Hadi Otrok

Mechanism Design-Based Secure Leader Election Model for Intrusion Detection in MANET

In this paper, we study leader election in the presence of selfish nodes for intrusion detection in mobile ad hoc networks (MANETs). To balance the resource consumption among all nodes and prolong the lifetime of an MANET, nodes with the most remaining resources should be elected as the leaders. However, there are two main obstacles in achieving this goal. First, without incentives for serving others, a node might behave selfishly by lying about its remaining resources and avoiding being elected. Second, electing an optimal collection of leaders to minimize the overall resource consumption may incur a prohibitive performance overhead, if such an election requires flooding the network. To address the issue of selfish nodes, we present a solution based on mechanism design theory. More specifically, the solution provides nodes with incentives in the form of reputations to encourage nodes in honestly participating in the election process. The amount of incentives is based on the Vickrey, Clarke, and Groves (VCG) model to ensure truth-telling to be the dominant strategy for any node. To address the optimal election issue, we propose a series of local election algorithms that can lead to globally optimal election results with a low cost. We address these issues in two possible application settings, namely, Cluster-Dependent Leader Election (CDLE) and Cluster-Independent Leader Election (CILE). The former assumes given clusters of nodes, whereas the latter does not require any preclustering. Finally, we justify the effectiveness of the proposed schemes through extensive experiments.

VANET QoS-OLSR: QoS-based clustering protocol for Vehicular Ad hoc Networks

In this paper, we address the problem of clustering in Vehicular Ad hoc Networks (VANETs) using Quality of Service Optimized Link State Routing (QoS-OLSR) protocol. Several clustering algorithms have been proposed for VANET and MANET. However, the mobility-based algorithms ignore the Quality of Service requirements that are important for VANET safety, emergency, and multimedia services while the QoS-based algorithms ignore the high speed mobility constraints since they are dedicated for Mobile Ad hoc Networks (MANETs). Our solution is a new QoS-based clustering algorithm that considers a tradeoff between QoS requirements and high speed mobility constraints. The goal is to form stable clusters and maintain the stability during communications and link failures while satisfying the Quality of Service requirements. This is achieved by: (1) considering the high mobility metrics while computing the QoS, (2) using Ant Colony Optimization for MPRs selection, and (3) using MPR recovery algorithm able to select alternatives and keep the network connected in case of link failures. Performance analysis and simulation results show that the proposed model can maintain the network stability, reduce the end-to-end delay, increase the packet delivery ratio, and reduce the communications overhead.

A game-theoretic intrusion detection model for mobile ad hoc networks

In this paper, we address the problem of increasing the effectiveness of an intrusion detection system (IDS) for a cluster of nodes in ad hoc networks. To reduce the performance overhead of the IDS, a leader node is usually elected to handle the intrusion detection service on behalf of the whole cluster. However, most current solutions elect a leader randomly without considering the resource level of nodes. Such a solution will cause nodes with less remaining resources to die faster, reducing the overall lifetime of the cluster. It is also vulnerable to selfish nodes who do not provide services to others while at the same time benefiting from such services. Our experiments show that the presence of selfish nodes can significantly reduce the effectiveness of an IDS because less packets are inspected over time. To increase the effectiveness of an IDS in MANET, we propose a unified framework that is able to: (1) Balance the resource consumption among all the nodes and thus increase the overall lifetime of a cluster by electing truthfully and efficiently the most cost-efficient node known as leader-IDS. A mechanism is designed using Vickrey, Clarke, and Groves (VCG) to achieve the desired goal. (2) Catch and punish a misbehaving leader through checkers that monitor the behavior of the leader. A cooperative game-theoretic model is proposed to analyze the interaction among checkers to reduce the false-positive rate. A multi-stage catch mechanism is also introduced to reduce the performance overhead of checkers. (3) Maximize the probability of detection for an elected leader to effectively execute the detection service. This is achieved by formulating a zero-sum non-cooperative game between the leader and intruder. We solve the game by finding the Bayesian Nash Equilibrium where the leaders optimal detection strategy is determined. Finally, empirical results are provided to support our solutions.

A Cooperative Approach for Analyzing Intrusions in Mobile Ad hoc Networks

In this paper, we consider the problem of reducing the number of false positives generated by cooperative intrusion detection systems (IDSs) in mobile ad hoc networks (MANETs). We define a flexible scheme using security classes, where an IDS is able to operate in different modes at each security class. This scheme helps in minimizing false alarms and informing the prevention system accurately about the severity of an intrusion. Shapley value is used to formally express the cooperation among all the nodes. To the best of our knowledge, there has not been any study for the case where the intrusions in MANETs are analyzed, in order to decrease false positives, using cooperative game theory. Our game theoretic model assists in analyzing the contribution of each mobile node on each security class in order to decrease false positives taking into consideration the reputation of nodes. Simulation results are given to validate the efficiency of our model in detecting intrusions and reducing false positives.

Game theoretic models for detecting network intrusions

In this paper, we study using game theory the problem of detecting intrusions in wired infrastructure networks. Detection is accomplished by sampling a subset of the transmitted packets over selected network links or router interfaces. Given a total sampling budget, our framework aims at developing a network packet sampling strategy to effectively reduce the success chances of an intruder. We consider two different scenarios: (1) A well informed intruder divides his attack over multiple packets in order to increase his chances of successfully intruding a target domain. (2) Different cooperating intruders distribute the attack among themselves each send their attack fragments to the target node. Each of the packets containing a fragment of the attack is transmitted through a different path using multi-path routing, where each path is selected with a different probability. Knowing that, if these packets are independently analyzed then the intrusion will not be detected, i.e., a series of packets form an intrusion. To the best of our knowledge, there has not been any work done for the case where the attack is split over multiple packets or distributed over cooperative intruders using game theory. Non-cooperative game theory is used to formally express the problem, where the two players are: (1) the smart intruder or the cooperative intruders (depends on which scenario we are solving) and (2) the Intrusion Detection System (IDS). Our game theoretic framework will guide the intruder or the intruders to know their attack strategy and the IDS to have an optimal sampling strategy in order to detect the malicious packets.

A Mechanism Design-Based Multi-Leader Election Scheme for Intrusion Detection in MANET

In this paper, we study the election of multiple leaders for intrusion detection in the presence of selfish nodes in mobile ad hoc networks (MANETs). To balance the resource consumption and prolong the lifetime of all nodes, each cluster should elect a node with the most remaining resources as its leader. However, without incentives for serving others, a node may behave selfishly by lying about its remaining resource and avoiding being elected. We present a solution based on mechanism design theory. More specifically, we design a scheme for electing cluster leaders that have the following two advantages: First, the collection of elected leaders is the optimal in the sense that the overall resource consumption will be balanced among all nodes in the network overtime. Second, the scheme provides the leaders with incentives in the form of reputation so that nodes are encouraged to honestly participate in the election process. The design of such incentives is based on the Vickrey, Clarke, and Groves (VCG) model by which truth-telling is the dominant strategy for each node. Simulation results show that our scheme can effectively prolong the overall lifetime of IDS in MANET and balance the resource consumptions among all the nodes.

Resource allocation in macrocell-femtocell network using genetic algorithm

In this paper, we consider the problem of resource allocation in two-tier networks taking into consideration nondense femtocell deployments. The following limitations can be remarked from the prior work in the field of resource allocation: (1) resources are underutilized due to the equal power distribution in macrocell, (2) access to public users in femtocells is restricted to avoid depriving own subscribers transmissions, and (3) degradation of signal-to-noise ratio due to noise effects has not been evaluated. To overcome these limitations, we propose a joint power and bandwidth allocation among two tiers together with base station selection using genetic algorithm. Our solution is able to: (1) maximize the overall system throughput, (2) find an appropriate serving base station for each user, and (3) bandwidth and power assigned to each user. Simulations were conducted and a comparison with a Weighted Water Filling algorithm is carried out.

A Moderate to Robust Game Theoretical Model for Intrusion Detection in MANETs

One popular solution for reducing the resource consumption of intrusion detection system (IDS) in MANET is to elect a head-cluster (leader) to provide intrusion detection service to other nodes in the same cluster. However, such a moderate mode is only suitable when the probability of attack is low. Once the probability of attack is high, victim nodes should launch their own IDSs to detect and thwart intrusions. Such a robust mode is, however, costly with respect to energy and leads nodes to die faster. Clearly, to reduce the resource consumption of IDSs and yet keep its effectiveness, a critical issue is: when should we shift from moderate to robust mode? In this paper, we formalize this issue as a nonzero-sum noncooperative game theoretical model that takes into consideration the tradeoff between security and IDS resource consumption. The game solution will guide the leader-IDS to find the right moment for notifying the victim node to launch its IDS once the security risk is high enough. To achieve this goal, the Bayesian game theory is used to analyze the interaction between the leader-IDS and intruder with incomplete information about the intruder. By solving such a game, we are able to find the threshold value for notifying the victim node to launch its IDS once the probability of attack exceeds that value. Simulation results show that our scheme can effectively reduce the IDS resource consumption without sacrificing security.

Energy-Efficient Resource-Allocation Model for OFDMA Macrocell/Femtocell Networks

Femtocells (FCs) are introduced to enhance the indoor coverage and system capacity of traditional cellular networks. However, the network performance could be significantly deteriorated due to the increase in cochannel interference in dense deployment. In the literature, three spectrum usage schemes that deal with the cross-tier interference have been proposed, i.e., orthogonal assignment, underlay, and controlled underlay using mainly closed-access FCs. This paper targets the optimization of resource allocation, together with the selection of base stations (BSs) in two-tier networks assuming hybrid access FCs, to reduce the cross-tier interference. Moreover, this model aims to achieve effective spatial reuse between the macrocell (MC) and FCs while guaranteeing quality-of-service (QoS) transmissions by means of joint power control in both tiers. Simulations are conducted to show a comparison with the other three approaches.

Agent-based game-theoretic model for collaborative web services: Decision making analysis

In agent and (web) service computing, collaboration takes place when distributed entities have limited knowledge and capabilities, so they cannot perform required tasks without interacting and helping each other. For instance, web services, which are loosely-coupled business applications, are called to cooperate in distributed settings for the sake of efficiency. In this context, agents that abstract and act on behalf of web services could act in cooperative groups that gather a number of agents sharing some common goals. Enabling those agent-based web services to decide about their strategies in terms of joining and acting within groups, inviting other agents to join, and leaving a group to act alone is an open issue that we address in this work. In this paper, we propose a framework where agent-based web services select strategies that maximize their outcomes. These strategies could be categorized into cooperative strategies involving other agents and strategies that highlight the single operative attitude. Although cooperation seems to bring better utility to cooperative agents, we highlight that web services in some environments obtain better outcome while they act individually (i.e., outside the group). This means that the cost of cooperation (in some particular cases) might negatively influence the outcome and obtained utility. As solution, we propose in this paper (1) an agent-based model that formalizes web services decision making where different parameters are considered; and (2) a game-theoretic framework that analyzes the web services strategies allowing them to maximize their acting performance where non-zero-sum games are being used. The paper presents theoretical results, which are also confirmed through extensive simulations.