Abstract: In a network or a system, any kind of unauthorized or unapproved activities are called Intrusions. An intrusion detection system (IDS) monitors network traffic and monitors for suspicious activity and alerts the system or network administrator. In some cases the IDS may also respond to anomalous or malicious traffic by taking action such as blocking the user or source IP address from accessing the network. An IDS inspects all inbound and outbound network activity and identifies suspicious patterns that may indicate a network or system attack from someone attempting to break into or compromise a system. They act as the first line of defense for our computer systems. New intelligent Intrusion Detection Systems (IDSs) which are based on sophisticated algorithms with less power consumption rather than current signature-based detections are in demand. In this paper, we propose a solution using LEACH protocol to detect intrusion with low power consumption and also to increase the level of security. LEACH (Low Energy Adaptive Clustering Hierarchy) is one of the most interested techniques that offer an efficient way to minimize the power consumption in sensor networks to identify the intrusions. In Watchdog-LEACH, some nodes are considered as watchdogs and some changes are applied on LEACH protocol for intrusion detection. Watchdog-LEACH is able to protect against a wide range of attacks and it provides security and energy efficiency.

Keywords: IDS, Leach, AODV, Watch dogs.