We estimate that by 2025, Signal will require approximately $50 million dollars a year to operate—and this is very lean compared to other popular messaging apps that don’t respect your privacy.
Wouldn’t that mean both have to have a connection at the same time? What if one is offline?
You can also just hook up any old phone or computer, install the app, and let it run as the server.
If you have a static IP address, if you want to bother with securing and maintaining it, if you’re willing to deal with downtime when something inevitably breaks, if you’re willing to deal with lost data or also maintaining a backup solution, if… a dozen other things that most people don’t want to deal with.
Sure, but you also just… don’t have to do that. None of that is necessary fore core functionality of a messaging service, IF you stipulate that both devices must be online at the same time to ping each other.
The only thing you need is some very basic addressing service so they can find each other, and there are entirely P2P solutions for this that already exist and work without issue. See: bittorrent.
The ONLY drawback of having no server, fundamentally, is that the two devices need synchronicity. If they both aren’t online at once, messages won’t get delivered. Which is not a big deal for a modern smartphone given that most of them are online close to all of the time.
