{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/98375"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/98375","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Performance and security tradeoffs of provable website traffic fingerprinting defenses over Tor","abstract":"The Internet has become an integral part of modern life. At the same time, as we spend increasingly more time online, our digital trails, including the identities of the websites we visit, can reveal sensitive personal information. As a result, researchers have devised schemes that seek to enable users to obfuscate the network traffic fingerprints of the websites they visit; however, being ad hoc attempts, these schemes have all been later found to be ineffective against more sophisticated attacks. Thus, researchers have recently proposed a family of provable defenses called BuFLO, or Buffered Fixed-Length Obfuscator, that provides strong privacy guarantees at the expense of high overhead. Orthogonal to these defenses, the popular Tor anonymity network provides some protection against these attacks but is nonetheless susceptible. In this dissertation, we propose a simple design that uses BuFLO to protect web browsing traffic over Tor: tunnel the BuFLO channel through Tor. In order to evaluate the design, for both live experiments as well as large-scale simulations, we need precise models of the traffic profiles generated by a browser's visiting websites. This in turn requires us to obtain a fine-grained model of the web page loading process, two key components of which are the browser and the web page. After diving into the immensely complex web page loading process, we instrument the browser in order to extract bits of information as it loads a web page; this enables us to obtain the models for 50 top Alexa-ranked global websites. Following that, we build a traffic generator framework to generate network traffic according to the models. Next, we design and implement from scratch CS-Tamaraw, a congestion-sensitive version of Tamaraw, the most secure member of the BuFLO family. With all the pieces in hand, we perform live experiments to confirm that CS-Tamaraw provides the predicted gains in privacy as in the original study. However, when CS-Tamaraw is tunneled through Tor as we propose, its defense degrades significantly. We then conduct experiments to determine whether CS-Tamaraw is at fault. Both CS-Tamaraw and a simple, barebone, application-layer defense work largely as expected without Tor but are similarly afflicted when tunneled through Tor. Further investigations suggest that the unexpected results are due to artifacts in network conditions and not due to flaws in the design or implementation of CS-Tamaraw. We end after discussing the large-scale simulation studies with various levels of adoption of CS-Tamaraw.","abstract_html":"The Internet has become an integral part of modern life. At the same time, as we spend increasingly more time online, our digital trails, including the identities of the websites we visit, can reveal sensitive personal information. As a result, researchers have devised schemes that seek to enable users to obfuscate the network traffic fingerprints of the websites they visit; however, being ad hoc attempts, these schemes have all been later found to be ineffective against more sophisticated attacks. Thus, researchers have recently proposed a family of provable defenses called BuFLO, or Buffered Fixed-Length Obfuscator, that provides strong privacy guarantees at the expense of high overhead. Orthogonal to these defenses, the popular Tor anonymity network provides some protection against these attacks but is nonetheless susceptible. In this dissertation, we propose a simple design that uses BuFLO to protect web browsing traffic over Tor: tunnel the BuFLO channel through Tor. In order to evaluate the design, for both live experiments as well as large-scale simulations, we need precise models of the traffic profiles generated by a browser's visiting websites. This in turn requires us to obtain a fine-grained model of the web page loading process, two key components of which are the browser and the web page. After diving into the immensely complex web page loading process, we instrument the browser in order to extract bits of information as it loads a web page; this enables us to obtain the models for 50 top Alexa-ranked global websites. Following that, we build a traffic generator framework to generate network traffic according to the models. Next, we design and implement from scratch CS-Tamaraw, a congestion-sensitive version of Tamaraw, the most secure member of the BuFLO family. With all the pieces in hand, we perform live experiments to confirm that CS-Tamaraw provides the predicted gains in privacy as in the original study. However, when CS-Tamaraw is tunneled through Tor as we propose, its defense degrades significantly. We then conduct experiments to determine whether CS-Tamaraw is at fault. Both CS-Tamaraw and a simple, barebone, application-layer defense work largely as expected without Tor but are similarly afflicted when tunneled through Tor. Further investigations suggest that the unexpected results are due to artifacts in network conditions and not due to flaws in the design or implementation of CS-Tamaraw. We end after discussing the large-scale simulation studies with various levels of adoption of CS-Tamaraw.","abstract_has_math":false,"creators":["Nguyen, Giang Truong Khoa"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Computer Science","degree_department":null,"school":null,"contributors":["Johnson, Rob","Borisov, Nikita","Caesar, Matthew","Godfrey, Philip B."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-09-29T17:56:45Z","date_published":"2017-09-29T17:56:45Z","updated_at":"2026-07-22T22:24:35Z","subjects":["Website traffic fingerprinting","Provable website traffic fingerprinting","Tor","Web page modeling"],"languages":["en"],"rights":["Copyright 2017 Giang Nguyen"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/98375","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Johnson, Rob","Borisov, Nikita","Caesar, Matthew","Godfrey, Philip B."]},{"key":"dc:creator","label":"Author","values":["Nguyen, Giang Truong Khoa"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-09-29T17:56:45Z","2017-07-12","2017-08"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Computer Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Website traffic fingerprinting","Provable website traffic fingerprinting","Tor","Web page modeling"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Giang Nguyen"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/98375"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The Internet has become an integral part of modern life. At the same time, as we spend increasingly more time online, our digital trails, including the identities of the websites we visit, can reveal sensitive personal information. As a result, researchers have devised schemes that seek to enable users to obfuscate the network traffic fingerprints of the websites they visit; however, being ad hoc attempts, these schemes have all been later found to be ineffective against more sophisticated attacks. Thus, researchers have recently proposed a family of provable defenses called BuFLO, or Buffered Fixed-Length Obfuscator, that provides strong privacy guarantees at the expense of high overhead. Orthogonal to these defenses, the popular Tor anonymity network provides some protection against these attacks but is nonetheless susceptible. In this dissertation, we propose a simple design that uses BuFLO to protect web browsing traffic over Tor: tunnel the BuFLO channel through Tor. In order to evaluate the design, for both live experiments as well as large-scale simulations, we need precise models of the traffic profiles generated by a browser's visiting websites. This in turn requires us to obtain a fine-grained model of the web page loading process, two key components of which are the browser and the web page. After diving into the immensely complex web page loading process, we instrument the browser in order to extract bits of information as it loads a web page; this enables us to obtain the models for 50 top Alexa-ranked global websites. Following that, we build a traffic generator framework to generate network traffic according to the models. Next, we design and implement from scratch CS-Tamaraw, a congestion-sensitive version of Tamaraw, the most secure member of the BuFLO family. With all the pieces in hand, we perform live experiments to confirm that CS-Tamaraw provides the predicted gains in privacy as in the original study. However, when CS-Tamaraw is tunneled through Tor as we propose, its defense degrades significantly. We then conduct experiments to determine whether CS-Tamaraw is at fault. Both CS-Tamaraw and a simple, barebone, application-layer defense work largely as expected without Tor but are similarly afflicted when tunneled through Tor. Further investigations suggest that the unexpected results are due to artifacts in network conditions and not due to flaws in the design or implementation of CS-Tamaraw. We end after discussing the large-scale simulation studies with various levels of adoption of CS-Tamaraw.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-09-29 without embargo terms","The student, Giang Nguyen, accepted the attached license on 2017-07-12 at 15:18.","The student, Giang Nguyen, submitted this Dissertation for approval on 2017-07-12 at 15:44.","This Dissertation was approved for publication on 2017-07-12 at 17:10.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11416 on 2017-09-29 at 11:29:52","Made available in DSpace on 2017-09-29T17:56:45Z (GMT). No. of bitstreams: 3 NGUYEN-DISSERTATION-2017.pdf: 822672 bytes, checksum: 54eb2c45632229bc529e8f29576c1d29 (MD5) LICENSE.txt: 4209 bytes, checksum: 604a29f98e97aa3df04358895d8efc00 (MD5) PROQUEST_LICENSE.txt: 4555 bytes, checksum: e1293f779c5a64ac7bf1806f126209d8 (MD5) Previous issue date: 2017-07-12"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Performance and security tradeoffs of provable website traffic fingerprinting defenses over Tor"]}]}],"canonical_facts":{"dc:contributor":["Johnson, Rob","Borisov, Nikita","Caesar, Matthew","Godfrey, Philip B."],"dc:creator":["Nguyen, Giang Truong Khoa"],"dc:date":["2017-09-29T17:56:45Z","2017-07-12","2017-08"],"dc:description":["The Internet has become an integral part of modern life. At the same time, as we spend increasingly more time online, our digital trails, including the identities of the websites we visit, can reveal sensitive personal information. As a result, researchers have devised schemes that seek to enable users to obfuscate the network traffic fingerprints of the websites they visit; however, being ad hoc attempts, these schemes have all been later found to be ineffective against more sophisticated attacks. Thus, researchers have recently proposed a family of provable defenses called BuFLO, or Buffered Fixed-Length Obfuscator, that provides strong privacy guarantees at the expense of high overhead. Orthogonal to these defenses, the popular Tor anonymity network provides some protection against these attacks but is nonetheless susceptible. In this dissertation, we propose a simple design that uses BuFLO to protect web browsing traffic over Tor: tunnel the BuFLO channel through Tor. In order to evaluate the design, for both live experiments as well as large-scale simulations, we need precise models of the traffic profiles generated by a browser's visiting websites. This in turn requires us to obtain a fine-grained model of the web page loading process, two key components of which are the browser and the web page. After diving into the immensely complex web page loading process, we instrument the browser in order to extract bits of information as it loads a web page; this enables us to obtain the models for 50 top Alexa-ranked global websites. Following that, we build a traffic generator framework to generate network traffic according to the models. Next, we design and implement from scratch CS-Tamaraw, a congestion-sensitive version of Tamaraw, the most secure member of the BuFLO family. With all the pieces in hand, we perform live experiments to confirm that CS-Tamaraw provides the predicted gains in privacy as in the original study. However, when CS-Tamaraw is tunneled through Tor as we propose, its defense degrades significantly. We then conduct experiments to determine whether CS-Tamaraw is at fault. Both CS-Tamaraw and a simple, barebone, application-layer defense work largely as expected without Tor but are similarly afflicted when tunneled through Tor. Further investigations suggest that the unexpected results are due to artifacts in network conditions and not due to flaws in the design or implementation of CS-Tamaraw. We end after discussing the large-scale simulation studies with various levels of adoption of CS-Tamaraw.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-09-29 without embargo terms","The student, Giang Nguyen, accepted the attached license on 2017-07-12 at 15:18.","The student, Giang Nguyen, submitted this Dissertation for approval on 2017-07-12 at 15:44.","This Dissertation was approved for publication on 2017-07-12 at 17:10.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11416 on 2017-09-29 at 11:29:52","Made available in DSpace on 2017-09-29T17:56:45Z (GMT). No. of bitstreams: 3 NGUYEN-DISSERTATION-2017.pdf: 822672 bytes, checksum: 54eb2c45632229bc529e8f29576c1d29 (MD5) LICENSE.txt: 4209 bytes, checksum: 604a29f98e97aa3df04358895d8efc00 (MD5) PROQUEST_LICENSE.txt: 4555 bytes, checksum: e1293f779c5a64ac7bf1806f126209d8 (MD5) Previous issue date: 2017-07-12"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/98375"],"dc:language":["en"],"dc:rights":["Copyright 2017 Giang Nguyen"],"dc:subject":["Website traffic fingerprinting","Provable website traffic fingerprinting","Tor","Web page modeling"],"dc:title":["Performance and security tradeoffs of provable website traffic fingerprinting defenses over Tor"],"dc:type":["text"],"thesis:degree_discipline":["Computer Science"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:35Z"}