SoK: Making Sense of Censorship Resistance Systems

Open access

Abstract

An increasing number of countries implement Internet censorship at different scales and for a variety of reasons. Several censorship resistance systems (CRSs) have emerged to help bypass such blocks. The diversity of the censor’s attack landscape has led to an arms race, leading to a dramatic speed of evolution of CRSs. The inherent complexity of CRSs and the breadth of work in this area makes it hard to contextualize the censor’s capabilities and censorship resistance strategies. To address these challenges, we conducted a comprehensive survey of CRSs-deployed tools as well as those discussed in academic literature-to systematize censorship resistance systems by their threat model and corresponding defenses. To this end, we first sketch a comprehensive attack model to set out the censor’s capabilities, coupled with discussion on the scope of censorship, and the dynamics that influence the censor’s decision. Next, we present an evaluation framework to systematize censorship resistance systems by their security, privacy, performance and deployability properties, and show how these systems map to the attack model. We do this for each of the functional phases that we identify for censorship resistance systems: communication establishment, which involves distribution and retrieval of information necessary for a client to join the censorship resistance system; and conversation, where actual exchange of information takes place. Our evaluation leads us to identify gaps in the literature, question the assumptions at play, and explore possible mitigations.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • [1] R. M. Bond C. J. Fariss J. J. Jones A. D. Kramer C. Marlow J. E. Settle and J. H. Fowler “A 61-Million-Person Experiment in Social Influence and Political Mobilization” Nature vol. 489 no. 7415 pp. 295-298 2012.

  • [2] N. Eltantawy and J. Wiest “The Arab Spring | Social Media in the Egyptian Revolution: Reconsidering Resource Mobilization Theory” International Journal of Communication vol. 5 no. 0 2011.

  • [3] Freedom House “Freedom in the World 2016.” https://freedomhouse.org/report/freedom-world/freedom-world-2016 2016.

  • [4] T. Elahi C. M. Swanson and I. Goldberg “Slipping Past the Cordon: A Systematization of Internet Censorship Resistance.” CACR Tech Report 2015-10 Aug. 2015.

  • [5] S. Khattak L. Simon and S. J. Murdoch “Systemization of Pluggable Transports for Censorship Resistance.” http://arxiv.org/pdf/1412.7448v1.pdf 2014.

  • [6] M. C. Tschantz S. Afroz D. Fifield and V. Paxson “SoK: Towards Grounding Censorship Circumvention in Empiricism” in Proceedings of the IEEE Symposium on Security and Privacy 2016.

  • [7] R. Clayton “Failures in a Hybrid Content Blocking System” in Privacy Enhancing Technologies (Cambridge England) pp. 78-92 Springer 2006.

  • [8] l7-filter “http://research.dyn.com/2013/08/myanmarinternet/.”

  • [9] Bro “https://www.bro.org.”

  • [10] Snort “https://www.snort.org.”

  • [11] nDPI “http://www.ntop.org/products/ndpi/.”

  • [12] A. Dainotti A. Pescape and K. Claffy “Issues and Future Directions in Traffic Classification” IEEE Network vol. 26 pp. 35-40 Jan 2012.

  • [13] R. Sommer and V. Paxson “Outside the Closed World: On Using Machine Learning For Network Intrusion Detection” in In Proceedings of the IEEE Symposium on Security and Privacy 2010.

  • [14] P. Dorfinger G. Panholzer and W. John “Entropy Estimation for Real-Time Encrypted Traffic Identification” in Traffic Monitoring and Analysis vol. 6613 of Lecture Notes in Computer Science pp. 164-171 Springer Berlin Heidelberg 2011.

  • [15] L. Bernaille and R. Teixeira “Early Recognition of Encrypted Applications” in Proceedings of the 8th International Conference on Passive and Active Network Measurement PAM’07 (Berlin Heidelberg) pp. 165-175 Springer- Verlag 2007.

  • [16] C. V. Wright F. Monrose and G. M. Masson “On Inferring Application Protocol Behaviors in Encrypted Network Traffic” J. Mach. Learn. Res. vol. 7 pp. 2745-2769 Dec. 2006.

  • [17] B. Wiley “Blocking-Resistant Protocol Classification Using Bayesian Model Selection” tech. rep. University of Texas at Austin 2011.

  • [18] B. Wiley “Dust: A Blocking-Resistant Internet Transport Protocol” tech. rep. School of Information University of Texas at Austin 2011.

  • [19] B. Leidl “obfuscated-openssh.”

  • https://github.com/brl/obfuscatedopenssh/blob/master/README.obfuscation 2009.

  • [20] A. Panchenko L. Niessen A. Zinnen and T. Engel “Website Fingerprinting in Onion Routing Based Anonymization Networks” in Proceedings of the Workshop on Privacy in the Electronic Society (WPES) ACM Oct. 2011.

  • [21] Q. Sun D. R. Simon Y.-M. Wang W. Russell V. N. Padmanabhan and L. Qiu “Statistical Identification of Encrypted Web Browsing Traffic” in Proceedings of the IEEE Symposium on Security and Privacy May 2002.

  • [22] A. Hintz “Fingerprinting Websites Using Traffic Analysis” in Proceedings of Privacy Enhancing Technologies workshop (PET) Springer-Verlag LNCS 2482 Apr. 2002.

  • [23] G. D. Bissias M. Liberatore and B. N. Levine “Privacy Vulnerabilities in Encrypted HTTP Streams” in Proceedings of Privacy Enhancing Technologies workshop (PET) pp. 1-11 May 2005.

  • [24] T. Wilde “Great Firewall Tor Probing.” https://gist.github.com/da3c7a9af01d74cd7de7 Nov. 2015.

  • [25] ONI “China’s Green Dam: The Implications of Government Control Encroaching on the Home PC.” https://opennet.net/chinas-green-dam-the-implicationsgovernment-control-encroaching-home-pc.

  • [26] J. Knockel J. R. Crandall and J. Saia “Three Researchers Five Conjectures: An Empirical Analysis of TOM-Skype Censorship and Surveillance” in Free and Open Communications on the Internet (San Francisco CA USA) USENIX 2011.

  • [27] T. Elahi K. Bauer M. AlSabah R. Dingledine and I. Goldberg “Changing of the Guards: A Framework for Understanding and Improving Entry Guard Selection in Tor” in Proceedings of the ACM Workshop on Privacy in the Electronic Society pp. 43-54 ACM 2012.

  • [28] A. Biryukov I. Pustogarov and R.-P. Weinmann “Trawling for Tor Hidden Services: Detection Measurement Deanonymization” in Proceedings of the IEEE Symposium on Security and Privacy May 2013.

  • [29] A. Johnson C. Wacek R. Jansen M. Sherr and P. Syverson “Users Get Routed: Traffic Correlation on Tor by Realistic Adversaries” in Proceedings of the 20th ACM conference on Computer and Communications Security Nov. 2013.

  • [30] R. Dingledine N. Hopper G. Kadianakis and N. Mathewson “One Fast Guard for Life (or 9 Months)” in 7th Workshop on Hot Topics in Privacy Enhancing Technologies 2014.

  • [31] T. Zhu D. Phipps A. Pridgen J. R. Crandall and D. S. Wallach “The Velocity of Censorship: High-Fidelity Detection of Microblog Post Deletions” in Proceedings of the 22nd USENIX Security Symposium USENIX 2013.

  • [32] R. Rife “Opinion: The Chilling Reality of China’s Cyberwar on Free Speech.” CNN (U.S. Edition) http://www.cnn.com/2015/03/24/opinions/china-internet-dissent-roseann-rife/ Mar. 2015.

  • [33] D. Bamman and B. O’Connor and N. Smith “Censorship and deletion practices in Chinese social media.” http://journals.uic.edu/ojs/index.php/fm/article/view/3943/3169 Nov. 2015.

  • [34] T. Zhu D. Phipps A. Pridgen J. R. Crandall and D. S. Wallach “The Velocity of Censorship: High-fidelity Detection of Microblog Post Deletions” in Proceedings of the 22Nd USENIX Conference on Security (Berkeley CA USA) pp. 227-240 USENIX Association 2013.

  • [35] Journalism and Media Studies Centre “Weiboscope.” http://weiboscope.jmsc.hku.hk Nov. 2015.

  • [36] K. Fisher “The Death of SuprNova.org.” Ars Technica http://arstechnica.com/staff/2005/12/2153/ Dec. 2005.

  • [37] D. Goodin “Massive denial-of-service attack on GitHub tied to Chinese government.” Ars Technica http://arstechnica.com/security/2015/03/massive-denial-of-service-attack-ongithub-tied-to-chinese-government/ Mar. 2015.

  • [38] C. Anderson “Dimming the Internet: Detecting Throttling as a Mechanism of Censorship in Iran” tech. rep. University of Pennsylvania 2013.

  • [39] “HTTP URL/keyword detection in depth.” http://gfwrev.blogspot.jp/2010/03/http-url.html 2010.

  • [40] P. Winter and S. Lindskog “How the Great Firewall of China is Blocking Tor” in Free and Open Communications on the Internet (Bellevue WA USA) USENIX 2012.

  • [41] Renesys “http://research.dyn.com/2011/01/egypt-leavesthe-internet/” Jan. 2011.

  • [42] Renesys “http://research.dyn.com/2011/08/the-battle-fortripolis-intern/” Aug. 2011.

  • [43] Renesys “http://research.dyn.com/2013/09/internetblackout-sudan/” Sep. 2013.

  • [44] Renesys “http://research.dyn.com/2013/08/myanmarinternet/” Aug. 2013.

  • [45] Anonymous “The Collateral Damage of Internet Censorship by DNS Injection” SIGCOMM Comput. Commun. Rev. vol. 42 pp. 21-27 June 2012.

  • [46] R. Dingledine N. Mathewson and P. Syverson “Tor: The Second-Generation Onion Router” in Proceedings of the 13th USENIX Security Symposium Aug. 2004.

  • [47] P. Winter T. Pulls and J. Fuss “ScrambleSuit: A Polymorphic Network Protocol to Circumvent Censorship” in Proceedings of the Workshop on Privacy in the Electronic Society ACM Nov. 2013.

  • [48] M. C. Tschantz S. Afroz V. Paxson and J. D. Tygar “On Modeling the Costs of Censorship.” arXiv preprint http://arxiv.org/pdf/1409.3211v1.pdf 2014.

  • [49] D. Fifield N. Hardison J. Ellithorpe E. Stark R. Dingledine P. Porras and D. Boneh “Evading Censorship with Browser-Based Proxies” in Privacy Enhancing Technologies Symposium (Vigo Spain) pp. 239-258 Springer 2012.

  • [50] P. Lincoln I. Mason P. Porras V. Yegneswaran Z. Weinberg J. Massar W. A. Simpson P. Vixie and D. Boneh “Bootstrapping Communications into an Anti-Censorship System” in Proceedings of the USENIX Workshop on Free and Open Communications on the Internet Aug. 2012.

  • [51] The Tor Project “Tor Bridges Specification.” https://gitweb.torproject.org/torspec.git/tree/attic/bridges-spec.txt May 2009.

  • [52] N. Feamster M. Balazinska W. Wang H. Balakrishnan and D. Karger “Thwarting web censorship with untrusted messenger discovery” in Privacy Enhancing Technologies pp. 125-140 Springer 2003.

  • [53] E. Y. Vasserman N. Hopper and J. Tyra “Silent knock : practical provably undetectable authentication.” Int. J. Inf. Sec. vol. 8 no. 2 pp. 121-135 2009.

  • [54] D. McCoy J. A. Morales and K. Levchenko “Proximax: A Measurement Based System for Proxies Dissemination” Financial Cryptography and Data Security vol. 5 no. 9 p. 10 2011.

  • [55] B. Laurie and R. Clayton “Proof-of-Work Proves Not to Work” in In Third Annual Workshop on Economics and Information Security (WEIS) (Minneapolis MN) May 2004.

  • [56] R. Dingledine and N. Mathewson “Tor Directory Protocol Version 3.” https://gitweb.torproject.org/torspec.git/tree/dirspec.txt Jan. 2006.

  • [57] H. Mohajeri Moghaddam B. Li M. Derakhshani and I. Goldberg “SkypeMorph: Protocol Obfuscation for Tor Bridges” in Proceedings of the 19th ACM conference on Computer and Communications Security Oct. 2012.

  • [58] A. Houmansadr T. Riedl N. Borisov and A. Singer “IP over Voice-over-IP for Censorship Circumvention.” arXiv preprint https://arxiv.org/pdf/1207.2683v2.pdf 2012.

  • [59] S. Burnett N. Feamster and S. Vempala “Chipping Away at Censorship Firewalls with User-Generated Content” in Proceedings of the 19th USENIX Security Symposium 2010.

  • [60] S. Khattak M. Javed P. D. Anderson and V. Paxson “Towards Illuminating a Censorship Monitor’s Model to Facilitate Evasion” in Free and Open Communications on the Internet (Washington DC USA) USENIX 2013.

  • [61] A. Houmansadr G. T. K. Nguyen M. Caesar and N. Borisov “Cirripede: Circumvention Infrastructure using Router Redirection with Plausible Deniability” in Proceedings of the 18th ACM conference on Computer and Communications Security Oct. 2011.

  • [62] I. Clarke O. Sandberg B. Wiley and T. W. Hong “Freenet: A Distributed Anonymous Information Storage and Retrieval System” in Proceedings of Designing Privacy Enhancing Technologies: Workshop on Design Issues in Anonymity and Unobservability pp. 46-66 Jul. 2000.

  • [63] M. Waldman and D. Mazières “Tangler: A Censorship- Resistant Publishing System based on Document Entanglements” in Proceedings of the 8th ACM Conference on Computer and Communications Security pp. 126-135 Nov. 2001.

  • [64] J. Geddes M. Schuchard and N. Hopper “Cover Your ACKs: Pitfalls of Covert Channel Censorship Circumvention” in Proceedings of the 20th ACM conference on Computer and Communications Security 2013.

  • [65] A. Houmansadr C. Brubaker and V. Shmatikov “The Parrot is Dead: Observing Unobservable Network Communication” in Proceedings of the 2013 IEEE Symposium on Security and Privacy May 2013.

  • [66] S. Li M. Schliep and N. Hopper “Facet: Streaming over Videoconferencing for Censorship Circumvention” in Proceedings of the Workshop on Privacy in the Electronic Society Nov. 2014.

  • [67] Y. Torbati “Iranians Face New Internet Curbs Before Presidential Election.” Reuters http://www.reuters.com/article/2013/05/21/net-us-iran-election-internetidUSBRE94K0ID20130521 May 2013.

  • [68] M. Schuchard J. Geddes C. Thompson and N. Hopper “Routing Around Decoys” in Computer and Communications Security ACM 2012.

  • [69] P. Vines and T. Kohno “Rook: Using Video Games as a Low-Bandwidth Censorship Resistant Communication Platform.” http://homes.cs.washington.edu/~yoshi/papers/techreport-rook.pdf 2015.

  • [70] B. Hahn R. Nithyanand P. Gill and R. Johnson “Games Without Frontiers: Investigating Video Games as a Covert Channel.” arXiv preprint http://arxiv.org/pdf/1503.05904v2.pdf 2015.

  • [71] T. Elahi J. A. Doucette H. Hosseini S. J. Murdoch and I. Goldberg “A Framework for the Game-theoretic Analysis of Censorship Resistance” Proceedings on Privacy Enhancing Technologies vol. 2016 no. 4 2016.

  • [72] The Tor Project “Pluggable Transports.” https://www.torproject.org/docs/pluggable-transports.html.en Jan. 2012.

  • [73] ifinity0 “Composing Pluggable Transports.” Pseudonymously https://github.com/infinity0/tor-//notes/blob/master/pt-compose.rst Oct. 2013.

  • [74] ifinity0 “Complete Specification for Generalised PT Composition.” Pseudonymously https://trac.torproject.org/projects/tor/ticket/10061 Oct. 2013.

  • [75] J. Massar I. Mason L. Briesemeister and V. Yegneswaran “JumpBox-A Seamless Browser Proxy for Tor Pluggable Transports” Security and Privacy in Communication Networks. Springer p. 116 2014.

  • [76] D. Luchaup K. P. Dyer S. Jha T. Ristenpart and T. Shrimpton “LibFTE: A Toolkit for Constructing Practical Format- Abiding Encryption Schemes” in USENIX Security Symposium USENIX 2014.

  • [77] D. Fifield “meek.” Tor Blog https://trac.torproject.org/projects/tor/wiki/doc/meek Jan. 2014.

  • [78] Psiphon Inc. “Psiphon.” https://psiphon.ca/en/index.html.

  • [79] The Tor Project “Fog.” https://gitweb.torproject.org/pluggable-transports/fog.git.

  • [80] The Tor Project “obfs3.” https://gitweb.torproject.org/pluggable-transports/obfsproxy.git/tree/doc/obfs3/obfs3-protocol-spec.txt.

  • [81] T. Elahi J. Doucette H. Hosseini S. Murdoch and I. Goldberg “A Framework for the Game-theoretic Analysis of Censorship Resistance” Tech. Rep. 2015-11 CACR 2015.

  • [82] “Adversary Lab.” https://github.com/blanu/AdversaryLab/.

  • [83] Paul Farrell “History of 5-Eyes â˘AS¸ Explainer.” The Guardian http://www.theguardian.com/world/2013/dec/02/history-of-5-eyes-explainer Dec. 2013.

  • [84] R. Dingledine “How to Handle Millions of New Tor Clients.” https://blog.torproject.org/blog/how-to-handle-millions-newtor-clients Sep. 2013.

  • [85] C. MiscBrubaker A. Houmansadr and V. Shmatikov “CloudTransport: Using Cloud Storage for Censorship- Resistant Networking” in Privacy Enhancing Technologies Symposium Springer 2014.

  • [86] B. Marczak N. Weaver J. Dalek R. Ensafi D. Fifield S. McKune A. Rey J. Scott-Railton R. Deibert and V. Paxson “China’s Great Cannon.” https://citizenlab.org/2015/04/chinas-great-cannon/ 2015.

  • [87] E. Dou and A. Barr “U.S. Cloud Providers Face Backlash From China’s Censors.” The Wall Street Journal http://www.wsj.com/articles/u-s-cloud-providers-face-backlash-fromchinas-censors-1426541126 2015.

  • [88] S. Köpsell and U. Hillig “How to Achieve Blocking Resistance for Existing Systems Enabling Anonymous Web Surfing” in Proceedings of the Workshop on Privacy in the Electronic Society Oct. 2004.

  • [89] C. S. Leberknight M. Chiang H. V. Poor and F. Wong “A Taxonomy of Internet Censorship and Anti-censorship.” https://www.princeton.edu/~chiangm/anticensorship.pdf 2012.

  • [90] G. Perng M. K. Reiter and C. Wang “Censorship Resistance Revisited” in Proceedings of Information Hiding Workshop pp. 62-76 Jun. 2005.

  • [91] S. Gardner “Freedom-supporting technologies: their origins and current state.” https://docs.google.com/document/d/1Pa566Vnx9MEuV9gltXOZkypQ3wXyzVyslg6xHuebqqU/edit# 2016.

  • [92] R. Dingledine and N. Mathewson “Design of a Blocking- Resistant Anonymity System” Tech. Rep. 2006-1 The Tor Project Nov. 2006.

  • [93] D. Nobori and Y. Shinjo “VPN Gate: A Volunteer-Organized Public VPN Relay System with Blocking Resistance for Bypassing Government Censorship Firewalls” in Networked Systems Design and Implementation USENIX 2014.

  • [94] R. Smits D. Jain S. Pidcock I. Goldberg and U. Hengartner “BridgeSPA: Improving Tor Bridges with Single Packet Authorization” in Proceedings of the 10th Annual ACM Workshop on Privacy in the Electronic Society (New York NY USA) pp. 93-102 ACM 2011.

  • [95] uproxy “uProxy.” https://www.uproxy.org/.

  • [96] Z. Weinberg J. Wang V. Yegneswaran L. Briesemeister S. Cheung F. Wang and D. Boneh “StegoTorus: A Camouflage Proxy for the Tor Anonymity System” in Proceedings of the 19th ACM conference on Computer and Communications Security Oct. 2012.

  • [97] I. Goldberg and D. Wagner “TAZ Servers and the Rewebber Network: Enabling Anonymous Publishing on the World Wide Web” First Monday vol. 3 Aug. 1998.

  • [98] foe-project “https://code.google.com/p/foe-project/.”

  • [99] L. Invernizzi C. Kruegel and G. Vigna “Message in a Bottle: Sailing Past Censorship” in Privacy Enhancing Technologies Symposium 2012.

  • [100] Y. Wang P. Ji B. Ye P. Wang R. Luo and H. Yang “Go- Hop: Personal VPN to Defend from Censorship” in International Conference on Advanced Communication Technology IEEE 2014.

  • [101] E. Wustrow S. Wolchok I. Goldberg and J. A. Halderman “Telex: Anticensorship in the Network Infrastructure” in Proceedings of the 20th USENIX Security Symposium Aug. 2011.

  • [102] R. Anderson “The Eternity Service” in Proceedings of Pragocrypt 1996.

  • [103] MailMyWeb “http://www.mailmyweb.com.”

  • [104] N. Feamster M. Balazinska G. Harfst H. Balakrishnan and D. R. Karger “Infranet: Circumventing Web Censorship and Surveillance.” in USENIX Security Symposium pp. 247-262 USENIX 2002.

  • [105] R. Clayton S. J. Murdoch and R. N. M. Watson “Ignoring the Great Firewall of China” in Proceedings of the Sixth Workshop on Privacy Enhancing Technologies pp. 20-35 Springer Jun. 2006.

  • [106] D. Fifield G. Nakibly and D. Boneh “OSS: Using Online Scanning Services for Censorship Circumvention” in Proceedings of the 13th Privacy Enhancing Technologies Sym posium Jul. 2013.

  • [107] E. Wustrow C. M. Swanson and J. A. Halderman “Tap- Dance: End-to-Middle Anticensorship Without Flow Blocking” in Proceedings of the 23rd USENIX conference on Security Symposium pp. 159-174 USENIX Association 2014.

  • [108] W. Zhoun A. Houmansadr M. Caesar and N. Borisov “SWEET: Serving the Web by Exploiting Email Tunnels” HotPETS 2013.

  • [109] “Scholar Zhang: Intrusion detection evasion and black box mechanism research of the Great Firewall of China.” https://code.google.com/p/scholarzhang/ 2010.

  • [110] “west-chamber-season-2.” https://code.google.com/p/westchamber-season-2/ 2010.

  • [111] “west-chamber-season-3.” https://github.com/liruqi/westchamber-season-3/ 2011.

  • [112] D. Fifield C. Lan R. Hynes P. Wegmann and V. Paxson “Blocking-resistant Communication through Domain Fronting” Privacy Enhancing Technologies vol. 1 no. 2 2015.

  • [113] J. Karlin D. Ellard A. W. Jackson C. E. Jones G. Lauer D. P. Mankins and W. T. Strayer “Decoy Routing: Toward Unblockable Internet Communication” in Free and Open Communications on the Internet (San Francisco CA USA) USENIX 2011.

  • [114] M. Waldman A. Rubin and L. Cranor “Publius: A Robust Tamper-Evident Censorship-Resistant and Source- Anonymous Web Publishing System” in Proceedings of the 9th USENIX Security Symposium pp. 59-72 Aug. 2000.

  • [115] J. Holowczak and A. Houmansadr “Cachebrowser: Bypassing chinese censorship without proxies using cached content” in Proceedings of the 22nd ACM SIGSAC Conference on Computer and Communications Security pp. 70-83 ACM 2015.

  • [116] D. Ellard C. Jones V. Manfredi W. T. Strayer B. Thapa M. Van Welie and A. Jackson “Rebound: Decoy routing on asymmetric routes via error messages” in Local Computer Networks (LCN) 2015 IEEE 40th Conference on pp. 91-99 IEEE 2015.

  • [117] A. Serjantov “Anonymizing Censorship Resistant Systems” in Proceedings of the 1st International Peer To Peer Systems Workshop Mar. 2002.

  • [118] W. Mazurczyk P. Szaga and K. Szczypiorski “Using Transcoding for Hidden Communication in IP Telephony.” arXiv preprint http://arxiv.org/pdf/1111.1250.pdf 2011.

  • [119] C. Connolly P. Lincoln I. Mason and V. Yegneswaran “TRIST: Circumventing Censorship with Transcoding- Resistant Image Steganography” in Free and Open Communications on the Internet USENIX 2014.

  • [120] K. P. Dyer S. E. Coull T. Ristenpart and T. Shrimpton “Protocol Misidentification Made Easy with Format- Transforming Encryption” in Proceedings of the 20th ACM conference on Computer and Communications Security (CCS 2013) Nov. 2013.

  • [121] bit-smuggler “tunnel traffic through a genuine bittorrent connection.” https://github.com/danoctavian/bit-smuggler.

  • [122] B. Jones S. Burnett N. Feamster S. Donovan S. Grover S. Gunasekaran and K. Habak “Facade: High-Throughput Deniable Censorship Circumvention Using Web Search” in Proceedings of the USENIX Workshop on Free and Open Communications on the Internet USENIX 2014.

  • [123] K. P. Dyer S. E. Coull and T. Shrimpton “Marionette: A Programmable Network Traffic Obfuscation System” in Proceedings of the 24th USENIX Security Symposium pp. 367-382 USENIX Association Aug. 2015.

  • [124] S. Cao L. He Z. Li and Y. Yang “SkyF2F: Censorship Resistant via Skype Overlay Network” in Information Engineering 2009. ICIE’09. WASE International Conference on vol. 1 pp. 350-354 IEEE 2009.

  • [125] T. Ruffing J. Schneider and A. Kate “Identity-Based Steganography and Its Applications to Censorship Resistance.” 6th Workshop on Hot Topics in Privacy Enhancing Technologies (HotPETs) 2013.

  • [126] The Tor Project “Tor: Hidden Service Protocol.” https://www.torproject.org/docs/hidden-services.html.en.

  • [127] yourfreedom “Your Freedom - VPN tunneling anonymization anti-censorship. Windows/Mac/Linux/Android.” https://www.your-freedom.net/.

  • [128] J. Salowey H. Zhou P. Eronen and H. Tschofenig. “MessageStreamEncryption.” http://wiki.vuze.com/w/Message_Stream_Encryption 2006.

  • [129] anchorfree “Get Behind The Shield.” http://www.anchorfree.com/.

  • [130] GTunnel “Garden Networks For Information Freedom.” http://gardennetworks.org/products.

  • [131] The Tor Project “obfs2.” https://gitweb.torproject.org/pluggable-transports/obfsproxy.git/tree/doc/obfs2/obfs2-protocol-spec.txt.

  • [132] JAP “JAP Anonymity & Privacy.” https://anon.inf.tudresden.de/index.html.

  • [133] Lantern “Open Internet for Everyone.” https://getlantern.org/.

  • [134] Yawning “obfs4.” Pseudonymously https://github.com/Yawning/obfs4/blob/5bdc376e2abaf5ac87816b763f5b26e314ee9536/doc/obfs4-spec.txt.

  • [135] Q. Wang X. Gong G. T. K. Nguyen A. Houmansadr and N. Borisov “CensorSpoofer: Asymmetric Communication using IP Spoofing for Censorship-Resistant Web Browsing” in Proceedings of the 19th ACM conference on Computer and Communications Security Oct. 2012.

  • [136] cgiproxy “HTTP/FTP Proxy in a CGI Script.” https://www.jmarshall.com/tools/cgiproxy/.

  • [137] Ultrasurf “http://ultrasurf.us.”

  • [138] freegate “Freegate | Dynamic Internet Technology Inc.” http://dit-inc.us/freegate.html.

Search
Journal information
Cited By
Metrics
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 1114 853 94
PDF Downloads 347 254 2