09-08-2012, 11:41 AM
A Routing Protocol based on Trusted and shortest Path
Selection for Mobile Ad hoc Network
A Routing Protocol based on Trusted and shortest.pdf (Size: 641.39 KB / Downloads: 44)
INTRODUCTION
Mobile ad hoc network (MANET) is a network composed
only of nodes, these nodes do not have fixed infrastructure or
any centralized controller such as access point or server to
determine the route of the paths. Thus, each node in an ad hoc
network has to rely on each other in order to forward packets
and there is a need to use a specific cooperation mechanism to
forward packet from hop to hop before it reaches a required
destination by using routing protocol. Examples of available
routing protocols for ad hoc network are ad hoc on-demand
distance vector (AODV) [1], destination sequenced distance
vector (DSDV) [2] and dynamic source routing (DSR) [3].The
main concept of these routing protocols is to find the shortest
path in the source-destination routes selection [4]. These
routing protocols can be attacked by several types of attacks
such as blackhole [5][6], denial of service DoS [7] [8] and
wormhole [9]. These attacks may modify or fabricate routing
of packets.
AD-HOC ON-DEMAND DISTANCE VECTOR ROUTING
PROTOCOL (AODV)
Currently, the most common ad-hoc protocol is the Ad-hoc
On-demand Distance Vector routing protocol AODV [1].it is
capable of both unicast and multicast routing. It is an on
demand algorithm, meaning that it builds routes between
nodes only when the source nodes needed it [10]. Also it is a
method of routing messages between mobile computers which
allows these mobile computers, or nodes, to pass messages
through their neighbors to nodes with which they cannot
directly communicate. When one node needs to send a
message to another node that is not its neighbor it broadcasts a
Route Request (RREQ) message. The RREQ message
contains: the source, the destination, the lifespan of the
message and a sequence number.
ATTACKS ON AD-HOC ON-DEMAND DISTANCE VECTOR
ROUTING PROTOCOL(AODV)
Attacks Using Modification
Attacks using modification are generally targeted against
the integrity of routing computations [11]. Those attacks may
modify the routing protocol so that attacker can control the
flows of traffic through a specific node. This traffic can be
dropped, redirected to a different destination, or take a longer
route to the destination increasing communication delays [12].
Example for modification is that attacker nodes send fake
routing packets to generate a routing loop, thus, packets will
keep passing through nodes in a cycle without getting their
actual destination.
RELIANT ON-DEMAND DISTANCE VECTOR ROUTING PROTOCOL(R-AODV)
AODV can be modified to select better path (best path (Bp))
during the route discovery cycle based on the trust and
number of hops (trusted and shortest). When the route request
and route reply (R-RREQ and R-RREP) messages in Reliant
R-AODV are generated or forwarded by the nodes in the
network, each node appends its own trust to the trust
accumulator (trust summation accumulator S[t]) on these
route discovery messages. Each node also updates its routing
table with all the information contained in the control
messages.