Introduction Point
A Tor relay chosen by a hidden service where clients begin the onion connection handshake before moving to a rendezvous point.
An introduction point is a Tor relay an onion service selects to receive first contact from clients. The service builds a circuit to it, lists it in its hidden service descriptor, and waits; a client that fetched the descriptor sends an introduction request through it.
Role in the handshake
The introduction point is a message relay, not the meeting place. It forwards the client’s encrypted introduction to the service, after which both sides independently build circuits to a client-chosen rendezvous point where the actual session runs. This split is the core of onion-service design: the introduction point learns that the service exists but never sees the client’s IP, and the rendezvous point sees traffic but knows neither side.
Limits and common mistakes
Because introduction points are listed in descriptors, they are the exposed surface of an onion service — flooding them is a known denial-of-service vector, which later protocol work, including proof-of-work defenses, targets. The common confusion is with the rendezvous point: introduction is where the knock lands; rendezvous is where the conversation happens.
Category: Network