1. Achieving Better Privacy Protection in WSNs Using Trusted Computing Yanjiang YANG, Robert DENG, Jianying ZHOU, Ying QIU

2. RFID Security Seminar 2008 2 Project Summary - why should it be done? Content Introduction Heterogeneous WSN Architecture Example: Achieving User Query Privacy Conclusion

3. RFID Security Seminar 2008 3 Project Summary - why should it be done? Introduction Wireless Sensor Networks (WSNs)

4. RFID Security Seminar 2008 4 Project Summary - why should it be done? Introduction Homogeneous WSNs –All sensor nodes have the same capability –Homegeneous WSNs have scalability problem. Theoretical and empirical studies have corroborate this P. Gupta and P.Kumar. The Capacity of Wireless Networks, IEEE Transactions on Information Theory, Vol 46(2), pp. 388-404, 2000. S. Das, C. Perkins and E. Royer. Performance Comparison of Two On-demand Routing Procotols for Ad Hoc Networks, Proceedings of Infocom 2000, Vol 1, pp. 3-12, IEEE Press, 2000

5. RFID Security Seminar 2008 5 Project Summary - why should it be done? Introduction Heterogeneous WSNs Are A Better Alternative –The network is partitioned into clusters, and each cluster is placed a cluster head –Cluster heads have better capability than sensor nodes –A cluster head acts an intermediary between sensor nodes and the base station

6. RFID Security Seminar 2008 6 Project Summary - why should it be done? Heterogeneous WSN Architecture

7. RFID Security Seminar 2008 7 Project Summary - why should it be done? Heterogeneous WSN Architecture Equip Each Cluster Head with Trusted Computing Technology –TPM is tamper resistant, acting as hardware based root of trust –Remote attestation enables detection of software compromises. –TC-equipped cluster heads are online trusted party, facilitating security enforcement in WSNs

8. RFID Security Seminar 2008 8 Project Summary - why should it be done? Achieving User Query Privacy Security Issues in WSNs –Content-related Security Key management Access control Authentication Encryption –Context-related Security Protection of contextual information, such as where, when

9. RFID Security Seminar 2008 9 Project Summary - why should it be done? Example: Achieving User Query Privacy Problem Statement: Users Query a WSN to Get Data from Particular Areas –Users may want to protect “areas of interest” –User Query Privacy ensures that the user gets the desired data, but the adversary watching the network does not know where the data are from

10. RFID Security Seminar 2008 10 Example: Achieving User Query Privacy access point forwarding node

11. RFID Security Seminar 2008 11 Achieving User Query Privacy Our Solution –Cluster heads establish transmission path to the access point –Use fake data transmission to hide the real one Every cluster head asks its nodes to retrieve data Along the transmission path, each cluster head sends encrypted data to its forwarding node

12. RFID Security Seminar 2008 12 Achieving User Query Privacy Our Solution --- continued A forwarding node either decrypts and then encrypts the data from the target cluster, or encrypts dummy data Transmission pattern of every cluster head is SAME!!!

13. RFID Security Seminar 2008 13 Achieving User Query Privacy Comparisons: we assume a global eavesdropper watching the whole network, while other work assumed a local eavesdropper Source Location Privacy –Use a similar approach

14. RFID Security Seminar 2008 14 Project Summary - why should it be done? Conclusion Heterogeneous WSNs Are More Scalable TC-equipped Cluster Heads Facilitate Security Enforcement We Showed How to Achieve Better User Query Privacy and Source Location Privacy

15. RFID Security Seminar 2008 15 Project Summary - why should it be done? Q & A Thank you for your kind attention.