22-05-2013, 12:25 PM
Defining Malicious Behavior of a Node and its Defensive Methods in Ad Hoc Network
Defining Malicious.pdf (Size: 203.63 KB / Downloads: 148)
ABSTRACT
Any node under attack in ad hoc network exhibits an anomalous
behavior called the malicious behavior. In this situation, the entire
operation of a network gets disturbed and to preclude such
malicious behavior several security solutions have been
discovered. In this paper, malicious behavior of a node is defined
and to defend such behavior, security solutions are presented
which are used in furnishing a secure and reliable communication
in ad hoc.
INTRODUCTION
Ad Hoc Network provides quick communication among nodes
(like mobile or a laptop) to transfer the packets from one node to
other. An example of an ad hoc network is given in figure 1 where
nodes are communicating directly with each other. All the links
between nodes are wireless. Bluetooth [1] is a typical example of
such networks. These networks are independent of any fixed
infrastructure or central entity like cellular networks [2] which
requires fixed infrastructure to operate.
NEED OF SECURITY IN AD HOC
NETWORK
Though the ad hoc networks are widely used but still it has some
vulnerability in it. Therefore, there is a need of security to defend
such problems. An intruder utilizes this vulnerability to know
about the network processes and then attack the network.
Following are some present vulnerability in ad hoc networks.
Mobility- Each node in ad hoc network is movable. It can
join or leave a network at any instant of time without
informing any node. This gives chance to intruder to easily
enter in the network and even participating in its
operations.
Open Wireless Medium- All the communication between
nodes is taking place through the medium of air instead of
wires. An intruder can easily access this medium to gain
information about the communication or can easily trap it.
Resource Constraint- Every node in mobile ad hoc network
has limited resources like battery, computational power,
bandwidth etc. An intruder can unnecessarily waste these
limited resources in order to make it unavailable to
perform.
DEFINING NORMAL AND MALICIOUS
BEHAVIOR OF A NODE
The vulnerabilities discussed in previous section provide intruder
a way to compromise legitimate nodes and make them malicious
in nature. In this section, an attempt has been made to define a
normal and malicious behavior of a node. First of all, normal
behavior of a node is defined and then malicious behavior.
SECURITY SOLUTION TO DEFEND
MALICIOUS BEHAVIOR
In order to defend the malicious behavior which is defined in
previous section, there are several security solutions which are
used in ad hoc networks. Security can be provided through the
methods of Cryptography, Protocols, Intrusion Detection System
(IDS) and Trusted Third Party (TTP) which are discussed below.
Security through Cryptography
In Ad Hoc Network, the data is sent using cryptography [5].
Cryptography means to convert (or encrypt) the original data
(which is to be send) into the unreadable format. Even if the
intruder accesses the data, it should not be able to understand the
content of it. Cryptography can be symmetric (which uses same
key to encrypt and decrypt the data) and asymmetric (which uses
one key to encrypt and other to decrypt the data). This security
preserves the integrity and confidentiality of data.
Techniques like MD5 (Message Digest 5), Digital Signature, SHA
(Secure Hash Algorithm), MAC (Message Authentication Codes)
are used to preserve the security principles.
CONCLUSION
In this paper, normal and malicious behavior of nodes is defined.
Security solution to defend such behavior is presented. Malicious
behavior which is defined in section 3 cannot be confined to any
number and depends on the operating environment and intruder’s
way to attack the network. Table 1 given below concludes the
malicious behavior of a node, the affected security principle and
the security solution for it.