ISSN (Print) : 2320 – 3765 ISSN (Online): 2278 – 8875 International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering (An ISO 3297: 2007 Certified Organization) Vol. 4, Issue 4, April 2015 Copyright to IJAREEIE 10.15662/ijareeie.2015.0404028 2053 Comparison of LEACH protocol with Wormhole Attack and without Wormhole Attack in Wireless Sensor Networks Dr.M.Pushpavalli 1 , P.Mahalakshmi 2 Assistant Professor (Sr.G), Dept. of ECE, Bannari Amman Institute of Technology, Sathy, Tamilnadu, India 1 PG Student, Dept. of ECE, Bannari Amman Institute of Technology, Sathy, Tamilnadu, India 2 ABSTRACT: In Wireless Sensor Networks, routing is the major concern. It comprises of small sensor nodes with limited resources. It is necessary to introduce a routing protocol to extend network life time and to reduce the power consumption in sensor nodes. LEACH is one of the most interested techniques that offer an efficient way to minimize the power consumption in sensor networks. It uses self organizing and dynamic cluster formation which makes it attractive to various routing attacks, such as Denial of Service (DoS), Black hole, Wormhole and Sybil attacks. Wormhole attack is a Denial of Service attack launched by malicious nodes. It records packets at one location and tunnels them into another location. To check the reliable operation of LEACH, implement wormhole attack and evaluated the LEACH protocol in terms of metrics like throughput, average end-to-end delay, Packet Delivery Ratio (PDR). The evaluation of LEACH with wormhole attack has been done with the help of NS2 simulator. Watchdog is a monitoring technique which detects the misbehaving nodes in the network. It can be implemented in LEACH. 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, energy efficiency and memory efficiency. Comparison made on LEACH with wormhole attack and LEACH with watchdog shows that LEACH with watchdog achieves high throughput, Packet Delivery Ratio and low End to End Delay. KEYWORDS: LEACH Protocol, NS2, Watchdog, Wireless Sensor Network (WSN), Wormhole Attack. I. INTRODUCTION Wireless sensor network (WSN) is composed of large number of small sized, inexpensive and computable sensors, which are limited in power, memory, and computation. Normally, large numbers of tiny sensors are deployed randomly to monitor one or more phenomena, to collect and process the sensed data and to send the data back to the sink. The important applications of WSN include environmental monitoring, personal healthcare, military applications, etc. Sometime the sensitive data is communicated to the destination node through an insecure medium. Thus, WSN can be easily attacked by Denial-of-Service (DoS) attacks, which cause information loss along with large energy expenditure. Cluster-based communication protocols have been proposed for Adhoc networks in general and sensor networks in particular for various reasons including scalability and energy efficiency. In cluster-based networks, nodes are organized into clusters; with cluster heads (CHs) that they relay messages from ordinary nodes in the cluster to the Base Stations (BS). LEACH is a clustering-based protocol that minimizes energy dissipation in sensor networks. The purpose of LEACH is to select sensor nodes randomly as cluster heads. The operation of LEACH is separated into two phases: the set-up phase and the steady phase. The duration of the steady phase is longer than the duration of the set-up phase in order to minimize the overhead. During the set-up phase, a sensor node n chooses a random number between 0 and 1. If this random number is less than a predetermined threshold, t, the sensor node becomes a cluster head. After a node is self-selected as a cluster head, it advertises this to all its neighbors. The sensor nodes inform their cluster head that they will be a member of the cluster, and then the cluster head assigns a time slot for every sensor node in which they can send data to the cluster head. During the steady phase, the sensor nodes can begin sensing and transmitting data to the cluster heads. The cluster heads also aggregate data from the nodes in their cluster before sending them to the base station.