Over 10 years ago Gustavo Niemeyer invented the geohash geographic
hashing system
https://en.wikipedia.org/wiki/Geohash for clearly and
concisely representing geographic locations at arbitrary precision.
Now, here is geocrypt, a package that returns or checks a cryptographic
hash of a geolocation. The hash is calculated using bcrypt in such a
way that hashing an angular area is approximately time-constant
irrespective of the geohash precision that the location is given.
The intention is for use in confirming locations of items whose
location should not be published, but which must be identifiable by
some participant. Examples of use are digital geocaching competitions,
lowish value eco-conservation sites* etc.
For locations at the equator (fastest case), hashing takes about 2-3
seconds per square meter of precision on my hardware. Interaction
between geocrypt and standard conservation location fuzzing techniques
means that they should probably not used together. As in all cases with
cryptographic protocols, you should assess your threat model, and don't
use packages you find on the internet.
https://godoc.org/github.com/kortschak/geocrypt
* high value conservation sites should not be published