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'''Tor''' is [[free software]] for enabling [[Internet anonymity|anonymous communication]]. The name is an acronym derived from the original software project name ''The Onion Router''.<ref name="onion-router" /> Tor directs Internet traffic through a free, worldwide, volunteer network consisting of more than six thousand relays<ref name="torstatus" /> to conceal a user's location and usage from anyone conducting [[Computer surveillance#Network surveillance|network surveillance]] or [[Traffic analysis#In computer security|traffic analysis]]. Using Tor makes it more difficult for Internet activity to be traced back to the user: this includes "visits to Web sites, online posts, instant messages, and other communication forms".<ref name="nyt-navels" /> Tor's use is intended to protect the personal privacy of users, as well as their freedom and ability to conduct confidential communication by keeping their Internet activities from being monitored. An extract of a [[Classified information#Top Secret (TS)|Top Secret]] appraisal by the [[National Security Agency]] (NSA) characterized Tor as "the King of high-secure, low-latency Internet anonymity" with "no contenders for the throne in waiting",<ref name="guardian-king" /> and the [[Parliamentary Office of Science and Technology]] deemed it, with approximately 2.5 million users daily "by far the most popular anonymous internet communication system." <ref name="The Daily Dot">{{cite web|url=https://www.dailydot.com/politics/uk-briefing-tor-*****-*****-minor-role/|title=U.K. Parliament says banning Tor is unacceptable and impossible|work=The Daily Dot|accessdate=19 April 2015}}</ref>

[[Onion routing]] is implemented by [[encryption]] in the [[application layer]] of a communication protocol stack, nested like the layers of an [[onion]], used to anonymize communication. Tor encrypts the original data, including the destination [[IP address]], multiple times and sends it through a [[virtual circuit]] comprising successive, randomly selected Tor relays. Each relay decrypts a layer of encryption to reveal only the next relay in the circuit in order to pass the remaining encrypted data on to it. The final relay decrypts the innermost layer of encryption and sends the original data to its destination without revealing, or even knowing, the source IP address. Because the routing of the communication is partly concealed at every hop in the Tor circuit, this method eliminates any single point at which the communication can be de-anonymized through network surveillance that relies upon knowing its source and destination.

An adversary unable to defeat the strong anonymity that Tor provides may try to de-anonymize the communication by other means. One way this may be achieved is by exploiting vulnerable software on the user's computer.<ref name="guardian-nsa-target" /> The NSA has a technique that targets outdated [[Firefox]] browsers codenamed EgotisticalGiraffe,<ref name="guardian-peeling" /> and targets Tor users in general for close monitoring under its [[XKeyscore]] program.<ref name="NDR">{{cite news|author1=J. Appelbaum, A. Gibson, J. Goetz, V. Kabisch, L. Kampf, L. Ryge|title=NSA targets the privacy-conscious|url=https://daserste.ndr.de/panorama/aktuell/nsa230_page-1.html|accessdate=4 July 2014|work=Panorama|publisher=Norddeutscher Rundfunk|date=3 July 2014}}</ref><ref>https://daserste.ndr.de/panorama/xkeyscorerules100.txt</ref> Attacks against Tor are an active area of academic research,<ref>{{cite web|url=https://arstechnica.com/security/2014/07/tor-developers-vow-to-fix-bug-that-can-uncloak-users/|title=Tor developers vow to fix bug that can uncloak users|work=Ars Technica}}</ref><ref>{{cite web|url=https://freehaven.net/anonbib/#2014|title=Free Haven's Selected Papers in Anonymity|publisher=}}</ref> which is welcomed by the Tor Project itself.<ref>{{cite web|url=https://research.torproject.org/|title=Tor Research Home|publisher=}}</ref>

==History==
{{Anchor|Tor project}}
[[File:Geographies of Tor.png|thumb|A [[cartogram]] illustrating Tor usage]]

The core principle of Tor, "onion routing", was developed in the mid-1990s by [[U.S. Naval Research Laboratory]] employees, [[mathematician]] [[Paul Syverson]] and [[computer scientist]]s [[G. Mike Reed|Michael Reed]] and [[David Goldschlag]], with the purpose of protecting U.S. [[United States Intelligence Community|intelligence]] communications online. Onion routing was further developed by [[DARPA]] in 1997.<ref>{{cite book|first1 = Joseph Babatunde|last1 = Fagoyinbo|first2 = |last2 = |first3 = |last3 = |first4 = |last4 = |title = The Armed Forces: Instrument of Peace, Strength, Development and Prosperity|url = https://books.google.com/books?id=qM0uxPH8RasC&printsec=frontcover&dq=The+Armed+Forces:+Instrument+of+Peace,+Strength,+Development+and+Prosperity&hl=en&sa=X&ei=_-oAVKD1J8uMyAS41IGYCA&ved=0CCoQ6AEwAA#v=onepage&q=The%20Armed%20Forces%3A%20Instrument%20of%20Peace%2C%20Strength%2C%20Development%20and%20Prosperity&f=false|publisher = AuthorHouse|journal = |date = 2013-05-24|location = |issn = |isbn = 9781477226476|pages = |volume = |series = |issue = |doi = |accessdate = 29 August 2014}}</ref><ref>{{cite book|first1 = David|last1 = Leigh|first2 = Luke|last2 = Harding|first3 = |last3 = |first4 = |last4 = |title = WikiLeaks: Inside Julian Assange's War on Secrecy|url = https://books.google.com/books?id=qGLjvFNuaM4C&printsec=frontcover&dq=WikiLeaks:+Inside+Julian+Assange%27s+War+on+Secrecy&hl=en&sa=X&ei=gesAVP36NNGPyATnhYLoCQ&ved=0CB8Q6AEwAA#v=onepage&q=WikiLeaks%3A%20Inside%20Julian%20Assange%27s%20War%20on%20Secrecy&f=false|publisher = PublicAffairs|journal = |date = 2011-02-08|location = |issn = |isbn = 1610390628|pages = |volume = |series = |issue = |doi = |accessdate = 29 August 2014}}</ref><ref>{{cite book|first1 = Michael|last1 = Ligh|first2 = Steven|last2 = Adair|first3 = Blake|last3 = Hartstein|first4 = Matthew|last4 = Richard|title = Malware Analyst's Cookbook and DVD: Tools and Techniques for Fighting Malicious Code|url = https://books.google.com/books?id=PFGelEx4LT4C&lpg=PP1&dq=Malware%20Analyst%27s%20Cookbook%20and%20DVD%3A%20Tools%20and%20Techniques&pg=PP1#v=onepage&q=Malware%20Analyst%27s%20Cookbook%20and%20DVD:%20Tools%20and%20Techniques&f=false|publisher = John Wiley & Sons|journal = |date = 2010-09-29|location = |issn = |isbn = 9781118003367|pages = |volume = |series = |issue = |doi = |accessdate = 29 August 2014}}</ref>

The [[alpha version]] of Tor, developed by Syverson and computer scientists [[Roger Dingledine]] and [[Nick Mathewson]]<ref name=":0">{{Cite news|url = https://pando.com/2014/07/16/tor-spooks/|title = Almost everyone involved in developing Tor was (or is) funded by the US government|last = Levine|first = Yasha|date = 16 July 2014|work = Pando Daily|accessdate = 30 August 2014}}</ref> and then called The Onion Routing project, or TOR project, launched on 20 September 2002.<ref name="prealpha" /><ref name="torproject-faq" /> On 13 August 2004, Syverson, Dingledine and Mathewson presented "Tor: The Second-Generation Onion Router" at the 13th [[USENIX]] Security Symposium.<ref name="usenix-design" /> In 2004, the Naval Research Laboratory released the code for Tor under a free licence, and the [[Electronic Frontier Foundation]] (EFF) began funding Dingledine and Mathewson to continue its development.<ref name=":0" />

== Reception and impact ==
Tor has been praised for providing privacy and anonymity to vulnerable Internet users such as political activists fearing surveillance and arrest, ordinary web users seeking to circumvent censorship, and women who have been threatened with violence or ***** by stalkers.<ref>{{Cite news|url = https://www.theverge.com/2014/5/9/5699600/domestic-violence-survivors-turn-to-tor-to-escape-*****rs|title = Domestic violence survivors turn to Tor to escape *****rs|last = Brandom|first = Russell|date = 9 May 2014|work = The Verge|accessdate = 30 August 2014}}</ref><ref>{{Cite news|url = https://dissidentvoice.org/2013/06/seated-between-pablo-escobar-and-mahatma-gandhi/|title = Seated Between Pablo Escobar and Mahatma Gandhi: The Sticky Ethics of Anonymity Networks|last = Gurnow|first = Michael|date = 1 July 2014|work = Dissident Voice|accessdate = 17 July 2014}}</ref> The U.S. National Security Agency (NSA) has called Tor "the king of high-secure, low-latency Internet anonymity",<ref name="guardian-nsa-target" /> and [[BusinessWeek]] magazine has described it as "perhaps the most effective means of defeating the online surveillance efforts of intelligence agencies around the world".<ref>{{Cite news|url = https://mobile.businessweek.com/articles/2014-01-23/tor-anonymity-software-vs-dot-the-national-security-agency|title = The Inside Story of Tor, the Best Internet Anonymity Tool the Government Ever Built|last = Lawrence|first = Dune|date = 23 January 2014|work = Businessweek magazine|accessdate = 30 August 2014}}</ref> Other media have described Tor as "a sophisticated privacy tool",<ref>{{Cite news|url = https://www.wired.com/2010/06/wikileaks-documents/|title = WikiLeaks Was Launched With Documents Intercepted From Tor|last = Zetter|first = Kim|date = 1 June 2010|work = Wired|accessdate = 30 August 2014}}</ref> "easy to use"<ref>{{Cite news|url = https://www.washingtonpost.com/blogs/wonkblog/wp/2013/06/10/five-ways-to-stop-the-nsa-from-spying-on-you/|title = Five ways to stop the NSA from spying on you|last = Lee|first = Timothy B.|date = 10 June 2013|work = Washington Post|accessdate = 30 August 2014}}</ref> and "so secure that even the world's most sophisticated electronic spies haven't figured out how to crack it".<ref name=":2">{{Cite news|url = https://thecable.foreignpolicy.com/posts/2013/10/04/not_even_the_nsa_can_crack_the_state_departments_online_anonymity_tool|title = Not Even the NSA Can Crack the State Department's Favorite Anonymous Service|last = |first = |date = 24 October 2014|work = Foreign Policy|accessdate = 30 August 2014}}</ref>

In June 2013, whistleblower [[Edward Snowden]] used Tor to send information about [[PRISM]] to the ''[[Washington Post]]'' and ''[[The Guardian]]''.<ref name="erste-darknet" />
In 2014, the Russian government offered a $111,000 contract to "study the possibility of obtaining technical information about users and users' equipment on the Tor anonymous network".<ref name="ars-111k" /><ref name="pcw-111k" />

Advocates for Tor say it supports [[freedom of expression]], including in countries where the Internet is censored, by protecting the privacy and anonymity of users.  The mathematical underpinnings of Tor lead it to be characterized as acting "like a piece of [[infrastructure]], and governments naturally fall into paying for infrastructure they want to use".<ref>{{cite web|url=https://pando.com/2014/12/09/clearing-the-air-around-tor/|title=Clearing the air around Tor|work=PandoDaily}}</ref>

The project was originally developed on behalf of the U.S. intelligence community and continues to receive U.S. government funding, and has been criticized as "more resembl[ing] a spook project than a tool designed by a culture that values accountability or transparency".<ref name=":0" /> 

Critics say Tor is not as secure as it claims,<ref>{{Cite news|url = https://www.infosecurity-magazine.com/news/tor-is-not-as-safe-as-you-may-think/|title = Tor is Not as Safe as You May Think|last = |first = |date = 2 September 2013|work = Infosecurity magazine|accessdate = 30 August 2014}}</ref> pointing to U.S. law enforcement's investigations and shutdowns of Tor-using sites such as web-hosting company Freedom Hosting and online marketplace [[Silk Road (marketplace)|Silk Road]].<ref name=":0" />  In October 2013, after analyzing documents leaked by Edward Snowden, the Guardian reported that the NSA had repeatedly tried to crack Tor and had failed to break its core security, although it had had some success attacking the computers of individual Tor users.<ref name="guardian-nsa-target" /> The Guardian also published a 2012 NSA classified slide deck, entitled "Tor Stinks", which said: "We will never be able to de-anonymize all Tor users all the time", but "with manual analysis we can de-anonymize a very small fraction of Tor users".<ref>{{Cite news|url = https://www.theguardian.com/world/interactive/2013/oct/04/tor-stinks-nsa-presentation-document|title = 'Tor Stinks' presentation – read the full document|last = |first = |date = 4 October 2014|work = The Guardian|accessdate = 30 August 2014}}</ref> When Tor users are arrested, it is typically due to human error, not to the core technology being hacked or cracked.<ref>{{cite web|url=https://www.dailydot.com/crime/silk-road-tor-arrests/|title=/silk-road-tor-arrests/|work=The Daily Dot}}</ref> On 7 November 2014, for example, a joint operation by the FBI, ICE Homeland Security investigations and European Law enforcement agencies led to 17 arrests and the seizure of 27 sites containing 400 pages.<ref name="arrests" /> A late 2014 report by ''[[Der Spiegel]]'' using a new cache of [[Edward Snowden]] leaks revealed, however, that as of 2012 the NSA deemed Tor on its own as a "major threat" to its mission, and when used in conjunction with other privacy tools such as [[Off-the-Record Messaging|OTR]], Cspace, [[ZRTP]], [[RedPhone]], [[Tails (operating system)|Tails]], and [[TrueCrypt]] was ranked as "catastrophic," leading to a "near-total loss/lack of insight to target communications, presence..."<ref name="spiegel1" /><ref name="spiegel2" />

== Usage ==
Tor enables users to surf the Internet, chat and send instant messages anonymously, and is used by a wide variety of people for both licit and illicit purposes.<ref>{{Cite news|url = https://archive.wired.com/politics/security/news/2005/05/67542?currentPage=all|title = Tor Torches Online Tracking|last = Zetter|first = Kim|date = 17 May 2005|work = Wired|accessdate = 30 August 2014}}</ref> 
Tor has for example been used by criminal enterprises, [[hacktivism]] groups, and law enforcement agencies at cross purposes, sometimes simultaneously;<ref name="cso-black-market" /><ref name="muckrock-hunting-*****" /> likewise, agencies within the U.S. government variously fund Tor (the U.S. State Department), the National Science Foundation, and (through the Broadcasting Board of Governors, which itself partially funded Tor until October 2012), [[Radio Free Asia]], and seek to subvert it.<ref name="guardian-nsa-target" /><ref name="bw-tor-vs" />

Tor is not meant to completely solve the issue of anonymity on the web.  Instead, it simply focuses on protecting the transportation of data so that certain sites cannot trace back the data to a given location.  It is still possible for sites to backtrack to a location.  The best way to avoid the dissemination of information is to be safe and smart about what you post.  Tor is not designed to erase a users tracks but to simply make it less likely for sites to trace back to them. <ref>https://www.torproject.org/about/overview.html.en</ref>

Tor is also used for illegal activities, e.g., to gain access to [[censorship|censored]] information, to organize political activities,<ref name="scm-egyptians" /> or to circumvent laws against criticism of heads of state.

Tor has been described by ''[[The Economist]]'', in relation to [[Bitcoin]] and the [[Silk Road (marketplace)|Silk Road]], as being "a dark corner of the web".<ref name="economist-bitcoin" /> It has been targeted by both the American [[NSA]] and the British [[GCHQ]] [[signals intelligence]] agencies, albeit with marginal success,<ref name="guardian-nsa-target" /> and more successfully by the British [[National Crime Agency]] in its Operation Notarise.<ref>{{cite web |url=https://phys.org/news/2014-07-tor-cops.html|title=Can you really be identified on Tor or is that just what the cops want you to believe?|publisher=Phys.org|date=28 July 2014|first1= Eerke|last1= Boiten|first2= Julio|last2= Hernandez-Castro}}</ref>
At the same time, GCHQ has been using a tool named SHADOWCAT for "end-to-end encrypted access to VPS over SSH using the TOR network".<ref>{{cite web|url=https://firstlook.org/theintercept/document/2014/07/14/jtrig-tools-techniques/|title=JTRIG Tools and Techniques|publisher=[[The Intercept]]|date=14 Jul 2014}}</ref><ref>{{cite web|url=https://www.documentcloud.org/documents/1217406-jtrigall.html#document/p4gz|publisher=documentcoud.org|title=document from an internal GCHQ wiki lists tools and techniques developed by the Joint Threat Research Intelligence Group|date=5 July 2012|accessdate=30 July 2014}}</ref> Tor can be used for anonymous defamation, unauthorized [[news leak]]s of sensitive information and [[copyright infringement]], distribution of illegal *****ual content,<ref name="bbr-cleaning-up" /><ref name="jones-forensics" /><ref name="gawker-kiddie-*****" /> selling [[controlled substance]]s,<ref name="gawker-any-drug" /> weapons, and stolen credit card numbers,<ref>{{Cite news|url = https://www.forbes.com/sites/josephsteinberg/2015/01/08/how-your-*****ren-can-buy-illegal-drugs-online/|title = How Your *****age Son or Daughter May Be Buying Heroin Online|first=Joseph |last=Steinberg |authorlink=Joseph Steinberg |date = 8 January 2015|work = Forbes|accessdate = 6 February 2015}}</ref> [[money laundering]],<ref name="ars-feds-narcotics" /> bank fraud,<ref>{{cite web|url=https://krebsonsecurity.com/2014/12/treasury-dept-tor-a-big-source-of-bank-fraud/|title=Treasury Dept: Tor a Big Source of Bank Fraud —  Krebs on Security|work=krebsonsecurity.com}}</ref> [[credit card fraud]], [[identity theft]] and the exchange of [[counterfeit currency]];<ref>{{cite web|url=https://arstechnica.com/tech-policy/2015/04/how-a-3-85-latte-paid-for-with-a-fake-100-bill-lead-to-counterfeit-kingpins-downfall/|title=How a $3.85 latte paid for with a fake $100 bill led to counterfeit kingpin’s downfall|work=Ars Technica|accessdate=19 April 2015}}</ref> the [[black market]] utilizes the Tor infrastructure, at least in part, in conjunction with Bitcoin.<ref name="cso-black-market" />

In its complaint against [[Ross William Ulbricht]] of the [[Silk Road (marketplace)|Silk Road]] the FBI acknowledged that Tor has "known legitimate uses".<ref name="compaint-ulbricht" /><ref name="eff-silk-road" /> According to [[CNET]], Tor's anonymity function is "endorsed by the [[Electronic Frontier Foundation]] and other civil liberties groups as a method for [[whistleblower]]s and human rights workers to communicate with journalists".<ref name="cnet-arrested" /> EFF's Surveillance Self-Defense guide includes a description of where Tor fits in a larger strategy for protecting privacy and anonymity.<ref name="eff-ssd-tor" />

In 2014 the EFF's [[Eva Galperin]] then again told BusinessWeek magazine that "Tor’s biggest problem is press. No one hears about that time someone wasn't stalked by their *****r. They hear how somebody got away with downloading ***** *****."<ref name=":2" />

The Tor Project states that Tor users include "normal people" who wish to keep their Internet activities private from websites and advertisers, people concerned about cyber-spying, users who are evading censorship such as activists and journalists, and military professionals. As of November 2013, Tor had about four million users.<ref>{{Cite news|url = https://www.theguardian.com/technology/2013/nov/05/tor-beginners-guide-nsa-browser|title = What is Tor? A beginner's guide to the privacy tool|last = Dredge|first = Stuart|date = 5 November 2013|work = Guardian|accessdate = 30 August 2014}}</ref> According to the Wall Street Journal, in 2012 about 14% of Tor's traffic connected from the United States, with people in "Internet-censoring countries" as its second-largest user base.<ref>{{Cite news|url = https://online.wsj.com/news/articles/SB10001424127887324677204578185382377144280|title = Tor: An Anonymous, And Controversial, Way to Web-Surf|last = Fowler|first = Geoffrey A.|date = 17 December 2012|work = Wall Street Journal|accessdate = 30 August 2014}}</ref> Tor is increasingly used by victims of [[domestic violence]] and the [[social worker]]s and agencies that assist them inasmuch as digital stalking has also increased, given the prevalence of digital media in contemporary [[on-line]] life.<ref name="boston-domestic-*****" />
Along with [[SecureDrop]], Tor is used by news organizations such as the Guardian, the [[New Yorker Magazine|New Yorker]], [[ProPublica]] and [[the Intercept]] to protect the privacy of whistleblowers.<ref>{{Cite news|url = https://www.niemanlab.org/2014/06/the-guardian-introduces-securedrop-for-document-leaks/|title = The Guardian introduces SecureDrop for document leaks|last = |first = |date = 5 June 2014|work = Nieman Journalism Lab|accessdate = 30 August 2014}}</ref>

In March 2015 the [[Parliamentary Office of Science and Technology]] released a briefing which stated that "There is widespread agreement that banning online anonymity systems altogether is not seen as an acceptable policy option in the U.K." and that ""Even if it were, there would be technical challenges." The report further noted that Tor "plays only a minor role in the online viewing and distribution of indecent images of *****ren" (due in part to its inherent latency); its usage by the [[Internet Watch Foundation]], the utility of its hidden services for [[whistle blowing|whistle blowers]], and its circumvention of the [[Great Firewall]] of China were touted.<ref name="The Daily Dot"/>

Tor's executive director, Andrew Lewman, also said in August 2014 that agents of the NSA and the GCHQ have anonymously provided Tor with bug reports.<ref>https://www.bbc.com/news/technology-28886462 NSA & GCHQ "leak Tor bugs" alleges developer.</ref>

The Tor Project's FAQ offers supporting reasons for EFF's endorsement:

{{quotation|Criminals can already do bad things. Since they're willing to break laws, they already have lots of options available that provide better privacy than Tor provides....

Tor aims to provide protection for ordinary people who want to follow the law. Only criminals have privacy right now, and we need to fix that....

So yes, criminals could in theory use Tor, but they already have better options, and it seems unlikely that taking Tor away from the world will stop them from doing their bad things. At the same time, Tor and other privacy measures can fight identity theft, physical crimes like stalking, and so on.<ref name="torproject-faq-*****" />|}}

Tor Browser can also be very useful for users who are not concerned with their anonymity online but want to get access to web content which is not available from their country. It is possible to configure the Tor Browser so it looks like we're browsing from a specific country by adding 'ExitNodes {xx}' line to the torrc config file. Replace xx with a two character country code.

==Operation==
{{Multiple image|image1 = Tor-onion-network.png|caption1 = [[Infographic]] about how Tor works, by [[Electronic Frontier Foundation|EFF]]|image2 = Deep Web.svg|caption2 = Illustration of the [[Deep Web]], Tor given as an example}}

Tor aims to conceal its users' identities and their online activity from surveillance and traffic analysis by separating identification and routing. It is an implementation of [[onion routing]], which encrypts and then randomly bounces communications through a network of relays run by volunteers around the globe. These onion routers employ [[encryption]] in a multi-layered manner (hence the onion metaphor) to ensure [[perfect forward secrecy]] between relays, thereby providing users with anonymity in network location. That anonymity extends to the hosting of censorship-resistant content by Tor's anonymous hidden service feature.<ref name="usenix-design" /> Furthermore, by keeping some of the entry relays (bridge relays) secret, users can evade [[Internet censorship]] that relies upon blocking public Tor relays.<ref name="torproject-bridges" />

Because the [[IP address]] of the sender and the recipient are not ''both'' in [[cleartext]] at any hop along the way, anyone eavesdropping at any point along the communication channel cannot directly identify both ends. Furthermore, to the recipient it appears that the last Tor [[Node (networking)|node]] (called the exit node), rather than the sender, is the originator of the communication.

===Originating traffic===
[[File:Ethe*****TorScreenShot.png|thumb|A visual depiction of the traffic between some Tor relay [[Node (networking)|nodes]] from the [[open-source]] [[packet sniffing]] program [[Ethe*****]]]]
A Tor user's [[SOCKS]]-aware applications can be configured to direct their network traffic through a Tor instance's SOCKS interface. Tor periodically creates virtual circuits through the Tor network through which it can [[multiplexing|multiplex]] and onion-route that traffic to its destination. Once inside a Tor network, the traffic is sent from router to router along the circuit, ultimately reaching an exit node at which point the [[cleartext]] packet is available and is forwarded on to its original destination. Viewed from the destination, the traffic appears to originate at the Tor exit node.

[[File:Tor-non-exit-relay-bandwidth-usage.jpg|thumb|A Tor non-exit relay with a maximum output of 239.69 KB/s]]
Tor's application independence sets it apart from most other anonymity networks: it works at the [[Transmission Control Protocol]] (T*****) stream level. Applications whose traffic is commonly anonymised using Tor include [[Internet Relay Chat]] (IRC), [[instant messaging]], and [[World Wide Web]] browsing.

===Hidden services===
{{see also|List of Tor hidden services}}
Tor can also provide anonymity to websites and other servers. Servers configured to receive inbound connections only through Tor are called hidden services. Rather than revealing a server's IP address (and thus its network location), a hidden service is accessed through its [[.torify.net|onion address]]. The Tor network understands these addresses and can route data to and from hidden services, even those hosted behind [[firewall (computing)|firewalls]] or [[network address translator]]s (NAT), while preserving the anonymity of both parties. Tor is necessary to access hidden services.<ref name="torproject-conf-hidden" />

Hidden services have been deployed on the Tor network since 2004.<ref name="or-locating" /> Other than the database that stores the hidden-service descriptors,<ref name="torproject-hidden" /> Tor is [[decentralized]] by design; there is no direct readable list of all hidden services, although a number of hidden services catalog publicly known onion addresses.

Because hidden services do not use exit nodes, connection to a hidden service is encrypted end-to-end and not subject to eavesdropping. There are, however, security issues involving Tor hidden services. For example, services that are reachable through Tor hidden services ''and'' the public Internet are susceptible to [[correlation attack]]s and thus not perfectly hidden. Other pitfalls include misconfigured services (e.g. identifying information included by default in web server error responses), [[uptime]] and [[downtime]] statistics, intersection attacks, and user error.<ref name="torproject-hidden" /><ref name="register-embassy-passwd" />

Hidden services could be also accessed from a standard web browser without [[client-side]] connection to the Tor network, using services like [[Tor2web]].<ref>{{cite web|first=Kim|last=Zetter|title=New Service Makes Tor Anonymized Content Available to All|url=https://www.wired.com/threatlevel/2008/12/tor-anonymized/|publisher=wired.com|accessdate=22 February 2014|date=12 December 2008}}</ref>

===Arm status monitor===
[[Image:ArmLogo.png|200px|right|Arm logo]]

[[Image:Arm partial screenshot.png|right|thumb|Arm's header panel and bandwidth graph.]]

The '''anonymizing relay monitor''' ('''arm''') is a [[Command-line interface|command-line]] status monitor written in [[Python programming language|Python]] for Tor.<ref>{{cite web |url=https://www.atagar.com/arm/ |title=Official Website}}</ref><ref>{{cite web |url=https://www.torproject.org/projects/arm.html.en |title=Tor Project: Arm |work=torproject.org}}</ref><ref>{{cite web |url=https://manpages.ubuntu.com/manpages/precise/man1/arm.1.html |title=Ubuntu Manpage: arm - Terminal Tor status monitor |newspaper=Manpages.ubuntu.com}}</ref> This functions much like [[Top (Unix)|top]] does for system usage, providing real time statistics for:
* resource usage (bandwidth, *****u, and memory usage)
* general relaying information (nickname, fingerprint, flags, or/dir/controlports)
* event log with optional [[Regular expression|regex]] filtering and deduplication
* connections correlated against tor's consensus data (ip, connection types, relay details, etc.)
* torrc configuration file with syntax highlighting and validation

Most of arm's attributes are configurable through an optional armrc [[Rc file|configuration file]]. It runs on any platform supported by [[Curses (programming library)|curses]] including [[Linux]], [[Mac OS X]], and other [[Unix-like]] variants.

The project began in the summer of 2009,<ref name="arm introductory blog posting">{{cite web|url=https://blog.torproject.org/blog/summer-conclusion-arm-project|title=Summer Conclusion (ARM Project)|work=torproject.org|accessdate=19 April 2015}}</ref><ref name="arm interview">[https://www.atagar.com/arm/resources/HFM_INT_0001.mp3 interview by Brenno Winter]</ref> and since July 18, 2010 it has been an official part of the tor project. It is [[free software]], available under the [[GNU General Public License]].

==Weaknesses==
Like all current [[low latency|low-latency]] [[anonymity network]]s, Tor cannot and does not attempt to protect against monitoring of traffic at the boundaries of the Tor network (i.e., the traffic entering and exiting the network). While Tor does provide protection against [[traffic analysis]], it cannot prevent traffic confirmation (also called ''end-to-end correlation'').<ref name="torproject-one-cell" /><ref name="torproject-fail-both-ends" />

In spite of known weaknesses and attacks listed here, Tor and the alternative network system [[Java Anon Proxy|JonDonym]] (Java Anon Proxy, JAP) are considered more resilient than alternatives such as [[VPN]]s. Were a local observer on an ISP or WLAN to attempt to analyze the size and timing of the encrypted data stream going through the VPN, Tor, or JonDo system, the latter two would be harder to analyze, as demonstrated by a 2009 study.<ref name="ccsw-attacking" />

Researchers from the [[University of Michigan]] developed a network scanner allowing identification of 86% of live Tor "bridges" with a single scan.<ref name="twe-zmap" />

===Eavesdropping===

==== Autonomous System (AS) eavesdropping ====
If an [[Autonomous System (Internet)|autonomous system]] (AS) exists on both path segments from a client to entry relay and from exit relay to destination, such an AS can statistically correlate trafﬁc on the entry and exit segments of the path and potentially infer the destination with which the client communicated. In 2012, LASTor proposed a method to predict a set of potential ASes on these two segments and then avoid choosing this path during path selection algorithm on client side. In this paper, they also improve latency by choosing shorter geographical paths between client and destination.<ref name="LASTor-2012" />

==== Exit node eavesdropping ====
In September 2007, Dan Egerstad, a [[Sweden|Swedish]] security consultant, revealed that he had intercepted usernames and passwords for e-mail accounts by operating and monitoring Tor exit nodes.<ref name="wired-rogue-nodes" /> As Tor cannot encrypt the traffic between an exit node and the target server, any exit node is in a position to capture traffic passing through it that does not use end-to-end encryption such as [[Secure Sockets Layer]] (SSL) or [[Transport Layer Security]] (TLS). While this may not inherently breach the anonymity of the source, traffic intercepted in this way by self-selected third parties can expose information about the source in either or both of payload and protocol data.<ref name="sf-tor-hack" /> Furthermore, Egerstad is circumspect about the possible subversion of Tor by intelligence agencies:<ref name="smh-hack-of-year" />

{{quote|If you actually look in to where these Tor nodes are hosted and how big they are, some of these nodes cost thousands of dollars each month just to host because they're using lots of bandwidth, they're heavy-duty servers and so on. Who would pay for this and be anonymous?}}

In October 2011, a research team from [[ESIEA (university)|ESIEA]] claimed to have discovered a way to compromise the Tor network by decrypting communication passing over it.<ref name="thn-compromised" /><ref name="01-chercheurs" /> The technique they describe requires creating a map of Tor network nodes, controlling one third of them, and then acquiring their encryption [[Key (cryptography)|keys]] and algorithm [[Random seed|seeds]]. Then, using these known keys and seeds, they claim the ability to decrypt two encryption layers out of three. They claim to break the third key by a statistical-based attack. In order to redirect Tor traffic to the nodes they controlled, they used a [[denial-of-service]] attack. A response to this claim has been published on the official Tor Blog stating that these rumours of Tor's compromise are greatly exaggerated.<ref name="torproject-rumors-exaggerated" />

===Traffic-analysis attack===
[[Steven Murdoch|Steven J. Murdoch]] and George Danezis from [[University of Cambridge]] presented an article at the 2005 [[Institute of Electrical and Electronics Engineers|IEEE]] [[Symposium]] on security and privacy on traffic-analysis techniques that allow adversaries with only a partial view of the network to infer which nodes are being used to relay the anonymous streams.<ref name="ieee-low-cost" /> These techniques greatly reduce the anonymity provided by Tor. Murdoch and Danezis have also shown that otherwise unrelated streams can be linked back to the same initiator. This attack, however, fails to reveal the identity of the original user.<ref name="ieee-low-cost" /> Murdoch has been working with and has been funded by Tor since 2006.

===Tor exit node block===
Operators of Internet sites have the ability to prevent traffic from Tor exit nodes or to offer reduced functionality to Tor users. For example, it is not generally possible to edit [[Wikipedia]] when using Tor or when using an IP address that also is used by a Tor exit node, due to the use of the [[mw:Extension:TorBlock|TorBlock]] MediaWiki extension, unless an [[Wikipedia:IP block exemption|exemption]] is obtained.

===Bad apple attack===
In March 2011, researchers with the Rocquencourt, France-based [[National Institute for Research in Computer Science and Control]] (Institut national de recherche en informatique et en automatique, INRIA), documented an attack that is capable of revealing the IP addresses of [[BitTorrent (protocol)|BitTorrent]] users on the Tor network. The "bad apple attack" exploits Tor's design and takes advantage of insecure application use to associate the simultaneous use of a secure application with the IP address of the Tor user in question. One method of attack depends on control of an exit node or hijacking tracker responses, while a secondary attack method is based in part on the statistical exploitation of [[distributed hash table]] tracking.<ref name="usenix-bad-apple" /> According to the study:<ref name="usenix-bad-apple" />

{{quote|This attack against Tor consists of two parts: (a) exploiting an insecure application to reveal the source IP address of, or trace, a Tor user and (b) exploiting Tor to associate the use of a secure application with the IP address of a user (revealed by the insecure application). As it is not a goal of Tor to protect against application-level attacks, Tor cannot be held responsible for the first part of this attack. However, because Tor's design makes it possible to associate streams originating from secure application with traced users, the second part of this attack is indeed an attack against Tor. We call the second part of this attack the bad apple attack. (The name of this attack refers to the saying "one bad apple spoils the bunch". We use this wording to illustrate that one insecure application on Tor may allow to trace other applications.)}}

The results presented in the bad apple attack research paper are based on an attack in the wild launched against the Tor network by the authors of the study. The attack targeted six exit nodes, lasted for 23 days, and revealed a total of 10,000 IP addresses of active Tor users. This study is particularly significant because it is the first documented attack designed to target [[Peer-to-peer|P2P]] file-sharing applications on Tor.<ref name="usenix-bad-apple" /> BitTorrent may generate as much as 40% of all traffic on Tor.<ref name="shining-light" /> Furthermore, the bad apple attack is effective against insecure use of any application over Tor, not just BitTorrent.<ref name="usenix-bad-apple" />

===Some protocols expose IP addresses===
Researchers from the [[French Institute for Research in Computer Science and Control]] (INRIA) showed that the Tor dissimulation technique in [[BitTorrent]] can be bypassed by attackers controlling a Tor exit node. The study was conducted by monitoring six exit nodes for a period of 23 days. Researches used three [[attack vector]]s:<ref name="manils-compromising" />
;Inspection of BitTorrent control messages: Tracker announces and extension protocol handshakes may optionally contain client IP address. Analysis of collected data revealed that 35% and 33% of messages, respectively, contained addresses of clients.<ref name="manils-compromising" />{{rp|3}}
;Hijacking trackers' responses: Due to lack of encryption or authentication in communication between tracker and peer, typical [[man-in-the-middle attack]]s allow attackers to determine peer IP addresses and even verify the distribution of content. Such attacks work when Tor is used only for tracker communication.<ref name="manils-compromising" />{{rp|4}}
;Exploiting distributed hash tables (DHT): This attack exploits the fact that [[distributed hash table]] (DHT) connections through Tor are impossible, so an attacker is able to reveal a target's IP address by looking it up in the DHT even if the target uses Tor to connect to other peers.<ref name="manils-compromising" />{{rp|4–5}}

With this technique, researchers were able to identify other streams initiated by users, whose IP addresses were revealed.<ref name="manils-compromising" />

===Sniper attack===
Jensen ''et al''., describe a [[DDoS]] attack targeted at the TOR node software, as well as defenses against that attack and its variants. The attack works using a colluding client and server, and filling the queues of the exit node until the node runs out of memory, and hence can serve no other (genuine) clients.  By attacking a significant proportion of the exit nodes this way, an attacker can degrade the network and increase the chance of targets using nodes controlled by the attacker.<ref name="andssy-sniper" />

===Heartbleed bug===
The [[Heartbleed bug|Heartbleed]] [[OpenSSL]] [[Computer bug|bug]] disrupted the Tor network for several days in April 2014 while [[private key]]s were renewed. The Tor Project recommended that Tor relay operators and hidden service operators revoke and generate fresh keys after patching OpenSSL, but noted that Tor relays use two sets of keys and that Tor's multi-hop design minimizes the impact of exploiting a single relay.<ref name="torproject-openssl-cve" /> 586 relays later found to be susceptible to the Heartbleed bug were taken off-line as a precautionary measure.<ref name="ml-rejecting" /><ref name="torproject-news-20140416" /><ref name="ars-ranks-cut" /><ref name="tp-blacklisting" />

===Use of Remote Nueral Technlogy===
USA government usually uses RNM technology to keep an eye on all those who use TOR and who have been acting suspicious.Snowden himself talked about Faraday cage to protect himself from RNM. They can read minds and also do electronic harassment to targets if they speak too much. Once you are identified and you are declared a threat you end up on RNM. RNM is mostly used on those who try to expose US government and Australian government involved in Monarch mind control ***** ***** programs. *****ren as ***** as 5 are put into this program. If you are a victim of RNM, try to understand how EMF waves work. Binueral beats and anti-EMF is only solution. They are involved in Voodoo which they ultilize at times as well.Singal jammers all 8 bands can clearly stop RNM but that is usually illegal.

==Implementations==
The main implementation of Tor is written primarily in the [[C programming language]] and consists of approximately 340,000 lines of source code.<ref name="openhub-tor" />

=== Tor Browser ===
<!-- [[Portable Tor]] and [[Tor Browser Bundle]] redirects to this section -->
{{Infobox web browser
|name = Tor Browser
|developer = Tor Project
|screenshot = File:Tor Browser Bundle start page.png
|caption = Tor Browser on [[Linux Mint]] showing its start page - about:tor
|operating system = {{flatlist|
* [[Windows XP]] and later
* [[Unix-like]] (inc. [[OS X]])}}
|engine = [[Gecko (software)|Gecko]]
|genre = [[Onion routing]], [[Anonymity application|Anonymity]], [[Web browser]], [[Feed reader]]
|language = 15 languages
|size = {{Nowrap|32–41 MB}}
|status = Active
|license = [[GNU General Public License|GPL]]
|website = {{URL|https://www.torproject.org/projects/torbrowser.html}}
}}

'''Tor Browser''', previously known as '''Tor Browser Bundle''' (TBB), is the flagship product of The Tor Project. It consists of a modified [[Mozilla Firefox ESR]] web browser, the TorButton, TorLauncher, [[NoScript]] and [[HTTPS Everywhere]] Firefox extensions and the Tor proxy.<ref name="tbb-design-document" /><ref name="wu8-ubuntu-ppa" /> It can be run from removable media and is available for Windows, Mac OS X, and Linux.<ref name="lj-portable" />

The Tor Browser automatically starts Tor background processes and routes traffic through the Tor network. Upon termination of a session the browser deletes privacy-sensitive data such as [[HTTP cookie]] and the browsing history.<ref name="wu8-ubuntu-ppa" />

Following a series of [[Global surveillance disclosures (2013–present)|global surveillance disclosures]], Stuart Dredge ([[The Guardian]]) recommended using Tor Browser to avoid eavesdropping and retain privacy on the Internet.<ref name="guardian-what-is-tor" />

====Firefox / JavaScript anonymity attack====
In August 2013, it was discovered that the [[Firefox]] browsers in many older versions of the Tor Browser Bundle were vulnerable to a [[JavaScript]] attack, as [[NoScript]] was not enabled by default.<ref>{{cite news |url=https://www.theguardian.com/world/interactive/2013/oct/04/egotistical-giraffe-nsa-tor-document |title='Peeling back the layers of Tor with EgotisticalGiraffe' – read the document |newspaper=Guardian |date=4 October 2013 }}</ref> This attack was being exploited to send users' MAC and IP addresses and Windows computer names to the attackers.<ref name="iw-info-stealing" /><ref name="wired-feds-are-suspects" /><ref name="ghowen-fby-analysis" /> News reports linked this to a United States [[Federal Bureau of Investigation]] (FBI) operation targeting Freedom Hosting's owner, Eric Eoin Marques, who was arrested on a provisional extradition warrant issued by a United States court on 29 July. The FBI is seeking to extradite Marques out of Ireland to Maryland on four charges&nbsp;— distributing, conspiring to distribute, and advertising [[***** *****ography]]&nbsp;— as well as aiding and abetting advertising of ***** *****ography. The warrant alleges that Marques is "the largest facilitator of ***** ***** on the planet".<ref name="mirror-marques" /><ref name="torproject-old-vulnerable" /> The FBI acknowledged the attack in a 12 September 2013 court filing in [[Dublin]];<ref name="wired-fbi-controlled" /> further technical details from a training presentation leaked by [[Edward Snowden]] showed that the codename for the exploit was ''EgotisticalGiraffe''.<ref name="guardian-how-nsa" />

The FBI, in Operation Tor*****, has been targeting Tor hidden servers since 2012, such as in the case of Aaron McGrath, who was sentenced to 20 years for running three hidden Tor servers containing ***** *****ography.<ref>{{cite web|url=https://www.wired.com/2014/08/operation_tor*****/|title=Visit the Wrong Website, and the FBI Could End Up in Your Computer|work=WIRED}}</ref>

===Third-party applications===
[[Vuze]] (formerly Azureus) [[BitTorrent (protocol)|BitTorrent]] client,<ref name="vuze-tor" /> [[Bitmessage]] anonymous messaging system,<ref name="bitmessage-faq" /> and [[TorChat]] instant messenger include Tor support.

[[The Guardian Project (software)|The Guardian Project]] is actively developing a free and open-source suite of application programs and firmware for the [[Android (operating system)|Android operating system]] to improve the security of mobile communications.<ref name="guardianproject-about" /> The applications include [[ChatSecure]] instant messaging client,<ref name="guardianproject-chatsecure" /> [[Orbot]] Tor implementation,<ref name="guardianproject-orbot" /> Orweb privacy-enhanced mobile browser,<ref name="guardianproject-orweb" /> ProxyMob [[Firefox add-on]]<ref name="guardianproject-proxymob" /> and ObscuraCam.<ref name="guardianproject-obscuracam" />

===Security-focused operating systems===
Several [[security-focused operating system]]s like GNU/Linux distributions including [[Hardened Linux From Scratch]], [[Incognito (operating system)|Incognito]], [[Security-focused operating system#Liberté Linux|Liberté Linux]], [[Qubes OS]], [[Tails (operating system)|Tails]], [[Tor-ramdisk]] and [[Whonix]], make extensive use of Tor.<ref name="xakep-whole-hog" />

==See also==
{{Div col|2|}}
* [[.torify.net]]
* [[Anonymous P2P]]
* [[Anonymous web browsing]]
* [[Crypto-anarchism]]
* [[Deep Web]]
* [[Freedom of information]]
* [[I2P]]
* [[Internet censorship]]
* [[Internet privacy]]
* [[Privoxy]]
* [[Proxy server]]
* [[Tor2web]]
{{Div col end}}
{{Portal bar| Cryptography | Free software | Freedom of speech | Information technology}} <!--It should be below the links-->

==References==
{{Reflist|colwidth=30em|refs=

<ref name="spiegel2">{{cite web|title=Presentation from the SIGDEV Conference 2012 explaining which encryption protocols and techniques can be attacked and which not|url=https://www.spiegel.de/media/media-35535.pdf|publisher=''Der Spiegel''|accessdate=23 January 2015|format=PDF|date=28 December 2014}}</ref>

<ref name="spiegel1">{{cite news|author=SPIEGEL Staff|title=Prying Eyes: Inside the NSA's War on Internet Security|url=https://www.spiegel.de/international/germany/inside-the-nsa-s-war-on-internet-security-a-1010361.html|newspaper=Der Spiegel|accessdate=23 January 2015|date=28 December 2014}}</ref>

<ref name="01-chercheurs">{{cite web| title=Announcement on 01net.com | url=https://pro.01net.com/editorial/544024/des-chercheurs-francais-cassent-le-reseau-danonymisation-tor/ | accessdate=17 October 2011|language=fr}}</ref>

<ref name="andssy-sniper">{{Cite conference |url=https://www.robgjansen.com/publications/sniper-ndss2014.pdf |title=The Sniper Attack: Anonymously Deanonymizing and Disabling the Tor Network |first1=Rob |last1=Jansen |first2=Florian |last2=Tschorsch |first3=Aaron |last3=Johnson |first4=Björn |last4=Scheuermann |conference=21st Annual Network & Distributed System Security Symposium |year=2014 |accessdate=28 April 2014}}</ref>

<ref name="ars-111k">{{cite web |url=https://arstechnica.com/security/2014/07/russia-publicly-joins-war-on-tor-privacy-with-111000-bounty/ |title=Russia publicly joins war on Tor privacy with $111,000 bounty |first=Sean |last=Gallagher |work=[[Ars Technica]] |date=25 July 2014 |accessdate=26 July 2014}}</ref>

<ref name="ars-feds-narcotics">{{cite web |url=https://arstechnica.com/tech-policy/news/2012/04/feds-shutter-online-narcotics-store-that-used-tor-to-hide-its-tracks.ars?src=fbk |title=Feds shutter online narcotics store that used TOR to hide its tracks |work=[[Ars Technica]] |last=Goodin |first=Dan |date=16 April 2012 |accessdate=20 April 2012}}</ref>

<ref name="ars-ranks-cut">{{cite web |url=https://arstechnica.com/security/2014/04/tor-networks-ranks-of-relay-servers-cut-because-of-heartbleed-bug/ |title=Tor network’s ranks of relay servers cut because of Heartbleed bug |first=Sean |last=Gallagher |work=[[Ars Technica]] |date=18 April 2014 |accessdate=28 April 2014}}</ref>

<ref name="bitmessage-faq">{{cite web |url=https://bitmessage.org/wiki/FAQ |title=Bitmessage FAQ |work=Bitmessage |accessdate=17 July 2013}}</ref>

<ref name="bbr-cleaning-up">{{cite web |url=https://www.broadbandreports.com/shownews/Cleaning-Up-Tor-82218 |title=Cleaning up Tor |first=Karl |last=Bode |work=Broadband.com |date=12 March 2007 |accessdate=28 April 2014}}</ref>

<ref name="bw-tor-vs">{{cite news |url=https://www.businessweek.com/articles/2014-01-23/tor-anonymity-software-vs-dot-the-national-security-agency |title=The Inside Story of Tor, the Best Internet Anonymity Tool the Government Ever Built |first=Dune |last=Lawrence |work=[[Bloomberg Businessweek]] |date=23 January 2014 |accessdate=28 April 2014}}</ref>

<ref name="boston-domestic-*****">{{cite web |url=https://betaboston.com/news/2014/05/07/as-domestic-*****-goes-digital-shelters-turn-to-counter-surveillance-with-tor/ |title=As domestic ***** goes digital, shelters turn to counter-surveillance with Tor |first=George |last=LeVines |work=[[Boston Globe]] |date=7 May 2014 |accessdate=8 May 2014}}</ref>

<ref name="boston-free-speech-tech">{{cite web |url=https://articles.boston.com/2012-03-08/business/31136655_1_law-enforcement-free-speech-technology/2 |title=Privacy software, criminal use |first=Jenifer B. |last=McKim |work=[[The Boston Globe]] |date=8 March 2012 |archiveurl=https://wayback.archive.org/web/20120312225054/https://articles.boston.com/2012-03-08/business/31136655_1_law-enforcement-free-speech-technology/2 |archivedate=12 March 2012}}</ref>

<ref name="ccsw-attacking">{{cite conference |url=https://epub.uni-regensburg.de/11919/1/authorsversion-ccsw09.pdf |title=Website Fingerprinting: Attacking Popular {{sic|hide=y|Privacy Enhancing}} Technologies with the Multinomial Naïve-Bayes Classifier |first1=Dominik |last1=Herrmann |first2=Rolf |last2=Wendolsky |first3=Hannes |last3=Federrath |conference=Cloud Computing Security Workshop |booktitle=Proceedings of the 2009 ACM Cloud Computing Security Workshop (CCSW) |location=New York, USA |publisher=[[Association for Computing Machinery]] |date=13 November 2009 |accessdate=2 September 2010}}</ref>

<ref name="cnet-arrested">{{cite news |title=Tor anonymity server admin arrested |first=Chris |last=Soghoian |url=https://news.cnet.com/8301-13739_3-9779225-46.html |newspaper=[[CNET Networks|CNET News]] |date=16 September 2007 |accessdate=17 January 2011}}</ref>

<ref name="compaint-ulbricht">{{cite web |url=https://www1.icsi.berkeley.edu/~nweaver/UlbrichtCriminalComplaint.pdf |title=Sealed compaint |first=Serrin |last=Turner |work=United States of America v. Ross William Ulbricht |date=27 September 2013 |archiveurl=https://wayback.archive.org/web/20131002221530/https://www1.icsi.berkeley.edu/~nweaver/UlbrichtCriminalComplaint.pdf |archivedate=2 October 2013}}</ref>

<ref name="cso-black-market">{{cite web |url=https://www.csoonline.com/article/705316/how-online-black-markets-work |title=How online black markets work |first=Brandon |last=Gregg |work=CSO Online |date=30 April 2012 |accessdate=6 August 2012}}</ref>

<ref name="economist-bitcoin">{{cite news |url=https://www.economist.com/node/21563752 |title=Bitcoin: Monetarists Anonymous |first= |work=[[The Economist]] |date=29 September 2012 |accessdate=19 May 2013}}</ref>

<ref name="eff-silk-road">{{cite web |url=https://www.eff.org/deeplinks/2013/10/silk-road-case-dont-blame-technology |title=In the Silk Road Case, Don't Blame the Technology |first=Parker |last=Higgins |work=[[Electronic Frontier Foundation]] |date=2013-10-03 |accessdate=2013-12-22}}</ref>

<ref name="eff-ssd-tor">{{cite web |url=https://ssd.eff.org/tech/tor |title=Surveillance Self-Defense: Tor |work=[[Electronic Frontier Foundation]] |accessdate=28 April 2014}}</ref>

<ref name="erste-darknet">{{cite news |url=https://www.daserste.de/information/wissen-kultur/ttt/sendung/br/20130630-ttt-darknet-102.html |language=de |title=Darknet – Netz ohne Kontrolle |first=Joachim |last=Gaertner |work=[[Das Erste]] |date=1 July 2013 |accessdate=28 August 2013 }}</ref>

<ref name="fsf-award">{{cite web |url=https://www.fsf.org/news/2010-free-software-awards-announced |title=2010 Free Software Awards announced |work=[[Free Software Foundation]] |accessdate=23 March 2011}}</ref>

<ref name="fp-top100-thinkers">{{cite web |url=https://www.foreignpolicy.com/articles/2012/11/26/the_fp_100_global_thinkers?page=0,48 |title=The FP Top 100 Global Thinkers |first=Alicia P.Q. |last=Wittmeyer |work=[[Foreign Policy (magazine)|Foreign Policy]] |date=26 November 2012 |accessdate=28 November 2012 |archivedate=28 November 2012 |archiveurl=https://www.webcitation.org/6CViUyRpk |deadurl=no}}</ref>

<ref name="gawker-any-drug">{{cite web |url=https://gawker.com/5805928/the-underground-website-where-you-can-buy-any-drug-imaginable |title=The Underground Website Where You Can Buy Any Drug Imaginable |first=Adrian |last=Chen |work=Gawker |date=1 June 2011 |accessdate=20 April 2012}}</ref>

<ref name="gawker-kiddie-*****">{{cite web |url=https://gawker.com/5916994/dark-net-kiddie-*****-website-stymies-fbi-investigation |title='Dark Net' Kiddie ***** Website Stymies FBI Investigation |first=Adrian |last=Chen |work=Gawker |date=11 June 2012 |accessdate=6 August 2012}}</ref>

<ref name="ghowen-fby-analysis">{{cite web |url=https://ghowen.me/fbi-tor-malware-analysis |title=FBI Malware Analysis |first=Gareth |last=Owen |accessdate=6 May 2014}}{{self-published inline|date=April 2014}}</ref>

<ref name="guardian-how-nsa">{{cite news |first=Bruce |last=Schneier |url=https://www.theguardian.com/world/2013/oct/04/tor-attacks-nsa-users-online-anonymity |title=Attacking Tor: how the NSA targets users' online anonymity |work=[[The Guardian]] |date=4 October 2013 |accessdate=22 December 2013}}</ref>

<ref name="guardian-king">{{cite news |url=https://www.theguardian.com/world/interactive/2013/oct/04/tor-high-secure-internet-anonymity |title=Tor: 'The king of high-secure, low-latency anonymity' |work=[[The Guardian]] |date=4 October 2013 |accessdate=5 October 2013}}</ref>

<ref name="guardian-nsa-target">{{cite news |url=https://www.theguardian.com/world/2013/oct/04/nsa-gchq-attack-tor-network-encryption |title=NSA and GCHQ target Tor network that protects anonymity of web users |first1=James |last1=Ball |first2=Bruce |last2=Schneier |first3=Glenn |last3=Greenwald |work=[[The Guardian]] |date=4 October 2013 |accessdate=5 October 2013}}</ref>

<ref name="guardian-peeling">{{cite news |url=https://www.theguardian.com/world/interactive/2013/oct/04/egotistical-giraffe-nsa-tor-document |title='Peeling back the layers of Tor with EgotisticalGiraffe' |work=[[The Guardian]] |date=4 October 2013 |accessdate=5 October 2013}}</ref>

<ref name="guardian-what-is-tor">{{cite news |url=https://www.theguardian.com/technology/2013/nov/05/tor-beginners-guide-nsa-browser |title=What is Tor? A beginner's guide to the privacy tool |first=Stuart |last=Dredge |work=[[The Guardian]] |date=5 November 2013 |accessdate=28 April 2014}}</ref>

<ref name="guardianproject-about">{{cite web |url=https://guardianproject.info/ |title=About |work=The Guardian Project |accessdate=10 May 2011}}</ref>

<ref name="guardianproject-chatsecure">{{cite web |url=https://guardianproject.info/apps/chatsecure/ |title=ChatSecure: Private Messaging |work=The Guardian Project |accessdate=20 September 2014}}</ref>

<ref name="guardianproject-orbot">{{cite web |url=https://guardianproject.info/apps/orbot/ |title=Orbot: Mobile Anonymity + Circumvention |work=The Guardian Project |accessdate=10 May 2011}}</ref>

<ref name="guardianproject-orweb">{{cite web |url=https://guardianproject.info/apps/orweb/ |title=Orweb: Privacy Browser |work=The Guardian Project |accessdate=10 May 2011}}</ref>

<ref name="guardianproject-proxymob">{{cite web |url=https://guardianproject.info/apps/proxymob-firefox-add-on/ |title=ProxyMob: Firefox Mobile Add-on |work=The Guardian Project |accessdate=10 May 2011}}</ref>

<ref name="guardianproject-obscuracam">{{cite web |url=https://guardianproject.info/apps/obscuracam/ |title=Obscura: Secure Smart Camera |work=The Guardian Project |accessdate=19 September 2014}}</ref>

<ref name="ieee-low-cost">{{cite web |title=Low-Cost Traffic Analysis of Tor |url=https://www.cl.cam.ac.uk/~sjm217/papers/oakland05torta.pdf |first1=Steven J. |last1=Murdoch |first2=George |last2=Danezis |date=19 January 2006 |conference=IEEE Symposium on Security and Privacy |booktitle=Proceedings of the 2005 IEEE Symposium on Security and Privacy. IEEE CS |accessdate=21 May 2007}}</ref>

<ref name="iw-info-stealing">{{cite web |url=https://www.infoworld.com/t/data-security/tor-browser-bundle-windows-users-susceptible-info-stealing-attack-224157 |title=Tor Browser Bundle for Windows users susceptible to info-stealing attack |first=Ted |last=Samson |work=[[InfoWorld]] |date=5 August 2013 |accessdate=28 April 2014}}</ref>

<ref name="jones-forensics">{{Cite book |title=Internet forensics |first=Robert |last=Jones |year=2005 |page=133 |publisher=O'Reilly |isbn=0-596-10006-X}}</ref>

<ref name="LASTor-2012">{{cite conference |url=https://lastor.cs.ucr.edu/oakland12.pdf |title=LASTor: A Low-Latency AS-Aware Tor Client |first1=Masoud |last1=Akhoondi |first2=Curtis |last2=Yu |first3=Harsha V. |last3=Madhyastha |conference=IEEE Symposium on Security and Privacy |location=Oakland, USA |date=May 2012 |accessdate=28 April 2014}}</ref>

<ref name="lj-portable">{{cite web |url=https://www.linuxjournal.com/content/tor-browser-bundle-tor-goes-portable |title=Tor Browser Bundle-Tor Goes Portable |first=John |last=Knight |work=[[Linux Journal]] |date=1 September 2011 |accessdate=28 April 2014}}</ref>

<ref name="manils-compromising">{{cite conference |url=https://hal.inria.fr/docs/00/47/15/56/PDF/TorBT.pdf |title=Compromising Tor Anonymity Exploiting P2P Information Leakage |first1=Pere |last1=Manils |first2=Chaabane |last2=Abdelberri |first3=Stevens |last3=Le Blond |first4=Mohamed Ali |last4=Kaafar |first5=Claude |last5=Castelluccia |first6=Arnaud |last6=Legout |first7=Walid |last7=Dabbous |conference=7th USENIX Symposium on Network Design and Implementation |date=April 2010 |arxiv=1004.1461 |bibcode=2010arXiv1004.1461M}}</ref>

<ref name="mirror-marques">{{cite news |url=https://www.mirror.co.uk/news/world-news/eric-eoin-marques-man-branded-3046701 |title=Man branded 'largest facilitator of ***** ***** on the planet' remanded in custody again |first=Jessica |last=Best |work=[[Daily Mirror]] |date=21 January 2014 |accessdate=29 April 2014}}</ref>

<ref name="ml-rejecting">{{cite mailing list |url=https://lists.torproject.org/pipermail/tor-relays/2014-April/004336.html |title=Rejecting 380 vulnerable guard/exit keys |first=Roger |last=Dingledine |mailinglist=tor-relays |date=16 April 2014 |accessdate=28 April 2014}}</ref>

<ref name="muckrock-hunting-*****">{{cite web |url=https://www.muckrock.com/news/archives/2012/jun/08/hunting-*****-*****-fbi-stymied-tor-undernet/ |title=Hunting for ***** *****, FBI stymied by Tor undernet |first=Michael |last=Morisy |work=Muckrock |date=8 June 2012 |accessdate=6 August 2012}}</ref>

<ref name="nyt-navels">{{cite news |url=https://www.nytimes.com/2006/01/25/technology/techspecial2/25privacy.html?_r=1 |title=Privacy for People Who Don't Show Their Navels |first=Jonathan D. |last=Glater |newspaper=[[The New York Times]] |date=25 January 2006 |accessdate=13 May 2011}}</ref>

<ref name="openhub-tor">{{cite web |url=https://www.openhub.net/p/tor |title=Tor |work=Open HUB | accessdate=20 September 2014}}</ref>

<ref name="onion-router">{{cite book |url=https://books.google.com/books?id=f7*****GTclfc8C&pg=PA113 |chapter=An Analysis of Anonymity Usage |first1=Bingdong |last1=Li |first2=Esra |last2=Erdin |first3=Mehmet Hadi |last3=Güneş |first4=George |last4=Bebis |first5=Todd |last5=Shipley |pages=113–116 |title=Traffic Monitoring and Analysis: Third International Workshop, TMA 2011, Vienna, Austria, April 27, 2011, Proceedings |editor1-first=Jordi |editor1-last=Domingo-Pascual |editor2-first=Yuval |editor2-last=Shavitt |editor3-first=Steve |editor3-last=Uhlig |publisher=Springer-Verlag |location=Berlin |isbn=978-3-642-20304-6 |date=14 June 2011 |accessdate=6 August 2012}}</ref>

<ref name="or-locating">{{cite conference |url=https://www.torify.net-router.net/Publications/locating-hidden-servers.pdf |title=Locating Hidden Servers |first1=Lasse |last1=Øverlier |first2=Paul |last2=Syverson |conference=IEEE Symposium on Security and Privacy |conferenceurl=https://www.ieee-security.org/TC/SP-Index.html |booktitle=Proceedings of the 2006 IEEE Symposium on Security and Privacy |page=1 |publisher= IEEE CS Press |date=21 June 2006 |location=Oakland, CA |doi= 10.1109/SP.2006.24 |format=PDF |accessdate=9 November 2013 |isbn=0-7695-2574-1}}</ref>

<ref name="pcw-111k">{{cite web |url=https://www.pcworld.com/article/2458420/russian-government-offers-money-for-identifying-tor-users.html |title=Russian government offers huge reward for help unmasking anonymous Tor users |first=Constantin |last=Lucian |work=[[PC World]] |date=25 July 2014 |accessdate=26 July 2014}}</ref>

<ref name=prealpha>{{cite mailing list |url=https://archives.seul.org/or/dev/Sep-2002/msg00019.html |title=pre-alpha: run an onion proxy now! |last=Dingledine |first=Roger |mailinglist=or-dev |date=20 September 2002 |accessdate=17 July 2008 }}</ref>

<ref name="register-embassy-passwd">{{cite web |url=https://www.theregister.co.uk/2007/09/10/misuse_of_tor_led_to_embassy_password_breach/ |title=Tor at heart of embassy passwords leak |last=Goodin |first=Dan |work=[[TheRegister]] |date=10 September 2007 |accessdate=20 September 2007}}</ref>

<ref name="scm-egyptians">{{cite web |url=https://www.scmagazine.com.au/News/246707,egyptians-turn-to-tor-to-organise-dissent-online.aspx |title=Egyptians turn to Tor to organise dissent online |first=Nate |last=Cochrane |work=[[SC Magazine]] |date=2 February 2011 |accessdate=10 December 2011}}</ref>

<ref name="shining-light">{{cite conference |url=https://www.cs.washington.edu/homes/yoshi/papers/Tor/PETS2008_37.pdf |title=Shining Light in Dark Places: Understanding the Tor Network |first=Damon |last1=McCoy |first2=Kevin |last2=Bauer |first3=Dirk |last3=Grunwald |first4=Tadayoshi |last4=Kohno |first5=Douglas |last5=Sicker |conference= 8th International Symposium on Privacy Enhancing Technologies |booktitle=Proceedings of the 8th International Symposium on Privacy Enhancing Technologies |pages=63–76 |publisher=Springer-Verlag |location=Berlin, Germany |year=2008 |isbn=978-3-540-70629-8 |doi=10.1007/978-3-540-70630-4_5 }}</ref>

<ref name="sf-tor-hack">{{cite web |url=https://www.securityfocus.com/news/11447 |title=Tor hack proposed to catch criminals |first=Robert |last=Lemos |work=SecurityFocus |date=8 March 2007}}</ref>

<ref name="smh-hack-of-year">{{cite web |url=https://www.smh.com.au/news/security/the-hack-of-the-year/2007/11/12/1194766589522.html?page=fullpage#contentSwap2 |title=The hack of the year |first=Patrick |last=Gray |work=[[Sydney Morning Herald]] |date=13 November 2007 |accessdate=28 April 2014}}</ref>

<ref name="tbb-design-document">{{cite web |url=https://www.torproject.org/projects/torbrowser/design/ |title=The Design and Implementation of the Tor Browser &#91;DRAFT&#93; |first1=Mike |last1=Perry |first2=Erinn |last2=Clark |first3=Steven |last3=Murdoch |work=Tor Project |date=15 March 2013 |accessdate=28 April 2014}}</ref>

<ref name="thn-compromised">{{cite web | url=https://thehackernews.com/2011/10/tor-anonymizing-network-compromised-by.html | title=Tor anonymizing network Compromised by French researchers | work=The Hacker News | publisher=Thehackernews.com | date=24 October 2011 | accessdate=10 December 2011}}</ref>

<ref name="torproject-bridges">{{cite web |url=https://www.torproject.org/docs/bridges |title=Tor: Bridges |work=Tor Project |accessdate=9 January 2011}}</ref>

<ref name="torproject-conf-hidden">{{cite web |url=https://www.torproject.org/docs/tor-hidden-service |title=Configuring Hidden Services for Tor |work=Tor Project |accessdate=9 January 2011}}</ref>

<ref name="torproject-corepeople">{{cite web |url=https://www.torproject.org/about/corepeople |title=Tor Project: Core People |work=Tor Project |accessdate=17 July 2008}}</ref>

<ref name="torproject-fail-both-ends">{{cite web|url=https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ?action=recall&rev=554#EntryGuards|title=TheOnionRouter/TorFAQ|accessdate=18 September 2007|quote=Tor (like all current practical low-latency anonymity designs) fails when the attacker can see both ends of the communications channel}}</ref>

<ref name="torproject-faq">{{cite web |url=https://www.torproject.org/docs/faq#WhyCalledTor |title=Tor FAQ: Why is it called Tor? |work=Tor Project |accessdate=1 July 2011}}</ref>

<ref name="torproject-faq-*****">{{cite web |url=https://www.torproject.org/docs/faq-*****.html.en#WhatAboutCriminals |title=Doesn't Tor enable criminals to do bad things? |work=Tor Project |accessdate=28 August 2013}}</ref>

<ref name="torproject-hidden">{{cite web |url=https://www.torproject.org/docs/hidden-services.html |title=Tor: Hidden Service Protocol, Hidden services |work=Tor Project |accessdate=9 January 2011}}</ref>

<!--ref name="torproject-investigation">{{cite web |url=https://boingboing.net/2013/08/04/anonymous-web-host-shut-down.html |title=Tor web host |publisher=BoingBoing.com |accessdate=5 August 2013}}</ref-->

<ref name="torproject-news-20140416">{{cite web |url=https://blog.torproject.org/blog/tor-weekly-news-%E2%80%94-april-16th-2014 |title=Tor Weekly News — April 16th, 2014 |author=Lunar |work=Tor Project |date=16 April 2014 |accessdate=28 April 2014}}</ref>

<ref name="torproject-old-vulnerable">{{cite web |url=https://blog.torproject.org/blog/tor-security-advisory-old-tor-browser-bundles-vulnerable |title=Tor security advisory: Old Tor Browser Bundles vulnerable |first=Roger |last=Dingledine |work=Tor Project |date=5 August 2013 |accessdate=28 April 2014}}</ref>

<ref name="torproject-one-cell">{{cite web |url=https://blog.torproject.org/blog/one-cell-enough |title=One cell is enough to break Tor's anonymity |first=Roger |last=Dingledine |work=Tor Project |date=18 February 2009 |accessdate=9 January 2011}}</ref>

<ref name="torproject-openssl-cve">{{cite web |url=https://blog.torproject.org/blog/openssl-bug-cve-2014-0160 |title=OpenSSL bug CVE-2014-0160 |first=Roger |last=Dingledine |work=Tor Project |date=7 April 2014 |accessdate=28 April 2014}}</ref>

<!-- ref name="torproject-pp">{{cite web |url=https://trac.torproject.org/projects/tor/wiki/TheOnionRouter/TorFAQ#WhydoweneedPolipoorPrivoxywithTorWhichisbetter |title=TheOnionRouter/TorFAQ |work=Tor Project |accessdate=28 December 2010}}</ref> -->

<ref name="torproject-rumors-exaggerated">{{cite web |url=https://blog.torproject.org/blog/rumors-tors-compromise-are-greatly-exaggerated |title=Rumors of Tor's compromise are greatly exaggerated |last=phobos |work=Tor Project |date=24 October 2011 |accessdate=20 April 2012}}</ref>

<ref name="torproject-sponsors">{{cite web |url=https://www.torproject.org/about/sponsors.html.en |title=Tor: Sponsors |work=Tor Project |accessdate=11 December 2010}}</ref>

<ref name="torstatus">{{cite web| title = Tor Network Status | url = https://torstatus.blutmagie.de/ | accessdate=14 February 2015}}</ref>

<ref name="tp-blacklisting">{{cite web |url=https://threatpost.com/tor-begins-blacklisting-exit-nodes-vulnerable-to-heartbleed/105519 |title=Tor begins blacklisting exit nodes vulnerable to Heartbleed |first=Michael |last=Mimoso |work=Threat Post |date=17 April 2014 |accessdate=28 April 2014}}</ref>

<ref name="twe-zmap">{{cite web |url=https://www.techweekeurope.co.uk/news/zmap-internet-scan-zero-day-125374 |title=Zmap’s Fast Internet Scan Tool Could Spread Zero Days In Minutes |last=Judge |first=Peter |work=TechWeek Europe |date=20 August 2013 |accessdate=28 April 2014}}</ref>

<ref name="usenix-bad-apple">{{cite conference |url=https://www.usenix.org/events/leet11/tech/full_papers/LeBlond.pdf |title=One Bad Apple Spoils the Bunch: Exploiting P2P Applications to Trace and Profile Tor Users |first1=Stevens |last1=Le Blond |first2=Pere |last2=Manils |first3=Abdelberi |last3=Chaabane |first4=Mohamed |last4=Ali Kaafar |first5=Claude |last5=Castelluccia |first6=Arnaud |last6=Legout |first7=Walid |last7=Dabbous |conference=4th USENIX Workshop on Large-Scale Exploits and Emergent Threats (LEET '11) |publisher=National Institute for Research in Computer Science and Control |date=March 2011 |accessdate=13 April 2011}}</ref>

<ref name="usenix-design">{{cite conference |last1=Dingledine |first1=Roger |last2=Mathewson |first2=Nick |last3=Syverson |first3=Paul |title=Tor: The Second-Generation Onion Router |booktitle=Proc. 13th USENIX Security Symposium |place=San Diego, California |date=13 August 2004 |url=https://www.usenix.org/events/sec04/tech/dingledine.html |accessdate=17 November 2008}}</ref>

<ref name="vuze-tor">{{cite web |url=https://wiki.vuze.com/w/Tor |title=Tor |publisher=Vuze |accessdate=3 March 2010}}</ref>

<ref name="verge-applebaum">{{cite web|url=https://www.theverge.com/2013/3/11/4091186/interview-uncut-jacob-appelbaum|title=Interview uncut: Jacob Appelbaum|author=Sirius, R. U.|work=theverge.com |date=11 March 2013}}</ref>

<ref name="wired-fbi-controlled">{{cite news |url=https://www.wired.com/threatlevel/2013/09/freedom-hosting-fbi/ |title=FBI Admits It Controlled Tor Servers Behind Mass Malware Attack |first=Kevin |last=Poulsen |work=[[Wired (magazine)|Wired]] |date=13 September 2013 |accessdate=22 December 2013}}</ref>

<ref name="wired-feds-are-suspects">{{cite news |url=https://www.wired.com/2013/08/freedom-hosting/ |title=Feds Are Suspects in New Malware That Attacks Tor Anonymity |first=Kevin |last=Poulsen |work=[[Wired (magazine)|Wired]] |date=8 May 2013 |accessdate=29 April 2014}}</ref>

<ref name="wired-rogue-nodes">{{cite news |url=https://www.wired.com/politics/security/news/2007/09/embassy_hacks?currentPage=all |title=Rogue Nodes Turn Tor Anonymizer Into Eavesdropper's Paradise |first1=Kim |last1=Zetter |authorlink=Kim Zetter |newspaper=[[Wired (magazine)|Wired]] |date=10 September 2007 |accessdate=16 September 2007}}</ref>

<ref name="wp-attacks-prompt">{{cite news |url=https://blog.washingtonpost.com/securityfix/2007/08/attacks_prompt_update_for_tor.html?nav=rss_blog |title=Attacks Prompt Update for 'Tor' Anonymity Network |first=Brian |last=Krebs |work=[[Washington Post]] |date=8 August 2007 |accessdate=27 October 2007}}</ref>

<ref name="wp-feds-pay">{{cite news |url=https://www.washingtonpost.com/blogs/the-switch/wp/2013/09/06/the-feds-pays-for-60-percent-of-tors-development-can-users-trust-it/ |title=The feds pay for 60 percent of Tor’s development. Can users trust it? |first=Brian |last=Fung |work=The Switch |publisher=[[Washington Post]] |date=6 September 2013 |accessdate=6 February 2014}}</ref>

<ref name="wsj-anonymous-contraversial">{{cite news |url=https://online.wsj.com/article/SB10001424127887324677204578185382377144280.html |title=Tor: an anonymous, and controversial, way to web-surf |first=Geoffrey A. |last=Fowler |work=[[Wall Street Journal]] |date=17 December 2012 |accessdate=19 May 2013}}</ref>

<ref name="wu8-ubuntu-ppa">{{cite web |url=https://www.webupd8.org/2013/12/tor-browser-bundle-ubuntu-ppa.html |title=Tor Browser Bundle Ubuntu PPA |first=Andrei |last=Alin |work=Web Upd8|date=2 December 2013 |accessdate=28 April 2014}}</ref>

<ref name="xakep-whole-hog">{{cite web |url=https://eng.xakep.ru/link/51074/ |title=Включаем Tor на всю катушку |trans_title=Make Tor go the whole hog |first=Антон |last=Жуков |work=Xakep |date=15 December 2009 |accessdate=28 April 2014}}{{Dead link|date=September 2014}}</ref>

<ref name="arrests">{{cite web |url=https://www.bbc.co.uk/news/technology-29987373 |title=Dark net experts trade theories on 'de-cloaking' after raids |date=7 November 2014 |accessdate=12 November 2014}}</ref>

<!--ref name=technologyreview>{{cite news |title=Home Internet with Anonymity Built In |first=Tom |last=Simonite |url=https://www.technologyreview.com/web/26981/?a=f |newspaper=[[Technology Review]] |date=22 December 2010 |accessdate=14 May 2011}}</ref-->

}}
.

==External links==
{{Commons category|Tor project}}
* {{Official website|https://www.torproject.org}}
** {{Official blog|https://blog.torproject.org}}
* {{YouTube|id=oZdeRmlj8Gw|title=Tor: Hidden Services and Deanonymisation <nowiki>[31c3]</nowiki>}}

{{Tor project}}
{{Cryptographic software}}
{{Tor hidden services}}

{{DEFAULTSORT:Tor (Anonymity Network)}}
[[Category:Tor (anonymity network)| ]]
[[Category:Internet security]]
[[Category:Internet Standards]]
[[Category:Internet protocols]]
[[Category:Secure communication]]
[[Category:Application layer protocols]]
[[Category:Software using the BSD license]]