View source for .onion

'''.onion''' is a pseudo-top-level domain host suffix (similar in concept to such endings as .bitnet and .uucp used in earlier times) designating an [[Hidden Service|anonymous hidden service]] reachable via the [[Tor]] network.  Such addresses are not actual DNS names, and the .onion TLD is not in the Internet DNS root, but with the appropriate proxy software installed, Internet programs such as Web browsers can access sites with .onion addresses by sending the request through the network of [[Tor]] servers.  The purpose of using such a system is to make both the information provider and the person accessing the information more difficult to trace, whether by one another, by an intermediate network host, or by an outsider.

== Format ==
Addresses in the .onion pseudo-TLD are opaque, non-mnemonic, 16-character alpha-semi-numeric hashes which are automatically generated based on a public [[KeY|key]] when a [[Hidden Service|Hidden service]] is configured. These 16-character hashes can be made up of any letter of the alphabet, and decimal digits beginning with 2 and ending with 7, thus representing an 80-bit number in base32.

The "onion" name refers to onion routing, the technique used by [[Tor]] to achieve a degree of [[anonymity]].

== WWW to .onion Gateways ==

Proxies into the [[Tor]] network like onion.cab and [[Tor]]2web allow access to hidden services from non-[[Tor]] browsers and for search engines that are not [[Tor]]-aware. By using a gateway, users give up their own [[anonymity]] and trust the gateway to deliver the correct content. Both the gateway and the [[Hidden Service|hidden service]] can fingerprint the browser, and access user IP address data. Some Proxies use caching techniques to provide a better page-loading To use a gateway, replace the domain suffix ''.onion'' of any [[Hidden Service|hidden service]] by ''.onion.cab''

== .exit ==
'''.exit''' is a pseudo-top-level domain used by [[Tor]] users to indicate on the fly to the [[Tor]] software the preferred exit [[node]] that should be used while connecting to a service such as a web server, without having to edit the configuration file for [[Tor]] (''torrc'')

The syntax used with this domain is ''hostname'' + ''.exitnode'' + ''.exit'', so that a user wanting to connect to
<nowiki>http://www.torproject.org/</nowiki> through [[node]] ''[[tor]]26'' would have to enter the URL ''
<nowiki>http://www.torproject.org.tor26.exit</nowiki> ''.

Example uses for this include accessing a site available only to addresses of a certain country or checking if a certain [[node]] is working.

Users can also type ''exitnode.exit'' alone to access the IP address of ''exitnode''.

The .exit notation is disabled by default as of version 0.2.2.1-alpha.

== See also ==
* [[Deep Web]]
* [[Hidden Service]]
* [[Tor]]
* [[The Hidden Wiki]]



==External links==
* [http://www.torproject.org/docs/tor-hidden-service.html Tor: Hidden Service Configuration Instructions]