Abstract not found

Countermeasures against node misbehavior and selfishness are mandatory requirements in mobile ad hoc networks. Selfishness that causes lack of node activity cannot be solved by classical security means that aim at verifying the correctness and integrity of an operation. In this paper we outline an original security mechanism (CORE) based on reputation that is used to enforce cooperation among the nodes of a MANET. We then investigate on its robustness using an original approach: we use game theory to model the interactions between the nodes of the ad hoc network and we focus on the strategy that a node can adopt during the network operation. As a first result, we obtained the guidelines that should be adopted when designing a cooperative security mechanism that enforces mobile nodes cooperation. Furthermore, we were able to show that when no countermeasures are taken against misbehaving nodes, network operation can be heavily jeopardized. We then showed that the CORE mechanism is compliant with guidelines provided by the game theoretic model and that, under certain conditions, it assures the cooperation of at least half of the nodes of a MANET. Keywords. Security, Denial of Service Attacks, Simulation, Game Theory. Table of Contents . 1.

Countermeasures against node misbehavior and selfishness are mandatory requirements in mobile ad hoc networks. Selfishness that causes lack of node activity cannot be solved by classical security means that aim at verifying the correctness and integrity of an operation. In this paper we outline an original security mechanism (CORE) based on reputation that is used to enforce cooperation among the nodes of a MANET. We then investigate on its robustness using an original approach: we use game theory to model the interactions between the nodes of the ad hoc network and we focus on the strategy that a node can adopt during the network operation. As a first result, we obtained the guidelines that should be adopted when designing a cooperative security mechanism that enforces mobile nodes cooperation. Furthermore, we were able to show that when no countermeasures are taken against misbehaving nodes, network operation can be heavily jeopardized. We then showed that the CORE mechanism is compliant with guidelines provided by the game theoretic model and that, under certain conditions, it assures the cooperation of at least half of the nodes of a MANET.

Countermeasures against node misbehavior and selfishness are mandatory requirements in mobile ad hoc networks. Selfishness that causes lack of node activity cannot be solved by classical security means that aim at verifying the correctness and integrity of an operation. In this paper we outline an original security mechanism (CORE) based on reputation that is used to enforce cooperation among the nodes of a MANET. We then investigate on its robustness using an original approach: we use game theory to model the interactions between the nodes of the ad hoc network and we focus on the strategy that a node can adopt during the network operation. As a first result, we obtained the guidelines that should be adopted when designing a cooperative security mechanism that enforces mobile nodes cooperation. Furthermore, we were able to show that when no countermeasures are taken against misbehaving nodes, network operation can be heavily jeopardized. We then showed that the CORE mechanism is compliant with guidelines provided by the game theoretic model and that, under certain conditions, it assures the cooperation of at least half of the nodes of a MANET Keywords. Security, Denial of Service Attacks, Simulation, Game Theory. Table of Contents .

This paper focuses on the formal assessment of the properties of cooperation enforcement mechanisms used to detect and prevent selfish behavior of nodes forming a mobile ad hoc network. Taking as a reference the CORE mechanism introduced in [9], we present two alternative approaches based on game theory that provide a powerful analytical method to study cooperation between self-interested players. We demonstrate that the formation of large coalitions of cooperating nodes is possible only when a mechanism like CORE is implemented in each node. Game theory also provides further insight to features of CORE such as the convergence speed to a cooperative behavior.

Countermeasures against node misbehavior and selfishness are mandatory requirements in mobile ad hoc networks. Selfishness that causes lack of node activity cannot be solved by classical security means that aim at verifying the correctness and integrity of an operation. In this paper we outline an original security mechanism (CORE) based on reputation that is used to enforce cooperation among the nodes of a MANET.We then investigate on its robustness using an original approach: we use game theory to model the interactions between the nodes of the ad hoc network and we focus on the strategy that a node can adopt during the network operation.As a first result, we obtained the guidelines that should be adopted when designing a cooperative security mechanism that enforces mobile nodes cooperation. Furthermore, we were able to show that when no countermeasures are taken against misbehaving nodes,network operation can be heavily jeopardized.We then showed that the CORE mechanism is compliant with guidelines provided by the game theoretic model and that, under certain conditions, it assures the cooperation of at least half of the nodes of a MANET. 1.

Abstract not found

Most of the end-to-end congestion control schemes are “voluntary” in nature and critically depend on end-user cooperation. We show that in the presence of selfish users, all such schemes will inevitably lead to a congestion collapse. Router and switch mechanisms such as service disciplines and buffer management policies determine the sharing of resources during congestion. We show, using a game-theoretic approach, that all currently proposed mechanisms, either encourage the behaviour that leads to congestion or are oblivious to it. We propose a class of service disciplines called the Diminishing Weight Schedulers (DWS) that punish misbehaving users and reward congestion avoiding well behaved users. We also propose a sample service discipline called the Rate Inverse Scheduling (RIS) from the class of DWS schedulers. With DWS schedulers deployed in the network, max-min fair rates constitute a unique Nash and Stackelberg Equilibrium. We show that RIS solves the problems of excessive congestion due to unresponsive flows, aggressive versions of TCP, multiple parallel connections and is also fair to TCP.