16-01-2013, 04:56 PM
Secure Transmission Services in Wireless Networks using Key Trees
Secure Transmission.pdf (Size: 537.62 KB / Downloads: 43)
Abstract
In contrast with conventional networks, mobile networks usually
do not provide on-line access to trusted authorities or to
centralized servers for secure message transmissions and exhibit
problems like frequent problems due to link-node failures and
pricey issues. For these reasons, existing solutions for secure
message transmission services in regular networks require
on-line trusted authorities or certificate repositories that are not
well suited for securing mobile networks. To reduce computation
overhead the core system is deployed at a Server and accessed via
mobile nodes. In this paper, we propose a fully self-organized
public-key management system that allows users to generate their
key message pairs and cipher/decipher them(using RSA
encryption), to issue access, to perform authentication regardless
of the network partitions and number of users using Key Tree
management schemes.
INTRODUCTION
The demand of wireless networks (WNs) is growing
exponentially. It has turned out that the sensor networks can be
widely applied in the areas of healthcare, environment
monitoring, and the military. One of the surveys on WNs
points out that, in the near future, wireless sensor networks will
be an integral part of our lives, more so than the present-day
personal computer [1].
A sensor node has low capability in terms of power,
computation, storage and communication. A wireless sensor
network is composed of a large number of wireless sensor
nodes and multi-hop communication is desired in WSNs. As a
result, security in wireless sensor networks has six challenges
to overcome: (i) the wireless nature of communication, (ii)
resource limitations of sensor nodes, (iii) very large and dense
WSNs, (iv) lack of fixed infrastructure, (v) unknown network
topology prior to deployment, (vi) high risk of physical attacks
on unattended sensors [2].
RELATED WORK
Kimetal [6] proposed a combination of key tree and
Diffie-Hellman key exchange to provide a simple fault-tolerant
key agreement for collaborative groups. The working [2]
reduces the number of rekey messages, while [9] and [2]
improve the reliability of rekey management. Balanced and
unbalanced key trees are discussed in [5] and[2]. Periodic
group rekeying is studied in[7] and [8] to reduce the rekey cost
for groups with frequent joins and leaves. Issues on how a key
tree is maintained and how encrypted keys are efficiently
placed in multicast rekey packets are studied in [8] and [2]
Moreover, the performance of LKH is thoroughly studied
[3],[8]. In broadcast Encryption, there are some key
management schemes in the literature for multicast and
broadcast services. Briscoe [2] used arbitrarily revealed key
sequences to do scalable multicast key management without
any over head on joins leaves. Wool[8] proposed two schemes
that insert an index head in to packets for decryption. Lubyand
Staddon[7] proposed a scheme for yield in gmaximal resilience
again starbitrary coalition so for on privileged users. However,
the size(entropy) of its broadcast key messages large, at least a
zero-message scheme [7], [8] which does not require the
broadcast server to disseminate any message in order to
generate a common key.
PROPOSED ARCHITECTURE
First, the proposed scheme takes advantage of the facts in
broadcast services. The proposed concept has more than a
couple of programsthat (instead of many like in existing
system) needs to be managed like Key Trees for user
management and RSA encryption policy for secure messaging.
The following schemes were used for user management and
program management.
Key Forest
In order to address scalability and flexibility in key
management, an intuitive solution is to use a key tree for each
program.LKH[7] is used as the basis of our scheme., but when
the user u1 subscribes to two programs simultaneously, he
needs to manage two sets of keys in both trees, which is not
very efficient , hence SKT is proposed to reduce this cost in
key management. We let the two programs share the same sub
key tree, so that users subscribing to both programs only need
to manage the keys in the gray triangle. The advantage of SKT
is that any user subscribing to both g1 and g2 only needs to
manage one set of keys for both programs. Moreover, when a
user joins or leaves a tree shared by multiple programs the
encryption and communication cost for rekey operations can
be significantly less than conventional LKH approaches fig 2.
EXPERIMENTAL RESULTS
This is the process of obtaining, analyzing, and recording
information about the relative worth of the system. It is the
analysis of successes and failures and suitability for further
improvement. The performance of KTR at the server side and
the client side, respectively are analyzed.
CONCLUSION AND FUTURE WORK
The issues of key management in support of secure wireless
broadcast services. We proposed the KTR as a scalable,
efficient, and secure key management approach in the
broadcast system. We used the key forest to exploit the
overlapping nature between users and programs in broadcast
services. KTR lets multiple programs share a single tree so that
the users subscribing these programs can hold fewer keys. In
addition, we proposed a novel shared key management
approach to further reduce rekey cost by identifying the
minimum set of keys that must be changed to ensure broadcast
security. This approach is also applicable to other LKH-based
approaches to reduce the rekey cost as in KTR.