Leave out everything that varies and an id becomes a pure function of its inputs, so every device lands on it with no messages. The price is permanence.

It is the trick behind the private space and one-to-one spaces.

Most ids are minted. A new space signs a header with a timestamp and a random seed. The hash is the id. Unique, unguessable.

Some ids are computed instead. Leave out everything that varies. The time. The random seed. For some objects, even the signature. Now the id is a pure function of its inputs.

The same recipe gives the same cake. Every device follows the recipe and lands on the same id. With zero messages.

That is how a second device finds the account's own space before it has talked to anyone. That space is the next idea.

The price is permanence. A computed object cannot be deleted. Delete it, follow the recipe again, and you get the same id with a fresh history.

Check yourself. Why can a computed object not be deleted?