Understanding Onion routing concept an example
Now suppose you are browsing the internet using Tor(the onion router) which is a special browser that lets you use the onion routers. You want to access YouTube but you live in China and since YouTube is banned in China you don’t want your government to know that you are visiting YouTube so you decide to use Tor. Your computer needs to contact a particular server to get the homepage of YouTube but it doesn’t directly contact that server. It does that through 3 nodes/servers/routers (these servers are maintained all over the world by volunteers) before that server so that no one can trace back your conversation with that server. To make this example simple I am using 3 nodes but a real Tor network can have hundreds of nodes in between.
- The client with access to all the encryption keys i.e key 1, key 2 & key 3 encrypts the message(get request) thrice wrapping it under 3 layers like an onion which have to be peeled one at a time.
- This triple encrypted message is then sent to the first server i.e. Node 1(Input Node).
- Node 1 only has the address of Node 2 and Key 1. So it decrypts the message using Key 1 and realizes that it doesn’t make any sense since it still has 2 layers of encryption so it passes it on to Node 2
- Node 2 has Key 2 and the addresses of the input & exit nodes. So it decrypts the message using Key 2 realizes that it’s still encrypted and passes it onto the exit node
- Node 3 (exit node) peels off the last layer of encryption and finds a GET request for youtube.com and passes it onto the destination server
- The server processes the request and serves up the desired webpage as a response.
- The response passes through the same nodes in the reverse direction where each node puts on a layer of encryption using their specific key
- It finally reaches the client in the form of a triple encrypted response which can be decrypted since the client has access to all the keys
Onion Routing
Onion routing is a technique for anonymous communication over a computer network. In an onion network, messages are encapsulated in layers of encryption, analogous to layers of an onion.
There is a large set of preventive measures and best practices to make web browsing safer and more secure for users. Let’s say that you send an HTTPS request to a server and someone intercepts that request but that person can’t know what that message says because it’s encrypted. But you are still not satisfied with this level of security and want to take this to the next level i.e. you don’t even want anyone sniffing on your network to know which server you are contacting and if you are making any requests or not. This is where onion routing comes in.
Table of Content
- How does onion routing work?
- Understanding Onion routing concept an example
- How does it provide anonymity?
- Vulnerability in Onion Routing
- features of onion routing
- Advantages of Onion Routing
- Disadvantages of Onion Routing
The Onion Routing program consists of studies that investigate, design, construct, and analyze anonymous communication networks. The focus is on realistic solutions for low-latency Internet-based connections that can withstand traffic analysis, eavesdropping, and other attacks from both outsiders (such as Internet routers) and insiders (such as hackers) (Onion Routing servers themselves). Onion Routing hides who is communicating with whom from the transport medium; the network just knows that communication is taking place. Furthermore, until the transmission leaves the OR network, the content of the conversation remains hidden from eavesdroppers. Refer to this image for details.