[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-503477-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-503477-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","the-new-casper-query-processing-for-location-services-without-compromising-privacy","The New Casper: Query Processing for Location Services - without Compromising Privacy","","A privacy-focused research paper addresses how current location-based services require continuous location reporting to a server, exposing users to threats when servers are untrusted. It proposes Casper, a framework enabling mobile and stationary users to use location-based services while protecting their location information. Casper combines a location anonymizer that blurs exact locations into cloaked regions and a privacy-aware query processor that operates on these regions. Experiments indicate high-quality service with anonymity for both data and queries.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/research-report/","Research & Report",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/the-new-casper-query-processing-for-location-services-without-compromising-privacy/503477/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/the-new-casper-query-processing-for-location-services-without-compromising-privacy/503477.png","ImageObject",300,407,{"name":42,"@type":43},"Ivy","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-11","2026-10-03",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",6,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What privacy problem does the paper focus on in location-based services?","Question",{"text":63,"@type":64},"Current location-based services often require users to continuously report exact locations to the server, which can lead to privacy threats when the server is untrusted.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"How does Casper protect users’ location information?",{"text":68,"@type":64},"Casper uses a location anonymizer to blur exact locations into cloaked spatial regions based on user-specified privacy requirements.",{"name":70,"@type":61,"acceptedAnswer":71},"What is the role of the privacy-aware query processor in Casper?",{"text":72,"@type":64},"The privacy-aware query processor is embedded in the location-based database server and evaluates queries using cloaked spatial areas rather than exact locations, supporting anonymity for both data and queries.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},503477,1791363660,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,101,105,110,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":97,"doc_module":4,"doc_module_name":25,"category_name":98,"show_sort_weight":99,"slug":100},5,"Comic",60,"comic",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":102,"show_sort_weight":103,"slug":104},"Technology",50,"technology",{"id":106,"doc_module":4,"doc_module_name":25,"category_name":107,"show_sort_weight":108,"slug":109},7,"Healthcare",40,"healthcare",{"id":111,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":112,"slug":113},8,30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":97,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":111,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":139,"language":140,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":12,"update_tm":144,"read_time":112},549758252649,"https://ap-avatar.wpscdn.com/avatar/8000253669c5317157?_k=1778319167496531819","The New Casper: Query Processing for Location Services  \nwithout Compromising Privacy ∗  \nMohamed F. Mokbel1 Chi-Yin Chow1 Walid G. Aref2  \n1 Department of Computer Science and Engineering, University of Minnesota, Minneapolis, MN  \n2 Department of Computer Science, Purdue University, West Lafayette, IN  \nABSTRACT  \nThis paper tackles a major privacy concern in current location-based services where users have to continuously report their locations to the database server in order to obtain the service. For example, a user asking about the nearest gas station has to report her exact location. With untrusted servers, reporting the location information may lead to several privacy threats. In this paper, we present Casper1 ; anew framework in which mobile and stationary users can entertain location-based services without revealing their location information. Casper consists of two main components, the location anonymizer and the privacy-aware query processor. The location anonymizer blurs the users’ exact location information into cloaked spatial regions based on userspeci􀀌ed privacy requirements. The privacy-aware query processor is embedded inside the location-based database server in order to deal with the cloaked spatial areas rather than the exact location information. Experimental results show that Casper achieves high quality location-based services while providing anonymity for both data and queries.  \n1. INTRODUCTION  \nThe explosive growth of location-detection devices (e.g. , cellular phones, GPS-like devices, and RFIDs) results ina wide spread of location-based applications. Examples of these applications include location-based store 􀀌nders (“Where is my nearest restaurant”), tra􀀎c reports (“Let me know if there is congestion within ten minutes of my route”), and location-based advertisements (“Send e-coupons to all cars that are within two miles of my gas station”) . Registered users with location-based services continuously send  \n∗ Mohamed Mokbel’s research is supported by the Grantsin-Aid, University of Minnesota. Walid Aref’s research is supported in part by the National Science Foundation under Grants IIS-0093116 and IIS-0209120 .  \n1 Casper, the friendly ghost, is a 1960’s cartoon character fora friendly ghost that can hide its location and help people.([http://www.toontracker.com/casper/newcaspr.htm](http://www.toontracker.com/casper/newcaspr.htm)).  \nPermission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Very Large Data Base Endowment. To copy otherwise, or to republish, to post on servers or to redistribute to lists, requires a fee and/or special permission from the publisher, ACM.  \nVLDB ‘06, September 12-15, 2006, Seoul, Korea.  \nCopyright 2006 VLDB Endowment, ACM 1-59593-385-9/06/09 .  \ntheir location information to the location-based database server. Upon requesting a service, a registered user has to issue a location-based query that is executed at the server based on the knowledge of the user location [24, 33, 36, 45] .  \nAlthough location-based applications along with the location-based query processing promise safety and convenience, they threaten the privacy and security of their customers. The location-based query processor relies mainly on the implicit assumption that users agree to reveal their private locations. In order to get a location-based service, a user has to report her location. In other words, a user trades her privacy with the service. If a user wants to keep her private location information, she has to turn-o􀀋 her locationaware device and (temporarily) unsubscribe from the service. With untrustworthy servers, such model provides several privacy threats. For example, an employer may check on her employee behavior by knowing the places she visitsand the ","cbCaieLHP4TEL2NB","https://ap.wps.com/l/cbCaieLHP4TEL2NB","pdf",571349,12,"English","# Abstract\n# Introduction","[{\"question\":\"What privacy problem does the paper focus on in location-based services?\",\"answer\":\"Current location-based services often require users to continuously report exact locations to the server, which can lead to privacy threats when the server is untrusted.\"},{\"question\":\"How does Casper protect users’ location information?\",\"answer\":\"Casper uses a location anonymizer to blur exact locations into cloaked spatial regions based on user-specified privacy requirements.\"},{\"question\":\"What is the role of the privacy-aware query processor in Casper?\",\"answer\":\"The privacy-aware query processor is embedded in the location-based database server and evaluates queries using cloaked spatial areas rather than exact locations, supporting anonymity for both data and queries.\"}]","The New Casper: Query Processing for Location Services - without Compromising Privacy | PDF",1791056907]