Detection of misbehaving node using Secure Acknowledgement in MANET

Mobile ad hoc networks (MANETs) can be defined as a collection of large number of mobile nodes. Due to self configuring ability of nodes and infrastructure less nature of network, MANET is preferred in variety of applications such as military, disaster stuck areas, emergency recovery etc. MANET is vulnerable to various attacks due to its open medium and wide distribution of nodes. This itself emphasize the importance of security and need for an efficient system, for example intrusion detection system in MANET. In literature, various intrusion detection systems (IDS) have been proposed for detecting the node that misbehaves in the network. The misbehaviour such as, delay or drop in data packets or acknowledgement packets, drop packets and modify routing information etc. are present. These misbehaviour need to be detected well in advance to keep network secure. In this paper we propose and implement, new IDS named as Secure Acknowledgement (ACK) System. The Secure ACK system is purely an acknowledgement based technique. The type of misbehaviour detected by proposed system is about delay in packet transmission. In this system, for every three consecutive nodes in the route, the third node is required to send back an acknowledgement packet to the first node in the group. Based on the non-receipt of ACK packet within predefine time to the first node in the group, it reports about misbehaviour activity in the network. As soon as the proposed system detects misbehaving node present in the network, it stops the further data transmission. So, the misbehaving node will not be able to damage network thereafter.