{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,1]],"date-time":"2025-11-01T13:53:46Z","timestamp":1762005226162,"version":"build-2065373602"},"reference-count":40,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2020,8,18]],"date-time":"2020-08-18T00:00:00Z","timestamp":1597708800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61502044"],"award-info":[{"award-number":["61502044"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Location-Based Services (LBSs) are playing an increasingly important role in people\u2019s daily activities nowadays. While enjoying the convenience provided by LBSs, users may lose privacy since they report their personal information to the untrusted LBS server. Although many approaches have been proposed to preserve users\u2019 privacy, most of them just focus on the user\u2019s location privacy, but do not consider the query privacy. Moreover, many existing approaches rely heavily on a trusted third-party (TTP) server, which may suffer from a single point of failure. To solve the problems above, in this paper we propose a Cache-Based Privacy-Preserving (CBPP) solution for users in LBSs. Different from the previous approaches, the proposed CBPP solution protects location privacy and query privacy simultaneously, while avoiding the problem of TTP server by having users collaborating with each other in a mobile peer-to-peer (P2P) environment. In the CBPP solution, each user keeps a buffer in his mobile device (e.g., smartphone) to record service data and acts as a micro TTP server. When a user needs LBSs, he sends a query to his neighbors first to seek for an answer. The user only contacts the LBS server when he cannot obtain the required service data from his neighbors. In this way, the user reduces the number of queries sent to the LBS server. We argue that the fewer queries are submitted to the LBS server, the less the user\u2019s privacy is exposed. To users who have to send live queries to the LBS server, we employ the l-diversity, a powerful privacy protection definition that can guarantee the user\u2019s privacy against attackers using background knowledge, to further protect their privacy. Evaluation results show that the proposed CBPP solution can effectively protect users\u2019 location and query privacy with a lower communication cost and better quality of service.<\/jats:p>","DOI":"10.3390\/s20164651","type":"journal-article","created":{"date-parts":[[2020,8,18]],"date-time":"2020-08-18T11:15:27Z","timestamp":1597749327000},"page":"4651","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Cache-Based Privacy Preserving Solution for Location and Content Protection in Location-Based Services"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3843-6673","authenticated-orcid":false,"given":"Yuanbo","family":"Cui","sequence":"first","affiliation":[{"name":"State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fei","family":"Gao","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenmin","family":"Li","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yijie","family":"Shi","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hua","family":"Zhang","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiaoyan","family":"Wen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Emmanouil","family":"Panaousis","sequence":"additional","affiliation":[{"name":"School of Computing and Mathematical Sciences, University of Greenwich, London SE10 9LS, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Niu, B., Zhang, Z., Li, X., and Li, H. (2014, January 10\u201314). Privacy-area aware dummy generation algorithms for location-based services. Proceedings of the 2014 IEEE International Conference on Communications (ICC), Sydney, Australia.","DOI":"10.1109\/ICC.2014.6883443"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Niu, B., Zhu, X., Li, W., Li, H., Wang, Y., and Lu, Z. (2015, January 16\u201319). A personalized two-tier cloaking scheme for privacy-aware location-based services. Proceedings of the 2015 International Conference on Computing, Networking and Communications (ICNC), Anaheim, CA, USA.","DOI":"10.1109\/ICCNC.2015.7069322"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.jnca.2019.02.018","article-title":"Security and privacy preservation in fog-based crowd sensing on the internet of vehicles","volume":"134","author":"Sun","year":"2019","journal-title":"J. Netw. Comput. Appl."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"616","DOI":"10.1016\/j.ins.2019.01.008","article-title":"Towards privacy preservation for \u201ccheck-in\u201d services in location-based social networks","volume":"481","author":"Sun","year":"2019","journal-title":"Inform. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1016\/j.future.2016.08.023","article-title":"L2P2: A location-label based approach for privacy preserving in LBS","volume":"74","author":"Sun","year":"2016","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/j.jnca.2016.10.011","article-title":"Efficient Location Privacy Algorithm for Internet of Things (IoT) Services and Applications","volume":"89","author":"Sun","year":"2016","journal-title":"J. Netw. Comput. Appl."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.jnca.2016.11.024","article-title":"User-Defined Privacy Location-Sharing System in Mobile Online Social Networks","volume":"86","author":"Sun","year":"2016","journal-title":"J. Netw. Comput. Appl."},{"key":"ref_8","first-page":"S0167739X17312384","article-title":"Enhancing privacy through uniform grid and caching in location-based services","volume":"86","author":"Zhang","year":"2017","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.future.2018.10.053","article-title":"A caching and spatial K-anonymity driven privacy enhancement scheme in continuous location-based services","volume":"94","author":"Zhang","year":"2019","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"6121","DOI":"10.1007\/s00500-017-2676-6","article-title":"A trajectory privacy-preserving scheme based on query exchange in mobile social networks","volume":"22","author":"Zhang","year":"2018","journal-title":"Soft Comput."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Gruteser, M., and Grunwald, D. (2003, January 5\u20138). Anonymous usage of location-based services through spatial and temporal cloaking. Proceedings of the 1st international conference on Mobile systems, applications and services, San Francisco, CA, USA.","DOI":"10.1145\/1066116.1189037"},{"key":"ref_12","unstructured":"Kido, H., Yanagisawa, Y., and Satoh, T. (2005, January 11\u201314). An anonymous communication technique using dummies for location-based services. Proceedings of the International Conference on Pervasive Services (ICPS\u201905), Santorini, Greece."},{"key":"ref_13","unstructured":"Mokbel, M.F., Chow, C.Y., and Aref, W.G. (2006, January 12\u201315). The new Casper: Query processing for location services without compromising privacy. Proceedings of the 32nd international conference on Very large data bases, Seoul, Korea."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TMC.2007.1062","article-title":"Protecting location privacy with personalized k-anonymity: Architecture and algorithms","volume":"7","author":"Gedik","year":"2008","journal-title":"IEEE Trans. Mob. Comput."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Chow, C.Y., Mokbel, M.F., and Liu, X. (2006, January 10\u201311). A peer-to-peer spatial cloaking algorithm for anonymous location-based service. Proceedings of the ACM International Symposium on Advances in Geographic Information Systems, Arlington, VA, USA.","DOI":"10.1145\/1183471.1183500"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Hu, H., and Xu, J. (April, January 29). Non-exposure location anonymity. Proceedings of the 2009 IEEE 25th International Conference on Data Engineering, Shanghai, China.","DOI":"10.1109\/ICDE.2009.106"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1007\/s10707-009-0099-y","article-title":"Spatial cloaking for anonymous location-based services in mobile peer-to-peer environments","volume":"15","author":"Chow","year":"2011","journal-title":"GeoInformatica"},{"key":"ref_18","unstructured":"Man, L.Y., Jensen, C.S., Huang, X., and Lu, H. (2008, January 21\u201324). SpaceTwist: Managing the Trade-Offs Among Location Privacy, Query Performance, and Query Accuracy in Mobile Services. Proceedings of the IEEE International Conference on Data Engineering, Vancouver, BC, Canada."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Lu, H., Jensen, C.S., and Man, L.Y. (2008, January 13). PAD: Privacy-area aware, dummy-based location privacy in mobile services. Proceedings of the ACM International Workshop on Data Engineering for Wireless and Mobile Access, Mobide 2008, Vancouver, BC, Canada.","DOI":"10.1145\/1626536.1626540"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Niu, B., Li, Q., Zhu, X., Cao, G., and Li, H. (May, January 27). Achieving k-anonymity in privacy-aware location-based services. Proceedings of the IEEE INFOCOM 2014-IEEE Conference on Computer Communications, Vancouver, BC, Canada.","DOI":"10.1109\/INFOCOM.2014.6848002"},{"key":"ref_21","unstructured":"Zhu, X., Chi, H., Niu, B., Zhang, W., Li, Z., and Li, H. (2014, January 8\u201312). MobiCache: When k-anonymity meets cache. Proceedings of the Global Communications Conference, Austin, TX, USA."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1109\/TDSC.2013.57","article-title":"Hiding in the Mobile Crowd: Location Privacy through Collaboration","volume":"11","author":"Shokri","year":"2014","journal-title":"IEEE Trans. Dependable Secur. Comput."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Niu, B., Li, Q., Zhu, X., and Li, H. (2014, January 4\u20137). A fine-grained spatial cloaking scheme for privacy-aware users in Location-Based Services. Proceedings of the International Conference on Computer Communication and Networks, Shanghai, China.","DOI":"10.1109\/ICCCN.2014.6911813"},{"key":"ref_24","first-page":"1710","article-title":"Protection of query privacy for continuous location based services","volume":"8","author":"Pingley","year":"2011","journal-title":"Proc. IEEE INFOCOM"},{"key":"ref_25","unstructured":"Peng, T., Liu, Q., and Wang, G. (2014). Enhanced Location Privacy Preserving Scheme in Location-Based Services. IEEE Syst. J., 1\u201312."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Peng, T., Liu, Q., Wang, G., and Xiang, Y. (2016). Privacy Preserving Scheme for Location and Content Protection in Location-Based Services, Springer International Publishing.","DOI":"10.1007\/978-3-319-49148-6_3"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Qiu, Y., Liu, Y., Li, X., and Chen, J. (2020). A Novel Location Privacy-Preserving Approach Based on Blockchain. Sensors, 20.","DOI":"10.3390\/s20123519"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"36155","DOI":"10.1109\/ACCESS.2018.2847314","article-title":"Falcon: Fused Application of Light based positioning Coupled with Onboard Network localization","volume":"6","author":"Daniel","year":"2018","journal-title":"IEEE Access"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Amoretti, M., Brambilla, G., Medioli, F., and Zanichelli, F. (2018, January 16\u201320). Blockchain-Based Proof of Location. Proceedings of the 2018 IEEE International Conference on Software Quality, Reliability and Security Companion (QRS-C), Lisbon, Portugal.","DOI":"10.1109\/QRS-C.2018.00038"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Saia, R., Carta, S., Reforgiato Recupero, D., and Fenu, G. (2018). Internet of Entities (IoE): A Blockchain-based Distributed Paradigm for Data Exchange Between Wireless-based Devices. arXiv.","DOI":"10.5220\/0007379600770084"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1016\/j.ins.2019.05.054","article-title":"A Trajectory Privacy-preserving Scheme Based on a Dual-K Mechanism for Continuous Location-based Services","volume":"527","author":"Zhang","year":"2019","journal-title":"Inf. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Habibzadeh, H., Nussbaum, B.H., Anjomshoa, F., Kantarci, B., and Soyata, T. (2019). A survey on cybersecurity, data privacy, and policy issues in cyber-physical system deployments in smart cities. Sustain. Cities Soc., 50.","DOI":"10.1016\/j.scs.2019.101660"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"567","DOI":"10.1016\/j.ins.2018.02.005","article-title":"Privacy-preserving smart IoT-based healthcare big data storage and self-adaptive access control system","volume":"479","author":"Yang","year":"2019","journal-title":"Inf. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1267","DOI":"10.1016\/j.future.2018.04.019","article-title":"Design and analysis of authenticated key agreement scheme in cloud-assisted cyber\u2013physical systems","volume":"108","author":"Challa","year":"2020","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1145\/1217299.1217302","article-title":"L-diversity:Privacy beyond k-anonymity","volume":"1","author":"Machanavajjhala","year":"2007","journal-title":"Acm Trans. Knowl. Discov. Data"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Amini, S., Lindqvist, J., Hong, J.I., Lin, J., Toch, E., and Sadeh, N.M. (2010, January 17\u201321). Cach: Caching location-enhanced content to improve user privacy. Proceedings of the International Conference on Mobile Systems, Seoul, Korea.","DOI":"10.1145\/1999995.2000015"},{"key":"ref_37","unstructured":"Stewart, R.R., and Xie, Q. (2001). Stream Control Transmission Protocol (SCTP):A Reference Guide: A Reference Guide, Addison-Wesley Longman Publishing Co., Inc."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Chow, C.Y., Leong, H., and Chan, A. (2005, January 9\u201313). Distributed group-based cooperative caching in a mobile broadcast environment. Proceedings of the 6th International Conference on Mobile Data Management (MDM 2005), Ayia Napa, Cyprus.","DOI":"10.1145\/1071246.1071261"},{"key":"ref_39","unstructured":"Zimmermann, R., Wang, H., and Nguyen, T. (2006, January 10\u201312). ANNATTO: Adaptive nearest neighbor queries in travel time networks. Proceedings of the 7th International Conference on Mobile Data Management (MDM\u201906), Nara, Japan."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Papadopouli, M., and Schulzrinne, H. (2001, January 4\u20135). Effects of power conservation, wireless coverage and cooperation on data dissemination among mobile devices. Proceedings of the Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc01), Long Beach, CA, USA.","DOI":"10.1145\/501431.501433"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/16\/4651\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:02:40Z","timestamp":1760176960000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/16\/4651"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,8,18]]},"references-count":40,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2020,8]]}},"alternative-id":["s20164651"],"URL":"https:\/\/doi.org\/10.3390\/s20164651","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2020,8,18]]}}}