Privacy preserving richer geolocation

[hellais]

When looking at OONI Probe measurements we often face a challenge in properly understanding what country (or more granular location) they are telling us things about.

Often times the location information (since it's based on geoip) is completely useless, because they GeoIP database we did the lookup on was stale.

On the other hand we also have a responsibility to protect user privacy to the extent that it's possible and therefore we don't collect IPs or store location information that is more granular than country level.

We have been discussing, especially within the scope of the internet blackouts methodology, of collecting more accurate location information, such as city level or regional level.

Initially we thought of doing this by splitting the world into regions or cities and resolving on the users device (in the case of mobile) which bounding box they fall under based on their GPS coordinates.

Another idea could be that of instead finding which is the closest airport (or railway station) to the current users coordinates and returning the IATA airport code or station code. See: https://openflights.org/data.html

[hellais]

This is a good resource instead for geographical polygons: https://github.com/CAIDA/ioda-geo-polygons

[hellais]

See also: https://lists.torproject.org/pipermail/ooni-talk/2019-November/000169.html

[hellais]

We discussed this further and came to the conclusion that the core of this issue is doing research.

Namely we would like to better understand how off our current geolocation approach is and what strategies we can adopt to improve it's accuracy. This might include using cell tower information and/or coarse GPS info.

Once we have done the research we might be able to move forward with implementation if considered acceptable.