1. CS 265 PROJECT Secure Routing in Wireless Sensor Networks : Directed Diffusion a study Ajay Kalambur

2. Outline Introduction Directed Diffusion Attacks Countermeasures

3. Introduction  Array of sensors deployed to monitor real time events  The concepts derived from adhoc networks  Much more energy starved than adhoc networks  Sensor nodes limited battery and memory

4. Introduction(contd)  Scalability  Self Organization  Data Collection, aggregation and processing  All protocols must be designed such that they are energy efficient

5. NETWORK ARCHITECTURE(My project)

6. Sensor Node Architecture Power Unit(Battery) Location finding system Transceiver SensorADC Sensing Unit Processing Unit Processor Storage

7. Directed Diffusion  Data centric, interest-based routing protocol  Base station or sink node disseminates interest  Gradient established in opposite direction for data flow  Positive and Negative Reinforcements possible  Interests also stored in interest cache at each node

8. Diffusion (in molecules) Diffusion (in molecules)

9. THE PICTURE THE PICTURE

10. Example Interest from Base station or sink node  Type=toxin  Interval=1s //send every second  Duration=50 seconds //for next 50 seconds  Rect=[-100,100,250,300]

11. Response from sensor node detecting the event  Type=toxin  Instance=mercury  Location=[120,225]  Intensity=0.6  Confidence=0.7  Timestamp=03:14:45

12. Attacks on Directed Diffusion  Denial of Service -jamming  Modification and spoofing of routing info  Dropping or selective forwarding of data

13. Denial of Service

14. Modification and Spoofing of routing info

15. Dropping or selective forwarding of data  Previous attack enables malicious node to get into path of data flow  The spoofed positive and negative reinforcements and spoofed data, Selective forwarding is trivial to achieve  Dropping all packets- similar to node being non existent.  Selective forwarding is a more dangerous security issue

16. COUNTERMEASURES  Link layer security with each node sharing a unique key with base station  Efficient Symmetric key cryptographic schemes needed  Public key cryptography not possible  Defense against internal attacks is very challenging  Routing protocol needs to be designed carefully

17. References [1] C. Intanagonwiwat, R. Govindan, and D. Estrin, “Directed Diffusion: A Scalable and Robust Communication paradigm for Sensor Networks,” Proc. ACM MobiCom, Boston, MA, pp. 42-49, 2000. [2]. Chris Karlof and David Wagner, “Secure Routing in Wireless Sensor Networks,” Adhoc Networks, Volume1, Issues 2-3, pp: 293-315, September 2003.