited bandwidth, and limited battery power, routing in a MANET is a particularly challenging task compared to a conventional network. Early work in MANET research has mainly focused on developing an efficient routing mechanism in such a highly dynamic and resource-constrained network. At present, several efficient routing protocols have been proposed for MANET. Most of these protocols assume a trusted and cooperative environment. However, in the presence of malicious nodes, the networks are vulnerable to various kinds of attacks. In MANET, routing attacks are particularly serious. In this article, we investigate the state-of-the-art of security issues in MANET. In particular, we examine routing attacks, such as link spoofing and colluding misrelay attacks, as well as countermeasures against such attacks in existing MANET protocols.

A Dynamic Anomaly Detection Scheme for AODV-Based Mobile Ad Hoc Networks

Mobile ad hoc networks (MANETs) are usually formed without any major infrastructure. As a result, they are relatively vulnerable to malicious network attacks, and therefore, security is a more significant issue than infrastructure-based wireless networks. In MANETs, it is difficult to identify malicious hosts as the topology of the network dynamically changes. A malicious host can easily interrupt a route for which it is one of the forming nodes in the communication path. In the literature, there are several proposals to detect such malicious hosts inside the network. In those methods, a baseline profile, which is defined as per static training data, is usually used to verify the identity and the topology of the network, thus preventing any malicious host from joining the network. Since the topology of a MANET dynamically changes, the mere use of a static baseline profile is not efficient. In this paper, we propose a new anomaly-detection scheme based on a dynamic learning process that allows the training data to be updated at particular time intervals. Our dynamic learning process involves calculating the projection distances based on multidimensional statistics using weighted coefficients and a forgetting curve. We use the network simulator 2 (ns-2) system to conduct the MANET simulations and consider scenarios for detecting five types of attacks. The simulation results involving two different networks in size show the effectiveness of the proposed techniques.

Fault-resilient sensing in wireless sensor networks

Research on wireless sensor networks (WSNs) has received tremendous attention in the past few years due to their potential applications and advances in the VLSI design. In WSNs with tiny sensors, mobility of a sink may provide an energy efficient way for data dissemination. Having a mobile sink in WSN, however, creates new challenges to routing and sensor distribution modeling in the network. In this paper, based on clustering and routing optimization algorithms, we propose a new scheme called K-means and TSP-based mobility (KAT mobility). After clustering the sensor nodes, the proposed method navigates the mobile sink to traverse through the cluster centers according to the trajectory of an optimized route. The mobile sink then collects the data from sensors at the visited clusters. Simulation results have demonstrated that the proposed scheme can provide not only better energy efficiency as compared to those obtained by conventional methods which assume random waypoint for the mobile sink, but also fault-resilience in case of malfunctions of some sensors due to attacks.

LTRT: An efficient and reliable topology control algorithm for ad-hoc networks

Broadcasting, in the context of ad-hoc networks, is a costly operation, and thus topology control has been proposed to achieve efficient broadcasting with low interference and low energy consumption. By topology control, each node optimizes its transmission power by maintaining network connectivity in a localized manner. Local Minimum Spanning Tree (LMST) is the state-of-the-art topology control algorithm, which has been proven to provide satisfactory performance. However, LMST almost always results in a 1-connected network, without redundancy to tolerate external factors. In this paper, we propose Local Tree-based Reliable Topology (LTRT), which is mathematically proven to guarantee k-edge connectivity while preserving the features of LMST. LTRT can be easily constructed with a low computational complexity of O(k(m + n log n)), where k is the connectivity of the resulting topology, n is the number of neighboring nodes, and m is the number of edges. Simulation results have demonstrated the efficiency of LTRT and its superiority over other localized algorithms.

A Novel Scheme for WSAN Sink Mobility Based on Clustering and Set Packing Techniques

Advances in technologies such as micro electro mechanical systems (MEMS) have empowered more efficient and smaller digital devices, which can be deployed in WSNs (wireless sensor networks) to gather useful information pertaining to a particular environment. In order to control effectively the physical system in a WSN, actuators may be employed to integrate such environmental information into the automation control system. Indeed, sophisticated entities deployed in wireless sensor and actuator networks (WSANs) act as functional robots. The approach of using the mobile sink, as an example of the actuator to control the movement of a sink, has been adopted by researchers in the past to achieve high efficiency in terms of gathering data from the sensors. This is due to the fact that in general, the sensors alone are unable to control the sink and need to send or relay a smaller amount of packet data. Although a number of methods exist in literature to utilize mobile sinks as actuators, most of these techniques are unable to guarantee data gathering from all of the sensors. As a consequence, more research effort is needed to improve the efficiency as well as fairness of data gathering. In WSANs, sinks and sensor entities should be actively controllable by the administrator. Therefore, we must consider an efficient way to access all nodes in the target networks. In this paper, we propose a novel method, based on the set packing algorithm and traveling salesman problem, to accomplish this goal. The effectiveness of our envisioned method is demonstrated through extensive computer-simulations.

Analysis of the node isolation attack against OLSR-based mobile ad hoc networks

Recent advances in wireless networking technologies have made it possible to construct a mobile ad hoc network (MANET) which can be applied in infrastructureless situations. However, due to their inherent characteristics, they are much more vulnerable to malicious attacks than a conventional wired network. In MANET, routing plays an important role in providing connectivity for mobile nodes who are not within the same radio range. Existing routing protocols in MANET assume a trusted and reliable environment. However, in hostile environment mobile nodes are susceptible to various types of routing attacks. This paper identifies a new routing attack, called node isolation attack, against optimized link state routing (OLSR) protocol, one of the four standard routing protocols for MANETs. We analyze in detail and demonstrate the impact of this attack in order to show the necessity for a countermeasure to guard against the attack. As a first step to defend against the attack, we present a simple technique to detect the attack and identify the source of the attack

NIS01-2: A Collusion Attack Against OLSR-based Mobile Ad Hoc Networks

Rapid advances in wireless networking technologies have made it possible to construct a mobile ad hoc network (MANET) which can be applied in infrastructureless situations. However, due to their inherent characteristics, MANETs are vulnerable to various kinds of attacks which aim at disrupting their routing operations. To develop a strong security scheme to protect against these attacks it is necessary to understand the possible form of attacks that may be launched. Recently, researchers have proposed and investigated several possible attacks against MANET. However, there are still unanticipated or sophisticated attacks that have not been well studied. In this paper, we present a collusion attack model against optimized link state routing (OLSR) protocol which is one of the four standard routing protocols for MANETs. After analyzed the attack in detail and demonstrated the feasibility of the attack through simulations, we present a technique to detect the attack by utilizing information of two hops neighbors.

Reliable Application Layer Multicast Over Combined Wired and Wireless Networks

During the last several years, the Internet has evolved from a wired infrastructure to a hybrid of wired and wireless domains by spreading worldwide interoperability for microwave access (WiMAX), Wi-Fi, and cellular networks. Therefore, there is a growing need to facilitate reliable content delivery over such heterogeneous networks. On the other hand, application layer multicast (ALM) has become a promising approach for streaming media content from a server to a large number of interested nodes. ALM nodes construct a multicast tree and deliver the stream through this tree. However, if a node leaves, it cannot deliver the stream to its descendant nodes. In this case, quality-of-service (QoS) is compromised dramatically. Especially, this problem is exacerbated in wireless networks because of packet errors and handovers. In order to cope with this problem, multiple-tree multicasts have been proposed. However, existing methods fail to deliver contents reliably in combined wired and wireless networks. In this paper, we propose a method to ensure the robustness of node departure, while meeting various bandwidth constraints by using layered multiple description coding (LMDC). Finally, we evaluate the proposed method via extensive simulations by using the network simulator (ns-2). By comparing our proposed method with the existing ones, we demonstrate that our method provides better performance in terms of total throughput, relative delay penalty (RDP), and relative delay variation (RDV). The results indicate that our approach is a more reliable content delivery system when compared with contemporary methods in the context of heterogeneous networks containing wired and wireless environments.

SA-OLSR: Security Aware Optimized Link State Routing for Mobile Ad Hoc Networks

Currently, mobile ad hoc network (MANET) has drawn great attention for being part of the ubiquitous network. Unlike the conventional network, MANETs have many unique features such as node resource constraint. That is why several efficient routing protocols have been proposed specifically for MANETs. Among these protocols, optimized link state routing (OLSR) is one of the four important routing protocol identified by IETF. The current OLSR protocol assumes that all nodes are trusted. However, in hostile environment, the OLSR is known to be vulnerable to various kinds of malicious attacks. In this paper, we propose a new security aware optimized link state routing (SA-OLSR) which is a secured version of current OLSR. Our approach is based on exchanging acknowledgement between 2-hop neighbors when the control traffic is successfully received. The main advantage of our approach is that it can protect against many sophisticated attacks such as link spoofing, colluding misrelay attack, and wormhole attack without requiring any location information as well as the knowledge of complete network topology. Our simulation results show that the proposed solution can achieve higher packet delivery ratio compared to the network using the standard OLSR in the presence of malicious nodes.

A self-adaptive intrusion detection method for AODV-based mobile ad hoc networks

Mobile ad hoc networks (MANET) are usually formed without any major infrastructure. As a result, they are relatively vulnerable to malicious network attacks and therefore the security is a more significant issue than in infrastructure-type wireless networks. In these networks, it is difficult to identify malicious hosts, as the topology of the network changes dynamically. A malicious host can easily interrupt a route for which the malicious host is one of the forming nodes in the communication path. In the literature, there are several proposals to detect such malicious host inside the network. In those methods usually a baseline profile is defined in accordance to static training data and then they are used to verify the identity and the topology of the network, thus avoiding any malicious host to be joined in the network. Since the topology of a MANET is dynamically changing, use of a static profile is not efficient. In this paper, we propose a new intrusion detection scheme based on a learning process, so that the training data can be updated at particular time intervals. The simulation results show the effectiveness of the proposed technique compared to conventional schemes