A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Countermeasures for node misbehavior and selfishness are mandatory requirements in MANET. 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. We suggest a generic mechanism based on reputation to enforce cooperation among the nodes of a MANET to prevent selfish behavior. Each network entity keeps track of other entities’ collaboration using a technique called reputation. The reputation is calculated based on various types of information on each entity’s rate of collaboration. Since there is no incentive for a node to maliciously spread negative information about other nodes, simple denial of service attacks using the collaboration technique itself are prevented. The generic mechanism can be smoothly extended to basic network functions with little impact on existing protocols. <s> BIB001 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Mobile ad-hoc networking works properly only if the participating nodes cooperate in routing and forwarding. However, it may be advantageous for individual nodes not to cooperate. We propose a protocol, called CONFIDANT, for making misbehavior unattractive; it is based on selective altruism and utilitarianism. It aims at detecting and isolating misbehaving nodes, thus making it unattractive to deny cooperation. Trust relationships and routing decisions are based on experienced, observed, or reported routing and forwarding behavior of other nodes. The detailed implementation of CONFIDANT in this paper assumes that the network layer is based on the Dynamic Source Routing (DSR) protocol. We present a performance analysis of DSR fortified by CONFIDANT and compare it to regular defenseless DSR. It shows that a network with CONFIDANT and up to 60% of misbehaving nodes behaves almost as well as a benign network, in sharp contrast to a defenseless network. All simulations have been implemented and performed in GloMoSim. <s> BIB002 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Most of the routing protocols in wireless ad hoc networks, such as DSR, assume nodes are trustworthy and cooperative. This assumption renders wireless ad hoc networks vulnerable to various types of Denial of Service (DoS) attacks. We present a distributed probing technique to detect and mitigate one type of DoS attacks, namely malicious packet dropping, in wireless ad hoc networks. A malicious node can promise to forward packets but in fact fails to do so. In our distributed probing technique, every node in the network will probe the other nodes periodically to detect if any of them fail to perform the forwarding function. Subsequently, node state information can be utilized by the routing protocol to bypass those malicious nodes. Our experiments show that in a moderately changing network, the probing technique can detect most of the malicious nodes with a relatively low false positive rate. The packet delivery rate in the network can also be increased accordingly. <s> BIB003 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> In military and rescue applications of mobile ad hoc networks, all the nodes belong to the same authority; therefore, they are motivated to cooperate in order to support the basic functions of the network. In this paper, we consider the case when each node is its own authority and tries to maximize the benefits it gets from the network. More precisely, we assume that the nodes are not willing to forward packets for the benefit of other nodes. This problem may arise in civilian applications of mobile ad hoc networks. In order to stimulate the nodes for packet forwarding, we propose a simple mechanism based on a counter in each node. We study the behavior of the proposed mechanism analytically and by means of simulations, and detail the way in which it could be protected against misuse. <s> BIB004 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Technological advances are leveraging the widespread deployment of mobile ad hoc networks. An interesting characteristic of ad hoc networks is their self-organization and their dependence of the behavior of individual nodes. Until recently, most research on ad hoc networks has assumed that all nodes were cooperative. This assumption is no longer valid in spontaneous networks formed by individuals with diverse goals and interests. In such environment, the presence of selfish nodes may degrade significantly the performance of the ad hoc network. This paper proposes a novel algorithm that aims to discourage selfish behavior in mobile ad hoc networks. <s> BIB005 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Mobile ad hoc networking has been an active research area for several years. How to stimulate cooperation among selfish mobile nodes, however, is not well addressed yet. In this paper, we propose Sprite, a simple, cheat-proof, credit-based system for stimulating cooperation among selfish nodes in mobile ad hoc networks. Our system provides incentive for mobile nodes to cooperate and report actions honestly. Compared with previous approaches, our system does not require any tamper-proof hardware at any node. Furthermore, we present a formal model of our system and prove its properties. Evaluations of a prototype implementation show that the overhead of our system is small. Simulations and analysis show that mobile nodes can cooperate and forward each other's messages, unless the resource of each node is extremely low. <s> BIB006 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> In wireless ad hoc networks, nodes communicate with far off destinations using intermediate nodes as relays. Since wireless nodes are energy constrained, it may not be in the best interest of a node to always accept relay requests. On the other hand, if all nodes decide not to expend energy in relaying, then network throughput will drop dramatically. Both these extreme scenarios (complete cooperation and complete noncooperation) are inimical to the interests of a user. In this paper we address the issue of user cooperation in ad hoc networks. We assume that nodes are rational, i.e., their actions are strictly determined by self interest, and that each node is associated with a minimum lifetime constraint. Given these lifetime constraints and the assumption of rational behavior, we are able to determine the optimal throughput that each node should receive. We define this to be the rational Pareto optimal operating point. We then propose a distributed and scalable acceptance algorithm called generous tit-for-tat (GTFT). The acceptance algorithm is used by the nodes to decide whether to accept or reject a relay request. We show that GTFT results in a Nash equilibrium and prove that the system converges to the rational and optimal operating point. <s> BIB007 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> The vision of nomadic computing with its ubiquitous access has stimulated much interest in the Mobile Ad Hoc Networking (MANET) technology. However, its proliferation strongly depends on the availability of security provisions, among other factors. In the open, collaborative MANET environment practically any node can maliciously or selfishly disrupt and deny communication of other nodes. In this paper, we present and evaluate the Secure Message Transmission (SMT) protocol, which safeguards the data transmission against arbitrary malicious behavior of other nodes. SMT is a lightweight, yet very effective, protocol that can operate solely in an end-to-end manner. It exploits the redundancy of multi-path routing and adapts its operation to remain efficient and effective even in highly adverse environments. SMT is capable of delivering up to 250% more data messages than a protocol that does not secure the data transmission. Moreover, SMT outperforms an alternative single-path protocol, a secure data forwarding protocol we term Secure Single Path (SSP) protocol. SMT imposes up to 68% less routing overhead than SSP, delivers up to 22% more data packets and achieves end-to-end delays that are up to 94% lower than those of SSP. Thus, SMT is better suited to support QoS for real-time communications in the ad hoc networking environment. The security of data transmission is achieved without restrictive assumptions on the network nodes' trust and network membership, without the use of intrusion detection schemes, and at the expense of moderate multi-path transmission overhead only. <s> BIB008 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Security is a critical issue in a mobile ad hoc network (MANET). We propose and investigate a novel scheme, security protocol for reliable data delivery (SPREAD), to enhance the data confidentiality service in a mobile ad hoc network. The proposed SPREAD scheme aims to provide further protection to secret messages from being compromised (or eavesdropped) when they are delivered across the insecure network. The basic idea is to transform a secret message into multiple shares by secret sharing schemes and then deliver the shares via multiple independent paths to the destination so that even if a small number of nodes that are used to relay the message shares are compromised, the secret message as a whole is not compromised. We present the overall system architecture and investigate the major design issues. We first describe how to obtain message shares using the secret sharing schemes. Then we study the appropriate choice of the secret sharing schemes and the optimal allocation of the message shares onto each path in order to maximize the security. The results show that the SPREAD is more secure and also provides a certain degree of reliability without sacrificing the security. Thirdly, the multipath routing techniques are discussed and the path set optimization algorithm is developed to find the multiple paths with the desired property, i.e., the overall path set providing maximum security. Finally, we present the simulation results to justify the feasibility and evaluate the effectiveness of SPREAD. <s> BIB009 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> We investigate the possibility of using directional antennas for medium access control in wireless ad hoc networks. Previous research in ad hoc networks typically assumes the use of omnidirectional antennas at all nodes. With omnidirectional antennas, while two nodes are communicating using a given channel, MAC protocols such as IEEE 802.11 require all other nodes in the vicinity to remain silent. With directional antennas, two pairs of nodes located in each other's vicinity may potentially communicate simultaneously, increasing spatial reuse of the wireless channel. Range extension due to higher gain of directional antennas can also be useful in discovering fewer hop routes. However, new problems arise when using directional beams that simple modifications to 802.11 may not be able to mitigate. This paper identifies these problems and evaluates the tradeoffs associated with them. We also design a directional MAC protocol (MMAC) that uses multihop RTSs to establish links between distant nodes and then transmits CTS, DATA, and ACK over a single hop. While MMAC does not address all the problems identified with directional communication, it is an attempt to exploit the primary benefits of beamforming in the presence of some of these problems. Results show that MMAC can perform better than IEEE 802.11, although we find that the performance is dependent on the topology and flow patterns in the system. <s> BIB010 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> A cross-layer approach is investigated to improve data security in Mobile Ad Hoc Networks (MANETs). The use of directional antennas and intelligent multipath routing is proposed to enhance end-to-end data confidentiality and data availability with respect to outsider attacks. The goal is to impede rogue attempts to gain unauthorized access to classified information or disrupt the information flow. The interplay between the physical, link, and network layers is considered. A novel simulator is developed to accurately quantify the data confidentiality benefits of these approaches. This study leverages the existence of multiple paths between end-nodes to statistically improve data confidentiality and data availability in hostile MANET environments, where both insider and outsider adversaries may be present. Simulation results show that the proposed mechanisms can greatly improve data confidentiality as compared to existing schemes. These mechanisms can also improve data availability. <s> BIB011 </s> A survey of survivability in mobile ad hoc networks <s> B. Data forwarding <s> Since mobile ad hoc networks (MANETs) are infrastructureless and multi-hop by nature, transmitting packets from any node to another usually relies on services provided by intermediate nodes. This reliance introduces a new vulnerability; one node could launch a Black Hole DoS attack by participating in the routing protocol and including itself in routes, then simply dropping packets it receives to forward. Another motivation for dropping packets in self-organized MANETs is resource preservation. Some solutions for detecting and isolating packet droppers have been recently proposed, but almost all of them employ the promiscuous mode monitoring approach (watchdog (WD)) which suffers from many problems, especially when employing the power control technique. In this paper we propose a novel monitoring approach that overcomes some WD's shortcomings, and improves the efficiency in detection. To overcome false detections due to nodes mobility and channel conditions we propose a Bayesian technique for the judgment, allowing node redemption before judgment. Finally, we suggest a social-based approach for the detection approval and isolation of guilty nodes. We analyze our solution and asses its performance by simulation. The results illustrate a large improvement of our monitoring solution in detection versus the WD, and an efficiency through our judgment and isolation techniques as well. Copyright © 2007 John Wiley & Sons, Ltd. <s> BIB012
Some works have proposed secure routing mechanisms to defend against several attacks  , BIB003 - BIB012 . Despite of those protocols ensure the correctness of the route discovery, they can not guarantee secure and undisrupted delivery of data. Intelligent attackers can easily gain unauthorized access to the network, follow the rules of the route discovery, place themselves on a route, and later redirect, drop or modify traffics, or inject data packets. In a nutshell, an adversary can hide its malicious behavior for a period of time and then attack unexpectedly, complicating its detection. For these reasons, mechanisms to provide data confidentiality, data availability and data integrity are necessary for guaranteeing secure data forwarding. Several mechanisms have been proposed for securing data forwarding. Lightweight cryptographic mechanisms as Message Authentication Code (MAC)  , for example, are used to data integrity. Nuglets BIB004 , Friends and Foes BIB005 , Sprite BIB006 and others  , BIB007 propose mechanisms to stimulate node participation in data forwarding, trying to guarantee data availability. CORE BIB001 and CONFIDANT BIB002 are examples of reputation systems that provide information to distinguish between a trustworthy node and a bad node. This information also encourages nodes to participate in the network in a trustworthy manner. Some solutions to provide data confidentiality and data availability have attempted to apply techniques as redundancy and message protection to be more resilient to attacks. In SPREAD BIB009 , SMT BIB008 and SDMP BIB010 , for example, the message is divided into multiple pieces by a message division algorithm. These pieces are simultaneously sent from the source to the destination over multiple paths. In BIB011 , a crosslayer approach is investigated to improve data confidentiality and data availability, using directional antennas and intelligent multipath routing with data redundancy.