DoS Attacks in MANETs: Detection and Countermeasures

1. Denial Of Service (Dos)

A DoS can be characterized as an attack with the purpose of preventing the legitimate users from using a victim computing system or a network resource. A DoS attack usually has the following properties:

• (a)

  Malicious - Intentional act of harming a node so as to cause a failure.

• (b)

  Disruptive - Degradation or disruption of some capability or service.

• (c)

  Asymmetric – The property of prevention/detection measure effort of an attack being greater that the effort required mounting it. For example, buffer overflow attacks are easy to execute but the effect may crash the server.

• (d)

  Remote – Attacks are usually carried out over the network using a spoofed IP to escape traceback.

DoS attacks are thus proving to be a serious and permanent threat to users, organizations and network resources.

Figure 1 outlines the taxonomy of DoS attacks at the lower three layers of the wireless protocol stack. In this chapter, we analyze attacks in terms of IEEE 802.11 standard, which covers physical and MAC layer. The standard currently defines a single MAC that interacts with three PHYs (running at 1 or 2 Mbit/s). We also survey attacks and defense mechanisms in the routing layer. In the remaining sections we discuss these attacks.

Figure 1.

Taxonomy of DoS attacks in MANET