Abstract: Security issues in Mobile Ad-hoc Networks have been a major focus in recent years. The development of fully secure schemes for these networks has not been entirely achieved till now. While a wireless network is more versatile than a wired one, it is also more vulnerable to attacks. This is due to the nature of radio transmissions, which are made on the air. On a wired network, an intruder would need to break into a machine of the network or to physically wiretap a cable. On a wireless network, an adversary is able to eavesdrop on all messages within the emission area, by operating in promiscuous mode and using a packet sniffer. The two most important security problems in MANET are Authentication and Cooperation. Due to absence of any centralized controller, the detection of problems and recovery from such issues is difficult. Different types of attacks are discussed in this paper.

Keywords: DoS, MANET, AODV, DSR.