In this paper we addressed existing potential security
threats in MANETs. In this study we found that most of the
work on MANET security focused on single layer attacks
i.e. active and passive attacks. In the meanwhile some
attacks involving multiple nodes have received little
attention since they are surprising and combined attacks i.e.
collaborative attacks. There have been no proper definition
and categorization of these kinds of collaborative attacks in
MANETs. Thus, protection of communication system
against these types of attacks is a challenging task.
Therefore, deep study on collaborative attacks and
development of new protocols/algorithms/model to manage
these attacks is the need of hour. Development of a multifence
security solution that is embedded into possibly every
component in the network, resulting in depth protection that
offer multiple line of defense against many known and
unknown security threats is also given importance. Further,
there is also a need to develop a detection and defense
mechanism for managing messages in secure manner.