International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 01 | Jan-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 1083 Security Issues & Challenging Attributes in Mobile Ad-Hoc Networks (MANET) S.Nithya 1 , S.Prema 2 , G.Sindhu 3 1 Asst.Professor, Department of ECE, KPR Institute of Engineering & Technology, Tamil Nadu, India 2 Asst.Professor, Department of ECE, KPR Institute of Engineering & Technology, Tamil Nadu, India 3 Asst.Professor, Department of CSE, Kalaivani College of Technology, Tamil Nadu, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - A Mobile Ad-hoc Network otherwise called as MANET is a collection of wireless nodes that can dynamically be set up anywhere & anytime without having the preexisting network infrastructure. It is an anonymous system in which mobile hosts connected by wireless links are free to move randomly. Here the nodes sometime act as a host & also sometime acts as a router. It plays a major role in Household, industry, Study & Military applications, but the security plays a major role in ad- hoc networks. The attacks may be classified into two types. One is Active & other is Passive Attack. This paper deals with the security issues & the challenges in mobile Ad-hoc Networks. Key Words: Mobile ad-hoc Networks, Attacks, Security. 1. INTRODUCTION A Mobile Ad hoc Network (MANET) is a system of wireless mobile nodes that dynamically self-organize in arbitrary and temporary network topologies. People and vehicles can thus be internetworked in areas without a preexisting communication infrastructure or when the use of such infrastructure requires wireless extension. In the mobile ad hoc network, nodes can directly communicate with all the other nodes within their radio ranges; whereas nodes that not in the direct communication range use intermediate node(s) to communicate with each other. In these two situations, all the nodes that have participated in the communication automatically form a wireless network, therefore this kind of wireless network can be viewed as mobile ad hoc network. The mobile ad hoc network has the following typical features. Fig -1: Mobile ad hoc network In the recent scenario, the Routing protocols in MANET play a vital role. There come major protocols like AODV (Ad hoc On Demand Distance Vector protocol), DSR (Dynamic Source Routing protocol), WRP (Wireless Routing Protocol) etc., but none of the routing protocols specifies the security issues. The reality is the MANET is very vulnerable to malicious attacks compared to traditional Wired Networks. In MANET basically two types of attacks will take place. One will be Active Attack & other is Passive attack. In passive attacks, the attackers typically involve eavesdropping of data, thus disclose the information of the location and move patterns of mobile nodes. This kind of attack is very difficult to detect, because the attacker seldom exhibits abnormal activities. Active attacks, on the other hand, involve actions performed by intruder. The target of the attack can be either data traffic or routing traffic [1]. The MANETS set new challenges for network security and the need of an hour is to pay more attention to the security threats posed on the network [2]. Following are the concerned issues in security of ad hoc networks: i. In MANET, many nodes are participating in transferring the information’s, so that any malicious nodes in the network can easily misuse the message traffic either by dropping the messages or by creating the duplicate or false messages. ii. Due to the limitation of network resources in mobile ad hoc networks, the various cryptographic solutions applicable to wired networks are not directly applicable. Therefore there is a need for new security solutions which can find their application in this challenging domain.