The International Journal of Engineering and Science (IJES)


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The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.

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The International Journal of Engineering and Science (IJES)

  1. 1. The International Journal of EngineeringAnd Science (IJES)||Volume|| 1 ||Issue|| 2 ||Pages|| 98-105 ||2012||ISSN: 2319 – 1813 ISBN: 2319 – 1805 ENHANCED GREEDY PERIMETER STATELESS ROUTING PROTOCOL (E-GPSR) 1, Kamiya shrivastava, 2, Asst Professor Satendra .k. Jain 1, M.Tech, Research Scholar 1,2, Department of Co mputer Application Samrat Ashok Technological Institute Vid isha (M.P.)-------------------------------------------------Abstract--------------------------------------------------------------Wireless sensor networks are collections of large nu mber of sensor nodes. The sensor nodes are fea tured withlimited energy, computation and transmission power. Each node in the network coordinates with every othernode in forwarding their packets to reach the destination. Since these nodes operate in a physically insecureenvironment; they are vulnerable to different types of attacks such as selective forwarding and sybil. Theseattacks can inject malicious packets by compro mising the node. Geographical routing protocols of wirelesssensor networks have been developed without considering the security aspects against these attacks. In thispaper, a mo re efficient routing protocol named enhanced greedy perimeter stateless routing protocol (E-GPSR)is proposed for mobile sensor networks by incorporating the concept of „observation time‟ to the existing tru stbased secured greedy perimeter stateless routing protocol (S-GPSR). Simu lation results proves that „Enhancedgreedy Perimeter stateless Routing‟ outperforms the S-GPSR by reducing the over head and improving thedelivery rat io of the network.Keywords: Wireless sensor network, GPSR protocol, secured GPSR, Enhanced GPSR, co mpro mised nodes,Sybil attack, selective fo rwarding attack.--------------------------------------------------------------------------------------------------------------------------------------Date of Submission: 1, December, 2012 Date of Publication: 15, December 2012---------------------------------------------------------------------------------------------------------------------------------------1. Introduction1.1 Wireless sensor Network Wireless sensor networks (WSN) are now used in many applications including military, environ mental,healthcare applications, home automation and traffic control. It consists of a large number of sensor n odes,densely deployed over an area. A wireless sensor network [1] typically consists of a very large number of small,inexpensive, disposable, robust, and low power sensor nodes working cooperatively. Wireless sensor networkgenerally co mposed of a large number of distributed sensor nodes that organize themselves into a mult i-hopwireless network. Each network is equipped with more than one sensors, processing units, controlling units, transmitting units etc. Typically, the sensor nodes coordinate themselves to perform acommon task. Sensor nodes are capable of collaborating with one another and measuring the condition of theirsurrounding environments. The sensed measurements are then transformed into [2] digital signals and processedto reveal some properties of the phenomena around sensors. Due to the fact that the sensor nodes in WSN haveshort radio transmission range, intermediate nodes act as relay nodes to transmit data towards the sink nodeusing multipath. The deploy ment of sensor nodes based upo n the application types. Recently wireless sensor networks have drawn a lot of attention due to broad applications in militaryand civilian operations. Sensor nodes in the network are characterized by severely constrained, energy resourcesand communicational capabilities. Due to small size and inattention of the deployed nodes, attackers can easilycapture and rework them as malicious nodes. Karloff and Wagner also have revealed that routing protocols ofsensor networks are insecure and highly vulnerable to malicious The IJES Page 98
  2. 2. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR) Figure 1: Basic structure of a Wireless sensor Network It can either join the network externally or may originate internally by compro mising an existingbenevolent node . The attacks launched by internally generated compro mised nodes are the most dangerous typeof attacks. These compro mised nodes can also carry out both passive and active attacks against the networks . Inpassive attack a malicious node only eavesdrops upon the packet contents, while in active attacks it may imit ate,drop or modify leg itimate packets . Sinkhole is one of the common type of active attack in which a node, candeceitfully modify the routing packets. So, it may lure other sensor nodes to route all traffic through it. Theimpact of sinkhole is to launch further active attacks on the traffic, wh ich is routed through itDue to limited capabilities of sensor nodes, providing security and privacy against these attacks is a challengingissue to sensor networks. In order to protect network against malicious attackers, numbers of routing protocolshave been developed to improve network performance with the help of cryptographic techniques. Securitymechanis ms used in these routing protocols of sensor networks detect the compro mised nod e and then revokethe cryptographic keys of the network. But, requirements of such secure routing protocols include configurationof the nodes with encryption keys and the creation of a centralized or distributed key repository to realizedifferent security services in the network. This paper is organized as follow : Section 2 describes about thegreedy perimeter stateless routing (GPSR). Section 3 deals with the Secured GPSR (S-GPSR). Sect ion 4elaborates the proposed Enhanced Greedy Perimeter Stateless Ro uting (E-GPSR) for Wireless Sensor Network.Simu lation result are described in section 5. Section 6 defines the conclusion.2. Greedy Perimeter Stateless Routing Routing in sensor networks is very challenging due to several characteristics that distinguish them fro mcontemporary co mmunication and wireless ad-hoc networks. First of all, it is not possible to build a globaladdressing scheme for the deployment of sheer number of sensor nodes. Therefore, traditional IP -basedprotocols cannot be applied to sensor networks. Second, in contrary to typical co mmunication networks almostall applications of sensor networks require the flow of sensed data from mult iple sources to a particular sink.Third, generated data traffic has significant redundancy in it since mu ltip le sensors may generate same datawithin the vicinity of a phenomenon. Such redundancy needs to be explo ited by routing protocols to improveenergy and bandwidth utilizat ion. Fourth, sensor nodes are tightly constrained in terms of transmission power,on-board energy, processing capacity and storage and thus require careful resource management. Due to theabove differences, many new algorith ms have been proposed for the problem of routing data in sensor networks.These routing mechanisms have considered the characteristics of sensor nodes along with the application andarchitecture requirements. Almost all routing protocols can be classified as data-centric, hierarchical or location-based although there are few distinct ones based on network flow or QoS awareness. Data-centric protocols arequery-based and depend on the naming of desired data, which helps in eliminating many redundanttransmissions. Hierarchical protocols aim at clustering the nodes so that cluster heads can do some aggregationand reduction of data in order to save energy . Location-based protocols utilize the position information to relaythe data to desired regions rather than the whole network. The Greedy Perimeter Stateless Routing is one of thecommonly used location-based routing protocols for establishing and maintaining a sensor network. Thisprotocol virtually operates in routing. In GPSR, it is assumed that all nodes recognize the geographical positionof destination node with which communicat ion is desired. This location information (i.e.) geographical positionis also used to route traffic to its requisite destination from the source node through the shortest path. Eachtransmitted The IJES Page 99
  3. 3. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR)packet fro m node contains the destination node‟s identification and its geographical position in the form of t wofour-byte float numbers. Each node also periodically transmits a beacon, to inform its adjacent nodes regardingits current geographical co-ordinates. The node positions are recorded, maintained and updated in aneighborhood table by all nodes receiving the beacon. To reduce the overhead due to periodic beacons, the nodepositions are piggy-backed onto forwarded data packets. GPSR supports two mechanisms for forwarding datapackets: greedy forward ing and perimeter forwarding2.1 .Greedy Forwarding In the first mechanism, all data packets are forwarded to an adjacent neighbor that is geographicallypositioned closer to the intended destination. This mechanis m is known as greedy forwarding. The forward ing isdone on a packet to packet basis . Hence, min imal state information is required to be retained by all nodes. Itmakes protocol most suitable for resource starved devices. The greedy forwarding mechanism is shown inFigure1. Ho wever, this mechanis m is susceptible to failure in situations where the distance between forwardingnode and final destination is less than the distance between the forwarding node‟s adjacent neighbors anddestination. Figure 1. Greedy forwarding mechanism2.2. Perimeter Forwardi ng To overcome routing problems in such scenarios, GPSR engages perimeter forwarding mode. Inperimeter mode, the data packet is marked as being in perimeter mode along with the location where greedyforwarding failed. These perimeter mode packets are forwarded using simple planar grap h traversal. Each nodereceiving a data packet marked as in perimeter mode uses the right-hand rule to forward packets to nodes, whichare located counterclockwise to the line joining forwarding node and the destination. The perimeter fo rwardingmechanis m is shown in Figure 2. Each node, while forwarding perimeter mode packets, compares its presentdistance to the destination from the point where greedy forwarding has failed. If the current distance is less,packet is routed through greedy forwarding repeatedly from that point onwards. The protocol has been designedand developed based on the assumption that all nodes in the network would execute the protocol in a sinceremanner. Ho wever, due to number of reasons including malice, inco mpetence and selfishnes s, nodes frequentlydeviate fro m defined standards leading to routing predicaments. Figure 2. Perimeter forwarding mechanis The IJES Page 100
  4. 4. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR)3. SECURED GREEDY PERIMETER STATELESS ROUTING (S-GPSR) GPSR scans its neighborhood table to retrieve the next hop which is optimal and leads to thedestination, during packet transmission to a known host. As there may be more than one such hop available,GPSR selects an adjacent neighbor that has the least distance to a p articular destination. In S-GPSR, the trustlevels used in conjunction with the geographical distances are incorporated in the neighborhood table to createthe most trusted distance route rather than the default min imal distance To compute direct trust in a node, aneffort-return based trust model is used . The accuracy and sincerity of immediate neighboring nodes is ensuredby observing their contribution to packet forwarding mechanis m. To imp lement the trust derivation mechanism,Trust Update Interval (TUI) of each forwarded packet is buffered in the node as (GPSR Agent::buffer packet).The TUI is a very critical co mponent of such a trust model. It determines the time a node should wait beforeassigning a trust or distrust level to a node based upon the results of a particular event. After transmission, eachnode promiscuously listens for the neighboring node to forward the packet. If neighbor forwards the packet inproper manner within the TUI, its corresponding trust level is incremented. However, if the neighboring nodemodifies the packet in an unexpected manner or does not forward the packet at all, its trust level is decremented.Every time a node transmits a data or control packet, it immediately brings its receiver into pro miscuous mode(GPSR Agent::tap), so as to overhear its immediate neighbor forwarding the packet . The sending node verifiesthe different fields in the forwarded IP packet for requisite modifications through a sequence of integrity checks(GPSR Agent::verify packet integrity). If the integrity checks succeed, it confirms that the node has acted in abenevolent manner and so its direct trust counter is incremented. On the other hand, if the integrity checkfails orthe forward ing node does not transmit the packet at all, then its corre sponding direct trust measure isdecremented so that the node is treated as malicious node. The S-GPSR is explained by using flow chart whichis illustrated through Figure 3.4. Enhanced Greedy Perimeter Stateless Routing (E-GPSR) In the basic GPSR method, it scans its neighborhood table to retrieve the next hop which is optimaland leads to the destination during packets transmission or data transmission to known host. As there may bemore than one such hop available , GPSR selects an adjacent neighbor that has the least distance to a particulardestination. In contrast to GPSR , Secured greedy perimeter stateless routing (S-GPSR) introduced the conceptof trust level wh ich resulted a more secured routing over a geographical area or over a location bas ed routing.But again S-GPSR lacked in terms of efficiency as a common o r constant trust update interval for several nodesmay be troublesome in case of heavy traffic. Efficient greedy perimeter stateless routing (E-GPSR) introducesthe concept of “OBSERVATION TIM E (OT)” for each node separately in addition to the trust level. Both theseObservation time (OT) and Trust level (TLC) is incorporated in the neighborhood table to established the mosttrusted distance route rather than the default min imal distance which not optimu m distance. To compute The IJES Page 101
  5. 5. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR) trust and an optimal next node‟s address , an effort return based model is used . The mechanism provesto be more efficient as the analysis is being observed on the basis of the accurate and sincere contribution of theimmed iate neighbor nodes. The whole mechanism o f generating the secure, trust base and efficient modelconsist of two major steps: 1. Generation of Observation time fo r each node. 2. Trusted route selection4.1 GEN EARTION OF OBS ERVATION TIME FOR EACH NODE:Since the trust level count (TLC) , fo r each node that forwards a packet is initialized ,at the same t ime the “Observation Time” of each node is maintained ,wh ich is calcu lated on the acc ount of the buffered forwardeddata packets in the node ( GPSR Agent :: buffer packet). The Observation Time is very critical and impo rtant measure for efficient routing. It determines the time that anode takes to decide a most trusted and minimal route rather than a default minimal distance. The Observationtime counter (OTC) is maintained by the observation of the neighboring nodes. The Observation Time Counter(OTC) field is updated by the monitoring of the average packet fo rwarding delay. Each t ime, if the packet isforwarded within the Observation Time the POSITIVE TRUST is generated for the particular node, else theNEGATIVE TRUST is generated for the Forwarding node4.2 .TRUS TED ROUTE S EL ECTION Whenever a packet is to be forwarded a best and optimal node is to be selected. The selection of thetrusted node is done on the basis of the TRUST COUNT for each nodes. A node with best TRUST COUNT isselected as the next node to be forward the packet along with the optimal minimu m distance. Every t ime a nodetransmits a data packet within an OBSERVATION TIM E , its neighbors overhears it immediately (forwardingpacket) . The sending node verifies the different field in the forwarded IP packets and check for integrity. If theintegrity check succeeds, it confirms that the node has acted in a benevolent The IJES Page 102
  6. 6. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR)5. Simulation Results The trust and the mobility model is imp lemented in the existing S-GPSR protocol to obtain EnhancedGPSR protocol. The E-GPSR protocol is simulated using OPNET 14.0 to emulate selective forwarding andSybil attacks in mobile sensor networks. The network animator outputs for 100 nodes with 10 malicious nodes.The performance parameters such as delay, packet dropped, routing traffic received and traffic sent and receivedbits/ sec and packets/ sec is calculated. SIMULATION PARAMETRS VALUES No. Of Nodes 100-150 Graphical Area 100X 100 m Packet Size 512 Traffic Type CBR No . of Malicious Nodes 5 to 25 Simulati on Time 100 s Fig : Total traffic sent in case of selecti ve forwarding and E-GPRS method and S-GPRS Fig : total packets dropped in case of selective forwarding The IJES Page 103
  7. 7. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR) Fig : total del ay in case of Selective Forwarding attack Fig : total traffic sent in case of Sybil attack Fig : packets dropped i n case of S ybil attack Fig :Total del ay in case of Sybil The IJES Page 104
  8. 8. Enhanced Greedy Perimeter Stateless Routing Protocol (E-GPSR)6. Conclusion Enhanced greedy perimeter stateless routing protocol is implemented for mobile sensor network withdifferent coverage area considering 100 and 150 number of nodes for simu lation. It is compared with securedgreedy perimeter stateless routing protocol for different nu mber of malicious nodes. The results show that on theaverage, the routing overhead achieved using the E-GPSR protocol was 7o% less than the standard S-GPSRprotocol. Further more, an imp rovement of 25% in the delivery rat io have been achieved in the E-GPSRprotocol. The improvement in the above mentioned network performance is mainly due to smaller trust values,shorter routing decisions and less number of control packets taken by the trust based model imp lemented inGPSR to get rid of the attackers.REFERENCES :[1] C.Karlof & D.Wagner, (2003) “Secure routing in wireless sensor networks: Attacks & countermeasures”, Proceedings of the 1st IEEE International Workshop on Sensor Network Protocols & Applications, Anchorage, AK, pp.113-127.[2] S.Carter & A.Yasinac, Y.C.Hu, (2002) “Secure position aided ad -hoc routing protocol”, Proceedings of the IASTED Conference on Co mmunications & Co mputer Networks (CCN), Cambridge, MA, USA, pp.329-324.[3] Y.C.Hu, A.Perrig & DB.Johnson,(2002) “Ariadne: A secure on-demand routing protocol for adhoc networks”, Proceedings of the Eighth Annual International Conference on Mobile Co mputing & Networking (MobiCo m), At lanta, Georgia, USA, pp.12-23.[4] B.Dahill, B.N.Levine, E.Royer & C.Shields, (2002) “A secure routing protocol for ad-hoc networks”, Proceedings of the IEEE International Conference on Network Protocols (ICNP), Paris, France, pp.78-87.[5] Adrian Perrig & Robert Szewczy k, Victor Wen, Dav id Culler & J.D.Tygar,(2001) “SPINS: Security Protocols for Sensor Netwo rks”, Proceedings of ACM Seventh Annual International Conference on Mobile Co mputing & Networking, Ro me, Italy, pp.189-199.[6] W.Stallings, (2000) Network Security Essentials , Prentice Hall.[7] Asad Amir Pirzada & Chris McDonald, (2005) “Circu mventing sinkholes & wormholes in wireless sensor networks”, Proceedings of 2nd IEEE International Workshop on Wireless Ad-hoc Networking, Colu mbus, USA, pp.132-150.[8] Jamal N.Al-Karaki and Ahmed E.Kamal, (2004) “Routing Techniq ues in Wireless Sensor Networks: A Survey”, IEEE Transactions on Wireless Co mmunication, Vol. 11, No.6, pp.6-20.[9] Brad Karp & H.T.Kung, (2000) “GPSR: Greedy Perimeter Stateless Routing for Wireless Networks”, Proceedings of Sixth Annual International Conference on Mobile Co mputing & Networking, Boston, pp.243-254.[10] A.Pirzada & C.McDonald, (2004) “Establishing trust in pure ad -hoc networks”, Proceedings of 27th Australasian Co mputer Science Conference (ACSC), Dunedin, New Zealand, Vol. 26, No.1, pp.47-54.[11] Asad Amir Pirzada & Chris McDonald, (2007) “Trusted greedy perimeter stateless routing”, Proceedings of 15th IEEE International Conference on Networks (ICON 2007), Adelaide, Australia, The IJES Page 105