Denial of Service in Sensor Networks

1. Denial of Service in Sensor Networks Anthony D. Wood John A. Stankovic Ching-Yao Wang M9415027 資工碩一

2. Outline • Introduction • Denial of Service Attack • Physical Layer Attacks • Link Layer Attacks • Network and Routing Layer Attacks • Transport Layer Attacks • Conclusion

3. Introduction • Applications of Sensor Network • Military • Disaster relief • Monitoring • Security is important • protect against enemy’s accesses • protect location and status of casualties from unauthorized disclosure • protect patient privacy

4. Denial of Service Attack • any event that diminishes or eliminates a network’s capacity to perform its expected function • Hardware failures, software bugs, resource exhaustion can cause a DoS.

6. Physical Layer Attack-Jamming Attack • Method: • Randomly deploy some nodes that interfere with the radio frequencies of the victim nodes • Defense: • Spread-Spectrum • Priority messages • Region mapping • Lower duty cycle • Mode change

7. Defense against a jamming attack, phase one. Nodes along the edge of a jammed region report the attack to their neighbors.

8. Defense against a jamming attack, phase two. Neighboring nodes collaborate to map the jamming reports, then reroute traffic around the jammed region.

9. Physical Layer Attack-Tampering Attack • Method: • Capture, destruct victim nodes. May also extract information, cryptographic key to gain access to higher levels of communication • Defense: • Tamper-proofing • Hiding

10. Link Layer Attack-Collision Attack • Method: • Listen for transmissions, induce a collision to disrupt an entire packet. or try to corrupt ACK messages to force victim nodes go into back-off mode • Defense: • Error-correcting code

11. Link Layer Attack-Exhaustion Attack • Method: • Repeatedly send out requests to access channel to elicit responses from victim nodes. Victim nodes’ energy is drained to exhaustion • Defense: • Rate limitation

12. Link Layer Attack-Unfairness Attack • Method: • Use channel to send large packets, denying channel access of legitimate nodes • Defense: • Small frames

13. Network Layer Attack-Neglect and Greed Attack • Method: • Malicious nodes neglect to forward, or intentionally drop, packets. They may only forward their packets • Defense: • Redundancy • Probing

14. Network Layer Attack-Homing Attack • Method: • Passively monitor and detect critical nodes (group leader, cryptographic key managers, data aggregator, etc.). Call in other collaborators to perform active attacks on critical nodes • Defense: • Encryption

15. Network Layer Attack-Misdirection Attack • Method: • Direct packets along wrong paths, by fabricating wrong route advertisements • One variant of misdirection, Internet smurf attack. • Defense: • Egress filtering • Authorization • Monitoring

16. Network Layer Attack-Black Holes Attack • Method: • In distance vector routing based sensor net: a malicious node advertises zero-cost routes to other nodes. Thus, traffic will be routed towards the malicious node, creating a hole • Defense: • Authorization • Monitoring • Redundancy

17. Transport Layer Attack-Flooding Attack • Method: • Send many connection establishment requests to a victim, forcing the victim to allocate resources to maintain the connections • Defense: • Limit number of connections

18. Transport Layer Attack-Desynchronization Attack • Method: • Repeatedly send forged messages to both ends of a connection to force both ends to request retransmission of packets (i.e., both ends have to repeatedly synchronize), causing energy drain on all involved victim nodes • Defense: • Authentication

19. Conclusion • Adaptive rate control • RAP (a real-time communication architecture for large-scale wireless sensor networks) • Security is important