go-geopoint

GPS Point encoding library with privacy in mind.

import "go.zenithar.org/geopoint"

func foo() {
  p := geopoint.Encode(43.603574, 1.442917)

  fmt.Printf("%d\n", uint64(p))
  // 75071809151126838

  fmt.Printf("%s\n", p.Code())
  // 10AB5:69A51:94D36
}

What's the difference with geohash ?

For compatibility, you should use geohash.

The main objectives is to find a way to encode point (lat,lon) as an uint64 (like geohash) and make it sortable.

Brain dump

I tryied to apply CryptoPan anonimyzer on the uint64 encoded coordinate, I know that this algorithm is told to be prefix-preserving, but after application of the algorithm point are not keeping their geospace properties at first sight.

I'm trying to find a cryptographic keyed hash function for GPS point, and the result should be a GPS point too. Maybe all GPS related arithmetic should be influenced by the cryptographic hash, like in homothecy. GPS Point anonymization are based on precision loss.

A real GPS point is projected in another planet GPS point. The other planet is generated with the key of the hash function. An origin point as always the same other planet point value (injective function but collision must be proved also). It could be visualized with a homothetic transformation of the original planet were the key could be part of the homogeneous dilatation factor, but not only countries of the generated earth should have different shapes.

Maybe I should investigate in Format Preserving Encryption field... I'm not a mathematician or a scientist, just an intuitive person.

Maybe this is a full bowl of shit, waiting for being flushed !

Fun ideas

🌟 It could be used to represents GPS coords on other planets !

$ <planet>:<tile>:<inner-x>:<inner-y>