Wormhole Attack
In the wormhole attack [15], an adversary tunnels messages received in one
part of the network over a low latency link and replays them in a di?®erent
part. Wormhole attacks usually involve two distant malicious nodes colluding
to understate their distance from each other by relaying packets along an outof-
bound channel available only to the attacker. An adversary situated close
409
an adversary can be in more than one place at once . ??? ???
Xiaojiang Du and Yang Xiao
to a base station may be able to completely disrupt routing by creating a wellplaced
wormhole. An adversary could convince nodes that would normally be
multiple hops from a base station that they are only one or two hops away via
the wormhole. Wormhole attacks would likely be used in combination with
selective forwarding or eavesdropping. Detection is potentially di?±cult when
used in conjunction with the Sybil attack.
Hello Flood (Unidirectional) Attack
In [3], the authors introduced a novel attack against sensor networks: the Hello
flood attack. It is an attack by utilizing unidirectional connections between
nodes. We also refer to this attack as unidirectional attack. Many protocols
require nodes to broadcast Hello packets to announce themselves to their
neighbors, and a node receiving such a packet may assume that it is within
(normal) radio range of the sender. This assumption may be false because
of the well-known unidirectional problem in ad hoc networks.
Pages:
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643