International Journal of Emerging Technology in Computer Science & Electronics (IJETCSE)

ISSN: 0976-1353 Volume 22 Issue 2 – MAY 2016.

226

EFFICIENT AND SECURED DATA

TRANSMISSIONIN DISRUPTION TOLERANT

OPPORTUNISTICNETWORK

PraisyRathna.G, and Senthilmurugan S.

Student M.E. Communication Systems, Valliammai Engineering College,Kattankulathur

Assistant Professor, Department of ECE, Valliammai Engineering College,Kattankulathur

Abstract-- This paper presents a secured communication of data

betweenmobile nodes in interminentenvironmentswhich suffers

from connectivity issues in an infrastructure less environment.

Disruption-tolerant network (DTN) technology is an upcoming

successful solution that offers the wireless devices to

communicate with each other and access the confidential

information or command reliably by exploiting external storage

dynamic nodes. Localization is done by Enhanced Position

Estimation based on RSSI Algorithm .DTNs introduce several

security and privacy challenges with regard to the attribute

revocation, key escrow, and coordination of attributes issued

from different authorities. This paper proposes a reliable route

selection on the basis of ImprovedProbabilistic Routing

Algorithm (IPRA) and the source encrypts the data using

Attribute SpecifiedIdentity Based Encryption Algorithm. The

DTN is used to authorize the nodesand DTN registers the node

details to Trust Authority. The Trust Authority generates Secret

Key and the route to transfer packet to destination.The time

stamp is added to the packet for updating the specific keys of the

nodes in the route. The unauthorized node is identified by the

time stamp and the wrong route selection. The secret key is also

automatically changed when the node joins a network and leaves

a network based on Fast Randomized Algorithm by which the

level of security is increased.

Index terms-- Disruption-tolerant network (DTN) technology,

Attribute specificIdentity based Encryption,IPRA ,Secret Key.

I INTRODUCTION

Network helps in sharing of data which have to be

done in a secured manner in the network to avoid

unauthorized usage. The network has several connectivity

issues due to disruption the environment. In case of Dynamic

nodes the case is very worst as the disruption rate is high and

the packet drop is also high. Disruption may occur because of

the limits of wireless radio range, scarcity of mobile nodes,

energy resources, attack, and noise .The connectivity is

necessary even in extreme environment conditions DTN

technologies are the trending solutions that allow nodes to

transmit information and communicate in these hostile regions

with security when there is no end to end connection[1]-

[3].With the challenging scenario of having dynamic nodes

localization is an issue as the security has to be maintained.

Using GPS makes the network under more risk. It has several

security and privacy challenges. The access control techniques

are enforced with cryptographic methods.[6]

This paper proposes a new strategy to reduce the

delay to make the network an efficient network. It also

proposes a strategy to overcome the security issues in

Disruption tolerant network technologies. The key revocation

is eliminated by node locating and continuous monitoring of

the node movement. The Routing path is also well defined by

the advanced routing algorithm. Immediate rekeying

procedure is done using Fast Randomized Algorithm. The key

escrow problem is eliminated by using ABE technique .[7]

The security is further increased by attaching a time stamp for

automatic change of key on timely basis.

II RELATED WORK

The Routing path selection based on the combination

of three AlgorithmsPRoPHET, Bubble and Spray and wait

algorithm. Two Hop Transmission and Multi hop

Transmission is done. The routing mechanisms that can

withstand disruptions need to be designed.In order to illustrate

the improvement of delivery ratio the differences are

considered AODV is for ad hoc wireless networks with

Symmetric Communication links whereas the ProPHet is for

heterogeneous sensor networks asymmetric ones.Identity-

based encryption (IBE) is an exciting alternative topublic-key

encryption, as IBE eliminates the need for a PublicKey

Infrastructure (PKI). The senders using an IBE donot need to

look up the public keys and the correspondingcertificates of

the receivers, the identities (e.g. emails or IPaddresses) of the

latter are sufficient to encrypt. Key escrow is inherent in

identity-based encryption (IBE). A curious key generation

Centre (KGC) can simply generate the user's private key to

decrypt a cipher text. Second, anew system architecture with

an anonymous private key generation protocol such that the

KGC can issue a private key to an authenticated user without

knowing the list of user‟s identities.This also better matches

International Journal of Emerging Technology in Computer Science & Electronics (IJETCSE)

ISSN: 0976-1353 Volume 22 Issue 2 – MAY 2016.

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the practice that authentication should be done with the local

registration authorities instead of the KGC.

In Cipher text-Policy Attribute-Based Encryption

(CP-ABE), a user secret key is associated with a set of

attributes, and the cipher text is associated with an access

policy over attributes[8]. The secret key is divided into two

shares, one share for the mediator and the other for the user.

To decrypt the data, the user must contact the mediator to

receive a decryption token. The mediator keeps an attribute

revocation list (ARL) and refuses to issue the decryption token

for revoked attributes.

This DTN architecture where multiple authorities

issue and manage their own attribute keys independently as a

decentralized DTN .

The main challenge is the security issues and the delay in

the DTN technology.

1. Attribute key revocation which occurs due to node

movement to other network which leads to the security

degradation in terms of the backward and forward secrecy.

The users such as soldiers may change their attributes

frequently, so the attribute keys are updated by periodic

rekeying backward secrecy.

2. To avoid hacking issue revocation is done which eliminates

the forward and backward secrecy. During revocation

bottleneck problem arises

3.Key escrow problem which occurs due to third party

interruption. Key escrow which is also known as a “fair”

cryptosystem is an arrangement in which the keys needed to

decrypt encrypted data are held in escrow so that, under

certain circumstances, an authorized third party may gain

access to those keys. Key disclosure law avoids some of the

technical issues and risks of key escrow systems, but also

introduces new risks like loss of keys and legal issues such as

involuntary self incrimination.

4. The other is the scalability problem.Opportunistic

Networking Environment”(ONE) with the transitivity of the

neighbor node

5. The Delay reduction will increase the efficiency of the

network. The Delay has to be reduced during the packet

transmission. The Delay is the main factor contributing to the

efficiency of the network. The Delay willlead to congestion.

The key authority periodically announces a key

update material by unicast at each time-slot so that all of the

non revoked users can update their keys. This results in the

problem, which means that the update of a single attribute

affects the whole non revoked users who share the

attribute.This could be a bottleneck for both the key authority

and all non revoked users.

IIIENHANCED MODEL

In this paper we propose a system to provide a

Delay Tolerant Disruption Network along with a secured data

transmission through mobile nodes in which by which the

node details are registered to a Trusted Authority which

monitor the details of the subnodes. The communication is

improved even in the interminent network environments by

using the Disruption tolerant Network technologies.[1] The

Delay parameter has to be reduced in the opportunistic

environment which will make the network an efficient

network. The nodes along with the basic details are stored in

the DTN nodes and the information is acknowledged from the

Trust Authority. The source nodes requests the Trust

Authority for data transmission in order to provide a trust

worthy fine grain access on the storage nodes

The router path is selected using Improved

Probabilistic routing algorithm which has reduced latency and

transitivity which makes the network efficient. IPRA

Algorithm is chosen as it based on knowledge base, similarity,

store and forward approach. This makes the selection of the

route that has minimum distance. The history of nodes is

collected and their similarity is checked. The history is

provided along with the distance by the improved by the

enhanced position estimation algorithm by RSSI .The node

details are matched with the information from the neighbor

nodes. The message is encrypted and accessed on the basis of

theAttributes and decrypted using Attribute specified Identity

basedencryption(CP-ABE ID). The key escrow problem is

fixed by using Trust Authority which assigns the basic keys.

The main aim is to provide a secured and guaranteed

transmission of data through the decentralized nodes without

packet drop. The mediator keeping the attribute list is revoked

and encrypted. A double layer encryption standard is provided

on the basis of identity and Attribute.

If the node travels in a route that is not mentioned or

if any node who is not having authorization over packet

transmission approaches for packet delivery then the

unauthorized node is found and the packet is not delivered.

This is done by the time stamp which is attached to the packet

delivered. The node that is transmitting has the knowledge of

the node that receives. The key changes automatically and the

previous node has the knowledge of the transmitting key. This

makes the security even more strong. Insertion of time stamp

has a challenge that the Average overhead has to be minimum

for an efficient network. The time stamp is of reduced size and

so the packet overhead ratio is low. Thus an efficient and

secured node is achieved.

International Journal of Emerging Technology in Computer Science & Electronics (IJETCSE)

ISSN: 0976-1353 Volume 22 Issue 2 – MAY 2016.

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Fig 1.Architecture of secure data retrieval in a disruption-

tolerant military network.

If a node is moved to opponent or any other

circumstances if the node disappears the key has to be

changed for security issues.Rekeying is done automatically by

the Trusted Authority which monitors the node movement.

Rekeying procedure eliminates the key escrow

problem.During rekeying the bottleneck problem is minimized

by fast randomized algorithm by which level of security is

improved.

A. System Description and Assumptions

As shown in Fig 1 the DTN architecture consists of the

following system entities

1)Trust Authorities: They are the main key generation centers

that generatePublic andsecret parameters for CP-ABE. The

trust authority is a central authority which manages all the sub

nodes. The initial setup and registration preprocessing along

with acknowledgement is obtained directly from the Trust

Authority. The local authority provides the Router selection

path which is decided by honest node path finding. The basic

misbehavior detection Algorithm gives history and details of

the neighboring nodes. This makes sure that the data is

travelled in a predetermined path selected by Trust Authority.

2) Storage node: This is anentity that stores data and also act

in the infrastructure less environmentand provide

corresponding access to users. It is either mobile or static.

They are external storage nodes.

3) Sender:This is an entity who owns confidential messages or

data (e.g., a commander) and wishes to store them into the

external data storage node for ease of sharing or for reliable

delivery to users in the extreme networking environments.A

sender is responsible for defining (attribute based) access

policy and enforcing it on its own data by encrypting the data

under the policy before storing it to the storage node.

4) User:This is a mobile node who wants to access the data

stored at the storage node (e.g., a soldier). If a user possesses a

set of attributes satisfying the access policy of the encrypted

data defined by the sender, and is not revoked in any of the

attributes, then he will be able to decrypt the cipher text and

obtain the data.

B. Modules Description

1) Network Construction

In this concept, first we have to construct a network

which consists of „N‟ number of Nodes. All nodes are

registered in the network. Network is used to store all the

Nodes information like Node Id and other information. The

nodes can request data from other nodes in the network. Since

the Nodes have the mobility property, they can move across

the network. Also network will monitor all the Nodes

Communication for security purpose.

2)Localization of Mobile Nodes

` Initialize the position estimation as whereas x and y

are the positions.

𝑓 𝑥, 𝑦 = 𝑥 − 𝑥𝑖 + 𝑦 − 𝑦𝑖 − 𝑟2𝑖

3

𝑖=1

2

Received signal strength estimated from the beacon node or

Anchor Node (distance), Three beacon nodes are considered

for the calculation.

αf(x, y) =∂ f (x, y)/ ∂x βf(x, y) =∂ f (x, y)/ ∂y

Update the position estimate

a.Compute the constraint from the anchor node

b. Intersect the constraint with the current position estimation

to get the new position estimate as

(x_, y_) = (x-λα(x, y), y-λβ(x, y)).

If the position is improved then the position is broadcasted to

all neighbors

3)Secret Key Assignment and Data transmission

Message is encrypted for secured transmission using

Attribute specific Identity based encryption. Trust Authority

Assigns the Public Keys. Trust Authority generates the secret

key (private key) based on Attribute specific Identity based

Encryption. Public key generation is common (ex. Mail-id)

and it is known to everyone. Private Key generation on

identity basis and access key created based on attribute

positioning. Source node in network send data to destination

means, before it sends the packet to Trust Authority. The

packet includes source node id, intermediate node id,

destination node id, packet size and time. After receiving that

packet Trust Authority (TA) finds which node act as

intermediate node. Then it sends request to all nodes for

identifying intermediate node information.

Based on that request each node sends the response to

TA. Trust Authority finds which node act as intermediate

node. TA audits the information for identifying intermediate

International Journal of Emerging Technology in Computer Science & Electronics (IJETCSE)

ISSN: 0976-1353 Volume 22 Issue 2 – MAY 2016.

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node trust worthiness. Routing path is identified by TA and

packet transfer alert is given.

4) Data Transmission

On the basis of TA verification each node identifies

the intermediate node behavior using Improved Probabilistic

Routing algorithm. By using this algorithm Reduced End-

End Delay, Reduced Average Overhead , Increased Delivery

Rate , Increased Throughput is achieved. The attribute and

identity is thus assigned using the analysis of the node

behavior. The source node encrypts data with destination

public key and securely transmits the data to destination node

via honest intermediate nodes. Finally destination node

decrypts the data with its private key based on id based

encryption algorithm.

5) Attaching Time Stamp for Key Changing

The data is transmitted in the selected path. Nodes in

the routing path are intimated about the information of packet

delivery. The transmitted data packet contains a timestamp

which is attached to it. The node that is transmitting has the

knowledge of the node that receives. The key changes

automatically and the previous node has the knowledge of the

transmitting key. This makes the security even more strong.

Insertion of time stamp has a challenge that the Average

overhead has to be minimized for an efficient network. Thus

an efficient and secured node is achieved. The packet is

transmitted and the time stamp will update the keys. This will

increase the security and reduce the delay. Identifying the

unauthorized node

6)Rekeying based on Node movement

The nodes are located and monitored in this module

and if the source node moves to other network then it suffers

from secret key being revealed. The existing network

completely changes each nodes private key for security

purpose (hacking using old private key). Fast Randomized

Algorithm is used to avoid bottleneck during the rekeying

procedure. But this private key changed so it didn‟t access

previous network data. By this algorithm for Rekeying Key

Escrow problem is eliminated, The attributes are properly

coordinated.

C. Advantages

a. Immediate attribute revocation enhances backward/forward

secrecy of confidential data by reducing the windows to

vulnerability.

b. The Disruption Tolerant is added with a feature of Delay

tolerant network.

c. Encryptors can define a fine-grained access policy using

any monotone access structure under attributes issued from

any chosen set of authorities.

d.The key escrow problem is resolved by an escrow-free key

issuing protocol that exploits the characteristic of the

decentralized DTN architecture.

e.Thus, users are not required to fully trust the authorities in

order to protect their data to be shared.

f. The data confidentiality and privacy can be

cryptographically enforced against any curious key authorities

or data storage nodes in the proposed scheme.

f. It radically eliminates the non-uniformity of energy

consumption among sensors.

g. It works well not only in a connected network, but also in a

disconnected network. The moving path of each mobile

collector acts as virtual links among separated sub-networks.

h. Attaching time stamp increases the security. The average

overhead is also reduced by the IPRA algorithm which makes

the system effective and efficient.

IV SIMULATION PARAMETERS

The network simulator tool is used to study the

function and performance of DTN Tolerant Network scheme.

We employ the IEEE 802.11 MAC with a channel data rate of

20 Mb/s.

The nodes are selected randomly and message is transferred to

the destination nodes .

A. Delay

Delay during the packet transfer is reduced. When the

node moves to the next region immediate rekeying is done

without any delay using fast randomized algorithm. The delay

is reduced from 20ms to less than 10ms. This makes the

network an efficient network

Fig 2 Delay Estimation

B. Efficiency

It is defined as the total amount of data transmitted to the

destination from the source divided to the time taken for the

packet to reach destination.The packets deliveredis measured

International Journal of Emerging Technology in Computer Science & Electronics (IJETCSE)

ISSN: 0976-1353 Volume 22 Issue 2 – MAY 2016.

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using the acknowledgement data.The message delivery ratio

defines the efficiency of the entire system.

The data is transferred securely using Attribute Specific

Identity Based algorithm. Theunauthenticated packet is not

deliverd and packet is completely dropped.Using the IPRA

Algorithm the unauthorized nodes are completely ignored.

The trust Authority continuously monitors the Area/ The

Security levels in increased to more than 80% which is shown

in Fig 3

Fig 3Efficiency

C. Average overhead

Overhead is a combination of excess or indirect computation

time or memory, bandwidth or other resources. Increased

overhead decreases the efficiency. The Average overhead is

reduced in the Disruption Tolerant Network.

Fig 4AverageOverhead

V CONCLUSION

The confidential data is securely and efficiently

managed and distributed in the decentralized disruption-

tolerant military network. DTN technologies allow wireless

devices to communicate with each other and access the

confidential information reliably by exploiting external

storage nodes .The CPABE-ID overcomes major security

issues providing more confidentiality in data transfer. The

monitoring of nodes and locating of positions avoids of

hacking of data. The IPRA reduces the delay avoids

unnecessary packet drops. Fast randomized algorithm avoids

key revocation issues and bottleneck problem within it.

Attaching the time stamp thus increases the efficiency and

security.

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