A New Region based Group Key Management Protocol for MANETs

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					                                                          (IJCSIS) International Journal of Computer Science and Information Security,
                                                          Vol. 8, No. 2, May 2010




         A New Region based Group Key Management
                  Protocol for MANETs
N. Vimala                                                                      Dr. R. Balasubramanian
Senior Lecturer, Department of Computer Science                                Dean Academic Affairs
CMS College of Science and Commerce                                            PPG Institute of Technology
Coimbatore, India.                                                             Coimbatore, India.
vimalarmd@rediffmail.com                                                       ramamurthybala2@gmail.com


Abstract-Key management in the ad hoc network is a challenging              the services among which authentication, data integrity and
issue concerning the security of the group communication. Group key         data confidentiality is the establishment of a key management
management protocols can be approximately classified into three             protocol. This protocol is liable for the generation and the
categories; centralized, decentralized, and distributed. The most           distribution of the traffic encryption key (TEK) to all the
suitable solution to provide the services like authentication, data
                                                                            members of a group. This key is used by the source to encrypt
integrity and data confidentiality is the establishment of a key
management protocol. This paper proposes an approach for the
                                                                            multicast data and by the receivers to decrypt it. Therefore
design and analysis of region-based key management protocols for            only legitimate members are able to receive the multicast flow
scalable and reconfigurable group key management in Mobile Ad               sent by the group source [4]. The elemental security services
Hoc Networks (MANETs). Most of the centralized key management               provided by every key management system are key
protocols arises an issue on data security on group communication.          synchronism,        secrecy,       freshness,    independence,
The proposed region-based group key management protocol divides             authentication, confirmation, forward and backward secrecy
a group into region-based subgroups based on decentralized key              [7].
management principles. This region-based group key management
protocols deal with outsider attacks in MANETs to preserve the
                                                                               Clustering is the concept of dividing the multicast group
security properties. A performance model to evaluate the network
traffic cost generated for group key management in the proposed
                                                                            into a number of sub-groups. Each sub-group is managed by a
region-based protocol for MANETs is developed. Cost for joining or          local controller (LC), accountable for local key management
leaving the group and the cost for group communication are                  within its cluster. Furthermore, not many solutions for
considered in evaluating the performance of the proposed region-            multicast group clustering did think about the energy problem
based group key management scheme.                                          to realize an efficient key distribution process, whereas energy
                                                                            constitutes a foremost concern in ad hoc environments [5] [6].
 Keywords- Cluster Head, Group Key, Key Management Protocol,                The group key is generated by the cluster head and
Mobile Ad Hoc Networks (MANETs), Region-based, and Rekeying.                communicated to other members through a secure channel that
                                                                            uses public key cryptography [14]. Clusters may be used for
                       I. INTRODUCTION                                      achieving different targets [8]. Some of them are clustering for
  Generally, an ad hoc network is an assortment of                          transmission management, clustering for backbone formation
independent nodes that communicate with each other, most                    and clustering for routing efficiency. Group key management
regularly using a multi-hop wireless network. Nodes do not                  must be opposing to an extensive range of attacks by both
inevitably know each other and come together to form an ad                  outsiders and rouge members. In addition, group key
hoc group for some particular reason. Key distribution systems              management must be scalable, i.e., their protocols should be
typically involve a trusted third party (TTP) that acts as an               efficient in resource usage and able to decrease the effects of a
intermediary between nodes of the network. A node in an ad                  membership change.
hoc network has straight connection with a set of nodes, called
neighboring nodes, which are in its communication range. The                   This paper proposes an approach for the design and analysis
number of nodes in the network is not essentially preset. New               of region-based key management protocols for scalable and
nodes may join the network while existing ones may be                       reconfigurable group key management in MANETs. This
compromised or become un-functional [1]. Key management                     region-based group key management protocols deal with
in the ad hoc network is a challenging issue concerning the                 outsider attacks in MANETs to preserve the security
security of the group communication. Group key management                   properties. A performance model to evaluate the network
protocols can be approximately classified into three                        traffic cost generated for group key management in the
categories; centralized, decentralized, and distributed [2].                proposed region-based protocol for MANETs is developed.

  MANET is one where there is no predetermined                                The remainder of this paper is structured as follows. Section
infrastructure such as base stations or mobile switching                    2 of this paper discusses some of the earlier proposed cluster
centers. Mobile nodes that are within each other’s radio range              based group key management techniques. Section 3 describes
communicate directly by means of a wireless network,                        our proposed method of new region based group key
whereas those far apart rely on other nodes to act as routers to            management protocol for MANETs. Section 4 explains the
relay its messages [3]. The most suitable solution to provide


                                                                      194                               http://sites.google.com/site/ijcsis/
                                                                                                        ISSN 1947-5500
                                                       (IJCSIS) International Journal of Computer Science and Information Security,
                                                       Vol. 8, No. 2, May 2010



performance evaluation of the proposed approach and section                 A new group key management protocol for wireless ad hoc
5 concludes the paper with fewer discussions.                            networks was put forth by Rony et al. in [12]. They put forth
                                                                         an efficient group key distribution (most commonly known as
                  II. BACKGROUND STUDY                                   group key agreement) protocol which is based on multi-party
  Key management is an indispensable part of any secure                  Diffie-Hellman group key exchange and which is also
communication. Most cryptosystems rely on some underlying                password-authenticated. The fundamental idea of the protocol
secure, robust, and efficient key management system. This                is to securely construct and distribute a secret session key, ‘K,’
section of the paper discusses some of the earlier proposed key          among a group of nodes/users who want to communicate
management schemes for secure group communication in                     among themselves in a secure manner. The proposed protocol
wireless ad hoc networks.                                                starts by constructing a spanning tree on-the-fly involving all
                                                                         the valid nodes in the scenario. It is understood, like all other
  Maghmoumi et al. in [9] proposed a cluster based scalable              protocols that each node is distinctively addressed and knows
key management protocol for Ad hoc networks. Their                       all its neighbors. The password ‘P’ is also shared among each
proposed protocol is based on a new clustering technique. The            valid member present in the scenario. This ‘P’ helps in the
network is partitioned into communities or clusters based on             authentication process and prevents man-in-the-middle attack.
affinity relationships between nodes. In order to ensure trusted         Unlike many other protocols, the proposed approach does not
communications between nodes they proposed two types of                  need broadcast/multicast capability.
keys generated by each cluster head. The protocol is adaptive
according to the limitation of the mobile nodes battery power              Bechler et al. in [13] described cluster-based security
and to the dynamic network topology changes. Their proposed              architecture for Ad hoc networks. They proposed and
approach of clustering based scalable key management                     estimated a security concept based on a distributed
protocol provided secured communications between the nodes               certification facility. A network is separated into clusters with
of the Ad hoc networks.                                                  one special head node for each cluster. These cluster head
                                                                         nodes carry out administrative functions and shares a network
  A key management scheme for secure group communication                 key among other members of the cluster. Moreover the same
in MANETs was described by Wang et al. in [10]. They                     key is used for certification. In each cluster, exactly one
described a hierarchical key management scheme (HKMS) for                distinguished node–the cluster head (CH)–is responsible for
secure group communications in MANETs. For the sake of                   establishing and organizing the cluster. Clustering is also used
security, they encrypted a packet twice. They also discussed             in some routing protocols for ad hoc networks.
group maintenance in their paper in order to deal with changes           Decentralization is achieved using threshold cryptography and
in the topology of a MANET. Finally, they carried out a                  a network secret that is distributed over a number of nodes.
performance analysis to compare their proposed scheme with               The architecture addresses problems of authorization and
other conventional methods that are used for key management              access control, and a multi-level security model helps to adjust
in MANETs. The results showed that their proposed method                 the complexity to the capabilities of mobile end systems.
performed well in providing secure group communication in                Based upon their authentication infrastructure, they provided a
MANETs.                                                                  multi level security model ensuring authentication, integrity,
                                                                         and confidentiality.
  George et al. in [11] projected a framework for key
management that provides redundancy and robustness for                     A scalable key management and clustering scheme was
Security Association (SA) establishment between pairs of                 proposed by Jason et al. in [15]. They projected a scalable key
nodes in MANETs. They used a modified hierarchical trust                 management and clustering scheme for secure group
Public Key Infrastructure (PKI) model in which nodes can                 communications in ad hoc networks. The scalability problem
dynamically assume management roles. Moreover they                       is solved by partitioning the communicating devices into
employed non-repudiation through a series of transactions                subgroups, with a leader in each subgroup, and further
checks to securely communicate new nodes information                     organizing the subgroups into hierarchies. Each level of the
among Certificate Authorities (CAs). They assumed that                   hierarchy is called a tier or layer. Key generation, distribution,
nodes could leave and join the network at any time. Nodes                and actual data transmissions follow the hierarchy. The
could generate their own cryptographic keys and were capable             Distributed Efficient Clustering Approach (DECA) provides
of securing communication with other nodes. In order to                  robust clustering to form subgroups, and analytical and
balance the flexibility and increased availability of the Key            simulation results demonstrate that DECA is energy-efficient
Management Scheme (KMS), security was provided by                        and resilient against node mobility. Comparing with most
introducing two concepts in addition to revocation and                   other schemes, their approach is extremely scalable and
security alerts: non-repudiation and behavior grading. The               efficient, provides more security guarantees, and is selective,
KMS sustained sufficient levels of security by combining                 adaptive and robust.
node authentication with an additional element, node behavior.             Apart from the above mentioned numerous researches have
A behavior grading scheme required each node to grade the                been conducted in the field of cluster-based group key
behavior of other nodes.                                                 management for mobile ad hoc networks (MANETs).




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                                                                                                     ISSN 1947-5500
                                                       (IJCSIS) International Journal of Computer Science and Information Security,
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 III. A NEW REGION BASED GROUP KEY MANAGEMENT FOR                        secure group communication is reliable transmission. This can
                      MANETS                                             be achieved by using acknowledgement (ACK) packets and
  The proposed region-based group key management protocol                packet retransmission upon timeout. Hexagon is used to model
divides a group into region-based subgroups based on                     a region [17]. Let R(n) denote the number of regions (i.e. 3n2
decentralized key management principles using Weighted                   + 3n + 1) in the operational area. For n=3, the number of
Clustering Algorithm (WCA). This partitioning of region into             regions in the operational area is 37, for n=2 and n=1, the
subgroups improves scalability and efficiency of the key                 number of regions in the operational area are 19 and 7
management scheme in providing a secure group                            respectively. Figure 2 shows the representation of the regions
communication. Figure 1 shows the partitioning of region into            in the operational area for n=1, 2, and 3.
subgroups on the basis of decentralized key management
principles [16, 18]. It is assumed that each member of the
group is equipped with Global Positioning System (GPS) and
therefore each one knows its location as it moves across the
regions. For secure group communications, all members of a
group share a secret group key, KG. In addition to ensure
security in communication between the members of each
subgroup all the members of the subgroups in the region ‘i’
hold a secret key KRi. This shared secret key is generated and
managed by a distributed group key management protocol that
enhances robustness. This region-based group key
management protocol will function at the optimal regional size                             n=1, Number of Regions=7
recognized to reduce the cost of key management in terms of
network traffic.




                                                                                          n=2, Number of Regions=19




         Figure 1 Region-based Group Key Management
  The average number of nodes in the system is N=λpA,
where λp denotes the node density of the randomly distributed
nodes and A indicates the operational area with radius ‘r’. The
random distribution of nodes is according to a homogeneous
spatial Poisson process. The nodes can join or leave a group at
any point of time. A node may leave a group at any time with
rate μ and may rejoin any group with rate λ. Therefore, the                               n=3, Number of Regions=37
probability that a node is in any group is λ/(λ+μ) and the                    Figure 2. Representation of Regions in operational area
probability that it is not in any group is μ / (λ+μ). Let AJ and         A.      Protocol Description
AL be the aggregate join and leave rates of all nodes,                     This describes the working of our proposed region-based
respectively. Then, AJ and AL, can be calculated as follows,             group key management for MANETs.
                                       μ
                      ΑJ = λ ×Ν×
                                    (λ + μ )                             1. Bootstrapping
                                                                            In this initial bootstrapping process, a node within a region
                                       λ                                 can take the responsibility of a regional “leader” to carry out
                       AL = μ × Ν ×
                                      λ+μ                                Group Diffie Hellman (GDH). If there are multiple initiators,
  Nodes in a group must satisfy the forward/backward                     then the node with the smallest id will prevail as the leader
secrecy, confidentiality, integrity and authentication                   and will implement GDH to completion to generate a regional
requirements for secure group communications in the presence             key. Once a leader is generated in each region, all leaders in
of malicious outside attackers. The important requirement for            the group will execute GDH to agree on a secret leader key,

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                                                                                                     ISSN 1947-5500
                                                        (IJCSIS) International Journal of Computer Science and Information Security,
                                                        Vol. 8, No. 2, May 2010



KRL, for secure communications among leaders. The group                   cluster head consumes more battery than an ordinary node
key KG can be generated using the following, KG = MAC                     because it has extra responsibilities. The cluster head election
(KRL, c), where MAC is a cryptographically secure hash                    algorithm finishes once all the nodes become either a cluster
function, KRL is the leader key used as the secret key to MAC,            head or a member of a cluster head. The distance between
and c is a fresh counter which will be incremented whenever a             members of a cluster head, must be less or equal to the
group membership event occurs. The generated group key KG                 transmission range between them. No two cluster heads can be
is then disseminated among the group members by the group                 immediate neighbors
leader. This group key provides secure group communication
across regions.                                                           B.       Rekeying protocol
2. Key Management                                                           Additional to group member join/leave events which cause
   The next important task is managing the generated key.                 rekeying of the group key, mobility-induced events may also
These shared secret keys at the subgroup (regional), leader,              cause rekeying. Below described is the proposed region-based
group levels may be rekeyed to preserve secrecy in response               key management protocol for a MANET in response to events
to events that occur in the system. Therefore, whenever there             that may occur in the system.
occur a change in the leader of the group, the leader key, KRL
is rekeyed. The regional key (KR) is rekeyed whenever there is            1.        Group Member Join
a regional membership change, including a local member                      The node willing to join the group initiates the process by
group join/leave, a node failure, a local regional boundary               sending a message “hello” along with its id and location
crossing, and a group merge or partition event.                           information. Neighboring nodes receiving the beacon forward
                                                                          the “hello” message to their regional leader. The regional
3. View Management                                                        leader authenticates the new nodes identity based on its public
   In addition to maintaining secrecy, the proposed region-               key. Then, the leader acts as a coordinator involving all
based key management protocol also allows membership                      subgroup members including the new node to execute GDH to
consistency to be maintained through membership views.                    generate a new regional key. The leader then updates the
Three membership views can be maintained by various                       regional membership list, and broadcasts the regional
parties: (a) Regional View (RV) contains regional membership              membership list to members in the region. This results in
information including regional (or subgroup) members’ ids                 rekeying of group key, KG. The regional leader informs the
and their location information, (b) Leader View (LV) contains             newly joined member’s information to all other leaders. All
leaders’ ids and their location information, and (c) Group                leaders then concurrently share out the new group key to
View (GV) contains group membership information that                      members in their regions by encrypting the group key with
includes members’ ids and their location information.                     their respective regional key KR.

4. Weighted Clustering Algorithm (WCA)                                    2.       Group Member Leave
  Weighted Clustering Algorithm (WCA) [18] selects a cluster                When a non-leader member, say B, leaves the group, it
head according to the number of nodes it can handle, mobility,            informs its leaving objective to its regional leader. When the
        transmission power and battery power. To avoid                    leader receives the leaving intention message from B, it
  communications overhead, this algorithm is not periodic and             updates its regional view and propagates the updated regional
  the cluster head election procedure is only invoked based on            view to its members. Since a group leave event originate a
 node mobility and when the current dominant set is incapable             regional membership change event, a new regional key is
 to cover all the nodes. To ensure that cluster heads will not be         generated by executing GDH and distributed to the regional
   over-loaded a pre-defined threshold is used which indicates            members. Next, the leader informs the membership change
   the number of nodes each cluster head can ideally support.             information to all other leaders. After all leaders receive the
  WCA selects the cluster heads according to the weight value             information on the current leave event, they also broadcast the
 of each node. The weight associated to a node v is defined as:           changed group view to all their members. Finally, all leaders
             Wv = w1 Δv + w2 Dv +w3 Mv +w4 Pv                             separately regenerate a group key and dispense it to their
The node with the minimum weight is selected as a cluster                 analogous members by encrypting the group key with their
head. The weighting factors are chosen so that w1 + w2 + w3               respective regional key KR.
+ w4 = 1. Mv is the measure of mobility. It is taken by
computing the running average speed of every node during a                3.       Boundary crossing by a non leader member
specified time T. Δv is the degree difference. Δv is obtained               If a non-leader member crosses a regional boundary, for
by first calculating the number of neighbors of each node. The            example, from region i to region j, a regional membership
result of this calculation is defined as the degree of a node v,          change occurs in both regions i and j. Thus, the regional keys
dv. To ensure load balancing the degree difference Δv is                  in the two involved regions are respectively rekeyed based on
calculated as |dv - δ | for every node v, where δ is a pre-               GDH and the members’ regional views in these two regions
defined threshold. The parameter Dv is defined as the sum of              are updated. Since the mobility event changes neither the
distances from a given node to all its neighbors. This factor is          leader view nor the group view, no leader or group view
related to energy consumption since more power is needed for              updates are necessary. No rekeying of the group key is needed
larger distance communications. The parameter Pv is the                   because the member leaving a region (subgroup) is still a
cumulative time of a node being a cluster head. Pv is a                   member of the group.
measure of how much battery power has been consumed. A

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                                                                                                     ISSN 1947-5500
                                                        (IJCSIS) International Journal of Computer Science and Information Security,
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4.       Boundary Crossing by a Leader Member                          key in the region from which the join event is originated, the
  If a leader member crosses a regional boundary from i to j,          cost of which is Cintra, as well as the update of the group view
there is a leadership change in addition to all operations             and the rekeying of a group key, the cost of which is Cgroup, i.
considered in the event of boundary crossing by a non-leader
member. Thus, as in the group member leave by a leader                                                                               [
                                                                                                             C Join,i = [C int ra ] + C group ,i   ]
member event, a new leader in the departing region is elected,
                                                                         The cost for group leave event includes two cases, namely,
the leader key is rekeyed among all leaders, and the leader
                                                                       when a non-leader member leaves and when a leader leaves
view is updated among all leaders.
                                                                       the group. Thus, the cost for a group leave event is given as
                                                                       follows,
5.       Leader Election                                                                                non −
  A group leave, a boundary crossing, or a disconnection by a                            C leave,i = C leave,leader + C leave,i
                                                                                                              i
                                                                                                                        leader

leader member prompts a fresh leader election in the involved
region. A member in the region after missing its regional              B.          Cost for Group Communication
leader’s beaconing message can commence the execution of                  It includes the cost of group communications between
GDH and WCA based on its regional using cluster head                   members. It is assumed that the publish/subscribe service is
election procedure. If there are more than one leader invoking         used to realize efficient group communications. For simplicity,
GDH, the member with the minimum weight wins and will                  it is assumed that all members are interested in all published
carry out GDH to produce a new regional key KR. The new                data by all members, and the data are published in each node
leader then announces itself as a new leader in the region by          with the rate of λpub. Thus, the aggregate rate that data are
broadcasting a beacon message “I-am-a-new-leader” along                published in each node is obtained as:
with the new regional view encrypted with the regional key                                                   ⎡ λ ⎤
KR.                                                                                            A pub = Ν × ⎢        ⎥ × λ pub
                                                                                                             ⎣λ + μ ⎦
C.        Group Communication Protocol                                    Whenever each node publishes its data, the published data
  For typical group communication, we accept to use the                should be disseminated to all members. Taking advantage of
publish/subscribe service. It is assumed that all members are          our hierarchical key management structure, the published data
interested in all published data by all members. Thus, all             can be distributed to all leaders first, and then each leader can
published data in each member are disseminated to all                  broadcast them to its members in the region.
members whenever each node publishes its data. By taking                                                 (
                                                                           C GC ,i = A pub × ( N region,i × M pub × H region ) + ( M pub × H leader ,i )          )
two-level hierarchical key management structure, the
published data in each node is broadcast to its members in the            Figure 3 (a) shows the comparison of number of regions and
region, and then the leader receiving the published data               cost for group join/leave and cost for group communication.
distributes it to other leaders. After then, each leader               Similarly Figure 3 (b) represents the comparison of CGC and
broadcasts the published data to its members respectively.             Cjoin/leave for no region and optimal region.
When all published data are disseminated to all members in
this way, a group key is used to encrypt/decrypt the published
                                                                                                                             Cgc          Cjoin/leave
data.
                                                                                                  1.20E+09
               IV. PERFORMANCE ANALYSIS                                                           1.00E+09
                                                                                hop bits/second




  The performance analysis helps identify the optimal                                             8.00E+08
regional size that will minimize the network traffic generated                                    6.00E+08
while satisfying security properties in terms of secrecy,                                         4.00E+08
availability and survivability. The cost metric used for
                                                                                                  2.00E+08
measuring the proposed group key management protocol is the
total network traffic per time unit incurred in response to                                       0.00E+00
                                                                                                                1      7     19      37      61        91   127
group key management events including regional mobility
                                                                                                                                  N Region
induced, group join/leave, periodic beaconing, and group
merge/partition events. To evaluate the performance of this                                                                (a)
proposed approach we discuss on group join/leave cost, and
group communication cost.

A.      Group Join/Leave Cost
  This is the cost per time unit for handling group join or
leave events. This cost also includes the cost caused by
connection/disconnection events by group members.
                         [          ] [             ]
           C Join / Leave,i = AJ × C Join,i + AL × C Leave,i
  Here AJ and AL are the aggregate group join and leave rates
of all members, respectively. A group join event requires the
update of the regional view and the rekeying of the regional

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                                                                                                                        ISSN 1947-5500
                                                                        (IJCSIS) International Journal of Computer Science and Information Security,
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                                                                                         [7]    Menezes, P. V. Oorschot, and S. A. Vanstone, “handbook of Applied
                                              Cgc   Cjoin/leave
                                                                                                Cryptography”, CRC Press, New York, 1997.
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         hop bits/second



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approach for the design and analysis of region-based key                                        of the Virginia Polytechnic Institute and State University.
management protocols for scalable and reconfigurable group                               [17]   J. W. Wilson, and I. R. Chen, “Performance Characteristics of Location-
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principles. This region-based group key management                                              Clustering Algorithm (WCA) for Ad hoc Networks,” in proceedings of
protocols deal with outsider attacks in MANETs to preserve                                      IEEE Globecom’00, pp. 1697–701, 2000.
the security properties. In order to evaluate the network traffic                                                       N. Vimala received her B.Sc., (CS) from
cost generated for group key management of the proposed                                                                 Avinashilingam Deemed University, Coimbatore,
region-based protocol for MANETs a performance model is                                                                 TamilNadu, in 1993. She obtained her M.Sc.,
developed. Cost for joining or leaving the group and the cost                                                           (CS) and        M.Phil degree from Bharathiar
                                                                                                                        University, Coimbatore, TamilNadu, in the year
for group communication are the parameters considered to                                                                1995 and 2001 respectively. She is currently
investigate the performance of the proposed region-based                                                                Senior Lecturer, Department of Computer
group key management scheme.                                                                                            Science, CMS College of Science and Commerce,
                                                                                                Coimbatore, TamilNadu. She has the long experience of teaching Post
                                                                                                graduate and Graduate Students. She has produced 43 M.Phil Scholars
                                       REFERENCES                                               in various universities. Her area of interest includes Network Security,
[1]   A. Renuka, and K. C. Shet, “Cluster Based Group Key Management in                         Database Management Systems, Object Oriented Programming and
      Mobile Ad hoc Networks,” IJCSNS International Journal of Computer                         Artificial Intelligence. She is currently pursuing her Research in the area
      Science and Network Security, vol. 9, no. 4, pp. 42-49, 2009.                             of Network Security under Mother Teresa University, Kodaikanal,
[2]   S. Rafaeli, and D. Hutchison, “A survey of key management for secure                      TamilNadu. She is a member of various professional bodies.
      group communication,” ACM Computing Surveys, vol. 35, no. 3, pp.
      309–329, 2003.
[3]   Hao Yang, Haiyun Luo, Fan Ye, Songwu Lu, and Lixia Zhang,                                                      Dr. R. Balasubramanian was born in 1947 in
      “Security in mobile Ad-Hoc networks-Challenges and Solutions,” IEEE                                            India. He obtained his B.Sc., and M.Sc., degree in
      Transactions on Wireless Communications, vol. 11, no. 1, pp. 38-47,                                            Mathematics from Government Arts College,
      2004.                                                                                                          Coimbatore, TamilNadu, in 1967 and PSG Arts
[4]   Mohamed-Salah Bouassida, Isabelle Chrisment, and Olivier Festor,                                               College, Coimbatore, TamilNadu, in 1969
      “Group Key Management in MANETs,” International Journal of                                                     respectively. He received his Ph.D., from PSG
      Network Security, vol. 6, no. 1, pp. 67-79, 2008.                                                              College of Technology, Coimbatore, TamilNadu,
[5]   L. Lazos, and R. Poovendram, “Energy-aware secure multicast                                                    in the year 1990. He has published more than 15
      communication in Ad Hoc networks using geographical location                              research papers in national and international journals. He has been
      information,” in IEEE International Conference on Acoustics Speech                        serving engineering educational service for the past four decades. He
      and Signal Processing, pp. 201-204, 2003.                                                 was formerly in PSG College of Technology, Coimbatore as Assistant
[6]   J. E. Wieselthier, G. D. Nguyen, and A. Ephremides, “On the                               Professor in the Department of Mathematics and Computer
      construction of energy-efficient broadcast and multicast trees in wireless                Applications. He served as Associate Dean of the Department of
      networks,” in INFOCOM 2000, pp. 585-594, 2000.                                            Computer Applications of Sri Krishna College of Engineering and
                                                                                                Technology, Coimbatore. Currently taken charge as Dean Academic


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                                                                                                                             ISSN 1947-5500
                                                          (IJCSIS) International Journal of Computer Science and Information Security,
                                                          Vol. 8, No. 2, May 2010



Affairs at PPG Institute of Technology, Coimbatore, before which he
was a Dean Basic Sciences at Velammal Engineering College, Chennai.
He has supervised one PhD thesis in Mathematics and supervising four
doctoral works in Computer Applications. His mission is to impart
quality, concept oriented education and mould younger generation.

He is member of the board of studies of many autonomous institutions
and universities. He was the principal investigator of UGC sponsored
research project. He is a referee of an international journal on
mathematical modeling. He has authored a series of books on
Engineering Mathematics and Computer Science. He is a life member of
many professional bodies like ISTE, ISTAM and CSI.




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                                                                                                     ISSN 1947-5500