Caps

Abstract

Preserving location privacy in vehicular ad hoc networks (VANET) is an important requirement for public acceptance of this emerging technology. Many privacy schemes concern changing pseudonyms periodically to avoid linking messages. However, the spatiotemporal information contained in beacons makes vehicles traceable and the driver's privacy breached. Therefore, the pseudonym change should be performed in a mix-context to discontinue the spatial and temporal correlation of subsequent beacons. Such mixcontext is commonly accomplished by using a silence period or in predetermined locations (e.g., mix-zone). In this paper, we propose a location privacy scheme that lets vehicles decide when to change its pseudonym and enter a silence period and when to exit from it adaptively based on its context. In this scheme, a vehicle monitors the surrounding vehicles and enters silence when it finds one or more neighbors silent. It resumes beaconing with a new pseudonym when its actual state is likely to be mixed with the state of a silent neighbor. We evaluate this scheme against a global multi-target tracking adversary using simulated and realistic vehicle traces and compare it with the random silent period scheme. Furthermore, we evaluate the quality of service of a forward collision warning safety application to ensure its applicability in safety applications. We measure the quality of service by estimating the probability of correctly identifying the fundamental factors of that application using Monte Carlo analysis. CCS Concepts•Security and privacy → Pseudonymity, anonymity and untraceability; Privacy-preserving protocols; Usability in security and privacy;

SGO: Semantic Group Obfuscation for Location-Based Services in VANETS

“…A context-aware location privacy scheme based on a silent period is introduced in Ref. [ 26 ], which allows vehicles entering a silent period to change their pseudonym adaptively using context information such as finding silent neighboring vehicles. Another location unlinkability mechanism is presented in Ref.…”

Virtual Pseudonym-Changing and Dynamic Grouping Policy for Privacy Preservation in VANETs

“…The vehicle will change pseudonyms in silent mode to meet a certain traffic threshold; otherwise, it will wait for another cooperative silent period. A context-based scheme is introduced in [17] in which the vehicle entry and exit from a silent period is based on the number of neighboring vehicles and pseudonyms are changed cooperatively. Similarly, in [18], the vehicle waits for at least k silent neighbors before changing the pseudonym.…”

“…In Equation ( 18), the GH will prohibit a vehicle joining if it has invalid certificates or other credentials. If it has a valid certificate, the vehicle is allowed to join the group, as shown in Equation (17). In Equation ( 19) on joining the group, the GH will provide Group Identity (GID) to the vehicles.…”

“…Pseudonyms should be changed periodically to confuse an adversary about the actual vehicle communicating during a road network journey. To solve the problem of location privacy in existing literature, various pseudonym-changing schemes have been proposed that are based on the concept of a mix zone concept [12][13][14][15] and a silent period [16][17][18]. In the mix zone method, vehicles' identities are mixed in specific areas that may be a fixed zone at a road intersection or some congested area of vehicles.…”

Transmission Range Changing Effects on Location Privacy-Preserving Schemes in the Internet of Vehicles

“…Forfastreactionandlessdelay,BSMcontentisnotencryptedandsentatleastonce persecondwitharadiusofabout300meters (Corseretal.,2016).Thus,anyentity havingadedicatedeavesdroppingstationwouldhaveaccesstothedriver'slocation andthiswillbeexploitednexttogenerateuserprofiles (Wiedersheimetal.,2010) whichhasanegativeimpactontheIoVusers'locationprivacy.Oneofthesolutions istousepseudonymsinsteadofrealidentitieswhilebroadcastingtheseBSMsand furthermore,makingthemtemporalandchangeableovertime (Emaraetal.,2016). Also, a cross-layer identifier (like MAC and IP) change is needed (Schoch et al, 2006).However,ifthepseudonymchangewasnotdoneinanappropriatetimeand/ orspace,acorrelationattackmaybeperformedbytheadversarytolinkthenewand theoldpseudonym.Theaforementionedissuehadmotivatedtheresearchcommunity to investigate the problem and develop a lot of robust schemes like (Beresford & Stajano,2003;Sampigethayaetal.,2005;Huangetal.,2005;Freudigeretal.,2007;Butty´anetal.,2009;Eckhoffetal.,2011;Tomandletal.,2012;Luetal.,2012;Emara et al, 2015;Ullah et al, 2017;)(areshowninmoredetailsinSection2)towell-protecttheuser'slocationand identityprivacy.…”