Three types of nodes participate in the Tor network. In this video, Mike Chapple explains the roles of entry nodes, exit nodes, and relay nodes.
- [Instructor] Nodes are at the heart of the Tor network. They're the servers located all around the internet that participate in the anonymized relay networks that create perfect forward secrecy. Individuals and organizations set up servers and configure them to accept inbound Tor connections, and relay communications to the next destination in the forward chain. Interestingly, there's no direct benefit to anyone for running a Tor node. It's purely a public service, as node owners are donating both their computer time and their network bandwidth to help the Tor network continue operations. The operators don't receive any payment or special privileges on the Tor network, only the satisfaction of knowing that they're contributing to the health of the network. The more nodes that exist, the more secure and faster the network operates. There are two special types of Tor nodes in any connection: entry nodes, and exit nodes. When a user selects their path through the Tor network, they select a minimum of three nodes. The first node is the node where their traffic enters the Tor network, and it's known as the entry node. Any node on the Tor network can serve as the entry node, and, from the server's perspective, there's really no difference between serving as the entry node or another node in the middle of the connection. There is one important difference from the client's perspective. The entry node is the only node that knows the true identity of the client. However, this is the extent of the entry node's knowledge. Because of perfect forward secrecy, the entry node knows only the identity of the user and the next node in the circuit. The entry node does not know the final destination of the traffic, so the only conclusion it can reach about the user is that the user is communicating with the Tor network. The relay nodes exist simply to unwrap additional layers of perfect forward secrecy. By default, you'll have one node in the middle of your Tor circuit, but you can increase this number, if you'd like. Just be aware that each node you add to your Tor circuit increases the delay in your communications. The other special node in the Tor network is the exit node. This is the node that communicates with the target system. Nodes must volunteer to serve as exit nodes, for an important reason. The target system sees the exit node as the source of the traffic headed to it. For this reason, the operators of exit nodes are frequently accused of causing whatever activity Tor users engage in using the network. This results in many inquires from law enforcement, and leaves exit node operators explaining how Tor works to investigators over and over again. The operators of Tor nodes perform a public service that helps keep the network running smoothly. Tor would not work without these nodes, and would grind to a halt if the number of nodes did not continue to increase with the level of usage of Tor.
- What is the dark web and who uses it?
- The purpose of the Tor Browser
- Cryptography and perfect forward secrecy
- Installing the Tor Browser
- Accessing the standard internet with the Tor Browser
- Safeguarding privacy on Tor
- The role of hidden servers on the dark web
- Locating and accessing hidden websites
- Vulnerabilities in Tor