this paper we propose two methods to evaluate the effectiveness of the CORE mechanism based on a cooperative game approach and a non-cooperative game approach: the results obtained using the first approach define a lower bound on the number of legitimate nodes in an ad hoc network when the CORE mechanism is adopted while the second approach describe the asymptotical behavior of a selfish node that is controlled by CORE

Sensor networks enable a wide range of applications in both military and civilian domains. However, the deployment scenarios, the functionality requirements, and the limited capabilities of these networks expose them to a wide-range of attacks against control traffic (such as wormholes, Sybil attacks, rushing attacks, etc). In this paper we propose a lightweight protocol called DICAS that mitigates these attacks by detecting, diagnosing, and isolating the malicious nodes. DICAS uses as a fundamental building block the ability of a node to oversee its neighboring nodes’ communication. On top of DICAS, we build a secure routing protocol, LSR, which in addition supports multiple node-disjoint paths. We analyze the security guarantees of DICAS and use ns-2 simulations to show its effectiveness against three representative attacks. Overhead analysis is conducted to prove the lightweight nature of DICAS.

Abstract—A hybrid ad hoc network is a structure-based network that is extended using multihop communications. Indeed, in this kind of network, the existence of a communication link between the mobile station and the base station is not required: A mobile station that has no direct connection with a base station can use other mobile stations as relays. Compared with conventional (single-hop) structure-based networks, this new generation can lead to a better use of the available spectrum and to a reduction of infrastructure costs. However, these benefits would vanish if the mobile nodes did not properly cooperate and forward packets for other nodes. In this paper, we propose a charging and rewarding scheme to encourage the most fundamental operation, namely packet forwarding. We use “MAC layering ” to reduce the space overhead in the packets and a stream cipher encryption mechanism to provide “implicit authentication ” of the nodes involved in the communication. We analyze the robustness of our protocols against rational and malicious attacks. We show that—using our solution—collaboration is rational for selfish nodes. We also show that our protocols thwart rational attacks and detect malicious attacks. Index Terms—Network-level security and protection, wireless communication, authentication security, payment schemes. 1

this paper solves both problems: It allows a mobile node to connect to a foreign Wireless Internet Service Provider (WISP) in a secure way while preserving its anonymity and it encourages the WISPs to provide the users with good QoS. We analyze the robustness of our solution against various attacks and we prove by means of simulations that our reputation model indeed encourages the WISPs to behave correctly

this article presents security threats and major solutions from the literature along routing, cooperation enforcement and key management in MANET

Securing ad hoc networks is notoriously challenging, notably due to the lack of an online infrastructure. In particular, key management is a problem that has been addressed by many researchers but with limited results. In this paper, we consider the case where an ad hoc network is under the responsibility of a mother certification authority (mCA). Since the nodes can frequently be collectively isolated from the mCA (e.g., for a remote mission) but still need the access to a certification authority, the mCA preassigns a special role to several nodes (called servers) that constitute a distributed certification authority (dCA) during the isolated period. We propose a solution, called DICTATE (DIstributed CerTification Authority with probabilisTic frEshness), to manage the dCA. This solution ensures that the dCA always processes a certificate update (or query) request in a finite amount of time and that an adversary cannot forge a certificate. Moreover, it guarantees that the dCA responds to a query request with the most recent version of the queried certificate in a certain probability; this probability can be made arbitrarily close to 1, but at the expense of higher overhead. Our contribution is twofold: 1) a set of certificate management protocols that allow trading protocol overhead for certificate freshness or the other way around, and 2) a combination of threshold and identity-based cryptosystems to guarantee the security, availability, and scalability of the certification function. We describe DICTATE in detail and, by security analysis and simulations, we show that it is robust against various attacks.

Abstract—We consider the problem of establishing a route and sending packets between a source/destination pair in ad hoc networks composed of rational selfish nodes whose purpose is to maximize their own utility. In order to motivate nodes to follow the protocol specification, we use side payments that are made to the forwarding nodes. Our goal is to design a fully distributed algorithm such that 1) a node is always better off participating in the protocol execution (individual rationality), 2) a node is always better off behaving according to the protocol specification (truthfulness), 3) messages are routed along the most energy-efficient (least cost) path, and 4) the message complexity is reasonably low. We introduce the COMMIT protocol for individually rational, truthful, and energy-efficient routing in ad hoc networks. To the best of our knowledge, this is the first ad hoc routing protocol with these features. COMMIT is based on the VCG payment scheme in conjunction with a novel game-theoretic technique to achieve truthfulness for the sender node. By means of simulation, we show that the inevitable economic inefficiency is small. As an aside, our work demonstrates the advantage of using a cross-layer approach to solving problems: Leveraging the existence of an underlying topology control protocol, we are able to simplify the design and analysis of our routing protocol and reduce its message complexity. On the other hand, our investigation of the routing problem in the presence of selfish nodes disclosed a new metric under which topology control protocols can be evaluated: the cost of cooperation. Index Terms—Wireless ad hoc networks, cooperation in ad hoc networks, cooperative routing, energy efficiency, topology control. Ç 1

We study routing misbehavior in MANETs (Mobile Ad Hoc Networks) in this paper. In general, routing protocols for MANETs are designed based on the assumption that all participating nodes are fully cooperative. However, due to the open structure and scarcely available battery-based energy, node misbehaviors may exist.[1]. One such routing misbehavior is that some selfish nodes [2], will participate in the route discovery and maintenance processes but refuse to forward data packets. In this paper, we develop a game theoretic based cooperation model that observes the behavior of an intermediary node (selfish neighbors) while forwarding packets for others on a route between a source and a destination. It also allows formally study and analyze the impact of selfish behavior on the system performance.

Mobile Ad-hoc networks are inherently prone to security attacks, with node mobility being the primary cause in allowing security breaches. This makes the network susceptible to Byzantyne faults with packets getting misrouted or dropped. We propose solutions using an unobtrusive monitoring technique to locate malicious packet dropping. This technique uses information from different network layers to detect malicious activity. Any single node can use unobtrusive monitoring without relying on cooperation from other nodes, making this technique easy to implement and deploy. We implemented our technique using ns-2 simulator and conducted extensive experiments using several mobility models. Results show that this technique has high detection effectiveness in detecting malicious behavior with a low false positive rate. 1.

Abstract — Ad-hoc sensor networks are becoming more common, yet security of these networks is still an issue. Node misbehavior due to malicious attacks can impair the overall functioning of the system. Existing approaches mainly rely on cryptography to ensure data authentication and integrity. These approaches only address part of the problem of security in sensor networks. However, cryptography is not sufficient to prevent the attacks in which some of the nodes are overtaken and compromised by a malicious user. Recently, the use of reputation systems has shown positive results as a selfpolicing mechanism in ad-hoc networks. This scheme can aid in decreasing vulnerabilities which are not solved by cryptography. We look at how a distributed reputation scheme can benefit the object tracking application in sensor networks. Tracking multiple objects is one of the most important applications of the sensor network. In our setup, nodes detect misbehavior locally from observations, and assign a reputation to each of their neighbors. These reputations are used to weight node readings appropriately when performing object tracking. Over time, data from malicious nodes will not be included in the track formation process. We evaluate the reputation system experimentally and demonstrate how it improves object tracking in the presence of malicious nodes. I.