A Novel Approach for Avoiding Wormhole Attacks in VANET

Different attacks on routing protocols in ad hoc networks occur that one of the most dangerous types is called wormhole attack. This attack happens with the assistance of at least two or more malicious nodes. In this attack nodes create a private tunnel which if a packet comes to one of them, it will be guided to other pair of these malicious nodes by this tunnel and that node broadcasts it into network. This action provides a short connection in the network that is controlled by these malicious nodes. Hence they control all Packets that come to them and threaten the security of data within packets or delete them. Totally, what a wormhole does is an incorrect understanding of network topology. This attack severely disrupts the network operation, especially in networks that use on demand routing protocols such as AODV or DSR. In this paper we try to introduce an efficient method to prevent wormhole attack in vehicular ad hoc networks and detect malicious nodes as far as possible. Occurrence of this type of attack in vehicular networks may cause irreparable lost and therefore the presented method in this paper concentrates on AODV. Routing protocols for unicast application can be extended to other sending protocols regardless of being unicast, broadcast or multicast. In this paper, we use packet leashes and new method of authentication called HEAP. Also, some correction has been done on packet leashes method. We will prove this scheme can avoid wormhole attack in these types of networks for all applications easily. We want to show that our suggested scheme has low overhead, increases security and performance in an acceptable level in the network.