1. Reliability of Wireless sensors with code attestation for intrusion detection Ing-Ray Chen, Yating Wang, Ding-Chau Wang Information Processing Letters Presented by Yang Chen 1CS5214 – Modeling and Evaluation of Computer Systems

2. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Outline Introduction System Model Performance Model and Analysis Conclusion 2

3. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Introduction Wireless sensors applications, widely Wireless sensors properties  Activities consume battery energy  Vulnerable to attacks Incorrect sensing data will cause disasters Code attestation  Deal with intrusion detection  Do not physical access to the sensor or secure part  Energy consumption, rate has not been investigated 3

4. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems System Model Object – Identify the best rate of Code Attestation  Trade-off between energy consumption and intrusion detection effectiveness Sensor Node’s functionality  Periodic sensing, Code attestation, Recovery as needed Reliability  Mean time to failure (MTTF)  Failure situation: 1. energy is depleted, 2. compromised and returns incorrect sensor reading. 4

5. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems System Model Model parameters  E: initial energy, 2.5 joules  Es: energy consumption by sensing event, 0.02 mjoules  Ec: energy consumption by code attestation, 0.01 mjoules  Er: energy consumption by recovery, 0.01~0.03 mjoules  Pfp: good nodes misidentify as bad nodes, less than 1%  Pfn: bad nodes misidentify as good nodes, less than 1%  T: sensor reading time interval, 1-10 seconds range.  λ: sensor compromised rate, 0.0058~0.0072 per hour  q: probability that code attestation will be performed 5

6. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Performance Model and Analysis Recall sensor’s failure  Energy depleted  Compromised Code attestation is performed, but fail to identify, false negative Code attestation is not performed  Other consume energy situation Sensor node is not compromised, but code attestation mistakenly identifies it as compromised. 6

7. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Performance Model and Analysis 7

8. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Performance Model and Analysis 8

9. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Performance Model and Analysis 9

10. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 10

11. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis Simulation:  smpl  batch means 20,000 observations Confidence level: 95% Accuracy requirement: 5% level Analytical results obtained are valid 11

12. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 12

13. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 13

14. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 14

15. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 15

16. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 16

17. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Result & Analysis 17

18. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Conclusion 18

19. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Conclusion First to address tradeoff between energy consumption of code attestation vs. its effectiveness in intrusion detection to maximize a sensor’s expected life-time 19

20. Chen-IPL10 CS5214 – Modeling and Evaluation of Computer Systems Thank you! Q&A 20