What is Onion Routing? How it Works?

Onion routing is an anonymous method used for communication over the computer network. The messages in the onion network will be encapsulated in the layers of encryption, comparable to the layers of an onion. The encrypted network will be transmitted through the series of network nodes called “Onion routers, ” and each of them peels away a single layer, which uncovers the data’s next destination. The message will arrive at the destination when the final layer is decrypted. The sender will remain anonymous as the intermediary only knows the location of directly preceding and following nodes.

Onion Routing

Onion Routing

History of Onion routing

Michael G. Reed, Paul Syverson, and David Goldschlag created the Onion routing in 1990 at U.S. Naval Research Laboratory to protect the U.S. intelligence communications online. DARPA (Defense Advanced Research Projects Agency) further developed the Onion organizations, and Navy in 1998 patented the Onion routing. In 2002, computer scientists Roger Dingledine and Nick Mathewson joined hands with Syverson to develop what would become the largest and best-known implementation of onion routing, called Tor. In 2006, Dingledine, Mathewson and five others founded the Tor Project as a non-profit organization with the commercial support of the Electronic Frontier Foundation and various other agencies.

How does Onion routing works?

Onion is the data structure formed by coating the message with the successive layers of encryption. The intermediary computers will decrypt These layers before arriving. The original message will remain hidden as it is transferred from one node to another and no intermediary will know both the origin and final destination of the data. To create and transmit the onion. The originator needs to select a set of nodes from the list provided by a “directory node.” The chosen nodes will be arranged into a path called “chain” or “circuit” through the message will be transmitted.

Onion Routing

How does Onion routing works

By using the asymmetric key cryptography, the originator receives a public key from the directory node to send encrypted data to the first node. Then the originator can relay the message through the first node to a second node in the chain by using the encryption. The connection will be established when the second node receives the message from the first node. The second node cannot decide whether the first node is the originator or just another node in the chain. Then the data will be sent to the third node through the first and second node, encrypted such that only the third node can decrypt it.

Then the third node will be connected to the originator but connects only with the second. This process will be repeated to create a larger chain but is typically limited to preserve performance. When the circuit is finished, the originator can send the message over the internet anonymously. When the final recipient of the data sends data back, the intermediary nodes keep the same link back to the originator, with data being re-layered, but the final node removes the first layer of encryption, and the first node extracts the last layer of encryption before sending the data.

Tor: Generation of Onion routing

The Tor Onion Routing system is freely available and runs on most of the standard operating systems. Tor is a secure network which uses the Onion routing to keep all of your activity as encrypted and hidden as possible. The term “Tor” actually stands for “the onion router.” Here is how onion routing works with the Tor.

Onion Routing

Onion Routing

  • The installed onion routing client (Tor) encrypts all the data packets sent from your computer.
  • Then your computer sends the data packet to the Node A.
  • The Node A encrypts your already-encrypted data packet and sends it to Node B.
  • Node B encrypts your already-encrypted data packet and sends it to Node C.
  • The cycle continues until the data packet reaches Node Z, which is called “exit node.”
  • The exit node decrypts all of the layers of encryption on your data packet and finally sends it off to the destination. Target thinks your data packet originated from Node Z, not you.
  • When the message is sent back to you, the chain will be reversed with Node Z becoming the first node and your PC being the exit node.

This is how the onion routing works, and if you have any doubts about Onion routing, please comment below.

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