Darknet

Definition
A darknet (also written as dark net) is a private virtual network where users connect only to people they trust. In its most general meaning, a darknet can be any type of closed, private group of people communicating, but the name is most often used specifically for file-sharing networks. "The darknet" can be used to refer collectively to all covert communication networks.

History
The term was originally coined in the 1970s to designate networks which were isolated from ARPANET (which evolved into the Internet) for security purposes. Some darknets were able to receive data from ARPANET but had IP addresses which did not appear in the network lists and would not answer pings or other inquiries. The root of the name is believed to be related to the term black box, which meant a system or device whose contents were unknown.

The term gained public acceptance following publication of The Darknet and the Future of Content Distribution, a 2002 article by Peter Biddle, Paul England, Marcus Peinado, and Bryan Willman, four employees of Microsoft who described the concept as follows:

The idea of the darknet is based upon three assumptions: The darknet is the distribution network that emerges from the injection of objects according to assumption 1 and the distribution of those objects according to assumptions 2 and 3.
 * 1) Any widely distributed object will be available to a fraction of users in a form that permits copying.
 * 2) Users will copy objects if it is possible and interesting to do so.
 * 3) Users are connected by high-bandwidth channels.

They argued that the presence of the darknet was the major hindrance to the development of workable DRM technologies.