Hailiang Mei H.Mei@tue.nl

1. Security and Privacy Concern in Remote Personal Device Management Framework Hailiang Mei H.Mei@tue.nl

2. Outline • Background of RPDM • Why RPDM is important • Security threat • Attack tree model and threat analysis • Examining current RDM systems • SNMP, VNC, MRDP, Web-based • Design of RPDM framework • Based on SyncML DM • Conclusion and future work

3. Background of RPDM Self observes problem + Remote diagnosis + Remote Repair Remote server can be within local network or at service provider’s site

4. Why RPDM is Important? • Recent studies show that there are at least 4 times as many electronic machines in the world as there are people. • This gap is still increasing fast • New devices require maintenance, but personnel are expensive • An online survey shows 57% users feel befuddled by their computer, mobile phone, home security system, etc.

5. Outline • Background of RPDM • Why RPDM is important • Security threat • Attack tree model and threat analysis • Examining current RDM systems • SNMP, VNC, MRDP, Web-based • Design of RPDM framework • Based on SyncML DM • Conclusion and future work

6. We are going to prevent Attack Tree Model

7. Security requirement Threat Analysis (one example) Vulnerability Rating (VR): A Probable; B Highly Possible; C Possible; D Unlikely; E Impossible.

8. Outline • Background of RPDM • Why RPDM is important • Security threat • Attack tree model and threat analysis • Examining current RDM systems • SNMP, VNC, MRDP, Web-based • Design of RPDM framework • Based on SyncML DM • Conclusion and future work

9. Evaluation Factors • System load & Network load • criteria related to performance • Expressive power • indicates the generalization of the technique • Device IQ • defines how intelligent the target device is when it is being managed • Security • the most important concern

10. Simple Network Management Protocol

11. Virtual Network Computing

12. Virtual Network Computing

13. Web Server • The device runs a small web server application • A service runs on the device to generate run-time HTML file • The remote terminal manager access the device via the web browser and execute scripts on the device

14. Web Server (example)

15. Inside client Server WAP client root client DM protocol proprietary proprietary Vendor SyncML upgrade client • Data Synch protocol • Add • Get • Replace • Exec X* … Logical tree for addressing purposes. In scope of DM standard! … … OMA DM SyncML DM (OMA) Over the air

16. OMA DM SyncML DM (OMA) • Server <Get> <CmdID>4</CmdID> <Item> <Target> <LocURI>Vendor/Ring_signals/Default_ring</LocURI> </Target> </Item> </Get> • Client <Results> <CmdRef>4</CmdRef> <CmdID>7</CmdID> <Item> <Data>MyOwnRing</Data> </Item> </Results>

17. Evaluation factor Weight SNMPv3 VNC Web-based RDP SyncMLDM System load 20% +/- - - - +/- Network load 20% + - +/- +/- +/- Expressive power 25% - + +/- + + Security 25% + - + +/- + Device IQ 10% + - +/- - + Equal weight score 20% each 0.4 -0.6 0 -0.2 0.6 Weighted score 0.3 -0.5 0.05 -0.05 0.6 OMA DM Comparison of RDM Systems *We define “+”=1, “+/-”=0 and “-”=-1 to calculate the overall performance score

18. Outline • Background of RPDM • Why RPDM is important • Security threat • Attack tree model and threat analysis • Examining current RDM systems • SNMP, VNC, MRDP, Web-based • Design of RPDM framework • Based on SyncML DM • Conclusion and future work

19. Security • Privacy • Performance RPDM Overview

20. Internal Architecture of RPDM Client

21. Connection Manager

22. Authentication Manager • PKI based authentication • MD5 digest authentication • Digest = H(B64(H(serverrname:password)):nonce) • PKs database itself is a Mobj, and it can be managed as well if the access right is granted. E.g. a trusted management server can introduce a new management server by adding its public key or its hashed name string into the PKs database.

23. Access Control List Tree • Each node (object) is identified by an URI • Each node has a set of properties • This tree can be extended by “add” message or a new installations on the device • Leaf node can be either a value or a pointer to an executable command

24. View of Prototype

25. Conclusion • SyncML DM based system offers good system performance and security protection • Our C prototype is one of the first open implementations based on the SyncML DM specifications. • But, the network load is a bit heavy • A “Get” SyncML message is 709 bytes v.s. 81 bytes in SNMP • However, it becomes better for a more realistic and complex management session

26. Future Work • Complete implementation • Think about management server? ?

27. Thanks for your attention!