Security Threats and Maintaince in Mobile Adhoc Networks

Mobile adhoc network (MANET) is a temporary network setup for a specific purpose without help of any pre-existing infrastructure. The nodes in MANET are empowered to exchange packet using a radio channel. The nodes not in direct reach of each other uses their intermediate nodes to forward packets. Therefore threats exist to a mobile ad hoc network both from external nodes unauthorized to participate in the mobile ad hoc networks, and from internal nodes, which have the authorization credentials to participate in the mobile ad hoc network. Internal nodes giving rise to threats can be further divided according to their be haviour - failed, badly failed, selfish and malicious nodes. Badly failed nodes may perform operations in correctly, introducing false and misleading information into the network. Malicious nodes may deliberately dis rupt the network using a variety of attacks. In this paper we have shown Adhoc networks present different threats due to their very different properties and how security is provided and maintained.