Secure Routing in Wireless Mesh Networks

Abstract

Physical layer attacksThe physical layer is responsible for frequency selection, carrier frequency generation, signal detection, modulation, and data encryption. As with any radio-based medium, the possibility of jamming attacks in this layer of WMNs is always there. Jamming is a type of attack which interferes with the radio frequencies that the nodes use in a WMN for communication (Shi et al., 2004). A jamming source may be powerful enough to disrupt communication in the entire network. Even with less powerful jamming sources, an adversary can potentially disrupt communication in the entire network by strategically distributing the jamming sources. An intermittent jamming source may also prove detrimental as some communications in WMNs may be time-sensitive. More complex forms of radio jamming attacks have been studied in (Xu et al., 2005), where the attacking devices do not obey the MAC layer protocols. MAC layer attacksDifferent types of attacks are possible in the MAC layer of a WMN. Some of the major attacks at this layer are: passive eavesdropping, jamming, MAC address spoofing, replay, unfairness in allocation, pre-computation and partial matching etc. These attacks are briefly described in this subsection. i. Passive eavesdropping: the broadcast nature of transmission of the wireless networks makes these networks prone to passive eavesdropping by the external attackers within the transmission range of the communicating nodes. Multi-hop wireless networks like WMNs are also prone to internal eavesdropping by the intermediate hops, whereby a malicious intermediate node may keep the copy of all the data that it forwards without the knowledge of any other nodes in the network. Although passive eavesdropping does not affect the network functionality directly, it leads to the compromise in data confidentiality and data integrity. Data encryption is generally employed using strong encryption keys to protect the confidentiality and integrity of data. ii. Link layer jamming attack: link layer attacks are more complex compared to blind physical layer jamming attacks. Rather than transmitting random bits constantly, the attacker may transmit regular MAC frame headers (no payload) on the transmission channel which conforms to the MAC protocol being used in the victim network (Law et al., 2005). Consequently, the legitimate nodes always find the channel busy and back off for a random period of time before sensing the channel again. This leads to the denialof-service for the legitimate nodes and also enables the jamming node to conserve its energy. In addition to the MAC layer, jamming can also be used to exploit the network and transport layer protocols (Brown et al., 2006). Intelligent jamming is not a purely transmit activity. Sophisticated sensors are deployed, which detect and identify victim network activity, with a particular focus on the semantics of higher-layer protocols (e.g., AODV and TCP). Based on the observations of the sensors, the attackers can exploit the predictable timing behavior exhibited by highe...

A non‐biased trust model for wireless mesh networks

“…By a blackhole attack, a malicious node will advertise itself as having the best route to the destination even though it does not have a route to it. It does this by sending a route reply packet immediately to the source node . The source node, upon receiving this malicious route reply, assumes that the route discovery is complete and ignores all other route reply packets from the other nodes and selects the path that now includes the malicious node as a relay node to forward the data packets.…”

“…Instead of dropping all the traffic, the node drops the packets selectively that makes grayhole attacks more difficult to detect as the selective packet dropping may be perceived as packet loss because of the unreliable wireless channels in the networks. Hence, the grayhole attacks may go undetected for a longer period of time than the blackhole attacks . Furthermore, the grayhole nodes may appear well‐behaved during the route discovery process or at the starting of data transmission.…”

“…However, because of the openness and the multi-hop nature of the WMNs, attacks can be launched at any layer of the Internet protocol stack. 3,4 While cryptography has been the traditional approach of providing network security for confidentiality, integrity, authentication, and non-repudiation, it is not sufficient to protect the network against nodes exhibiting selfish behaviors, that is, nodes that refrain from forwarding packets to save scarce resources. Such selfish behavior is hard to detect as they appear to be legitimate nodes with valid cryptographic keys.…”

Information security in computer networks with dynamic topology

“…An attacker node does not transmit traffic and data does not reach a recipient and gets lost [3]. There is a subtype of that attack called «grayhole»: not all of the sent packets are transmitted [4].…”

Avoidance of misbehaving nodes in wireless mesh networks

“…The enhanced secure routing protocol for wireless mesh networks (E‐SRPM) uses information of previous unsuccessful communications with neighboring nodes as one of the parameters for selecting routes. Two secure WMN routing protocols were proposed by Sen . The first protocol relies on estimated reliability of routing paths by collecting information regarding the wireless links to one‐hop neighbor nodes, whereas the second is a trust‐based protocol that uses local observations for detecting selfish nodes.…”