1. Trust Based Routing In
wireless sensor
Network

2. About Sensor Network
Characteristics: Applications:
Temporarily formed Military battlefield
Nodes act as routers networks.
Infrastructure-less Personal Area Networks
Limited resources Disaster and rescue
 wireless medium operation

3. Attacks on Wireless Networks
Passive attacks
Do not change the routing information
Listen to get valuable information
Active attacks
Use its energy to manipulate the routing
information

4. Passive attack
passive attack "attempts to learn or make use
of information from the system but does not
affect system resources"
Traffic analysis
 each message is encrypted because it is not important whether the
data is
readable(understandable) to the attacker. Here, the adversary attempts
to
find patterns in the communication between two node, which might allow
the adversary to derive certain assumptions based on these patterns.

5. Passive attack
Traffic analysis
Attacker
Node Node

6. Active Attack
Active attacks include security threats in which an node tries
to manipulate code or data while it is transmitted between
nodes. The most common examples of this kind of attack are
alterations, in which an data is deleted or tampered with by
an intruder .

7. Active Attacks
Modification:
Malicious node can modify routing information
Fabrication:
Generating false routing message
Impersonation:
Initiate attack by masquerading as another
node

8. Active attack
A B
C
Malicious Node

9. Existing Security Solutions
Intrusion prevention
Encryption, authentication.
Nodes are required to have pre-shared keys or digital
certificates.
Central trust authority or pre configuration is not practical
for ad-hoc networks

10. Dynamic Source Routing (DSR) Protocol
On demand protocol: route information
discovered only as needed.
Source routing: entire path to destination
supplied by source in packet header.
Procedure:
•Route discovery
•Route maintenance
•Routing

11. Route Discovery
.
Route Request:
Source broadcasts Route Request message for specified
destination
Intermediate node adds itself to path in message and
forwards message toward destination
A A,B A,B,C A,B,C,D
A B C D E

15. DSR Based Model
Trust Based Routing
To compute the direct trust in a node. In doing so we measure the
accuracy and sincerity of the immediate neighboring nodes by monitoring
their participation in the packet forwarding.
As soon as it hears its immediate neighbour forwarding the packet, the
node
checks the integrity of the packet by verifying it for requisite
modifications.
If the integrity check passes, it confirms that the node has acted in a
benevolent manner and so its direct trust counter is incremented. Similarly, if
the integrity check fails or the forwarding node does not transmit the packet,
its
corresponding direct trust measure is decremented.

16. Trust Calculation

17. Trust Propagation
To propagate trust information beyond a single hop, piggyback the direct
trust value of nodes along with the ROUTE REQUEST packets.
Before forwarding a ROUTE REQUEST packet, appends the direct trust
value of the preceding node from which it had received the ROUTE
REQUEST packet.
When the ROUTE REQUEST packet is propagated, it also spreads the trust
information of other nodes in the network.

18. Trust Propagation
Tba,
Tax
Tax
A B
Tcx,
Tcx
Tdc
X C D Y
Tex,
Tfe
Tex
E F

19. References
1.TRUST-BASED ROUTING FOR AD-HOC WIRELESS NETWORKS , Asad Amir Pirzada., Amitava
Datta, Chris McDonald School of Computer Science & Software Engineering, The University of
Western Australia Crawley, WA 6009, Australia
2. An Intrusion Detection System for Wireless Sensor NetworksIlker Onat Ali Miri School of Information
Technology and Engineering University of Ottawa, Canada
e-mail: ionat@site.uottawa.ca, samiri@site.uottawa.ca
3. Intrusion Detection Techniques for Mobile Wireless Networks ,Yongguang Zhang ,HRL Laboratories
LLC, Malibu, California Wenke Lee,College of Computing, Georgia Institute of Technology
E-mail: wenke@cc.gatech.edu
Yi-An Huang,College of Computing, Georgia Institute of Technology
E-mail: yian@cc.gatech.edu

20. Thank you