[Cursuviam]

You could use this to prove that N devices are spread fairly geographically evenly near the line between two devices you know the location of, if the transport latency was fairly constant.

If you cross this line over multiple countries, you now have a system where you can prove that the devices are spread across some number of the different countries, which probably has some useful properties, like making nation-state attacks slightly more difficult.

[marcosdumay]

I don't think you can prove they have a minimal distance between them, just maximal. Thus, any data stream may have always came from a single country, you can only impose an upper limit.

[Cursuviam]

Sure, you can prove a minimal distance. Think of this problem as a metal chain. Each link of the chain enforces a maximal distance on the nodes it adjoins. The chain is bound on either end to some fixed point.

In an non-constrained case, sure, there's no-minimal link distance. You just have a pile of chain.

However, if you make the chain taut between the two points, say by decreasing the number of nodes in the chain or the maximal distance of links, the minimal distance between nodes then approaches the maximal distance between nodes. When you have a chain constrained to the straight line between the two points, the maximal distance between nodes is equal to the minimal distance between nodes.