Post on 17-Dec-2015
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PReFilter: An Efficient Privacy-preserving Relay Filtering Scheme for Delay Tolerant Networks
University of Waterloo & UOIT & INRIA Lille
Presenter: Rongxing Lu
Rongxing Lu, Xiaodong Lin, Tom Luan, Xiaohui Liang, Xu Li, Le Chen, and Xuemin (Sherman) Shen
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Outline
• Introduction of Delay Tolerant Networks• Security & Privacy Challenges in DTNs• Proposed PReFilter Scheme • Security Analysis• Performance Evaluation• Conclusions
3 R. Lu et al., PReFilter: An Efficient Privacy-preserving Relay Filtering Scheme for Delay Tolerant Networks
Introduction
• Infrastructure Non-infrastructure• High density Low density• Performance : Highly depend on mobility• Delay Tolerant Network (DTN)
High transmission delay Frequent link disruption Non-exist end-to-end connections
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Applications of DTN
Inter-planetary communication
Networking in sparse rural area
Vehicular Ad-hoc Network
Underwater Sensor Network
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DTN Routing
• DTN Routing increase the delivery ratio reduce the average delay
• Single copy Multi-copy• Balance Performance & Resource Consumption
Probabilistic routing Spray and wait Relaycast
D
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[1] A. Lindgren, A. Doria, and O. Schelen, “Probabilistic routing in intermittently connected networks,” Mobile Computing and Communications Review, vol. 7, no. 3, pp. 19–20, 2003.[2] T. Spyropoulos, K. Psounis, and C. S. Raghavendra, “Spray and wait: an efficient routing scheme for intermittently connected mobile networks,” in Proc. of WDTN ’05, 2005, pp. 252–259.[3] U. Lee, S. Y. Oh, K.-W. Lee, and M. Gerla, “Relaycast: Scalable multicast routing in delay tolerant networks,” in Proc. of ICNP’08, 2008.
6 R. Lu et al., PReFilter: An Efficient Privacy-preserving Relay Filtering Scheme for Delay Tolerant Networks
Security Challenges
• Without solving security issues well-designed DTN routing not practical
• Selfish issues incentive mechanism avoid black/grey hole
[1] S. Upendra, H. H. Song, L. Qiu, and Y. Zhang, “Incentive-aware routing in dtns,” in Proc. of ICNP’08, 2008, pp. 238–247.[2] R. Lu, X. Lin, H. Zhu, X. Shen, and B. R. Preiss, “Pi: a practical incentive protocol for delay tolerant networks,” IEEE Transactions on Wireless Communications, vol. 9, no. 4, pp. 1483–1493, 2010.
D
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Selfish
Selfish
Selfish
Incentive
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Security Challenges (2)
• Traffic storm problem caused by the malicious nodes false data waste scarce DTN resources
• Countermeasure fundamental packet authentication access control
detect false data by relay nodes drop false data early save scarce DTN resources
[1] N. Asokan, K. Kostiainen, P. G. J. Ott, and C. Luo, “Towards securing disruption-tolerant networking,” Nokia Research, Tech. Rep. NRC-TR-2007-007.[2] H. Zhu, X. Lin, R. Lu, X. Shen, D. Xing, and Z. Cao, “An opportunistic batch bundle authentication scheme for energy constrained DTNs,” in Proc. IEEE INFOCOM’10, 2010, pp. 605–613.
D
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Security Challenges (3)
• Encrypted “junk” packet --- New Challenge encrypted, sent by the legitimate nodes “junk” of no interest to the destination decrypted, discarded by the destination
• But, before being discarded TTL expire or encounter with destination also waste scarce DTN resources
• No countermeasure, ▼
encrypted sent by legitimate nodes
D
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BIG CHALLENGE
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Our Contribution
• From traditional Email System DTN
• Differences Transmission: Infrastructure DTN nodes Filtering: centralized decentralized (effectively filter) Privacy: protected easily violated
• Our Contribution PReFilter: Privacy-preserving relay filtering for DTN
Filtering Keyword
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Our PReFilter Scheme
• Each node sets its filtering keyword list• Distribute encrypted keyword list to its friends
friends can use the encrypted keyword list for filtering but cannot read the keywords in plaintext
• Packet format
iN
1iFP
2iFP
3iFP
4iFP
5iFP
Rule 1Rule 2- - -
1N
2N
3N4N
5N
Social Connection
Sparse DTN
1N
2N
3N
4N
5N
6N
7N
8N
Destination Keyword Payload TTL Authenticator
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PReFilter Mechanism
S
D
Junk packet S Source D Destination Destination’s friend
Intermediate node w/o packet dropping Intermediate node with packet dropping
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Security Analysis• Achieve privacy-preserving policy
distribution privacy-preserving filtering integrity, confidentiality
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Performance Evaluation
1000 m x 1000 m
Simulation Area Random waypoint model
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Performance EvaluationDelivery ratio in forwarding ordinary beneficial packets with different n, v and tr
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Performance EvaluationAverage delay and network storage cost in forwarding ordinary beneficial packets with different n, v and tr
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Performance EvaluationAverage network storage cost in forwarding a “junk” packet under PReFilter with different n, v and tr
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Performance EvaluationAverage replicas distribution of a “junk” packet under with different n, v and tr
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Conclusion
• In this talk, we have discussed a Privacy-preserving relay filtering (PReFilter) scheme for DTNs Privacy-preserving filtering policy distribution Relay node to filter “junk” packets as early as possible Avoid the significant waste of scarce DTN resources
• In our future work, Heterogeneous mobility of DTN nodes Distribute the filtering policy at high social friend nodes
Thank you!