International Journal of Computer Applications (0975 – 8887) Volume 124 – No.14, August 2015 7 Algorithm to Detect and Recover Wormhole Attack in MANETs Darshana Sorathiya PG Scholar Computer Engineering RK University Rajkot, Gujarat, India Haresh Rathod Assistant Professor Computer Engineering RK University Rajkot, Gujarat, India ABSTRACT A Mobile Ad-Hoc Network (MANET) is a network in which the mobile nodes are randomly connected with each other. Nodes are dynamically in nature. It usually works by broadcasting the information. Its nature is broadcasting so there is a chance to disrupt network by attacker. The number of attack can be done in Mobile Ad Hoc Network. In this paper we have studied about wormhole attack in AODV. We have analyzed different technique to detect and prevent wormhole attack. In our proposed solution detect and overcome the effect of wormhole attack in MANET. Keywords MANET, Wormhole attack, Wormhole detection techniques 1. INTRODUCTION MANETs is a collection of dynamic mobile nodes. It is a structure less network in which mobile nodes are free to move in any direction. There is no any centralized controller in network. A communication have been established which each other using a multi hop links. It behaves like a router. There is no any base station. It is useful in situations where we have lack of fixed network infrastructure, such as an emergency situations or rescue operation, medical assistance, disaster relief services, mine site operations, and military mobile network in battlefields. In MANETs, identification of malicious node is very hard because mobile node has volatile nature. Fig 1: Mobile Ad Hoc Network [11] Security is providing protected communication between mobile nodes in wireless network. Many routing protocols are available for MANET. It has been proposed to facilitate rapid and efficient network design and restructuring. 2. AODV ROUTING PROTOCOL Ad hoc on-demand distance vector (AODV) is a reactive routing protocol which is designed for ad hoc network. Route is not predefine it established when it’s needed. AODV routing protocol is used for both unicast routing as well as multicast routing. AODV uses a sequence number for find the routing message is fresh. It applies a destination sequence numbers for finding the fresher path. AODV has three types of controlling message RREQ, RREP, RERR. Fig 2: RREQ Broadcast Fig 3: RREP Forwarded Path In an AODV, RREQ is used for the route broadcasting. Source node uses this route request packet for broadcast the route request. RREP is route reply which is send if node has a valid route to the destination. 3. WORM HOLE ATTACK Among various attacks, worm hole is very dangerous as it does not exploit any other node in the network. Due to wormhole attack on proactive type of protocol like AODV first it generates the tunnel between two malicious nodes. In this tunnel it contains data packet for a long time so in result End –to –End delay is affected. In both proactive and reactive routing protocol wormhole attack has significant impact. It performs an operation like packet dropping while it shows in low network throughput. Tunnel is being generated by using out band or in band channel. Tunnel tried to show direct path between source and destination. This make the tunnelled packet get there either faster or with minimum hops compared to the simple multi hop path on which packet will be transmitted. This creates a false impression crated by this comparison that the two end points of the tunnel also say wormhole points are very close to each other means that that one is a shorter route. In the following figure s2 and s9 are two malicious end nodes that makes wormhole tunnel to received RREQ packets.