What are Introduction Points, and how does a hidden service announce itself without a central registry?

The service connects to several Tor relays as Introduction Points and publishes its reachability in a distributed hash table (DHT), so clients can find it by .onion address with no central server.

After creating its .onion address, the hidden service:

1. Connects to several Tor nodes designated as Introduction Points.
2. Shares its public key with those nodes.
3. Records its reachability in a distributed hash table (DHT) — the "distributed directory."
4. Clients can then look up and reach the service by its .onion address, with no central register.

The Introduction Points act as a buffer: a client contacts them to request a meeting with the service, but they never carry the actual session — that keeps the service's real location hidden.

Tip: Introduction Points are like a receptionist who can pass a message to someone without revealing where that person actually sits.