A Quantitative Study and Comparison of Secure OLSR Routing Protocol

Transcription

1 A Quantitative Study and Comparison of Secure OLSR Routing Protocol S.Tamilarasan 1 M.Sathyam Reddy 2 1 Associate Professor cum HOD, Department of Information Technology, 2 Assistant Professor, Department of Information Technology, Loyola Institute of Technology & Management (LITAM), Dullipala (village) Sattenpalli (Mandal) Guntur, Andhra Pradesh, , India. Stamilarasan74@rediffmail.com Abstract This paper presents the comparison of the secure OLSR (Optimized Link State Routing Protocol) in mobile ad-hoc network with other approach. We compare the security from the different approach and their effect on the existing OLSR. The Main aim of this paper is to study the various securities and compare the different attacks in MANET. Different approaches uses different cryptography security scheme and trying to provide the security to OLSR routing protocols. We also concern the different possible attacks on the OLSR and check that which security scheme is better to provide the security from the attacks. Keywords OLSR, protocol, HASH chain, Encryption algorithm; 1. Introduction A MANET is a collection of mobile nodes that can communicate with each other without the use of predefined infrastructure or centralized administration. Due to self-organize and rapidly deploy capability, MANET can be applied to different applications including battlefield communications, emergency relief scenarios, law enforcement, public meeting, virtual class room and other security-sensitive computing environments. There are 15 major issues and subissues involving in MANET such as routing, multicasting/broadcasting, location service, clustering, mobility management, TCP/UDP, IP addressing, multiple access, radio interface, bandwidth management, power management, security, fault tolerance, QoS/multimedia, and standards/products. Currently, the routing, power management, bandwidth management, radio interface, and security are hot topics in MANET research. Although in this paper we only focus on the OLSR routing protocol and security issues in MANET. 2. Routing Protocol MANET protocols are used to create routes between multiple nodes in mobile ad-hoc networks. IETF (Internet Engineering Task Force) MANET working group is responsible to analyze the problems in the ad-hoc networks and to observe their performance. There are different criteria for designing and classifying routing protocols for wireless ad-hoc networks. The MANET protocols are classified into three huge groups, namely Proactive (Table-Driven), Reactive (On-Demand) routing protocol and hybrid routing protocols. The following figure shows the classification of protocols [18]. Fig.1: Different type of routing protocols in wireless Ad-hoc network Proactive (Table-Driven) routing protocol: - In proactive routing protocol perform consistent and up-to-date routing information to all the nodes is maintained at each node. Reactive (On-Demand) routing protocol: - This type of protocols find route on demand by flooding the network with Route Request packets Proactive vs. Reactive Routing Proactive s determine the routes to various nodes in the network in advance, so that the route is already present whenever needed. Route Discovery overheads are larger in such schemes as 632

2 one has to discover all routes. Examples of such schemes are the conventional routing schemes, Destination Sequenced Distance Vector (DSDV). Reactive s determine the route when needed. Therefore they have smaller Route Discovery overheads. Examples for such schemes are Ad Hoc On-Demand Distance Vector (AODV) routing protocol Single-Path vs. Multi-Path There are several criteria for comparing singlepath routing and multi-path routing in ad-hoc networks. First, the overhead of route discovery in multi-path routing is much more than that of singlepath routing. On the other hand, the frequency of route discovery is much less in a network which uses multi-path routing, since the system can still operate even if one or a few of the multiple paths between a source and a destination fail. Second, it is commonly believed that using multi-path routing results in a higher throughput. Third, multi-path networks are fault tolerant when dynamic routing is used, and some routing protocols, such as OSPF (Open Shortest Path First), can balance the load of network traffic across multiple paths with the same metric value Proactive vs. Source Initiated A proactive (Table-Driven) routing protocols are maintaining up-to-date information of both source and destination nodes. It is not only maintained a single node s information, it can maintain information of each and every nodes across the network. The changes in network topology are then propagated in the entire network by means of updates. Some protocols are used to discover routes when they have demands for data transmission between any source nodes to any destination nodes in network, such protocol as DSDV(.Destination Sequenced Distance Vector ) routing protocol. These processes are called initiated on-demand routing. Examples include DSR (Dynamic Source Routing) and AODV (Ad-hoc On Demand Distance Vector) routing protocols [18]. 3. Optimized Link State Routing Protocol (OLSR) OLSR is a proactive routing protocol. It is bored on periodic exchange of topology information. The key point of the OLSR protocol is that the use of multipoint relay (MPR) to provide an efficient flooding mechanism by reducing the number of transmission required. In OLSR, each node selects its own MPR from its neighbours. Each MPR node maintains the list of nodes that were selected as an MPR; this list is called an MPR selector list. Only nodes selected as MPR nodes are responsible for advertising, as well as forwarding an MPR selector list advertised by other MPRs [19]. 3.1 OLSR Control Traffic Control traffic in OLSR is exchanged through two different types of messages: HELLO and TC messages. HELLO messages are exchanged periodically among neighbour nodes, in order to detect links to neighbours, to detect the identity of neighbours and to signal MPR selection. TC (Topology Control) messages are periodically flooded to the entire network, in order to signal link-state information to all nodes HELLO Message A HELLO message is the message that is used for neighbour sensing and MPR selection. In OLSR, each node generates a HELLO message periodically. A node s HELLO message contains its own address and the list of its one-hop neighbours. By exchanging HELLO messages, each node can learn a complete topology up to two hops. HELLO messages are exchanged locally by neighbour nodes and are not forwarded further to other nodes TC Message A TC message is the message that is used for route calculation. In OLSR, each MPR node advertises TC messages periodically. A TC message contains the list of the sender s MPR selector. In OLSR, only MPR nodes are responsible for forwarding TC messages. Upon receiving TC messages from all of the MPR nodes, each node can learn the partial network topology and can build a route to every node in the network. 3.2 Multipoint Relay Selection and Signalling Each node must select MPRs from among its neighbour nodes such that a message emitted by a node and repeated by the MPR nodes will be received by all nodes two hops away. MPR selection is performed based on the 2-hop neighbour set received through the exchange of HELLO messages, and is signalled through the same mechanism: a link-status of MPR specifies that the link between the originator of the HELLO message and the listed address is symmetric and that the node with the included address is selected as MPR by the originator. Figure 2 shows a node with neighbours and 2-hop neighbours. In order to achieve a network-wide broadcast, it suffices that a broadcast transmission be repeated by a subset of the neighbours. This subset is made up from the MPR-set of the node. Fig 2: Two hop neighbours and multipoint relays (the solid circles) of a node. (a) Illustrates the 633

3 situation where all neighbours retransmit a broadcast, (b) illustrates where only the MPRs of a node retransmit the broadcast. 3.3 Security Problems in OLSR There are various type of attacks are possible on OLSR protocols. In the present OLSR routing protocol there is various security weaknesses. That s why we are presenting the new security scheme in the present OLSR routing protocols. For the table driven routing protocols it is necessary that to generate or forward the routing information correctly. If this is not happened then the either the false path is made between the node or there is no path between the node when the actual data sending is take place. If it is not correctly generate or forward the messages then such node are called the influence node. There is various type of security problem in OLSR. 4. Routing Attacks against MANETs Protocols 4.1 Flooding Attack The flooding attack is to exhaust the network resources, such as bandwidth and to consume a node s resources, such as computational and battery power or to disrupt the routing operation to cause severe degradation in network performance [1] [19]. 4.2 Black Hole Attack A malicious node sends fake routing information, claiming that it has an optimum route and causes other good nodes to route data packets through the malicious one. This method is called black hole attack [11] [19]. 4.3 Link withholding Attack A malicious node ignores the requirement to advertise the link of specific nodes or a group of nodes, which can result in link loss to these nodes, called a link withholding attack [19]. 4.4 Link Spoofing Attack A malicious node advertises fake links with nonneighbours to disrupt routing operations. For example, in the OLSR protocol, an attacker can advertise a fake link with a target s two-hop neighbours. This causes the target node to select the malicious node to be its MPR. As an MPR node, a malicious node can then manipulate data or routing traffic, for example, modifying or dropping the routing traffic or performing other types of DoS attacks. Figure 3 shows an example of the link spoofing attack in an OLSR MANET. In the figure, we assume that node A is the attacking node, and node T is the target to be attacked. Before the attack, both nodes A and B are MPRs for node T. During the link spoofing attack, node A advertises a fake link with node T s two-hop neighbour, that is, node D. According to the OLSR protocol, node T will select the malicious node A as it s only MPR since node A is the minimum set that reaches node T s two-hop neighbours. By being node T s only MPR, node A can then drop or withholds the routing traffic generated by node T [4] [19]. Fig 3: Example of a link spoofing attack on OLSR 4.5 Replay Attack MANET topology frequently changes due to mobility so that the current network topology cannot exist in future. In the replay attack old control message is used by the node for making the communication in the network. An attacker can perform a replay attack by recording the old valid control message and resending them to make other nodes update their routing tables with old values. 4.6 Wormhole Attack In the Wormhole attack, two colluding nodes that are far apart are connected by a tunnel giving an illusion that they are neighbours. Each of these nodes receive route request and topology control messages from the network and send it to the other colluding node via tunnel which will then replay it into the network from there. By using this additional tunnel, these nodes are able to advertise that they have the shortest path through them. Once this link is established, the attackers may choose each other as multipoint relays (MPRs), which then lead to an exchange of some topology control (TC) messages and data packets through the wormhole tunnel. Since these MPRs forward flawed topology information, it results in spreading of incorrect topology information throughout the network [7] [19]. Figure describes it with two nodes X and Y. In the figure node A and B are 3hop away from each other. And attacker node X and X show that they are neighbour of A and B respectively. So they make the tunnel between node A and B. And they can drop the packet received from A or B. Fig 4: Wormhole attack, X and Y are the attacker 634

4 4.7 Colluding Miss Relay Attack In this attack, multiple attackers work in collusion to modify or drop routing packets to disrupt routing operation in a MANET. This attack is difficult to detect by using the conventional methods such as watchdog and pathrater. Figure 4 shows an example of this attack. Consider the case where node A1 forwards routing packets for node T. In the figure, the first attacker A1 forwards routing packets as usual to avoid being detected by node T. However, the second attacker A2 drops or modifies these routing packets [19]. Fig 5: Example of a colluding miss-relay attack 5. Different Security 5.1 Hybrid protection of OLSR The approach is defined in paper A. M. Hegland, P. Spilling, L. Nilsen and Q.Kure, Hybrid Protection of OLSR, Electronic Notes in Theoretical Computer Science, 2006[20]. It s using The Hash Chain for providing the security to the routing protocol. In this approach we calculate the Hash of some Initial value up to total no of Hop count and distribute it to the entire network. And the sender node sends the one time hash of initial value to the next neighbour which is MPR of it. Now the intermediate node calculate the difference of TTL and Hop count and doing the hash of received hash value up to calculated difference time. If both the value is same then there is no malicious node changed the value in between them. If both the value is not same then there is some malicious node and it changed the value of Hop count and TTL for making the path to itself. 5.2 Signature And other approach is Amanpreet Kaur, Gurpreet Kaur Deol, Secure Optimized Link State Routing Protocol.2006 [21] provide the security with the help of signature scheme. And the signature scheme and the approach provide the on between the two nodes. For providing the signature the approach uses the two functions. First one is for signature and the second is for verification 1. Sign (nodeid, key, message) A signature for a message can be verified in a node using a function: 2. Verify (originator id, key, message, and signature). To prevent malicious nodes from injecting incorrect information into the OLSR network, the originator of each control generates an additional security element called signature message and transmitted with the control message. A timestamp is associated with each signature in order to estimate message freshness. Thus, upon receiving the control message, a node can determine if the message originates from a trusted node, or if message integrity is preserved. Signatures are separate entities from OLSR control traffic: while OLSR control messages perform the purpose of acquiring and distributing topological information, signatures serve to validate information origin or 5.3 Secure OLSR This security scheme is work on two levels. In the first level we just concern on the hello message and try to stop the unauthorized nodes to participate in the route creation process and in the second level try to implement the hash chain in the OLSR to secure from the other attack possible in the OLSR protocols. The steps are as 1. Encryption algorithm. 2. Hash chain Encryption In MANET, when the node wanted to create a route between the nodes first of all the hello message is send by the node for finding the neighbour of it. Every node sends a hello message after a certain period of time in the network with TTL (time to live) value 1 and hop count 1. In the OLSR when a node receive the hello message from a new neighbour then it remark him as a Asymmetric node in its routing table and when it getting the response back from that node it make it the symmetric node. And the MPR selection process is completed by that symmetric node only. So according to our approach when a node is identify in the routing table then it send the encrypted nonce (a fixed length input) to that node if the node respond back with correct nonce that it is the node which have the encrypted else a node which have not the key can t send back the response, and if the node receives the correct response than mark it as symmetric node. Fig.6: Asymmetric or Symmetric link in OLSR Figure contains two nodes A and B. Node A finds that the B is asymmetric node and then he sends the nonce N1 encrypted with the secret key. Now if node B knows the secret key then it decrypt 635

5 the nonce and send back to particular node A. Now A check the nonce if it is correct then it is mark B as a symmetric neighbour else identify him as an attacker node. And as we know that only symmetric node can make the MPR in the OLSR routing protocol. So with the help of this scheme only certified nodes can participate in the network and only they can make the route between the nodes. The encryption algorithm is an implementation issue we can use any algorithm which is sufficient according to the complexity and the space. There are many algorithms as AES, DES, triple DES and many others Hash Chain Hash chain is used in the OLSR routing protocol for security from other attacks. In the hash chain every node using a random no which we called the pivot. And generating node finds the (Hn), n time hash of it. After making the MPR generating node having the idea how many MPR are there in the root for reaching the every node in the network. And n is that no. And it also distributes the Hn to every node which going to receive this distribute the Hn to every node which going to receive this message. Now suppose node A distribute Hn to other nodes and now A send TC message to next MPR B. A send TC message to B with Hop count times hash of that pivot no. Now B receive the TC message it s calculate the TTL value of that TC message and now it hash the pivot no, TTL no of times. If the value of it is equal to the Hn than the last node is performing right otherwise it is not responding correct and it is working as an attacker. Fig 7: Example of Hash Chain The following figure describe that there are n+ 1 node in the chain. The Kn is the pivot value which is known to the sender and its find the K0 from it with the help of hash function (Kn=H (H (H...n (K0)))). Sender distributes the value of K0 with the help of hello message to all the needed MPRs. Now when the sender sends the TC message, it calculates the one time hash(x) of Kn and forwards the TC message along with that hash (X). Now receiver node checks the TTL and hashing this X same no of times. If the value it calculated is equal to the K0 which is distributed, there is no attack on the message otherwise the attacker change the value of Hop count or TTL (mutable field). Now the intermediate node repeat the process and they hash the X once more and forward it to next MPR. And receiver also doing the same process until the value of TTL is reached to 0. So with the help of hash chain the node to node on is provided. Every node can authenticate that the last node is responding well or not. Hash chain also provides the sender to receiver on. Because the value of K0 is distributed by the sender so every node when compare it with the value it get, is sender on. Table: 1. Difference between the schemes Sl. no Hybrid 1 Provide the node to node o n between the nodes. 2 Provide the source to destination o n. 3 There is a chance of Id spoofing attack. 4 A node can use the previous send message to other place. 5 Provide 6 Complexity is less comparison to other scheme. Signature It s not providing the node to node on between the nodes. Provide the source to destination on. Its provide safety from such attack for external nodes. A node cannot use the previous send message to other place. Provide The complexity is less than SOLSR but more than the hybrid scheme. Secure OLSR It does also provide the node to node on between the nodes. Provide the source to destination on. Its provide safety from such attack for external nodes. A node can use the previous send message to other place. Provide The complexity of the scheme is more than the other two approaches. 7. Security from Various Attacks The table describes the security provided by the different security schemes at various attacks. Table: 2. Security at different attacks Sl. Attacks No 1 Wormhol e attack Black 2 hole attack Hybrid Signature SOLSR Yes No Yes Yes No Yes 636

6 3 4 5 Id spoofing attack Replay attack Route corruptio n attack No Yes Yes No Yes No Yes No Yes 8. References [1]. P.Purniemaa, K. Manikandan, M.A.Saleem Durai; A Framework for Securing Enhancement in Mobile-Adhoc Network, (IJCST) Internal Journal of Computer Science and Technology, Vol.2, issue 2, June 2011, PP: [2]. Rasid Hafeez Khokhar, Md Asri Nagadi and Satria Mandala; A Review of Current Routing Attacks in Mobile Ad Hoc Networks, International Journal of Computer Science and Security, Volume 2, Issue 3, PP: [3]. Cedric Adjih, Daniele Raffo, Paul Muhlethales; Attacks Against OLSR: Distributed Key Management for Security, INRA, Domaine de Voluceau, France. [4]. Amirt Suman, Praneet Saurabh, Bhupendra Verma, A Behavioral Study of Wormhole Attack in Routing for MANET, International Journal of Computer Applications, volume 26, No 10, July 2011, PP: [5]. Abari Bhattacharya and Prof Himadri Nath Saha; A Study of Secure Routing in MANET various attacks and their Countermeasures, IEMCON 2011 Organized by IEM in Collaboration with IEEE on 5th & 6th of Jan2011, PP: [6]. Reshmi Maulik and Nabendu Chaki; A Study on Wormhole Attacks in MANET, International Journal of Computer Information Systems and Industrial Management Applications, Vol 3 (2011), PP: [7]. PRADIP M. JAWANDHIYA, NAGESH M. GHONGE, DR M.S.ALI and Prof J.S.DESHPANDE; A Survey of Mobile Ad Hoc Network Attacks, international Journal of Engineering Science and Technology, Vol 2 (9), 2010, PP: [8]. Sunil Taneja and Ashwani Kush, A survey of Routing Protocols in Mobile Ad Hoc Networks, International Journal of Innovation, Management and Technology, Vol 1, No 3, August 2010, PP: [9]. Emmanouil A. Panaousis, George Drew, Grant P.Millar, Tipu A.Ramrekha and Christos Politis; A T EST-BED IMPLEMENTATION FOR SECURING OLSR IN MOBILE AD-HOC NETWORKS, International Journal of Network Security & Its Applications (IJNSA), Vol 2, No 4, Oct 2010, PP: [10]. IRSHAD ULLAH SHOAIBUR REHMAN; Analysis of Black Hole attack On MANETS using different MANET Routing Protocols, Master Thesis Electrical Engineering Thesis No: MEE June [11]. Niren Mahajan, Mailreya Natu and Adarshpal Sethi; ANALYSIS OF WORMHOLE INTRUSION ATTACKS IN MANETS, IEEE-2008, PP: 1-7. [12]. Daniel Sterne, Geoffrey Loiwler, Richard Gopaul, Brian Rivera, Kelvin Marcus, Peter Kruus; Countering False Accusations and collusion in the Detection of In- Band wormholes, Communications and Network consortium by us Army Research Laboratory. [13]. Farid Nait-Abdesselam, Brahim Bensaou, and Tarik Taleb; Detecting and Avoiding Wormhole Attacks in Wireless Ad Hoc Networks. [14]. Mohamed Amine FERRAG, Securing the OLSR routing Protocol for Ad Hoc Detecting and Avoiding Wormhole Attack, ISAT- April Edition 2011, PP: [15]. S.A.Adel and P.A Tijare, performance Comparison of AODV, DSDV, OLSR and DSR Routing protocols in Mobile Ad Hoc Networks, International Journal of Information Technology and Knowledge Management, July-Dec [16]. Cedric Ajih, Thomas Clausen, Anis Laouiti, Paul Mahlethaler, Daniele Ratto; Securing the OLSR routing protocol with or without compromised nodes in the network, [17]. S.Tamilarasan, A Performance Analysis of Multihop Wireless Ad-Hoc Network Routing Protocols in MANET, International Journal of Computer science and Information Technologies (IJCSIT), Vol 2 (5), 2011, PP: [18]. Bounpadith Kannhavong, Hidehisa Nakayama, Voshiaki Nemoto and Neikato: A Survey of Routing Attacks in Mobile Ad-hoc Networks, IEEE Wireless Communications, October 2007, PP: [19]. A.M.Hagland, P.Spilling, L.Nilsen and Q.Kure; Hybrid Protection of OLSR, Electronic Notes in Theoretical Computer Science [20]. Amanpreet Kaur, Gurpreet Kaur Deol; Secure Optimized Link State Routing Protocol, Networks. S. Tamilarasan, M.E. Associate professor cum Head of Department, Loyola institute of Technology and management, Guntur, Andhra Pradesh, India. Specialization: Mobile computing, Advanced Data Structure, Design and analysis of algorithm, Computer 637

7 M.Sathyam Reddy, M.Tech Assistant Professor of Department of Information Technology, Loyola institute of Technology and management, Guntur, Andhra Pradesh, India. Specialization: Mobile computing, Advanced Data Structure, Design and analysis of algorithm, Computer networks. 638