Dark Net (or Darknet) 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.^[1] "Darknet" is often associated with the encrypted part of the Internet called Tor network where illicit trading takes place such as the infamous online drug bazaar called Silk Road.^[2] It is also considered part of the deep web.^[3] Anonymous communication between whistle-blowers, journalists and news organisations is facilitated by the "Darknet" Tor network through use of applications including SecureDrop.^[4]

The term originally described computers on ARPANET that were hidden, programmed to receive messages but not respond to or acknowledge anything, thus remaining invisible, in the dark.An account detailed how the first online transaction related to drugs transpired in 1971 when students of the Massachusetts Institute of Technology and Stanford University traded marijuana using ARPANET accounts in the former's Artificial Intelligence Laboratory.^[5]

The term has in later usage incorporated services such as the dark web, which is an overlay network that can be accessed only with specific software, configurations, or authorization, often using non-standard communication protocols and ports. Types of dark webs include friend-to-friend networks (usually used for file sharing with a peer-to-peer connection) and privacy networks such as Tor.^[6][7] The reciprocal term for an encrypted darknet is clearnet or surface web when referring to content indexable by search engines.^[8][9][10]

As of 2015, the term "darknet" is often used interchangeably with the "dark web" due to the quantity of hidden services on Tor's darknet. The term is often inaccurately used interchangeably with the deep web due to Tor's history as a platform that could not be search-indexed. Mixing uses of both these terms has been described as inaccurate, with some commentators recommending the terms be used in distinct fashions.^[11][12][13]

"Darknet" was coined in the 1970s to designate networks isolated from ARPANET (the government-founded military/academical network which evolved into the Internet), for security purposes.^[14] Darknet addresses could receive data from ARPANET but did not appear in the network lists and would not answer pings or other inquiries.

The term gained public acceptance following publication of "The Darknet and the Future of Content Distribution", a 2002 paper by Peter Biddle, Paul England, Marcus Peinado, and Bryan Willman, four employees of Microsoft who argued the presence of the darknet was the primary hindrance to the development of workable digital rights management (DRM) technologies and made copyright infringement inevitable.^[15] This paper described "darknet" more generally as any type of parallel network that is encrypted or requires a specific protocol to allow a user to connect to it.^[1]

Journalist J. D. Lasica, in his 2005 book Darknet: Hollywood's War Against the Digital Generation, described the darknet's reach encompassing file sharing networks.^[16] Subsequently, in 2014, journalist Jamie Bartlett in his book The Dark Net used the term to describe a range of underground and emergent subcultures, including camgirls, cryptoanarchists, darknet drug markets, self harm communities, social media racists, and transhumanists.^[17]

Telegram because of its features with encryption and after the ban on the territory of different countries, also belongs to the darknet.^[18] It is because of the anonymity that it contains encrypted channels for the sale of prohibited substances, recruiting various organizations and coordinating anti-government actions.^[19]

Darknets in general may be used for various reasons, such as:

All darknets require specific software installed or network configurations made to access them, such as Tor, which can be accessed via a customised browser from Vidalia (aka the Tor browser bundle), or alternatively via a proxy configured to perform the same function.