Mitigating the effect of malicious node in Mobile Ad Hoc Networks using Trust based Explicit No Technique

8/12/2019 Mitigating the effect of malicious node in Mobile Ad Hoc Networks using Trust based Explicit No Technique

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CS

CInternational Journal of Computer Networks and Communications Security

VOL.1, NO.6, NOVEMBER 2013, 210215

Available online at: www.ijcncs.orgISSN 2308-9830

Mitigating the effect of malicious node in Mobile Ad Hoc

Networks using Trust based Explicit No Technique

Dr. M.Hassan Islam1, Misbah Zareen

2

1, 2 Center of Advance Studies in Engineering, Department of Computer Engineering, U.E.T Taxila Pakistan

E-mail: [email protected], [email protected]

ABSTRACT

Mobile Ad Hoc Networks (MANETS) are vulnerable to malicious node attacks because they spoil the

integrity of network by consuming network resources, dropping packets and false routing. Routing

misbehavior can be avoided by following trusted path for data transmission. Existing Trust based

mechanisms for secure routing increase overhead and complexity w.r.t processing and architecture. We

compare multiple trust based secure routing techniques. The primary focus of this paper is to present an ad-

on technique named Explicit No with reduced complexity, for evaluating trust worthiness of a

neighboring node. This scheme helps in mitigating the effect of malicious nodes by correct identification.

Results are presented through simulation in NS2.

Keywords:MANETS, Trust, Malicious nodes, AODV, Network Simulator (NS2), Security.

1 INTRODUCTIONIn MANETS, the core concept is informationsharing, dissemination and collaboration among

routing devices [7]. Node cooperation is mandatory

for proper functioning of MANETS and this can be

compromised by black sheep. To mitigate the effect

of malicious misbehavior of nodes, we introduce a

trust based secure routing scheme that helps in

evaluation of node trustworthiness using a special

packet called Explicit No. We have studied the

existing ad on techniques and have compared their

performance with our proposed algorithm. Results

show that Explicit No technique is convergent,

less complex with simple design and more reliable

for calculating the trust value of neighboring nodes.

2 TRUST MANAGEMENT SCHEMES2.1 Confident

It is a reputation based dynamic and weighted

transitive trust management system based on DSR

protocol. Trust in this mechanism is established

through direct and indirect observations [2].

2.1.1 ArchitectureCONFIDANT consists of four major compon-

ents:

Monitor: Observes behavior of neighboring

nodes by observing transmission and identifies

misbehavior.

Reputation Manager: This component maintains

a table that has rating for nodes which is updated as

per nodes own experience and reported experience.

Path Manager: It deals with path re-ranking, path

deletion, action on malicious node request and

action on request for a route containing malicious

node.

Trust Manager: It deals with trust table

management, trust level calculations, alarms

generated by nodes on observation of a maliciousactivity.

2.1.2 DescriptionWhen a malicious activity is observed by any

node, this suspicious event is detected by monitor

and Reputation System is called in turn. Reputation

System checks the significance of the event and

number of occurrences of events and update rating


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of nodes accordingly. In case of intolerable rating,

Path Manager is called for deletion of all routes

entries containing this malicious node and an Alarm

is send to Monitor. Monitor passes this alarm to

Trust manager and it evaluates trust of the node due

to which the alarm has been generated. If the source

of the alarm is trusted one, the alarm table is

updated. In case, the source of alarm is malicious,

the Reputation System is called which again

evaluate the alarm [8].

2.1.3 Performance Analysis Throughput increases because of decrease

in number of drop packets.

Overhead due to Alarms increases if the

numberof malicious node increases.

Malicious behavior is an exception andfalse praise attack is not possible because of sharing

negative information.

A malicious node when see negative

information about itself can change its strategy and

node of good reputation may stop sharing negative

information because of the fear of revenge.

Malicious node that is excluded from the

network may reenter the network after timeout.

CONFIDANT treats faulty and malicious

node in same way.

This scheme not only detects the

misbehaving nodes but also refrain malicious nodes

from getting benefits from other cooperating nodes.

2.2 Watchdog PathraterWatchdog Pathrater is a dynamic trust manage-

ment scheme which is an extension of DSR

protocol.

2.2.1 ArchitectureWatchdog Pathrater consists of two

components:Watchdog: In promiscuous mode, it

listens and monitors that the next node forward

packets.

Pathrater: Pathrater is used to delete the

misbehaving nodes, to create new paths, avoid

usage of misbehaving nodes and select a reliable

path for data delivery.

2.2.2 DescriptionWD runs on every node in the network and all

nodes in the network are in promiscuous mode i.e.

they can hear the transmission from other nodes.

When a node forwards a packet to neighboring

node, WD monitors this forwarding. If neighbor

node does not forward the packet to next node or

fails to do so, it is detected as a mischievous node

and gets reported to Pathrater. WD maintains a

buffer for storing recently sent packets [1]. The

buffer packet is then matched with the overheard

packet. If the packet is matched then no failure is

detected and the buffered packet is removed.

However, if a mismatch is detected or the packet is

not overheard within timeout then failure is

incremented for the node and when the failure

exceeds the threshold then the node is marked as

misbehaving. The source of the packet is informed

about this misbehaving node

2.2.3 Performance Analysis More than one node in collusion can

circumvent the WD. For example, a node Bforwards a packet to node C but node B does not

informs A if C drops the packet.

WD does not know regarding the collision

occurs at the receiver of the packet. This collision

can either be by chance or due to malicious act of

the node.

Malicious node can drop fewer packets

that can be lower than the threshold of the WD

2.3 CoreCORE is a dynamic reputation based distributed

scheme based on DSR protocol [5] and enforcesnode cooperation based on Collaborative monitor-

ing technique [3].

2.3.1 ArchitectureCORE has three major components:

Network Entity: The Network entity corresponds

to a mobile node. Entity that request the execution

of a particular function is called a Requester and

entity that executes that particular requested

function is called a Provider.

Reputation Table: The Reputation Table has

entries for nodes that correspond to Subjective

Reputation, Unique Identifier for the network

entity, Collection of Indirect Reputation and

Reputation value evaluated for each function.

Watchdog Mechanism: The WD mechanism

detects the misbehaving network entities, examines

the correct execution of the requested function and

updates the reputation value accordingly.

2.3.2 DescriptionIn CORE nodes operate in promiscuous mode

and are required to contribute in network activities


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in order to remain trusted and to maintain their

reputation. If the node does not participate in

network activates or remain idle for a specific time

then its reputation degrades. If a provider does not

cooperate in network activities then it leads to

exclusion. Requestor requires the provider for

execution of a particular function activates WD for

the corresponding function and waits for outcome

from WD. Reputation value for provider is updated

accordingly as per outcome of WD scenarios when

no misbehavior is detected, misbehavior is detected

and a request by misbehaving entity is made.

2.3.3 Performance Analysis CORE handles misbehaving nodes, DOS

attacks and propagation of fake/negative informat-

ion.

Only positive information is shared withother nodes.

There is no fear of revenge by sharing

positive information instead of negative

information.

CORE uses functional reputation. A

network work entity is considered for execution of

a particular function if its reputation value is above

a certain threshold else it is ignored.

CORE does not exclude malicious node

from network if the node is well reputed in a

function.

CORE is generic mechanism that can be

integrated with network and application layer

functions.

3 FINDINGS1. CONFIDANT, Watchdog Pathrater and

CORE have complex architectures. Every

node in MANETS should have the respective

components in order to avail the benefits of

corresponding techniques.

2. Processing overhead increases because ofcomplicated architecture.

3. Node energy keep on wasting whilemonitoring the immoral behavior of network

entities.

4. More computation power is required bydevices for trust computation of neighboring

nodes [4].

5. All these schemes are divergent i.e.Takeforwarding behavior of source node to

evaluate the trust of neighboring node.

In the realm of above findings we have proposed

Explicit No scheme that address all aforementioned

concerns with reduced complexity, efficient

processing and energy saving.

4 CPROPOSED SCHEME EXPLICIT NOMalicious nodes always have intensions for

grabbing network resources by dropping packets,

causing DOS attacks and by sending packets to

wrong destination [6]. In Explicit No technique,

node itself informs the source node about its

unavailability by sending intimation through an

EXPLICIT NO packet. We have implemented thisad-on on AODV protocol.

4.1 DescriptionIn AODV, broadcasted RREQ packet is received

by all neighboring nodes. If any neighboring node

is not available for some reason like link broken,

low battery or congestion then it will send an

Explicit No packet to originating node with a flag

raise for unavailability and estimated time for

which the node is not available. On receiving the

Explicit No packet, source node marks the entry as

idle against the respective node till the time of

unavailability. It Source node then increments thetrust value of respective node that sends Explicit

No reply. This is because, that node is behaving fair

enough as it itself informs about its inadequacy.

Malicious node will never send back Explicit No

as it is always interested in receiving packets for

devastating network operations. Source node will

select any other alternate route for transmitting data

to destination.

Fig.1. Explicit No scenario


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Fig.2. Explicit No algorithm

5 SIMULATIONTable 1: Configuration Parameters

Method Value

Simulator NS-2.35

Network Area 1500 *500

Channel Type WirelessChannel

Propagation Model TwoRayGround

Radio Range 3.65E-10

Duration 5sec

MAC Layer 802.11

Max packet in ifq 50

Number of nodes 50

Routing Protocol AODV

Antenna Model Omni Directional

Transmission Range 0.2818

Traffic Source UDP/CBR

Fig.3. Simulation Topology for MANETS with 50 nodes

Fig.4. Delay increases in start as there is overhead in

transmitting through alternate route.

Fig.5. Packet loss is less when transmission takes place

through a trusted node.


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Fig.6. Throughput increases as trusted node forwardsmaximum packets

Table 2: Comparison of Trust Management Schemes for Secure Routing

6 COMPARATIVE ANALYSIS

Fig. 7. Comparative Analysis of AODV and AODV withExplicit NO

Table 3: Throughput, PD Ratio and Number ofDropped packets for AODV and AODV with Explicit NO

Fig. 8. Comparison of number of routing packets forAODV and AODV with Explicit NO

7 OBSERVATIONS AND RESULTS1. Explicit No scheme has less simple

architecture. No complex components

are required in architecture.

2. Nodes need not to be engaged inmonitoring the misbehavior of malicious

nodes hence node energy is conserved.


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3. Trustworthiness for node sendingExplicit No increases with more

reliability.

4. Computation overhead reduces inproportion to the Explicit No packets

received.

5. Bandwidth is utilized efficiently becauseno bandwidth will be consumed on the

route that has unavailable node.

6. Explicit No is convergent technique as itconverges towards source node.

Neighboring node themselves give

intimation of being unavailable.

7. Node availability decreases though thenode is trustworthy enough but as it is

not available for specific period of time

hence its overall credibility will be

reduced.

8. Overall network availability gets reducedand is directly proportion to the number

of nodes sending Explicit No packets for

specified time interval.

9. Due to congestion, delay, long hopsthroughput can vary depending on the

status of the selected alternate route.

8 CONCLUSIONTrust Management in MANET is an existing field

of research as trust is a multidimensional concept.

There is no standard protocol or technique for

calculating the Trust on network entities in

MANET. In MANET trust based decisions are

challenging tasks due to constraints in the form of

dynamicity that include varying topology, node

mobility, channel conditions along with resource

constraints of memory, battery and processing

power and bandwidth.Our proposed scheme Explicit No is robust w.r.t

architecture, helps to evaluate trust with less

complexity and saves power in terms of sensing

malicious activities and misbehaving network

entities. However, it offers overhead in terms of

network and node availability.

Most of the schemes are based on AODV and

DSR protocols and Trust Management for secure

routing is in its incubation phase. Interoperability

among different trust management systems need to

be addressed. Gathering information from remote

nodes other than neighboring nodes can improve

trust evaluation. Robust schemes need to be

developed for motivating nodes to share trust

values honestly.

9 REFERENCES[1] S.Marti, T. Guiuli, K. Lai and M. Baker,

Mitigating Routing Misbehavior in Mobile

Ad Hoc Networks, Proc. 6th Annual

ACM/IEEE Mobile Computing and

Networking, Boston, MA, Aug.2000, pp.255-

265

[2] S. buchegger and J. Y. Le Boudec,Performance Analysis of the CONFIDANT

Protocol: Cooperation Of Nodes-Fairness In

Dynamic Ad-hoc Networks, Proc. 3rdIEEE/ACM Symposium on Mobile Ad Hoc

Networking and Computing, Lausanne, CH, 9-11 June 2002, pp.226-236

[3] P. Michiardi and R. Molva, CORE: ACollaborative Reputation Mechanism to

Enforce Node Cooperation in Mobile Ad Hoc

Networks, The 6th IFIP Conf. on Security

Communications, and Multimedia, Porotoz,

Slovenia, 2002.

[4] K. Govindan and P. Mohapatra, TrustComputations and Trust Dynamics in Mobile

Adhoc Networks: A Survey, IEEE

Communications Surveys and Tutorials, 2012,

pp.279-298

[5] D.B.Jhonson and D.A.Maltz, Dynamic SourceRouting in Ad Hoc Wireless Networks,Mobile Computing, Kluwer Academic

Publishers, vol.353, pp. 153-181, 1996

[6] Y. Hu and A. Perrig, A Survey of SecureWireless Ad Hoc Routing, IEEE Security and

Privacy, vol.2, no. 3, pp. 28-39, May 2004

[7] Jin-Hee Cho, Anathram Swami, Ing-Ray Chen,A Survey on Trust Management for Mobile

Ad Hoc Networks, IEEE Communications

Survey & Tutorials, vol. 13, No. 4, Fourth

Quarter 2011

[8] Patroklos G. Argyroudis and DonalOMahony,Secure Routing for Mobile Adhoc Networks,IEEE Communications Surveys, vol.7, No. 4

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Mitigating the effect of malicious node in Mobile Ad Hoc Networks using Trust based Explicit No Technique