  Trilateration is one of the well-known threat models to the user's location
privacy in location-based apps, especially those contain highly sensitive
information such as dating apps. The threat model mainly bases on the publicly
shown distance from a targeted victim to the adversary to pinpoint the victim's
location. As a countermeasure, most of location-based apps have already
implemented the 'hide distance' function, or added noise to the publicly shown
distance in order to protect their user's location privacy. The effectiveness
of such approaches however is still questionable.
