1. Secure Cell Relay Routing Protocol for Sensor Networks Xiaojiang Du, Fengiing Lin Department of Computer Science North Dakota State University 24th IEEE International Performance, Computing, and Communications Conference (IPCCC), 2005 Chien-Ku Lai

2. Outline Introduction System Assumptions and Attacks on Routing The Secure Cell Relay Routing Protocol Performance Evaluation Conclusions

3. Introduction - Sensor Networks Application areas  Military surveillance  Environmental monitoring  Target tracking Routing protocols for sensor networks  Direct Diffusion  TTDD  Mesh  Energy-Aware Delay-Constrained routing

4. Introduction - Sensor Networks (cont.) The main research focus has been on making sensor networks feasible and useful  Less emphasis was placed on security

5. Introduction - Security Security is important and even critical for many sensor network applications  Military  Homeland security

6. Introduction - Recent Researches Most of the existing sensor network routing protocols  Do not consider security issues during the design of the protocols

7. Introduction - Challenges Hardware limitation  Processing capability  Storage  Bandwidth  Energy

8. Introduction - About this paper Secure Cell Relay (SCR) routing protocol  is resistant to several attacks on sensor networks  is also an energy efficient routing protocol

9. System Assumptions and Attacks on Routing 1. Network Model 2. System Assumptions 3. Attacks on Routing

10. Network Model Cell a: side length R: transmission range a = R / 2

11. System Assumptions Each sensor is static and aware of its own location Base stations are trusted computing base

12. Attacks on Routing Manipulating routing information Selective forwarding Sybil sinkhole Wormhole Hello flooding (unidirectional) attacks

13. Attacks on Routing - Sybil sinkhole A B C DH Sink Normal sensor Compromised sensor

14. Attacks on Routing - Wormhole 3 4 4 2 5 3 5 5 5 2 4 3 11 1 1 Normal sensor Compromised sensor

15. Attacks on Routing - Hello flooding (unidirectional) attacks Can’t reach Normal sensor A powerful device e.g. laptop

16. The Secure Cell Relay Routing Protocol 1. Initial Deployment of Sensor Networks 2. The Secure Data Dissemination Scheme 3. Defense against Sensor Network Attacks

17. Initial Deployment of Sensor Networks K G  a globally shared key  is stored in each sensor node and the base station before sensor deployment All the sensor nodes and the base station are synchronized before deployment

18. Initial Deployment of Sensor Networks BA Check the time-stamp < pre-set value : valid > pre-set value : discard {node-ID, time-stamp} K G B0 Hello

19. Initial Deployment of Sensor Networks BA Challeng e {node-ID, time-stamp, nonce N 0 } K G A15

20. Initial Deployment of Sensor Networks BA {node-ID, time-stamp, K AB, K B, N 0 +1} K G Ack B26

21. Routing Cells

22. The Secure Data Dissemination Scheme S R1 R4 R2 R5 R3 {RTS}K S t d = a(t)/ E + t r {CTS}K S

23. The Secure Data Dissemination Scheme S R1 R4 R2 R5 R3 packet-ID + {Data}K SR1

24. Defense against Sensor Network Attacks Against The Sybil Attack Against The Wormhole and Sinkhole Attacks Against The Selective Forwarding Attack Against The Hello Flood Attack

25. Against The Sybil Attack Authentication is used to ensure one node cannot pretend to be other nodes Thus, the Sybil attack can not work

26. Against The Wormhole and Sinkhole Attacks – Examples A powerful adversary (like a laptop) has a real, high quality route to the base station However  the neighbor sensors will not use the advertised route  they will only route the packets via the routing cells

27. Against The Wormhole and Sinkhole Attacks

28. Against The Wormhole and Sinkhole Attacks – Examples (cont.) An adversary broadcasts to its neighbors about an artificial link to the base station This attack does not work for the same reason as above

29. Against The Selective Forwarding Attack – Solution If one node serves as the relay node for more than M times (where M is a system parameter)  neighbor nodes will send an alarm to the base station and neighbor nodes

30. Against The Selective Forwarding Attack – Solution (cont.) If one node serves as the relay node for more than M times  the upstream node (the sender) will send the packet to another node in the cell encrypted with the corresponding shared secret key

31. Against The Hello Flood Attack Since sensor nodes use the three-way handshake protocol The hello flood attack does not work

32. Performance Evaluation

33. Performance Evaluation - Parameters Simulator: QualNet Compared with SP and Mesh MAC protocol: 802.11 DCF Base stations: 4 Sensor Nodes: 300 Simulation area: 300m x 300m Transmission range: 60m

34. Performance Evaluation SCR routing protocol has high delivery ratio and low energy consumption (close to single path routing)

35. Conclusions 1. Security 2. Energy Efficiency

36. Conclusions - Security The nature of SCR routing (cell relay via routing cells) makes it resistant to  Spoofed routing information  Selective forwarding  Sinkhole  Wormhole attacks

37. Conclusions - Security (cont.) The three-way handshake can defense against  Sybil attack  Hello flooding attack

38. Conclusions - Energy Efficiency In SCR routing  only an active node with more remaining energy (than other nodes) in the routing cells forwards packet

39. Question? Thank you.