you have to be more specific lol

just tesselate the world with hexagons and say you’re in a specific one? that doesn’t give precise proximity but does expose your general area.

this does the opposite, doesn’t expose your general area but let’s you determine if it is close to some other location via an expensive comparison. the precision of proximity isn’t tied to how precise a location/small a hexagon you’re exposing

as per the first paragraph of the intro of the linked paper, it’s safer to store this than it is an actual location. if data gets leaked it’s like leaking a hashed password instead of a plaintext one. their example is device trackers.