There are a number of ways to access the dark web, including the use of Tor, Freenet and I2P. Of these, the most popular is Tor (originally called The Onion Router), partly because it is one of the easiest software packages to use. Tor downloads as a bundle of software that includes a version of Firefox configured specifically to use Tor.
Tor provides secrecy and anonymity by passing messages through a network of connected Tor relays, which are specially configured computers. As the message hops from one node to another, it is encrypted in a way that each relay only knows about the machine that sent the message and the machine it is being sent to.
Rather than conventional web addresses, Tor uses “onion” addresses, which further obsure the content. There are even special versions of search engines like Bing and Duck Duck Go that will return onion addresses for Tor services.
It is a mistake to think that Tor is entirely anonymous. If a web site is accessed, it can still potentially find out information about whoever is accessing the site because of information that is shared, such as usernames and email addresses. Those wanting to stay completely anonymous have to use special anonymity services to hide their identity in these cases.
The real deal is only virtual. Antana/Flickr, CC BY-SA
Services on the dark web would not have been as popular without a means of paying for them. This is something that Bitcoin has made possible. A recent study by Carnegie Mellon researchers Kyle Soska and Nicolas Christin has calculated that drug sales on the dark net total US$100 million a year. Most, if not all, was paid for in Bitcoin.
Bitcoin is made even more difficult to track on the dark web through the use of “mixing services” like Bitcoin Laundry, which enables Bitcoin transactions to be effectively hidden completely.