25-05-2012, 11:32 AM
Security Issues in MANETs
Security Issues in MANETs.pdf (Size: 182.57 KB / Downloads: 81)
Abstract
Mobile Ad hoc Networks (MANET) has become an exciting
and important technology in recent years because
of the rapid proliferation of wireless devices. A mobile
adhoc network consists of mobile nodes that can
move freely in an open environment. Communicating
nodes in a Mobile Adhoc Network usually seek the help
of other intermediate nodes to establish communication
channels. In such an environment, malicious intermediate
nodes can be a threat to the security of conversation
between mobile nodes. The security experience
from the Wired Network world is of little use in Wireless
Mobile Ad hoc networks, due to some basic dierences
between the two Networks. Therefore, some novel
solutions are required to make Mobile Adhoc Network
secure.
Introduction
A Mobile Adhoc Network is a group of wireless mobile
computers in which nodes cooperate by forwarding
packets for each other to allow them to communicate
beyond direct wireless transmission range. Application
such as military excercises, disaster relief, and mine
site operation may benet from adhoc networking, but
secure and reliable communication is a necessary prerequisite
for such applications.
MANETS are more vulnerable to attacks than wired
networks due to open medium, dynamically changing
network topology, cooperative algorithms, lack of centralized
monitoring and lack of clear line of defense.
Security is a process that is as secure as its weakest
link. So, in order to make MANETs secure, all its
weak points are to be identied and solutions to make
all those weak points safe, are to be considered. Some
of the weak points and solutions to strengthen them are
considered in this article. However the list is possibly
incomplete, and some more weak points of MANETs
are likely to be discovered in near future. So Security
issues in MANETs will remain a potential research area
in near future.
Routing
The knowledge of routing protocols of MANETs is
important to understand the security problems in
MANETs. The routing procols used in MANETs are
dierent from routing protocols of traditional wired
world. Some of the reasons are listed below:
Frequent Route updates.
Mobility.
Limited transmission range.
The performance criteria of nodes in MANETs are different
than that of wired networks. Some of the performance
metrics of MANET routing protocols are listed
below:
Energy consumption.
Route Stability despite mobility.
Routing protocols in Mobile Adhoc Networks are majorly
of two categories:
Proactive Protocols
Reactive Protocols
Reactive Routing protocols are based on nding routes
between two nodes , when it is required. This is different
from traditional Proactive Routing Protocols in
which nodes periodically sends messages to each other
in order to maintain routes. Only Reactive Protocols
are considered in this article, as they are extensively
studied and used in MANETs. Among many Reactive
Routing Protocols, only two of them are described
below as they are mostly studied.
2.4.1 Dynamic Source Routing
Dynamic Source Routing (DSR) uses source routing to
deliver packets from one node in the network to some
other node. The source node adds the full path to
the destination in terms of intermediate nodes in every
packet . This information is used by intermediate
node to determine whether to accept the packet and
to whom to forward it. DSR operates on two mechanisms:
Route Discovery and Route Maintainance.
Route Discovery is used when the sender does not
know the path upto the destination. In this mechanism,
the sender broadcasts a ROUTE REQUEST message
which contains Source Address, Destination Address
, Identier. Each intermediate node adds its address
in ROUTE REQUEST message and rebroadcast it, unless
it has not rebroadcasted earlier. With this controlled
broadcast, the ROUTE REQUEST will ultimately reaches
the destination. The destination then sends a unicast
ROUTE REPLY message in reverse direction whose information
is obtained from list of intermediate nodes in
ROUTE REQUEST message.
When the ROUTE REPLY packet reaches the source, it
records the route contained in it and saves in its cache
for the specic destination. For better performance,
intermediate nodes also records this route information
from the two route messages. All nodes overhearing
these packet adds meaningfull route entries in their
caches.
Finally, Route Maintainance Mechanism is used to notify
souce and potentially trigger new route discovery
events when changes in the network topology invalidates
a cached route.
2.4.2 Adhoc On-demand Distance Vector Routing
Adhoc On demand Distance Vector rouing (AODV) is
another on-demand protocol. It has similar mechanism
of ROUTE REQUEST and ROUTE REPLY as that in DSR.
However, it does not rely on source routing, rather it
makes use of routing tables at intermediate nodes. The
nodes maintain routing table entries of all reachable
nodes in the network. The entries in routing tables are
of the form: < Destination, Next Hop, No. of hops,
Sequence Number>. Sequence number is used to maintain
freshness. The route table is used to route data
packets destined for a particular node and to respond
to ROUTE REQUEST. The advantage of AODV over DSR
is that, a data packet does not need to contain whole
route to the destination.
3 Security basics
Before proceeding further, the reader should have the
knowledge of following terminologies of Network Security:
Conclusion
The following colclusions are made based on the study
of MANET attacks and solutions:
The mobile nodes are considered to be resource
constrained. If public key operations are used,
care needs to be taken to limit the frequency of
these operations to prevent DOS attacks.
Security Issues in MANETs.pdf (Size: 182.57 KB / Downloads: 81)
Abstract
Mobile Ad hoc Networks (MANET) has become an exciting
and important technology in recent years because
of the rapid proliferation of wireless devices. A mobile
adhoc network consists of mobile nodes that can
move freely in an open environment. Communicating
nodes in a Mobile Adhoc Network usually seek the help
of other intermediate nodes to establish communication
channels. In such an environment, malicious intermediate
nodes can be a threat to the security of conversation
between mobile nodes. The security experience
from the Wired Network world is of little use in Wireless
Mobile Ad hoc networks, due to some basic dierences
between the two Networks. Therefore, some novel
solutions are required to make Mobile Adhoc Network
secure.
Introduction
A Mobile Adhoc Network is a group of wireless mobile
computers in which nodes cooperate by forwarding
packets for each other to allow them to communicate
beyond direct wireless transmission range. Application
such as military excercises, disaster relief, and mine
site operation may benet from adhoc networking, but
secure and reliable communication is a necessary prerequisite
for such applications.
MANETS are more vulnerable to attacks than wired
networks due to open medium, dynamically changing
network topology, cooperative algorithms, lack of centralized
monitoring and lack of clear line of defense.
Security is a process that is as secure as its weakest
link. So, in order to make MANETs secure, all its
weak points are to be identied and solutions to make
all those weak points safe, are to be considered. Some
of the weak points and solutions to strengthen them are
considered in this article. However the list is possibly
incomplete, and some more weak points of MANETs
are likely to be discovered in near future. So Security
issues in MANETs will remain a potential research area
in near future.
Routing
The knowledge of routing protocols of MANETs is
important to understand the security problems in
MANETs. The routing procols used in MANETs are
dierent from routing protocols of traditional wired
world. Some of the reasons are listed below:
Frequent Route updates.
Mobility.
Limited transmission range.
The performance criteria of nodes in MANETs are different
than that of wired networks. Some of the performance
metrics of MANET routing protocols are listed
below:
Energy consumption.
Route Stability despite mobility.
Routing protocols in Mobile Adhoc Networks are majorly
of two categories:
Proactive Protocols
Reactive Protocols
Reactive Routing protocols are based on nding routes
between two nodes , when it is required. This is different
from traditional Proactive Routing Protocols in
which nodes periodically sends messages to each other
in order to maintain routes. Only Reactive Protocols
are considered in this article, as they are extensively
studied and used in MANETs. Among many Reactive
Routing Protocols, only two of them are described
below as they are mostly studied.
2.4.1 Dynamic Source Routing
Dynamic Source Routing (DSR) uses source routing to
deliver packets from one node in the network to some
other node. The source node adds the full path to
the destination in terms of intermediate nodes in every
packet . This information is used by intermediate
node to determine whether to accept the packet and
to whom to forward it. DSR operates on two mechanisms:
Route Discovery and Route Maintainance.
Route Discovery is used when the sender does not
know the path upto the destination. In this mechanism,
the sender broadcasts a ROUTE REQUEST message
which contains Source Address, Destination Address
, Identier. Each intermediate node adds its address
in ROUTE REQUEST message and rebroadcast it, unless
it has not rebroadcasted earlier. With this controlled
broadcast, the ROUTE REQUEST will ultimately reaches
the destination. The destination then sends a unicast
ROUTE REPLY message in reverse direction whose information
is obtained from list of intermediate nodes in
ROUTE REQUEST message.
When the ROUTE REPLY packet reaches the source, it
records the route contained in it and saves in its cache
for the specic destination. For better performance,
intermediate nodes also records this route information
from the two route messages. All nodes overhearing
these packet adds meaningfull route entries in their
caches.
Finally, Route Maintainance Mechanism is used to notify
souce and potentially trigger new route discovery
events when changes in the network topology invalidates
a cached route.
2.4.2 Adhoc On-demand Distance Vector Routing
Adhoc On demand Distance Vector rouing (AODV) is
another on-demand protocol. It has similar mechanism
of ROUTE REQUEST and ROUTE REPLY as that in DSR.
However, it does not rely on source routing, rather it
makes use of routing tables at intermediate nodes. The
nodes maintain routing table entries of all reachable
nodes in the network. The entries in routing tables are
of the form: < Destination, Next Hop, No. of hops,
Sequence Number>. Sequence number is used to maintain
freshness. The route table is used to route data
packets destined for a particular node and to respond
to ROUTE REQUEST. The advantage of AODV over DSR
is that, a data packet does not need to contain whole
route to the destination.
3 Security basics
Before proceeding further, the reader should have the
knowledge of following terminologies of Network Security:
Conclusion
The following colclusions are made based on the study
of MANET attacks and solutions:
The mobile nodes are considered to be resource
constrained. If public key operations are used,
care needs to be taken to limit the frequency of
these operations to prevent DOS attacks.