Sasikumar G

1. Wireless Sensor Network & Security
Presented by-
G. Sasikumar
Assistant Professor

2. WSN combines sensing, computation,
and communication into single tiny
device called sensor node.
Group of sensors linked by wireless
media to perform distributed sensing
task

3. Sensor is a device, which senses
information and passes it to the mote.
Figure : Wireless sensor network device

4. Figure : Progression of sensor technology
(motes) over time

6. Unstructured WSN Structured WSN
Dense collection of nodes Few distributed nodes
Ad-hoc deployment Pre-planned deployment
Difficult in network
maintenance
Lower network
maintenance

7. A Power unit (Battery)
Computational logic & Storage
Sensor Transducer Communication
ComponentsofSensorNode
1. HARDWARE

8. Figure : The architecture of a sensor node.

9. Operating System Microcode
Sensor Drivers
Communication Processors
Communication Drivers
Data Processing Mini-Apps

10. Sensor Node
* Processor: 4Mhz
* Memory: 128KB Flash & 4KB RAM
* Radio: 916Mhz and 40Kbits/second.
* Transmission Range: 100 Feet
T i ny O S
* Operating System(small)
* Open Source
* Energy Efficient

11. Available Wireless Technologies
Standard Data Rate Range Power
Consumption
ZigBee
(802.15.4)
20 kbps to
250 kbps
Up to 10 m Ultralow
Bluetooth
(802.15.1)
Up to 3 mbps 1m to 100 m low
Wi-Fi
(802.11)
54 mbps 45 m to 90 Medium
m

12.  WSNs are becoming a cost effective,
practical way to go about deploying
sensor networks.
 Protecting confidentiality, integrity
and availability of communications.
 Large range of applications from
civilian to military purposes.

13. Attacks
1) Sybil Attack
* Introduced by “Brain Zill” in 2002
* Subverted by Foreign identities in
peer-to peer Network
2) Traffic Analysis
* Intercepting & Examine messages to
deduce info. from patterns in
Communications.
* Able to detect Encrypted messages but
* Not able to Decrypt it.

14. SMACS
Self organizing medium access
control for sensor networks.
Encryption
Encoding info. in such a way that
hackers can’t read it, but authorized one
can.
Cryptography & Steganography
Techniques for Secure
Communication in presence of Third
parties.

15.  Home and Office Applications
 Environmental Applications
 Medical & Health Applications
 Military Applications

16.  Implementation cost is cheaper
than wired network
Ideal for non-reachable places
 It avoids hell lot of wiring
 It can accommodate new
devices at any time

17.  Less secure because hacker's laptop
can act as Access Point.
 Lower speed as compare to
wired networks.
 Affected by surrounding. E.g.: walls
(blocking), microwave oven , far distance