Abstract: Ad hoc network is a group of wireless mobile computers for temporary communication. Here autonomous and self-interested nodes in the network and the broadcast nature of radio transmission make the network highly vulnerable to serious security attacks. In a multi-hop wireless ad hoc network, packet losses are attributed to harsh channel conditions and intentional packet discard by malicious nodes. Packet losses may due to link errors or the combined effect of link errors and malicious drop. It becomes more difficult to detect internal attacks, whereby a malicious node that is part of the route exploits communication information to selectively drop a small number of packets which may critically affect network performance. Secure and efficient communication is one of the most important aspects in ad-hoc wireless networks, so it needs to a develop protocol strategy which take less computational power, better performance and efficiently utilizes the bandwidth. Here I reviewed various security aspects in adhoc networks, and proposed the countermeasures to prevent them. Performance comparison between two network scenarios has also been studied, a standard network scenario and packet dropping attack scenario.
Keywords: Security, AODV, Trust, Encryption, Integrity.