Well, in the world that grew up around IP addresses, in our world, you need to have security contexts like that because somebody can just reach in from anywhere and do something bad to you. But if I try to envision an alternative... one where we're not addressing machines, then I figure we're probably working in terms of users (identified by public key) and data (identified by hash).
In this world security looks a bit different. You're not open to remote action by third parties, they don't know where to reach you unless they're already in the room with you. Instead you've got to discover some peers and see if they have any data that you want. Then the game becomes configuring the machines so that data sort of... diffuses in the appropriate direction based on what users are interested in. It would be worse in many ways, but better in a few others.
So suppose the whole neighborhood, and the delivery driver, all subscribe to a topic called "business hours". One neighbor owns a business and recently decided that it's closed on Sunday. So at first there's just one machine in the neighborhood with the updated info, and everybody else has it wrong. But then the driver swoops by, and since they're subscribed to the same topic as the homeowners, their nodes run some topic-specific sync function. The new hours are signed by the owner of the restaurant with a timestamp that's newer than the previous entry, so the sync function updates that entry on the driver's device. Everyone else who runs this protocol and subscribes to this topic has the same experience, with the newer more authoritative data overwriting the older staler data as the driver nears their house. But at no point does the data have a sender or a receiver which are separated by more than a single hop, and we trust or distrust data based on who signed it, not based on where we found it.
I have an application in mind that I think would run well on it, but because our world has crystalized around point-to-point machine-addressed networking, like a million tiny phone calls, it feels like a pretty big lift whereas innovating at other layers in the stack feels much easier--a consequence of the thin waist.
I guess I'm not persuaded that a system like you describe wouldn't have its own lower layers that serve equivalent functions to IP. While what you describe is something that sounds plausible to implement as application-layer stuff that would work on a wide variety of raw network implementations.
In this world security looks a bit different. You're not open to remote action by third parties, they don't know where to reach you unless they're already in the room with you. Instead you've got to discover some peers and see if they have any data that you want. Then the game becomes configuring the machines so that data sort of... diffuses in the appropriate direction based on what users are interested in. It would be worse in many ways, but better in a few others.
So suppose the whole neighborhood, and the delivery driver, all subscribe to a topic called "business hours". One neighbor owns a business and recently decided that it's closed on Sunday. So at first there's just one machine in the neighborhood with the updated info, and everybody else has it wrong. But then the driver swoops by, and since they're subscribed to the same topic as the homeowners, their nodes run some topic-specific sync function. The new hours are signed by the owner of the restaurant with a timestamp that's newer than the previous entry, so the sync function updates that entry on the driver's device. Everyone else who runs this protocol and subscribes to this topic has the same experience, with the newer more authoritative data overwriting the older staler data as the driver nears their house. But at no point does the data have a sender or a receiver which are separated by more than a single hop, and we trust or distrust data based on who signed it, not based on where we found it.
I have an application in mind that I think would run well on it, but because our world has crystalized around point-to-point machine-addressed networking, like a million tiny phone calls, it feels like a pretty big lift whereas innovating at other layers in the stack feels much easier--a consequence of the thin waist.