Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh Accepted August 2014 Research Article Improving ZRP Routing Protocol Against Black Hole Attacks In Mobile Adhoc Networks(MANET) Ali Gheibi Dehnashi1, Iman Attarzadeh1, Alireza Osareh2 1 Department of Computer, Dezful Branch, Islamic Azad university, Dezful, Iran 2 Department of Computer, Shahid Chamran University, Ahwaz, Iran Abstract Mobile adhoc network (MANET) is the network in which mobile devices are connected by wireless media and there is no centralized management and fixed network infrastructure. Generally, routing protocols in adhoc networks are classified into proactive, reactive and hybrid. One of the important challenges in hybrid routing properties is the security of these protocols. As ZRP hybrid routing protocol has not appropriate security features against black hole attacks, in this paper, we propose a security mechanism based on estimated latency of the route reply packets reaching the source node and selecting the shortest secure route and it is protected against black hole attacks and finally a new hybrid routing protocol is presented. After simulating this protocol by simulation toolNS2, The simulation result shows that the proposed protocol showed less failure compared to standard ZRP protocol in the presence of malicious nodes of black hole in terms of some parameters as quality of service (QOS) such as the packets loss, packet delivery ratio, end to end delay. Keywords: Mobile adhoc networks, quality of service, quality of service-based routing, Black hole attack, ZRP I. Introduction Mobile adhoc network (MANET) is used in shared spaces and it is one of the highly applied types of wireless networks without any network structure and central station. Each node acts as a router in these networks. In recent years, adhoc networks have been of great importance in public non-military organizations, commercial and industrial regions. Normally, they are used in rescue missions, industrial robots, traffic management and educational workshops in universities. The 55 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh routing protocols for MANET can be categorized into three types according to updating topology as proactive, reactive and hybrid (Chlamtac et al., 2003). Proactive routing protocols are called as table driven routing protocols, because the routs to all destinations are stored in routing tables. Each node maintains one or more tables containing routing information. The routing table should be updated periodically or they can do this in case of network topology change or changing the condition of links. One of the examples of this protocol group is DSDV (Alotaibi et al., 2012). Another category of routing protocols in a MANET is reactive protocols or also called on demand protocols. In this protocols routes are created whenever it is required. Source node first checks its routing table for the available route from source to destination if the route is available then it uses that path to transmit the data packet but if the route is not available then it initiates route discovery process. Reactive protocols add latency to the network due to the route discovery mechanism. Each intermediate node involved in the route discovery process adds latency. These protocols decrease the routing overhead but at the cost of increased latency in the network. Hence these protocols are suitable in the situations where low routing overhead is required. One of the protocols of this group is AODV routing protocol (Perkins et al., 1999). Route maintenance: Due to dynamic topology of the network cases of the route failure between the nodes arises due to link breakage etc, so route maintenance is done. Reactive protocols have acknowledgement mechanism due to which route maintenance is possible. But in hybrid routing protocols, by combining the property of both proactive and reactive protocols, the overhead of proactive routing protocols is reduced and route discovery delay of reactive protocols is also reduced and ideal routing protocols are achieved. Thus, these protocols have better research ground compared to two previous groups. For example ZRP is a hybrid routing protocol (Alotaibi et al., 2012). II. Related Works In this section, some of the security mechanisms are investigated that were regarding the routing protocols of mobile adhoc networks to resist against black hole attacks (Raj et al., 2009) alarmed the nods by dynamic learning system and sending alarm packets against black holde attact in ADOV based mangment(Selvavinayaki et al.,2010) aplied general key and digital signature to issue digital certificates with basic DSR algorithm(VeUoso et al.,2010) study is based on trust model as neighboring nodes are obtained by recommendation. The recommendations with high 56 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh relationship age are on priority based on time and they are used against black hole attack(Venkat et al.,2007) presented a trust-based model composed of detection and reaction. The detection component collectes nodes behavior by recommendations and reaction component enforces decsion. III. ZRP routing protocol This protocol divides the network into various zones and each zone is included of local neighbors, each node is overlapped in some zones. The size of each zone with the number of Hop to the perimeter of the region is obtained and each node has its specific zone. Thus, ZRP reduces the proactive routing method to the central zone of a node. In a limited zone, routing information maintenance is easier. The size of zone is determined by radius ρ and ρ is the lowest number of hop to the perimeter of the zone. In figure 1, routing zone radius of node s is ρ=2. Node S is center of zone. Node S has some routes to node J. One, the routs with length equal 2 and another is routs with length above 2. The nodes with length less than 2 are called interior nodes A,B,C,D,E,F and the nodes with the length equal 2 are called peripheral nodes like I,G,J,H and the nodes with radius greater than 2 are outside the zone that are called exterior node as example the node M is an exterior node(Haas et al, 2001a). Fig. 1 The zone of ZRP protocol routing zone One of the most important issues in ZRP protocol is preventing malicious nodes attack with its great impact on the quality of service of this protocol. One of the attacks is called black hole attack as getting the packets and discarding them or sending them to a nameless destination. The present study aimed to present a new method to prevent this attack. IV. ZRP routing protocol architecture 57 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh As shown in Figure.2 (Haas et al., 2002b), ZRP routing protocol is consists of three parts: Generally, the zone routing protocol consists of several components, which only together provide the full routing benefit to ZRP. A. Intrazone Routing Protocol (IARP) B.Interzone Routing Protocol (IERP) C. Bordercast Resolution Protocol (BRP) Fig. 2 Architecture of ZRP routing protocol A) Intrazone Routing Protocol(IARP) This protocol is implemented by a node to connect with interior nodes of routing zone. A node was located in this zone as its distance from central node is smaller or equal to radius. The nodes should update routing information continually to determine peripheral nodes and also keep a map to reach as locally. This protocol by receiving an interrupt from NDP protocol update on-hop neighbors of central node in case of movement and it can receive a packet form ip layer for routing. There is a field called TTL in this protocol and it initialized to ρ-1 for path discovery and is reduced after each packet of node reaches until it achieves ρ =0. This guarantees that IARP path doesn’t go outside the routing zone (Haas et al., 2002a). B) Interzone Routing Protocol (IERP) It is considered as interzone routing component of ZRP. IERP uses the local known topology benefits and by reactive method, activates the communication between nodes in various zones. Path query is based on demand in IERP as a path demand is occurred. The delay of using route discovery was reduced by Bordercasting method. In this method, the node can not send query to 58 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh all local nodes but they can sent them to their peripheral nodes. In addition, a node cannot return back query to the nodes requesting even they are peripheral nodes. To use interzone routing protocol in ZRP, it is required to inactive updates of proactive method for intrazoneroutes. This active capability is provided by IARP. Flooding sending of a route request to all nodes should be done by Bordercast method with BRP protocol and route request starts only by peripheral nodes. In the next section, Bordercast operation is explained in details (Haas et al.,2001c). C) Bordercast Resolution Protocol (BRP) BRP protocol is used to direct route request as query to peripheral nodes. This is done by Bordercasting. Bordercasting applies known zone routing structure for effective re-broadcasting the messages to the uncovered parts of network. Bordercasting method is better than message flooding applied in reactive protocols. Because this method has query control mechanism by which repetitive queries are prevented and the packets reach the destination rapidly. As shown in architecture of figure.2, BRP is used to direct route requests by IERP protocol, when the interzone routing is done by IERP. Finally, after sending route reply packets from destination node to source node, the shortest route in terms of number of hops is selected and the source sends its main data via the route to the destination node (Haas et al.,2001b). D) Black Hole Attack Mechanism Black hole node is a malicious node advertising that it has the shortest route to destination node by a routing protocol and as receiving the packet, it is dropped and doesn’t forward to the neighbors. For example, node 1 is source node and node 7 is destination node. Node 3 shows misbehavior and this node send a false reply to rout request packet sent from source node and it advertises, it has the shortest route to destination or itself is destination. Thus, node 1 by a false judgment about route discovery process sends data packets to node 3 and this node drops the packets and this node is called black hole node. This attack is one of the attacks of third layer, network disturbing routing process (Jhaveri et al., 2012). 59 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh Fig. 3 An example of black hole attack E) Proposed Method In routing protocol of standard ZRP, the source node sends a packet to destination node without considering the route security, the route is not investigated in terms of black hole attacks and the send data were dropped to destination node on the way by black hole node and the efficiency of network was reduced in some parameters including packet delivery ratio, throughput, packet loss and delay. The present study applies a security mechanism against black hole attacks to ZRP routing protocol to prevent these attacks and lead to efficient routing. The proposed mechanisms are based on two stages: A. Detection of a malicious node The source node performs the following evaluations for each Route Reply packet of destination node: Step 1- By receiving route reply packets by source node, if the number of hops of each route less or equal to 2is considered as suspicious node. As it was said, black hole attack is as malicious node is located near the sender node requesting route or source node and it consumes all the traffic towards itself and doesn’t forward to other nodes. Step 2- To be sure of suspicious node as the attack of real black hole, a test packet is send to the same destination node. Step 3- If acknowledgment packet is not sent from destination node, it is considered as malicious node. Black hole attack receives packet and drops it and never replies and then next phase is applied. 60 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh B. Selecting shortest and secure route among the required routes This mechanism is based on time and is used to identify the attackers or malicious nodes. As the malicious node replies rapidly to the route request packet and source nodes have no accurate information of the accuracy of their distance to destination and they are received about the early reply of these nodes. Thus, to avoid this, round-trip time of all the routes between source and destination nodes is calculated to determine the real time or the real distance between source and destination node to take a true decision about sending the data to destination node. Calculation of Round Trip Time (RTT): Round Trip Time is measured as the time interval when the source node relay HELLO message and when HELLO message reply is received in destination and vice versa. Equations: Sending time =value of receive timestamp (destination) – value of original timestamp (Source)(1) Equation (1) defines the sending time and it is timestamp as received timestamp in destination node minus transmit timestamp from source node. Receiving time = time the packet returned (source) – value of transmit timestamp(destination)(2) Equation (2) defines receiving time and it is timestamp as returning timestampto source node minus transmitting time stamp from destination node. By combining equation (1, 2), equation 3 is achieved: Round-Trip Time = Sending time + Receiving time(3) Equation 3 shows Round Trip Time (RTT). It is the sum of sending time and receiving time. The node with data to be sent to destination should detect the required route to destination and then sends data with the route. This is done only for detecting short and secure routes. To do this, the data sending node or source node does the following calculations: a. For each existing or detected route that in the first phase is found by reply packets, its RTT is calculated from source to destination. 61 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh b. Then, the sum of RTT values of all detected routes is calculated. c. The average of RTT all detected routes of above values is computed. d. Among all the existing routes, the route its RTT has less difference from average RTT, selects the route and with the secure route the data is send to destination. As a Sample: S node is source node D node is destination node M Node is malicious node RTT(S-L-T-C-D)=4ms value of route(1) sending time RTT(D-C-T-L-S)=4ms value of route(1) Receiving time RTT(SLTCD)=8ms value of route(1) sending time+Receiving time RTT(S-N-R-H-P-K-D)=6ms value of route(2) sending time RTT(D-K-P-H-R-N-S)=6ms value of route(2) Receiving time RTT(SNRHPD)=12ms value of route(2) sending time+Receiving time AVG(RTT)=(8+12+2)/3=7.33 RTT (S-L-M)=2ms route of malicious node 8-7.33=0.67 Route(1) is secure route and shortest path 12-7.33=4.67 Route(2) 2-7.33=-5.33 Route(3) V. Results and Discussion The simulation parameters in a scenario file are presented as followings. This parametersareshown in table I.In this scenario, 50 nodes are defined moving in a space with area 1000*1000 m2. 62 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh Table I The simulation space conditions values The features of simulation environment Simulation time 500 ms Simulation space size 1000*1000m2 Number of nodes 50 Maximum length of queue 200 byte Channel type wireless Queue type Drop tail MAC protocol IEEE 802.11 Traffic type FTP Number of malicious nodes 1,2,3 The proposed protocol is named with red as SZRP and standard ZRP protocol is shown by blue. The first parameter of packet delivery ratio is tested in Figure. 4,Figure. 5, Figure. 6, respectively both protocol with 1, 2, 3 malicious nodes. As shown in Figure. 4, the test is done by the presence of one malicious node by increasing simulation time, packet delivery ratio was decreased in standard ZRP protocol. In the proposed protocol, despite the increasing simulation time, packet delivery ratio is ascending because our proposed method is a secure mechanism for preventing black hole attacks in ZRP routing protocol. 63 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh Packet Delivery Ratio ( % ) 1 Maliciuse Node 102 100 98 96 94 92 90 88 86 84 82 99.82 99.91 99.94 98.72 99.67 98.88 99.95 99.96 95.44 84.66 0 100 200 300 400 500 600 Time (sec) ZRP under blackhole attack sZRP(Proposed Method) Fig. 4 Packet delivery ratio chart under one malicious node In figure.5, figure.6, the simulation result is done with the presence of two and three malicious nodes. It shows that as the simulation time increases, the packet delivery ratio is decreased in standard protocol. In the proposed protocol, despite the increasing simulation time, packet delivery ratio is ascending and increasing, because by increasing simulation time more packets are sent to destination. 64 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh Packet Delivery Ratio ( % ) 2 Maliciuse Node 102 100 98 96 94 92 90 88 86 84 82 99.82 99.9 99.92 98.51 99.3 98.79 99.93 99.95 93.71 83.9 0 100 200 300 400 500 600 Time ( sec ) ZRP under blackhole attack sZRP(Proposed Method) Fig. 5 Packet delivery ratio chart under two malicious nodes Packet Delivery Ratio ( % ) 3 Maliciuse Node 120 99.51 99.94 99.91 99.47 82.47 88.47 82.1 88.21 83.41 100 200 300 400 500 98.82 100 80 60 40 20 0 0 Time ( sec ) ZRP under blackhole attack sZRP(Proposed Method) Fig. 6 Packet delivery ratio chart under three malicious nodes 65 600 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh The next simulation parameter is end to end delay. As shown in Figure. 7, Figure. 8, Figure. 9 the chart of end-to end delay is shown under one and two and three black hole malicious node. 1 Maliciuse Node End To End Delay (mili sec) 160 136.733 140 107.38 120 100 127.74 84.015 67.414 71.329 63.732 61.885 200 300 400 500 61.128 80 60 70.489 40 20 0 0 100 600 Time (sec) ZRP under blackhole attack sZRP(Proposed Method) Fig. 7 End to end delay chart under one malicious nodes End to end delay in the proposed protocol is less compared to standard protocol and the reason of more delay of standard protocol is as black hole nodes receive data packets and absorb them continually and generates much traffic in network. Finally, the end to end delay chart with three malicious nodes is shown in Figure. 9. It means that in three points of mobile adhoc network with random location, these three nodes are located and drop the packets. As shown in Figure. 9., standard protocol is shown in blue chart due to the disturbance in network and the lack of security mechanism against black hole attack; it has more delay than proposed protocol. 66 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh End To End Delay (mili sec) 2 Maliciuse Node 166.667 180 160 140 120 100 80 60 40 20 0 125.869 122.163 120.645 105.854 55.598 0 100 57.657 57.657 200 300 65.277 58.599 400 500 600 Time (sec) ZRP under blackhole attack sZRP(Proposed Method) Fig. 8 End to end delay chart under two malicious nodes End To End Delay (mili sec) 3 Maliciuse Node 124.257 140 130.273 125.502 126.52 120 114.866 100 80 62.8465 60 40 55.6096 59.1953 70.5454 61.8945 20 0 0 100 200 300 400 500 Time (sec) ZRP under blackhole attack sZRP(Proposed Method) Fig. 9 End to end delay chart under three malicious nodes 67 600 Journal of Academic and Applied Studies (Special Issue on Applied Sciences) Vol. 4(8) August 2014, pp. 55-70 Available online @www.academians.org ISSN 1925-931X Improving ZRP Routing Protocol … by A. Gheibi Dehnashi, I. Attarzadeh, A.R. Osareh VI. Conclusion and Future Works ZRP routing protocol is one of hybrid routing protocols in mobile adhoc networks without any security mechanism against third layer attacks including black hole attack and is vulnerable to this attack. Black hole attack starts by sending a false route and it deceives source node and send data from source node are dropped. Thus, the source node is notsure of the accuracy of its distance to source. The present study presented a proposed method based on round trip time calculation of routes from source to destination to select the shortest and secure route. After performing simulation by ns-2 simulator on both standard ZRP and proposed protocols with the presence of malicious nodes of black hole, the simulation results showed that the proposed protocol was improved in some parameters including packet delivery ratio, end to end delay ratio compared to standard protocol. Finally, we achieve a secure ZRP protocol against black hole attacks. 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