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PATH TUNNELS
The link between two PATH networks. An agreement both sign, a gate at each end, and one search that returns every holder the gates admit.
LIVE — specified in PIP-0018.
What it is for
A PATH network is a club: its directory answers its members. A payer in one network may need to reach a subject held in another. A tunnel lets the search cross, within what both networks admit.
CROSSWAY reaches registries outside PATH. A tunnel links two PATH networks.
A member never deals with the other network. It asks its own, which routes.
Closed by default
A network with no tunnel takes no search from another network. A tunnel exists only when both networks sign it, and either revokes it alone.
The gate
Each end of a tunnel has a gate: what that network sends, and what it answers.
| Setting | Example |
|---|---|
| Identifier types | alias and phone in, alias only out |
| Zones | +221 for phone, SN for reg and tax |
| Budget | 50 000 inbound searches a day |
A search crosses only when the sender's outbound gate and the receiver's inbound gate both admit it.
Who is findable: federated
| Level | Findable by |
|---|---|
private | Nobody, through the directory |
network | Members of the subject's network |
federated | Members of the subject's network, and of the networks it has a tunnel with |
public | Anyone with access to a directory query |
Only federated and public entries answer through a tunnel. The subject chooses federated. A
member may keep all of its subjects out of tunnels.
One search, every holder
Within one network a key has at most one holder. Across networks it may have several.
- The payer's network searches its own index and, at the same time, sends the search through every tunnel whose gates admit it. An alias goes only to the network it names.
- Each other network hashes the identifier under its own pepper and answers, signed.
- The payer's network returns every holder found, each with its network. The payer chooses.
- RESOLVER and the payee check go directly to the chosen holder.
What each party sees
| Party | Sees |
|---|---|
| The payer's network | The search, and the requesting member |
| Each network the gates admit the search to | The identifier, the requesting network and the tunnel. Not the requesting member |
| The holding member | The RESOLVER call |
What a gate does not close
The directory. A subject's PATH link or address can be read and paid by anyone who holds it.
Disputes
Every tunnel names the rulebook that governs a dispute between its two networks. When the networks agree on no other, it is the rulebook of the payee's network.
PATH CROSSWAY
The external-network resolution layer. Which outside registry knows a key, which participant holds it, where to send, and whether the name matches — without PATH becoming a directory of other networks' accounts.
PATH INTEROP
One HTTPS link, a marker that identifies it offline, and a discovery document that says which network stands behind it.