Shining a light on the secrets of the internet

The so-called dark web is appearing in the headlines with ever more frequency, but few understand exactly how it works.

The dark web is a subsection of what is known as the deep web – sites inaccessible via standard search engines, meaning you need to know the exact site address to find it. The brainchild of US military researchers, it was created in the mid-1990s to allow intelligence officials to exchange information anonymously.

They called this system Tor, an abbreviation for “The Onion Router”. If a Tor user wants to visit a website, their computer sends a request to that site just like a normal web browser, but it wraps this request in three layers of encryption, like an onion. This message is then sent through a network of around 8,000 computers which act as a relay, further masking the user’s location and protecting their IP address – the unique marker that identifies every computer. The anonymity afforded by Tor has helped citizens of countries where internet access is restricted, and served as host to whistleblowers such as Edward Snowden.

But the technology’s dark reputation is not undeserved. The communities found within have garnered a reputation as a hotbed for illegal activity: online drug markets, scams and even child abuse.

The latter has become such a problem it now accounts for around half of all recorded offences. In August, independent think-tank Reform said 12,000 IT experts are needed to give UK police “confidence to patrol an online beat”.