Essay Example on Two or more collaborating malicious nodes can Establish

Two or more collaborating malicious nodes can establish this attack by constructing a low latency tunnel and transmitting the captured packet again to various parts of the network The architecture of the wireless network is such that it has exposes itself to these malicious nodes these nodes capture the packets which are not addressed to these them and transmits the packet back to the other collaborating malicious partner present at the other end of the tunnel giving an illusion of these nodes being physically very close to each other This attacks creates a disturbance in the routing for the nodes get an notion that the link consists of one or two hops shorter as compared to multiple hops which may also lead to flooding and packet dropping These attacks are therefore very dangerous and also are difficult to detect as the wormhole tunnels are private and out of bound in nature hence won t be visible to the network The Wormhole and black hole attacks create an idea of rendering the shortest path which results in the entire traffic coming through to this route which can also result in Denial of service attack The wormhole attack can be classified into the following categories Open Wormhole attack Closed Wormhole Attack Half open wormhole attack Open wormhole In this kind of attack the malicious nodes alter the RREQ packet by including themselves in header of the RREQ packet following the route discovery procedure 

The malicious nodes will prohibit the other network nodes from discovering the legitimate nodes Let us study the attack by considering a scenario in which a node A sends a packet to B by finding the shortest path considering the network to contain two malicious nodes X and Y Upon receiving a packet X it transmits it to Y through the existing path U V W Z on reception of the packet Y de marshals it and broadcasts it again If we notice the hop count hasn t increased due to encapsulation In this scenario the RREQ got sent from A to B through the path C D E now the node B has two paths to consider from one being A C D E B which contain 4 hops and the second route A X Y B which gives an appearance of containing only 3 hops Node B will unknowingly choose the smaller route which in reality has 7 hops The network which implements shortest path is open to these kinds of attacks Out of band channel This mode of attack can be established by using either a direct wired link or a long range directional wireless link This attack needs a particular hardware making it is more difficult to launch consider a scenario in which two malicious nodes X and Y are existing in the network having an out of band channel between them when the node X sends a RREQ packet to Y which is a neighbor of B When Y broadcast its packet B receives 2 RREQ request with paths A C D E F B and A X Y B The first is obviously discarded as it seems longer and the second is selected Packet Relay In this mode of attack the malicious node transmits the packets between two nodes which are located at a long distance location and sets them up to be neighbors This attack is very dangerous as it can be enforced even with one node A case in which network containing a large number of malicious nodes the neighboring list can be enlarged and can get extended to several hops Wormhole with High Power Transmission In this mode of attack the malicious node on reception of a RREQ packet broadcasts the RREQ at a very high power level this ability is not present with any other node When the node hears the broadcast it re broadcasts toward the destination