Abstract: Vehicular Ad-hoc Network (VANET) is taking more
attention in automotive industry due to the safety concern of human
lives on roads. Security is one of the safety aspects in VANET. To be
secure, network availability must be obtained at all times since
availability of the network is critically needed when a node sends any
life critical information to other nodes. However, it can be expected
that security attacks are likely to increase in the coming future due to
more and more wireless applications being developed and deployed
onto the well-known expose nature of the wireless medium. In this
respect, the network availability is exposed to many types of attacks.
In this paper, Denial of Service (DOS) attack on network availability
is presented and its severity level in VANET environment is
elaborated. A model to secure the VANET from the DOS attacks has
been developed and some possible solutions to overcome the attacks
have been discussed.