The term "darknet" was popularized by major news outlets to associate with Tor Onion services, when the infamous drug bazaar Silk Road used it, despite the terminology being unofficial. Technology such as Tor, I2P, and Freenet are intended to defend digital rights by providing security, anonymity, or censorship resistance and are used for both illegal and legitimate reasons. Anonymous communication between whistle-blowers, activists, journalists and news organisations is also facilitated by darknets through use of applications such as SecureDrop.
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.
The term "darknet" is often used interchangeably with "dark web" because of the quantity of hidden services on Tor's darknet. Additionally, the term is often inaccurately used interchangeably with the deep web because of 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.
"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. 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. 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.
All darknets require specific software installed or network configurations made to access them, such as Tor, which can be accessed via a customized browser from Vidalia (aka the Tor browser bundle), or alternatively via a proxy configured to perform the same function.
Tor is the most popular instance of a darknet, often mistakenly equated with darknet in general.
anoNet is a decentralized friend-to-friend network built using VPN and software BGP routers.
I2P (Invisible Internet Project) is an overlay proxy network that features hidden services called "Eepsites".
IPFS has a browser extension that may backup popular webpages.
RetroShare is a friend-to-friend messenger communication and file transfer platform. It may be used as a darknet if DHT and Discovery features are disabled.
Riffle is a government, client-server darknet system that simultaneously provides secure anonymity (as long as at least one server remains uncompromised), efficient computation, and minimal bandwidth burden.
Secure Scuttlebutt is a peer-to peer communication protocol, mesh network, and self-hosted social media ecosystem