@conference {
	title = {Coalition Formation in MANETS},
	author = {Jiang, Tao., Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {11/2006},
	abstract = {Wireless ad-hoc networks rely on the cooperation of participating nodes for almost all their functions. However, due to resource constraints, nodes are generally selfish and try to maximize their own benefit when participating in the network. Therefore, it is important to study mechanisms which can be used as incentives to form coalitions inside the network. In this paper, we study coalition formation based on game theory, especially cooperative game theory. First, the dynamics of coalition formation proceeds via pairwise bargaining. We show that the size of the maximum coalition is a decreasing function of the cost for establishing a link. After the coalition formation process reaches the steady state, we are interested in the stability of coalitions. We prove that coalitions are stable in terms of both pairwise stability and coalitional stability.},
	address = {Orlando, FL},
	booktitle = {25th Army Science Conference},
	pages = {pp.1-8}
}
@conference {
	title = {A Game for Ad Hoc Network Connectivity in the Presence of Malicious Users},
	author = {Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {11/2006},
	abstract = {Ad hoc network users are resource constrained: Before transmitting data, they have to take into account the energy expenditure involved. Even if a user is, in principle, willing to spend energy to improve network connectivity, his actual decision will be heavily influenced by the decisions of his neighboring users, since they act as relay nodes for him. Moreover, some of the neighbors may not be as benign as he is; in fact, they could be outright malicious. We are abstracting the tradeoff between spending energy and increasing connectivity by modeling the interaction of a user with his one-hop neighbors in a game theoretic fashion. Two types of users exist: Good users willingly trade energy for connectivity, but only if they expect their neighbors to do the same; Bad users try to destroy connectivity, but also lure the Good users to waste energy. Within our model for user behavior and sophistication, we explore outcomes that can arise in this graphical game.},
	address = {San Francisco, CA},
	booktitle = {2006 IEEE Globecom Technical Conference},
	pages = {pp. 1-5}
}
@conference {
	title = {A Testbed for Comparing Trust Computation Algorithms},
	author = {Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {11/2006},
	abstract = {Trust is the expectation of a person about another person{\textquoteright}s behavior. Trust is important for many security related decisions about, e.g., granting or revoking privileges, controlling access to sensitive resources and information, or evaluating intelligence gathered from multiple sources. More often than not, the issue is complicated even further because the person making the decision has no direct trust relationship with every single subject whose trustworthiness needs to be evaluated. So, the decision maker needs to rely on recommendations by others, and then somehow aggregate the trust related information that is collected. In this work we provide an algebraic framework in which we can describe multiple ways that trust related information can be aggregated to form a single value. We show the similarities and differences that the various so called trust computation algorithms have, and associate these with the algebraic properties of the frame- work that we consider.},
	address = {Orlando, FL},
	booktitle = {25th Army Science Conference},
	pages = {pp. 1-8}
}
@conference {
	title = {Enhancing Benign User Cooperation in the Presence of Malicious Adversaries in Ad Hoc Networks},
	author = {Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {08/2006},
	abstract = {Decentralized and unstructured networks are becoming more prevalent today (e.g. ad hoc networks). Like every network, they depend on the cooperation of their users to survive. However, each user does not necessarily know who the others are, or what their intentions are. Since there is no centralized infrastructure, the users can only base their decision on what they observe themselves. Ideally, they would like to cooperate only with users that have common interests with them. In this paper, we use a game theoretic model for the above situation. We assume there are only two kinds of users, Good (benign) and Bad (malicious). Good users receive a high game theoretic payoff when they cooperate with other Good users, but a low payoff when they cooperate with Bad users. We propose behavior rules (strategies) to achieve equilibria that enable as many Good users as possible to cooperate with each other, and at the same time minimize the number of Good-Bad cooperations.},
	address = {Baltimore, MD},
	booktitle = {2006 IEEE Communications Society/CreateNet International Conference on Security and Privacy in Communication Networks}
}
@conference {
	title = {Linear Iterations on Ordered Semirings for Trust Metric Computation and Attack Resiliency Evaluation},
	author = {Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {07/2006},
	abstract = {Within the realm of network security, we interpret the concept of trust as a relation among entities that participate in various protocols. Trust relations are based on evidence created by the previous interactions of entities within a protocol. In this work, we are focusing on the evaluation of trust evidence in Ad Hoc Networks. Because of the dynamic nature of Ad Hoc Networks. Because of the dynamic nature of Ad Hoc Networks, trust evidence may be uncertain and incomplete. Also, no pre-established infrastructure can be assumed. The evaluation process is modelled as a path problem on a directed graph, where nodes represent entities, and edges represent trust relations. We develop a novel formation of trust computation as linear interactions on ordered semirings. Using the theory of semirings, we analyze several key problems on the performance of trust algorithms. We also analyze the resilience to attacks of the resulting schemes.},
	address = {Kyoto, Japan},
	booktitle = {Proceedings of the 17th International Symposium on Mathematical Networks and Systems},
	pages = {pp. 509-514}
}
@conference {
	title = {On Trust Models and Trust Evaluation Metrics for Ad Hoc Networks},
	author = {Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {02/2006},
	abstract = {Within the realm of network security, we interpret the concept of trust as a relation among entities that participate in various protocols. Trust relations are based on evidence created by the previous interactions of entities within a protocol. In this work, we are focusing on the evaluation of trust evidence in ad hoc networks. Because of the dynamic nature of ad hoc networks, trust evidence may be uncertain and incomplete. Also, no preestablished infrastructure can be assumed. The evaluation process is modeled as a path problem on a directed graph, where nodes represent entities, and edges represent trust relations. We give intuitive requirements and discuss design issues for any trust evaluation algorithm. Using the theory of semirings, we show how two nodes can establish an indirect trust relation without previous direct interaction. We show that our semiring framework is flexible enough to express other trust models, most notably PGP{\textquoteright}s Web of Trust. Our scheme is shown to be robust in the presence of attackers.},
	booktitle = {IEEE Journal on Selected Areas in Communications},
	pages = {pp. 318-328}
}
@conference {
	title = {Coalition Formation in MANET and Other Networks},
	author = {Jiang, Tao., Theodorakopoulos, George., Baras, John S.},
	year = {2006},
	month = {01/2006},
	abstract = {Wireless ad-hoc networks rely on the cooperation of participating nodes for almost all their functions. However, due to resource constraints, nodes are generally selfish and try to maximize their own benefit when participating in the network. Therefore, it is important to study mechanisms which can be used as incentives to form coalitions inside the network. In this paper, we study coalition formation based on game theory, especially cooperative game theory. First, the dynamics of coalition formation proceeds via pairwise bargaining. We show that the size of the maximum coalition is a decreasing function of the cost for establishing a link. After the coalition formation process reaches the steady state, we are interested in the stability of coalitions. We prove that coalitions are stable in terms of both pairwise stability and coalitional stability.},
	address = {Orlando, FL},
	booktitle = {25th Army Science Conference}
}
