The Onion Router helps to access darknet

Hyderabad: Tor's basic platform was designed by the US intelligence before it went public and became a free software. Cyber intelligence gathering works when the agencies can track down the location of the user, but Tor hides the very location of its users. It also allows users to reach the otherwise blocked destinations or content, cyber security experts say.

Deep web/or darknet is the part of World Wide Web that are not catalogued and cannot be discovered by means of standard search engines. The users will have their password-protected or dynamic pages and encrypted networks to scour through the deep web. “Tor is the software with which you can access this deep web,” says K. Arjun, a cyber security firm employee from Hyderabad. Not just terrorist activities, but other illegal things like child pornography, firearms, and even assassins for hire are available in the darknet.

Tor uses a lyered technology for encryption.

Tor’s routing is implemented by encryption in the application layer of a communication protocol stack, nested like the layers of an onion. Tor encrypts the data, including the destination IP address, multiple times, and sends it through a virtual circuit comprising successive, randomly selected Tor relays.

Each relay decrypts a layer of encryption to reveal only the next relay in the circuit in order to pass the remaining encrypted data onto it.
The final relay decrypts the innermost layer of the encryption and sends the original data to its destination without revealing, or even knowing, the source of the IP address.