Last updated
Logo of SIGAINT.png
Type of site
Webmail, E-Mail service
Available in English language English, sigaintevyh2rzvw.onion(defunct) [1]
Users about 370,000 [2]
Current statusOffline

SIGAINT was a Tor hidden service offering secure email services. According to its FAQ page, its web interface used SquirrelMail which does not rely on JavaScript. Passwords couldn't be recovered. Users received two addresses per inbox: one at for receiving clearnet emails and the other at its .onion address only for receiving emails sent from other Tor-enabled email services. Free accounts had 50 MB of storage space and expired after one year of inactivity. Upgraded accounts had access to POP3, IMAP, SMTP, larger size limits, full disk encryption, and never expired.

Email Method of exchanging digital messages between people over a network

Electronic mail is a method of exchanging messages ("mail") between people using electronic devices. Invented by Ray Tomlinson, email first entered limited use in the 1960s and by the mid-1970s had taken the form now recognized as email. Email operates across computer networks, which today is primarily the Internet. Some early email systems required the author and the recipient to both be online at the same time, in common with instant messaging. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect only briefly, typically to a mail server or a webmail interface for as long as it takes to send or receive messages.

SquirrelMail open source web-based email client

SquirrelMail is a project that provides both a web-based email client and a proxy server for the IMAP protocol.

JavaScript, often abbreviated as JS, is a high-level, interpreted scripting language that conforms to the ECMAScript specification. JavaScript has curly-bracket syntax, dynamic typing, prototype-based object-orientation, and first-class functions.

The service was recommended by various security specialists as a highly secure email service. [3] [4] [1]

In April 2015, a number of user accounts were compromised in what was speculated at the time to be a government-sponsored de-anonymization attack from 70 different exit nodes. [5] [6] A SIGAINT administrator said that the hidden service was not hacked but malicious exit nodes had modified their clearnet page so that its link to the hidden service pointed to an imposter hidden service, effectively tricking users with a phishing attack that harvested login credentials. [2] SIGAINT has since added SSL to their gateway to protect against such attacks. [7]

Phishing act of attempting to acquire (sensitive) information by posing as a trustworthy entity

Phishing is the fraudulent attempt to obtain sensitive information such as usernames, passwords and credit card details by disguising oneself as a trustworthy entity in an electronic communication. Typically carried out by email spoofing or instant messaging, it often directs users to enter personal information at a fake website which matches the look and feel of the legitimate site.

The service is currently down. Both its ".org" website and its onion link return error code 500. [8]

See also

Related Research Articles

Webmail is any email client implemented as a web application running on a web server. Examples of webmail software are Roundcube and SquirrelMail. Examples of webmail providers are AOL Mail, Gmail,, Rackspace Email, Yahoo! Mail and IceWarp Mail Server. Many webmail providers also offer email access by a desktop email client using standard email protocols, while many internet service providers provide a webmail client as part of the email service included in their internet service package.

Hushmail is an encrypted proprietary web-based email service offering PGP-encrypted e-mail and vanity domain service. Hushmail uses OpenPGP standards. If public encryption keys are available to both recipient and sender, Hushmail can convey authenticated, encrypted messages in both directions. For recipients for whom no public key is available, Hushmail will allow a message to be encrypted by a password and stored for pickup by the recipient, or the message can be sent in cleartext. In July, 2016, the company launched an iOS app that offers end-to-end encryption and full integration with the webmail settings.

Onion routing is a technique for anonymous communication over a computer network. In an onion network, messages are encapsulated in layers of encryption, analogous to layers of an onion. The encrypted data is transmitted through a series of network nodes called onion routers, each of which "peels" away a single layer, uncovering the data's next destination. When the final layer is decrypted, the message arrives at its destination. The sender remains anonymous because each intermediary knows only the location of the immediately preceding and following nodes. There are methods to break the anonymity of this technique, e.g. timing analysis.

Dark Net is an umbrella term describing the portions of the Internet purposefully not open to public view or hidden networks whose architecture is superimposed on that of the Internet. "Darknet" is often associated with the encrypted part of the Internet called Tor network where illicit trading takes place such as the former infamous online drug bazaar called Silk Road. It is also considered part of the deep web. Anonymous communication between whistle-blowers, journalists and news organisations is facilitated by the "Darknet" Tor network through use of applications including SecureDrop.

.onion pseudo-top-level domain host suffix

.onion is a special-use top level domain suffix designating an anonymous onion 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 Tor network.

The following tables compare general and technical information for a number of notable webmail providers who offer a web interface in English. webmail service from Microsoft is a web-based suite of webmail, contacts, tasks, and calendaring services from Microsoft. One of the world's first webmail services, it was founded in 1996 as Hotmail by Sabeer Bhatia and Jack Smith in Mountain View, California, and headquartered in Sunnyvale. Microsoft acquired Hotmail in 1997 for an estimated $400 million and launched it as MSN Hotmail, later rebranded to Windows Live Hotmail as part of the Windows Live suite of products. Microsoft released the final version of Hotmail in October 2011 and it was replaced by in 2012.

Tor (anonymity network) Free and open-source anonymity network based on onion routing

Tor is free and open-source software for enabling anonymous communication. The name is derived from an acronym for the original software project name "The Onion Router". Tor directs Internet traffic through a free, worldwide, volunteer overlay network consisting of more than seven thousand relays to conceal a user's location and usage from anyone conducting network surveillance or traffic analysis. Using Tor makes it more difficult to trace Internet activity to the user: this includes "visits to Web sites, online posts, instant messages, and other communication forms". Tor's intended use is to protect the personal privacy of its users, as well as their freedom and ability to conduct confidential communication by keeping their Internet activities unmonitored.

The Hidden Wiki censorship-resistant wiki

The Hidden Wiki is the name used by several censorship-resistant wikis operating as Tor hidden services that anyone can anonymously edit after registering on the site. The main page serves as a directory of links to other .onion sites.

Tor Mail

Tor Mail is a former Tor hidden service that went offline in August 2013 after an FBI raid on Freedom Hosting. The service allowed users to send and receive email anonymously, to email addresses inside and outside the Tor network.

Freedom hosting is a defunct Tor specialist web hosting service that was established in 2008. At its height in August 2013, it was the largest Tor webhost.

The dark web is the World Wide Web content that exists on darknets, overlay networks that use the Internet but require specific software, configurations, or authorization to access. The dark web forms a small part of the deep web, the part of the Web not indexed by web search engines, although sometimes the term deep web is mistakenly used to refer specifically to the dark web.

ProtonMail end-to-end encrypted email service

ProtonMail is an end-to-end encrypted email service founded in 2014 at the CERN research facility by Andy Yen, Jason Stockman, and Wei Sun. ProtonMail uses client-side encryption to protect email contents and user data before they are sent to ProtonMail servers, unlike other common email providers such as Gmail and The service can be accessed through a webmail client, the Tor network, or dedicated iOS and Android apps.

Grams was a search engine for Tor based darknet markets launched in April 2014, and closed in December 2017. The service allowed users to search multiple darknet markets for products like drugs and guns from a simple search interface, and also provided the capability for its users to hide their transactions through its bitcoin tumbler Helix.

Clearnet (networking) unencrypted, or non-darknet, non-Tor Internet

Clearnet is a term typically referring to the publicly accessible Internet, the opposite of the darknet that typically describes the encrypted, anonymous services built on the Tor Internet service, and similar.

The Tor Carding Forum (TCF) was a Tor-based forum specializing in the trade of stolen credit card details, identity theft and currency counterfeiting. The site was founded by an individual known as 'Verto' who also founded the now defunct Evolution darknet market.

Ahmia is a clearnet search engine for Tor's hidden services created by Juha Nurmi. Together with VPN and Tor, this technology is crucial in exploring the dark web, which is reported to be about ten times bigger than normal web content.

facebookcorewwwi.onion Tor onion service of Facebook

facebookcorewwwi.onion is a site that allows access to Facebook through the Tor protocol, using its .onion top-level domain. In April 2016, it had been used by over 1 million people monthly, up from 525,000 in 2015. Neither Twitter nor Google operate sites through Tor, and Facebook has been applauded for allowing such access, which makes it available in countries that actively try to block Facebook.

Dread (forum)

Dread is a Reddit-like dark web discussion forum featuring news and discussions around darknet markets. The site's administrator goes by the alias of 'HugBunter'.


  1. 1 2 "Interview With "Sigaint DarkNet Email" Admin". DeepDotWeb . 2015-02-16. Archived from the original on 2015-03-23.
  2. 1 2 SIGAINT Admin. "SIGAINT email service targeted by 70 bad exit nodes". tor-talk. Tor Project. Retrieved 2016-08-31.
  3. Pauli, Darren (4 May 2016). "How to evade the NSA: OpSec guide for journalists also used by terrorists" . Retrieved 26 May 2016.
  4. Maria, Korolov (13 May 2016). "Terrorists opt for consumer tools" . Retrieved 26 May 2016.
  5. Paganini, Pierluigi (26 April 2015). "Dark Web Email Service SIGAINT hacked by the Intelligence" . Retrieved 26 May 2016.
  6. Franceschi-Bicchierai, Lorenzo (24 April 2015). "After Hacks, A Dark Web Email Provider Says a Government Spied on Its Users" . Retrieved 25 September 2016.
  7. SIGAINT. "SIGAINT Incidents Report" . Retrieved 25 September 2016.
  8. Leyden, John. "Dark net webmail provider Sigaint still in the, er, dark" . Retrieved 6 March 2017.