My guess is that the intention was "E2E encrypted".

Yes, i guessed the same, but after i posted the original answer.

No love for SpiderOak's Semaphor. It's a secure end-to-end encrypted system. Free for 5 users or less. https://spideroak.com/semaphor/

How do you call P2P that is strictly without any third party?

What does "third party" in your question refer to? Are you referring to servers that route client-side encrypted messages from user to user?

Yes, so that messages can reach a user even if the receiving and sending users are never online at the same time (a server could be another user/peer(s) that isn't part of the communication, so it could possibly still be called p2p?)

p2p strictly implies no third parties.

If there is a third party involved, you are not p2p.

That is incorrect. You've just defined P2P such that no commonly accepted P2P application meets it. At a minimum every P2P app you've likely ever heard of or used, baring maybe one exception, has at a minimum used third parties for orchestration.

so if other users (not part of the conversation) are used as temporary servers so that messages get delivered even if the sender or receiver are never connected at the same time, what would it be called?

AFAIK there isn't a modern word to describe the common architecture that you describe.

About a decade ago, the phrase "hub-and-spokes network" was thrown around to describe an architecture with a central server that acted as the mediator. The term "p2p" became popular in this context. (

Napster, bittorrent, tox are all "p2p" because they don't connect to single server. Skype is not "p2p" because all packets go through the skype servers.

Skype used to be p2p, except for the original auth/login. But since then microsoft bought the company and push everything through their servers.