Rongxing Lu, Xiaodong Lin, Xiaohui Liang, Xuemin (Sherman) Shen Sacrificing the Plum Tree for the Peach Tree: A Socialspot Tactic for Protecting Receiver-location Privacy in VANET Rongxing Lu, Xiaodong Lin, Xiaohui Liang, Xuemin (Sherman) Shen University of Waterloo, University of Ontario Institute of Technology Presenter: Rongxing Lu Email: rxlu@bbcr.uwaterloo.ca

Our Observation and Solution Security Analysis Simulation Results Outline Introduction VANET, Location Privacy Challenging Issue How to Protect Receiver-Location Privacy Our Observation and Solution Socialspot-Based Solution Security Analysis Simulation Results Conclusion 16/11/2018

Introduction: VANET Architecture Application Safety-Related V-2-I V-2-V Vehicle equipped with OnBoard Unit (OBU) Road Side Unit (RSU) Application Safety-Related Non-Safety-Related V-2-V V-2-I Hybrid Collision Warning Traffic Analysis Talking File Downloading Packet Forwarding 16/11/2018

Introduction: Location Privacy Security Privacy Confidentiality Authentication Integrity Non-repudiation Identity Privacy Location Privacy 16/11/2018

Introduction: Challenging Issue Destination Source Packet Forwarding in VANET ==> Vehicular Delay Tolerant Network [1] R. Lu, X. Lin, and X. Shen, "SPRING: A Social-based Privacy-preserving Packet Forwarding Protocol for Vehicular Delay Tolerant Networks", Proc. IEEE INFOCOM'10, San Diego, California, USA, March 14 - 19, 2010. 16/11/2018

Introduction: Challenging Issue (2) receiver-location privacy Source However, in order to protect receiver-location privacy, the receiver’s location is unknown, which could cause the existing packet forwarding protocol inefficient. 16/11/2018

Introduction: Challenging Issue (3) receiver-location privacy Source A Possible solution is flooding. However, the flooding technique will result in a large number of duplicate packets in the network. Very inefficient, esp. when the vehicle’s storage is constrained. 16/11/2018

Introduction: Challenging Issue (4) How to simultaneously protect the receiver-location privacy and improve the performance of packet delivery in VANET has become a new challenging issue. To the best our knowledge, this challenging issue has not be explored. Receiver-location privacy Performance of packet delivery (high delivery ratio & low average delay ) challenge 16/11/2018

Our Observation Privacy location sensitive socialspot Home non-sensitive Home Shopping mall School 16/11/2018

Our Solution Sacrificing the Plum Tree for the Peach Tree --- One of the Thirty-Six Strategies of Ancient China It means sacrificing something non-critical to ensure the overall interests. 16/11/2018

Our Solution (2) Sacrificing the Plum Tree for the Peach Tree Each vehicle reveals one socialspot, i.e., shopping mall, that he often visits. The socialspot is non-sensitive, since many vehicles also visit. The socialspot serves as as a stationary relay node (deployed with RSU), to help packet forwarding, at the same time, protect other sensitive location privacy. 16/11/2018

Our Solution (3) Trusted RSU Each vehicle’s trajectory contains at least one socialspot. TA grants each vehicle a large number of (pseudo-id, key) + one special pseudo-id ( ) ( ) 16/11/2018

Security Analysis The packet is encrypted, which can protect the receiver's identity-privacy. Session key is established between Vehicle and RSU to unlink the relation between packet and receiver Social spot serves as a mix server, protects the contextual privacy. Secure channel 16/11/2018

Simulation Results 16/11/2018

Conclusion In this talk, based on the “Sacrificing the Plum Tree for the Peach Tree” — one of the Thirty-Six Strategies of Ancient China, we introduced a socialspot tactic for protecting receiver-location privacy in VANET. In our future work, we are ready to evaluate the performance with the real-world tracing. Thank you! 16/11/2018