How TOR Hides You - Onion Routing, Circuits and Hidden Services : Down The Rabbit Hole Part 3
Hidden services skip the exit node entirely. A rendezvous point splices two anonymous circuits so neither side reveals its IP.
TOR, or The Onion Router, is a system designed to provide anonymity to internet users. It works by creating a circuit through multiple relays, or routers, that your data passes through before reaching its final destination. This process, known as onion routing, ensures that your data remains secure and private.
To begin, Alice uses the TOR Browser, which works alongside the Onion Proxy to manage her session and handle the encryption and decryption of data as it passes through the circuit. The Onion Proxy starts by sending a request to the Directory Authorities, which are semi-trusted servers that maintain a list of all available TOR relays.
Next, the Onion Proxy selects three random relays to create a circuit, which consists of an entry node, a middle node, and an exit node. Each relay in the circuit only knows the relay before and after it, ensuring that no single relay has complete knowledge of the data's path or destination.
The entry node, or guard node, is the first relay in the circuit and knows who Alice is but not her destination. The middle node is completely invisible, as it only knows the guard node and the exit node. The exit node, which sends data back to its original source, knows where Alice wants to go but not who she is.
As Alice's request to access facebook.com travels through the circuit, each relay encrypts or decrypts the data using a relay cell attached to the TCP packet. This relay cell is encrypted incrementally at each hop, using a single entity authentication method called Diffie-Hellman key exchange. This method allows the Onion Proxy to establish a symmetric key with each node separately without revealing Alice's identity.
Once the response from facebook.com reaches the exit node, it is sent back through the circuit, with each relay decrypting and re-encrypting the data as necessary. This ensures that Alice's request remains private and secure, even as it passes through multiple relays and traverses the internet.
Written by urgent.news from HackerNoon's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
