This book presents the new reputation and cluster based mechanism to identify the sources of attack (i.e. attackers) may lead to the routing in MANETs to be more secure, reliable and authenticated by reducing the control packets as well as packet loss. In this book detection mechanism, the attacker identification can be achieved in two different granularities according to different MANET circumstances. To accomplish the attack node identification, a detection mechanism is developed which is based on reputation scheme. Finally, develop a reaction mechanism against the malicious node attack. This reaction mechanism can help the victim network recovery from the malicious node attack by removing the malicious node from the network.