Tor glossary version 1.0
A
add-on, extension, or plugin
Add-ons, extensions, and plugins are components that can be added to #WebBrowser to give them new features. #TorBrowser comes with two add-ons installed: #NoScript and #HTTPS-Everywhere. You should not install any additional add-ons to Tor Browser because that can compromise some of its privacy features.
antivirus software
An antivirus software is used to prevent, detect and remove malicious software. Antivirus software can interfere with #TorTornetworkCoreTor running on your computer. You may need to consult the documentation for your antivirus software if you do not know how to allow Tor.
App
A web application (web app), is an application which the #client runs in a #WebBrowser. App can also refer to software that you install on mobile #OperatingSystemOS.
Atlas
Atlas is a web application to learn about currently running Tor #relay.
B
bandwidth authority
To determine a relay's throughput, special relays called bandwidth authorities take periodic measurements of the #relay in the #consensus.
bridge
Like ordinary Tor #relay, bridges are run by volunteers; unlike ordinary relays, however, they are not listed publicly, so an adversary cannot identify them easily. #pluggabletransports are a type of bridge that help disguise the fact that you are using Tor.
bridge authority
A special-purpose relay that maintains the list of #bridge.
browser fingerprinting
Fingerprinting is the process of collecting information about a device or service to make educated guesses about its identity or characteristics. Unique behavior or responses can be used to identify the device or service analyzed. #TorBrowser prevents fingerprinting.
browsing history
A browser history is a record of requests made while using a #WebBrowser, and includes information like websites visited and when. #TorBrowser deletes your browsing history after you close your #session.
C
CAPTCHA
Captchas are a challenge-response test used in computing to determine whether the user is human or not. #TorTornetworkCoreTor users are often served captchas because Tor #relay make so many requests that sometimes websites have a hard time determining whether or not those requests are coming from humans or from bots.
checksum
Checksums are #hash values of files. If you are downloaded the software without errors, the given checksum and the checksum of your downloaded file will be identical.
circuit
A path through the #TorTornetworkCoreTor built by #client consisting of randomly selected nodes. The circuit begins with either a #bridge or a #guard. Most circuits consist of three nodes - a guard or bridge, a #middlerelay, and an #exit. Most [[#onionservices|onion services use six hops in a circuit (with the exception of [[singleonionservices| single onion services]]), and never an exit node. You can view your current Tor circuit by clicking on the onion button in Tor Browser.
client
In #TorTornetworkCoreTor, a client is a node in the Tor network, typically running on behalf of one user, that routes application connections over a series of #relay.
Compass
Compass is a web application to learn about currently running #relay in bulk.
consensus
In Tor terms, a single document compiled and voted on by the #directoryauthority once per hour, ensuring that all #client have the same information about the #relay that make up the #TorTornetworkCoreTor.
cookie
An #HTTP cookie (also called web cookie, Internet cookie, browser cookie or simply cookie) is a small piece of data sent from a website and stored on the user's computer by the user's #WebBrowser while the user is browsing. #TorBrowser does not store cookies.
cross-site scripting (XSS)
Cross-Site Scripting (XSS) allows an attacker to add malicious functionality or behavior to a website when they shouldn't have the ability to do so.
cryptographic signature
A cryptographic signature proves the authenticity of a message or file. It is created by the holder of the private portion of a #publickeycryptography key pair and can be verified by the corresponding public key. If you download software from torproject.org, you will find it as sig files (.asc). These are PGP signatures, so you can verify that the file you have downloaded is exactly the one that we intended you to get. For more information about how you can verify signatures, please see https://www.torproject.org/docs/verifying-signatures.html.en.
D
Daemon
A daemon is a computer program that runs as a background process, rather than being under the direct control of a user.
directory authority
A special-purpose #relay that maintains a list of currently-running relays and periodically publishes a #consensus together with the other directory authorities.
E
encryption
The process of taking a piece of data and scrambling it into a secret code that can only be read by the intended recipient. #TorTornetworkCoreTor uses three layers of encryption in the Tor #circuit; each #relay decrypts one layer before passing the request on to the next relay.
end-to-end encrypted
Transmitted data which is #encryption from origin to destination is called end-to-end encrypted.
exit
The last #relay in the #circuit which sends #traffic out onto the public Internet. The service you are connecting to (website, chat service, email provider, etc..) will see the #IPaddress of the exit.
ExoneraTor
The ExoneraTor service maintains a database of #relay #IPaddress that have been part of the Tor network. It answers the question whether there was a #TorTornetworkCoreTor relay running on a given IP address on a given date. This service is often useful when dealing with law enforcement.
F
Firefox
Mozilla Firefox is a free and open-source #WebBrowser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. #TorBrowser is built from a modified version of Firefox ESR (Extended Support Release). Firefox is available for Windows, OS X and Linux #OperatingSystemOS, with its mobile versions available for Android, and Firefox OS.
firewall
A firewall is a network security system which monitors and controls the incoming and outgoing network #traffic. This traffic filter is based on predetermined rules. A firewall typically establishes a barrier between a trusted, secure internal network and another outside network but it can also be used as a content filter in the sense of #networkcensorship. Sometimes people have trouble connecting to #TorTornetworkCoreTor because their firewall blocks Tor connections. You can reconfigure or disable your firewall and restart Tor to test this.
Flash Player
Flash Player is a #add-onextensionorplugin for Internet #App to watch audio and video content. You should never enable Flash to run in #TorBrowser as it is unsafe. Many services that use Flash also offer an HTML5 alternative, which should work in the Tor Browser.
fte
FTE (format-transforming encryption) is a pluggable transport that disguises #traffic as ordinary web (HTTP) traffic.
G
GetTor
It is a service that automatically responds to messages (Email, XMPP, Twitter) with links to the latest version of #TorBrowser, hosted at a variety of locations, such as Dropbox, Google Drive and Github.
GSoC
The Tor Project participates in the Google Summer of Code, which is a summer program for university students.
guard
The first #relay in the #circuit, unless using a #bridge. When using a bridge, the bridge takes the place of the guard.
H
hash
A cryptographic hash value is the result of a mathematical algorithm that maps data to a bit string of a fixed size. It's designed as one-way-function which means the value is easy to calculate in one direction but infeasible to invert. Hash values serve to verify the integrity of data.
hidden services
Former name for "#onionservices", sometimes still in use in #TorTornetworkCoreTor documentation or communication.
hop
In #TorTornetworkCoreTor terms, a "hop" refers to #traffic moving between #relay in a #circuit.
HTTP
The Hypertext Transfer Protocol (HTTP) is a channel used to send files and data between devices on a network. Originally used to transfer only web pages, it is now relied upon to deliver many forms of data and communication.
HTTPS
Hypertext Transfer Protocol Secure is the #encryption version of the HTTP channel used to transfer files and data between devices on a network.
HTTPS-Everywhere
HTTPS Everywhere is a #Firefox, Chrome, and Opera #add-onextensionorplugin that makes #HTTPS the default on websites that have set up HTTPS but have not made it the default. HTTPS Everywhere is installed in #TorBrowser.
I
Internet Service Provider (ISP)
An Internet service provider (ISP) is an organization that provides services for accessing and using the Internet. When using #TorBrowser, your ISP cannot see what websites you're visiting.
IP address
An Internet Protocol address (IP address) is a numerical (or alpha-numeric in the case of IPv6) label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication. IP addresses are the location address of the device, similar to the addresses of physical locations. #TorBrowser obscures your location by making it look like your #traffic is coming from an IP address that is not your own.
J
JavaScript
JavaScript is a programming language that websites use to offer interactive elements such as video, animation, audio, and status timelines. Unfortunately, JavaScript can also enable attacks on the security of the #WebBrowser, which might lead to deanonymization. The #NoScript #add-onextensionorplugin in #TorBrowser can be used to manage Javascript on different websites.
K
L
little-t tor
"little-t tor" is one way of referring to tor the network daemon, as opposed to Tor Browser or Tor Project.
M
meek
These #pluggabletransports all make it look like you are browsing a major web site instead of using #TorTornetworkCoreTor. Meek-amazon makes it look like you are using Amazon Web Services; meek-azure makes it look like you are using a Microsoft web site; and meek-google makes it look like you are using Google search.
middle relay
The middle position in the #circuit. Non-exit relays can function as either a "middle" or a "#guard" for different users.
N
New Identity
New Identity is a #TorBrowser feature if you want to prevent your subsequent browser activity from being linkable to what you were doing before. Selecting it will close all your open tabs and windows, clear all private information such as #cookie and #browsinghistory, and use New #circuit for all connections. Tor Browser will warn you that all activity and downloads will be stopped, so take this into account before clicking “New Identity”. New Identity can also help if Tor Browser is having trouble connecting to a particular site, similarly to "#NewTorCircuitforthisSite".
New Tor Circuit for this Site
This option is useful if the #exit you are using is unable to connect to the website you require, or is not loading it properly. Selecting it will cause the currently-active tab or window to be reloaded over a new #circuit. Other open tabs and windows from the same website will use the new circuit as well once they are reloaded. This option does not clear any private information or unlink your activity, nor does it affect your current connections to other websites.
network censorship
Sometimes the direct access to the #TorTornetworkCoreTor is blocked by your #InternetServiceProviderISP or by a government. Tor Browser includes some circumvention tools for getting around these blocks, including #bridge, #pluggabletransports, and #GetTor.
NoScript
#TorBrowser includes an #add-onextensionorplugin called NoScript, accessed through the “S” icon at the top-left of the window, which allows you to control the #JavaScript that runs on individual web pages, or to block it entirely.
nyx
The anonymizing #relay monitor (formerly arm, now nyx) is a terminal status monitor for #TorTornetworkCoreTor, intended for command-line usage. This is a tool for monitoring the core Tor process on a system, often useful for relay operators.
O
obfs3
Obfs3 is a #pluggabletransports that makes #TorTornetworkCoreTor #traffic look random, so that it does not look like Tor or any other protocol. Obfs3 bridges will work in most places.
obfs4
Obfs4 is a #pluggabletransports that makes #TorTornetworkCoreTor #traffic look random like obfs3, and also prevents censors from finding bridges by Internet scanning. Obfs4 bridges are less likely to be blocked than obfs3 #bridge.
onion address
A standardized internet domain name used by onion services that ends in .onion and is designed to be #self-authenticatingaddress.
OONI
OONI stands for "Open Observatory of Network Interference", it is a global observation network for detecting #networkcensorship, surveillance and #traffic manipulation on the internet.
onion services
Onion services (formerly known as “#hiddenservices”) are services (like websites) that are only accessible through the #TorTornetworkCoreTor. Onion services offer advantages over ordinary services on the non-private web, including: hidden location and #IPaddress #end-to-endencrypted #traffic between Tor users and onion services
Onionoo
Onionoo is a web-based protocol to learn about currently running #relay and #bridge. Onionoo provides the data for other applications and websites(compass, atlas, etc..) which in turn present Tor network status information to humans.
onionsite
An onionsite is another name for an #onionservices, but refers exclusively to websites. These websites use the .onion Top Level Domain (TLD).
onionspace
The set of available #onionservices. For example, you can say "my site is in onionspace" instead of "my site is in the Dark Web."
Operating System (OS)
The main system software that manages computer hardware and software resources and provides common services for computer programs. The most used desktop operating systems are Windows, OS X and Linux. Android and iOS are the dominant mobile operating systems.
Orbot
Orbot is a free #App from The Guardian Project that empowers other apps on your device to use the internet more securely. Orbot uses #TorTornetworkCoreTor to #encryption your Internet #traffic and hide it by bouncing through a series of computers around the world.
Orfox
Orfox is free #App from The Guardian Project built from the same source code as #TorBrowser (which is built upon #Firefox), but with a few minor modifications to the privacy enhancing features to make them compatible with Firefox for Android and the Android #OperatingSystemOS.
P
pluggable transports
Tools that #TorTornetworkCoreTor can use to disguise the #traffic it sends out. This can be useful in situations where an #InternetServiceProviderISP or other authority is actively blocking connections to the #TorTornetworkCoreTor.
private key
The private portion of a #publickeycryptography. This is the key that must be kept private, and not disseminated to others.
proxy
A proxy is a middle man between a #client (like a #WebBrowser) and a service (like a #server). Instead of connecting directly to the service, a client sends the message to the proxy. The proxy makes the request on behalf of the client, and passes the response back to the client. The service only communicates with and sees the proxy.
public key
The public portion of a #publickeycryptography. This is the key that can be disseminated to others.
public key cryptography
A public-key cryptography system uses pairs of mathematical keys. The #publickey can be disseminated widely while its belonging #privatekey is known only by the owner of the key pair. Any person can #encryption a message using the public key of the receiver but only the receiver in possession of the private key is able to decrypt the message. Additionally the private key can be used to create a #cryptographicsignature to proof the identity of the creator of a message or other files. This signature can be verified by the public key.
Q
R
relay
A publicly-listed node in the #TorTornetworkCoreTor that forwards #traffic on behalf of #client, and that registers itself with the #directoryauthority.
S
Satori
It is an #add-onextensionorplugin for the Chrome or Chromium browsers that allows you to download several security and privacy programs, including #TorBrowser, from different sources. You can Install Satori from the Chrome App Store.
scramblesuit
Scramblesuit is similar to obfs4 but has a different set of #bridge.
script
Elements used for offering dynamic/interactive content via websites.
Security Slider
#TorBrowser includes a “Security Slider” that lets you increase your security by disabling certain web features that can be used to attack your security and anonymity. It is located in Torbutton’s “Privacy and Security Settings” menu. Increasing the level (Low, Medium-Low, Medium-High, High) of the Security Slider will disable or partially disable certain #WebBrowser features to protect against possible attacks.
self-authenticating address
The specialized address format of #onionaddress is self-authenticating. The format automatically guarantees that the onion address is bound to the key used to protect connections to the #onionsite. Ordinary internet domain names require site owners to trust and be approved by a Certificate Authority (CA) for this binding, and they are subject to hijack by the CA and typically by many other parties as well.
server
A device on a network which offers a service, such as file and web page storage, email or chat.
session
A session refers to a conversation between two devices communicating on a network. Using #TorBrowser means that your session data will be wiped when you close the #WebBrowser.
single onion service
A single onion service is an onion service that can be configured for services that do not require anonymity, but want to offer it for clients connecting to their service. Single onion services use only three hops in the #circuit rather than the typical six hops for onion services.
Stem
Stem is a Python(programming language) controller library for core #TorTornetworkCoreTor. If you want to control core Tor with python, this is for you.
Sybil attack
The Sybil attack in computer security is an attack wherein a reputation system is subverted by creating a large number of identities, and using them to gain a disproportionately large influence in the network.
T
Tails
Tails is a "live" #OperatingSystemOS, that you can start on almost any computer from a DVD, USB stick, or SD card. It aims to preserve your privacy and anonymity.
The Tor Project
The Tor Project can refer to either The Tor Project Inc, a 501(c)3 US nonprofit responsible for maintaining the Tor software, or the Tor Project community made up of thousands of volunteers from all over the world who help create Tor.
third-party tracking
Most websites use numerous third-party services, including advertising and analytics trackers, which collect data about your #IPaddress, #WebBrowser, #OperatingSystemOS and your browsing behavior itself, all of which can link your activity across different sites. #TorBrowser prevents a lot of this activity from happening.
Tor / Tor network/ Core Tor
Tor is a program you can run on your computer that helps keep you safe on the Internet. It protects you by bouncing your communications around a distributed network of #relay run by volunteers all around the world: it prevents somebody watching your Internet connection from learning what sites you visit, and it prevents the sites you visit from learning your physical location. This set of volunteer relays is called the Tor network. Sometimes the software associated with this network is called Core Tor, and sometimes #littlettor. The way most people use Tor is with #TorBrowser, which is a version of #Firefox that fixes many privacy issues.
Tor Browser
Tor Browser uses the #TorTornetworkCoreTor to protect your privacy and anonymity. Your internet activity, including the names and addresses of the websites you visit, will be hidden from your #InternetServiceProviderISP and from anyone watching your connection locally. The operators of the websites and services that you use, and anyone watching them, will see a connection coming from the Tor network instead of your real Internet #IPaddress, and will not know who you are unless you explicitly identify yourself. In addition, Tor Browser is designed to prevent websites from “#browserfingerprinting” or identifying you based on your browser configuration. By default, Tor Browser does not keep any #browsinghistory. #cookie are only valid for a single #session (until Tor Browser is exited or a #NewIdentity is requested).
Tor Launcher
When you run #TorBrowser for the first time, you will see the Tor Launcher window. It offers you the option to connect directly to the #TorTornetworkCoreTor, or to configure Tor Browser for your connection. In the second case Tor Launcher will take you through a series of configuration options.
Tor log
"Tor log" is an automatically-generated list of #TorTornetworkCoreTor’s activity that can help diagnose problems. When something goes wrong with Tor, you may see an option with the error message to "copy Tor log to clipboard". If you don't see this option and you have #TorBrowser open, you can navigate to the #Torbutton (on the top left of the browser immediately to the left of the URL bar). Click the Tor button, then open Tor Network Settings. You should see an option at the bottom to copy the log to your clipboard, which you can then paste to a document to show whoever is helping you troubleshoot.
Tor Messenger
Tor Messenger is a cross-platform chat program that aims to be secure by default and sends all of its #traffic over #TorTornetworkCoreTor. It supports Jabber (XMPP), IRC, Google Talk, Facebook Chat, Twitter, Yahoo, and others; enables Off-the-Record (OTR) Messaging automatically; and has an easy-to-use graphical user interface localized into multiple languages.
TorBirdy
This #add-onextensionorplugin configures Thunderbird to make connections over #TorTornetworkCoreTor.
Torbutton
A button marked by a little green onion to the left of the URL bar. Its menu offers you "#NewIdentity", "#NewTorCircuitforthisSite", "Privacy and Security Settings...", "Tor Network Settings..." and "Check for #TorBrowser Update..." options.
torrc
The core #TorTornetworkCoreTor configuration file.
Torsocks
Torsocks allows you to use many applications in a safer way with #TorTornetworkCoreTor. It ensures that DNS requests are handled safely and explicitly rejects any #traffic other than TCP from the application you're using.
Tor2Web
Tor2web is a project to let users access #onionservices without using the #TorBrowser. NOTE: This is not as safe as connecting to the #hiddenservices via Tor Browser, and will removes all #TorTornetworkCoreTor-related protections the #client would otherwise have.
TPI
TPI is an acronym for The Tor Project, Inc.
tpo
People on IRC often use tpo to abbreviate torproject.org when writing hostnames. For example, trac.tpo is an abbreviation for trac.torproject.org.
traffic
Traffic is the data sent and received by #client and #server.
U
V
W
Web Browser
A web browser (commonly referred to as a browser) is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. Major web browsers include #Firefox, Chrome, Internet Explorer, and Safari.
website mirror
A website mirror is an one-to-one copy of a website which you can find under other web addresses. A current list of torproject.org mirrors is available at https://www.torproject.org/getinvolved/mirrors.html.en.
X
Y
Z
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