Elhadi M. Shakshuki

EAACK—A Secure Intrusion-Detection System for MANETs

The migration to wireless network from wired network has been a global trend in the past few decades. The mobility and scalability brought by wireless network made it possible in many applications. Among all the contemporary wireless networks, Mobile Ad hoc NETwork (MANET) is one of the most important and unique applications. On the contrary to traditional network architecture, MANET does not require a fixed network infrastructure; every single node works as both a transmitter and a receiver. Nodes communicate directly with each other when they are both within the same communication range. Otherwise, they rely on their neighbors to relay messages. The self-configuring ability of nodes in MANET made it popular among critical mission applications like military use or emergency recovery. However, the open medium and wide distribution of nodes make MANET vulnerable to malicious attackers. In this case, it is crucial to develop efficient intrusion-detection mechanisms to protect MANET from attacks. With the improvements of the technology and cut in hardware costs, we are witnessing a current trend of expanding MANETs into industrial applications. To adjust to such trend, we strongly believe that it is vital to address its potential security issues. In this paper, we propose and implement a new intrusion-detection system named Enhanced Adaptive ACKnowledgment (EAACK) specially designed for MANETs. Compared to contemporary approaches, EAACK demonstrates higher malicious-behavior-detection rates in certain circumstances while does not greatly affect the network performances.

Video transmission enhancement in presence of misbehaving nodes in MANETs

Mobile Ad-hoc NETworks (MANET) are infrastructureless networks where self-configuring mobile nodes are connected by wireless links. Because of its decentralized operation, these nodes rely on each other to store and forward packets. Video transmission over MANETs is more challenging than over conventional wireless networks due to rapid topology changes and lack of central administration. Most of the proposed MANET protocols assume that all nodes are working within a cooperative and friendly network context. However, misbehaving nodes that exhibit abnormal behaviors can disrupt the network operation and affect the network availability by refusing to cooperate to route packets due to their selfish or malicious behavior. In this paper, we examine the effect of packet dropping attacks on video transmission over MANETs. We also study the effects of mitigation using intrusion detection systems to MANET in presence of video traffic. To the best of our knowledge, this is the first attempt to study multimedia over such environments. We propose a novel intrusion detection system, which is an adaptive acknowledgment scheme (AACK) with the ability to detect misbehaved nodes and avoid them in other transmissions. The aim of AACK scheme is to overcome watchdog weaknesses due to collisions and limited transmission power and also to improve TWOACK scheme. To demonstrate the performance of our proposed scheme, simulation experiments are performed. The results of our experiments show that MPEG4 is more suitable for our simulation environment than H264 video traffic. The simulation results show that AACK scheme provides better network performance with less overhead than other schemes; it also shows that AACK outperforms both TWOACK and watchdog in video transmission applications in the presence of misbehaving nodes.

Detecting misbehaving nodes in MANETs

There has been a tremendous growth in the use of wireless communication in the past few decades. Mobile Ad hoc NETwork (MANET) is one of the most important one among various wireless communication mechanisms. In MANET, each node in a network performs as both a transmitter and a receiver. They rely on each other to store and forward packets. Its unique infrastructureless network and self-configuring capability makes it ideal for many mission critical applications, including military use and remote exploration. However, these characteristics also make MANET vulnerable to passive and active attacks due to its open medium, changing topology and lack of centralized monitoring. To address the new security challenges, Intrusion Detection System (IDS) is required to detect the malicious attackers before they can accomplish any significant damages to the network. Many existing IDSs for MANETs are based upon Watchdog mechanism. In this paper, we propose a new IDS called Enhanced Adaptive ACKnowledgement (EAACK) that solves four significant problems of Watchdog mechanism, which are ambiguous collisions, receiver collisions, limited transmission power and false misbehavior report. We use Network Simulator 2 to simulate the proposed mechanism and compare the results with existing mechanisms.

Detecting Forged Acknowledgements in MANETs

Over the past few years, with the trend of mobile computing, Mobile Ad hoc Network (MANET) has become one of the most important wireless communication mechanisms among all. Unlike traditional network, MANET does not have a fixed infrastructure, every single node in the network works as both a receiver and a transmitter. Nodes directly communicate with each other when they are both within their communication ranges. Otherwise, they rely on their neighbors to store and forward packets. As MANET does not require any fixed infrastructure and it is capable of self configuring, these unique characteristics made MANET ideal to be deployed in a remote or mission critical area like military use or remote exploration. However, the open medium and wide distribution of nodes in MANET leave it vulnerable to various means of attacks. It is crucial to develop suitable intrusion detection scheme to protect MANET from malicious attackers. In our previous research, we have proposed a mechanism called Enhanced Adaptive Acknowledgement (EAACK) scheme. Nevertheless, it suffers from the threat that it fails to detect misbehaving node when the attackers are smart enough to forge the acknowledgement packets. In this paper, we introduce Digital Signature Algorithm (DSA) into the EAACK scheme, and investigate the performance of DSA in MANET. The purpose of this paper is to present an improved version of EAACK called EAACK2 that performs better in the presence of false misbehavior and partial dropping.

Multi-agent development toolkits: an evaluation

One of the difficulties of using Artificial Neural Networks (ANNs) to estimate atmospheric temperature is the large number of potential input variables available. In this study, four different feature extraction methods were used to reduce the input vector to train four networks to estimate temperature at different atmospheric levels. The four techniques used were: genetic algorithms (GA), coefficient of determination (CoD), mutual information (MI) and simple neural analysis (SNA). The results demonstrate that of the four methods used for this data set, mutual information and simple neural analysis can generate networks that have a smaller input parameter set, while still maintaining a high degree of accuracy.

AACK: Adaptive Acknowledgment Intrusion Detection for MANET with Node Detection Enhancement

A Mobile Ad-hoc NETwork (MANET) is an infrastructureless network consisting of self-configuring mobile nodes connected by wireless links. Nodes rely on each other to store and forward packets. Most of the proposed MANET protocols assume cooperative and friendly network context, and do not address security issues. Furthermore, MANETs are highly vulnerable for passive and active attacks because of their open medium, rapidly changing topology, lack of centralized monitoring. Encryption and authentication solutions, which are considered as the first line of defense, are not sufficient to protect MANETs from packet dropping attacks. Most of the current Intrusion Detection Systems (IDSs) for MANETS rely on the Watchdog technique. In this research we study the behavior of this technique and propose a novel mechanism, named: Adaptive ACKnowledgment (AACK), for solving two significant problems: the limited transmission power and receiver collision. This mechanism is an enhancement to the TWOACK scheme where its detection overhead is reduced while the detection efficiency is increased. NS2 is used to simulate and evaluate the proposed scheme and compare it against the TWOACK and Watchdog methods. The obtained results show that the new AACK scheme outperforms both of the TWOACK and Watchdog methods in terms of network packet delivery ratio and routing overhead.

An architecture for cooperative information systems

With the fast growth of the information space in the Internet and large-scale Intranet computing environments, a new design paradigm is required for information systems. In such environments, the amount, the dynamic, the heterogeneity and the distributed nature of the information make it difficult for a user to locate and retrieve the desired information. Moreover, these computing environments are open environments, where the information resources may join or disjoin at anytime. To this end, this paper proposes a multi-agent multi-tier architecture. These agents are autonomous and goal driven agents that cooperatively assist different users to locate and retrieve information from distributed resources. The system architecture comprises of three tiers. At the front end, User Agents interact with the users to fulfill their interests and preferences. At the back end, Resource Agents access and capture the content and changes of the information resources. At the middle tier, Broker Agents facilitate cooperation among the agents. A prototype of this system is implemented to demonstrate how the agents can transparently cooperate to locate and retrieve information from dynamic and distributed information resources.

Software agent-based directed diffusion in wireless sensor network

In an environment where node density is massive, placement is heterogeneous and redundant sensory traffic is produced; limited network resources such as bandwidth and energy are hastily consumed by individual sensor nodes. Equipped with only a limited battery power supply, this minimizes the lifetime of these sensor nodes. At the network layer, many researchers have tackled this issue by proposing several energy efficient routing schemes. All these schemes tend to save energy by elevating redundant data traffic via in-network processing and choosing empirically good and shortest routing paths for transfer of sensory data to a central location (sink) for further, application-specific processing. Seldom has an attempt been made to reduce network traffic by moving the application-specific code to the source nodes. We unmitigated our efforts to augment the node lifetime within a sensor network by introducing mobile agents. These mobile agents can be used to greatly reduce communication costs, especially over low bandwidth links, by moving the processing function to the data rather than bringing the data to a central processor. Toward this end, we propose an agent-based directed diffusion approach to increase sensor node efficiency and we present the experimental results.

Agent-based system architecture for wireless sensor networks

This paper presents an ongoing research on developing an agent based system architecture for wireless sensor networks. The main objective of this system is to facilitate the design, implementation, and maintenance of applications for sensor networks that consist of wireless sensor nodes. The proposed system architecture contains four types of agents: interface, regional, cluster, and query agents. The interface agents receive queries from the users and return the results back to them. The regional agent is responsible for sending query packets to the cluster agents. The cluster agents disseminate query into the network and provide efficient in-network processing. Finally, the query agents process the query in the sensor node. The delegation of specific tasks to different software agents facilitates the development and maintenance of sensor network applications.

Multi-agent-based clustering approach to wireless sensor networks

This paper presents a multi-agent system for hierarchical routing in a Wireless Sensor Network (WSN). The agents communicate and collaborate with each other and benefit from learning techniques, more specifically genetic algorithms. The proposed system consists of four types of agents, including regional, interface, cluster and query agents. The regional agent resides on the base-station and performs genetic algorithm intense computing. The interface agent interacts with the users to fulfil their interests. The cluster agents manage all agents within clusters for query dissemination and efficiency in network. The query agents reside in each sensor and acquire, aggregate, process the useful data, and transmit the desired results. A prototype of all agents is simulated. For a given radio model our test results revealed that our multi-agent-based approach for hierarchical routing not only outperforms other routing protocols such as LEACH, but also determines the set of optimum clusters for various topologies.