The requirement of safety, roadway capacity and efficiency in the vehicular network, which makes vehicular platoons concept continue to be of interest. For the authentication in vehicular platoons, efficiency and cooperation are the two most important things. Cooperative authentication is a way to recognize false identities and messages as well as saving resources. However, taking part in cooperative authentication makes the vehicle more vulnerable to privacy leakage which is commonly done by location tracking. Moreover, vehicles consume their resources when cooperating with others during the process of cooperation authentication. These two significant factors cause selfish behaviors of the vehicles not to participate in cooperate cooperation actively. In this paper, an infinitely repeated game for cooperative authentication in vehicular platoons is proposed to help analyze the utility of all nodes and point out the weakness of the current collaborative authentication protocol. To deal with this weakness, we also devised an enhanced cooperative authentication protocol based on mechanisms which makes it easier for vehicles to stay in the cooperate strategy rather than tend to selfish behavior. Meanwhile, our protocol can defense insider attacks.

The reward of the Bitcoin system is designed to be proportional to miner's computational power. However, rogue miners can increase their rewards by using the block withholding attacks. For raising awareness on the Bitcoin reward system, a new attack scheme is proposed, where the attackers infiltrate into an open pool and launch the selfish mining as well as the block withholding attack. The simulation results demonstrate that the proposed attack outperforms the conventional block withholding attacks.

In this paper, we investigate multi-service forwarding in selfish wireless networks (SeWN) with selfish relay nodes (RN). The RN's node-selfishness is characterized from the perspectives of its residual energy and the incentive paid by the source, by which the degree of intrinsic selfishness (DeIS) and the degree of extrinsic selfishness (DeES) are defined. Meanwhile, a framework of the node-selfishness management is conceived to extract the RNs' node-selfishness information (NSI). Based on the RN's NSI, the expected energy cost and expected service profit are determined for analyzing the effect of the RN's node-selfishness on the multi-service forwarding. Moreover, the optimal incentive paid by the source is obtained for minimizing its cost and, at the same time, effectively stimulating the multi-service delivery. Simulation validate our analysis.

Autonomous ad hoc networks are networks with nodes belonging to different authorities, and cooperative behavior of nodes is not guaranteed in such networks. In this paper, defense mechanisms are introduced to protect nodes against injecting traffic attacks in an autonomous ad hoc network, and to stimulate nodes to forward packets for each other. We have a cross-layer approach in the design of our mechanisms, and nodes use information from medium access control (MAC) layer for selecting a good route. In addition, nodes attempt to drop packets of those nodes that violate MAC layer backoff mechanism. Analytical and simulation results demonstrate the effectiveness of our proposed mechanisms in the presence of injecting traffic attacks and MAC layer misbehaviors in an ad hoc network that consists of selfish nodes.

A selfish routing game is a simple model of selfish behaviors in networks. It is called that Braess's paradox occurs in the selfish routing game if an equilibrium flow achieved by players' selfish behaviors is not the optimal minimum latency flow. In order to make the minimum latency flow a Nash equilibrium, a marginal cost tax has been proposed. Braess graphs have also been proposed to discuss Braess's paradox. In a large population of selfish players, conflicts between purposes of each player and the population causes social dilemmas. In game theory, to resolve the social dilemmas, a capitation tax and/or a subsidy has been introduced, and players' dynamical behaviors have been formulated by replicator dynamics. In this paper, we formulate replicator dynamics in the Braess graphs and investigate stability of the minimum latency flow with and without the marginal cost tax. An additional latency caused by the marginal cost tax is also shown. To resolve the problem of the additional latency, we extend the capitation tax and the subsidy to a state-dependent tax and apply it to the stabilization problem of the minimum latency flow.

In a shared medium communication system, mobile users contend for channel access according to a given set of rules to avoid collisions and achieve efficient use of the medium. If one or more users do not comply with the agree rules either due to selfish or malicious behaviours, they will cause some impacts on the system performance, especially to the well-behaved users. In this paper, we consider the problem of user misbehaviours on the performance of a wireless infrastructure-based network using reservation-based MAC protocols. Key misbehaving strategies possible in such a network are identified and explained. To quantify the impact of these misbehaviours upon the network performance, three different misbehaving scenarios are developed to allow a systematic investigation of each misbehaving strategy. For each scenario, we have derived mathematical formulations for evaluating and analyzing the key performance metrics, i.e., probabilities of success of well-behaved and misbehaved users and the fairness index. Numerical results show that the presence of misbehaviours can cause different levels of damage depending on the misbehavior strategy used. The combined multi-token and increasing permission probability strategies where the misbehaved user selfishly accesses the channel more times and with higher probabilities than allowed is shown to cause the most severe impairment of performance and fairness.

Due to the lack of end-to-end paths between the communication source and destination, the routing of Delay Tolerant Networks (DTN) exploits the store-carry-and-forward mechanism. This mechanism requires nodes with sufficient energy to relay and forward messages in a cooperative and selfless way. However, in the real world, the energy is constrained and most of the nodes exhibit selfish behaviors. In this paper, we investigate the performance of DTN routing schemes considering both the energy constraint and selfish behaviors of nodes. First, we model the two-hop relay and epidemic routing based on a two-dimensional continuous time Markov chain. Then, we obtain the system performance of message delivery delay and delivery cost by explicit expressions. Numerical results show that both the energy constraint and node selfishness reduce the message delivery cost at the expense of increasing the message delivery delay. Furthermore, we demonstrate that the energy constraint plays a more important role in the performance of epidemic routing than that of two-hop relay.

In mobile ad hoc networks, as the communications have to be achieved autonomously and via third parties, a variety of risks against stable communication and session completion can be predicted. Many researchers have been studying these issues, i.e., mobility, broadcast storm, selfish behavior on data forwarding, security, and so forth. However, availability of routes against selfish power off is still to be addressed. This paper defines a new, realistic and practical problem beyond the scope of malicious program modification, called selfish power off, and evaluates the influence of it. Here, a selfish user turns his terminal on only when it has some data to send or receive and decline to work as an intermediate user by turning its terminal power off. In addition, this paper proposes a solution, called Proactive COoperation Mechanism (PCOM) against selfish power off in order to eliminate the influence of selfish power off. In PCOM, each user holds the cooperation records of its adjacent users, and forwards only those packets that are generated by users with good cooperation records. PCOM thus prevents SUs from joining the network. Extensive simulation shows the efficiency of our proposal in maintaining network connectivity and fairness in resource consumption.