The Case for Energy-aware Trust Establishment in Dynamic Networks of Cyber Physical Devices

1. The Case for Energy-aware Trust Establishment in Dynamic Networks of Cyber Physical Devices AmrutaGokhale, John McCabe, VinodGanapathy, Ulrich Kremer

2. Motivation • Wireless devices becoming ubiquitous • 1.39 billionphones sold in 2010, 302.6M were smart phones • (Source: International Data Corporation market research)

3. Motivation • Computing power can be exploited • Physical location can be exploited

4. Dynamic Networks • Spontaneous, dynamic sets of cooperating devices • Potentially mobile and heterogeneous • Applications are location- and time-sensitive • Applications are accountable for resource usage

5. Sample Application: Amber Alert

6. Sample Application: Amber Alert

7. Sample Application: Amber Alert

8. Devices are untrusted May misbehave Malicious intent Faulty software Dynamic Networks: Security Challenges

9. Dynamic Networks: Security Challenges

10. Trust in Dynamic Networks • How to trust the query requests • Mechanisms to establish authenticity of launcher device • How to trust the query results • Mechanisms to establish trustworthiness of launchee devices

11. Hardware Based Attestation • One way to establish trust in dynamic networks Verifier Device Prover Device TPM Chip

12. Hardware Based Attestation Protocols Verifier Device Request Quote Prover Device Respond with Quote TPM Chip

13. Hardware Based Attestation Protocols Verifier Device Request Quote Prover Device PCR Contents TPM Chip Measurement Log

14. Goal • To measure and understand resource consumption of hardware based attestation protocols • SARANA – Our prototype architecture

15. SARANA • SARANA - Space-Aware, Resource-Aware Network Architecture • Developed by Prof. Ulrich Kremer and his group • Language, compiler, and run-time infrastructure • Parallel macroprogramming framework • Support for spatial and temporal constraints • Application-centric cost model / resource management

16. Execution Model Aggregate results Launcher Device Query request Query response Launchee Device Launchee Device Launchee Device Query execution

17. Attestation Model Launcher Device Attestation Challenge Launchee Device Launchee Device Launchee Device

18. Attestation Model Verification Launcher Device Query request Attestation + Query response Launchee Device Launchee Device Launchee Device Attestation computation + Query execution

19. Attestation Model Aggregate results Launcher Device Query request Attestation + Query response Launchee Device Launchee Device Launchee Device

20. Measurements • Measurement of • Time • Energy • Different Configurations • Number of nodes in the network (10, 100, 1000, 10000) • Increasing execution times of the task (0ms, 0.5ms, 1ms, 500ms) • Programs of different complexity (single visit operation, amber alert operation)

21. Experimental Setup • Basis for measurements • TPM-enabled desktop machine • Implemented Integrity Measurement Architecture (IMA) protocol • Measured the execution time for prover and verifier • Other timings by profiling a Nokia N900 • Simulator • Time measurements by modeling time utilization • Energy measurements based on resource consumption

22. Evaluation of Time spent

23. Evaluation of Energy Consumption Remote Attestation

24. Evaluation of Energy Consumption Remote Attestation

25. Observations and Conclusion • 97% energy spent in attestation for small payloads • Remote attestation increases the energy budget of Amber Alert – like application by a factor of 2 • Trust Establishment protocols should be energy-conserving specially on resource-constrained devices • Need to focus on energy efficiency of these protocols

26. Thank you!