Sports and fitness apps don’t protect privacy enough | Inland

Millions of sports enthusiasts around the world regularly share information about their cycling and jogging activities with other users of sports apps such as Strava or Runtastic. The apps do make it possible to hide certain privacy-sensitive information, such as the location of a place of residence, but researchers from the imec-DistriNet group at KU Leuven have found that this option, the so-called endpoint privacy zones, is not so watertight after all. is.

The researchers analyzed 1.4 million Strava activities and were able to uncover up to 85 percent of the hidden locations, based solely on the extra data that was made public. “The overview of your protected activity still contains so much data about, for example, the distance traveled and the route followed that, in combination with a street map, these still reveal your point of departure or arrival,” says researcher Karel Dhondt.

The researchers have submitted their findings to the platforms. Strava, which has more than 100 million users worldwide, has already invited them to discuss their suggestions for improvements. For example, the apps could better hide or even omit the information about the distance traveled within the hidden zone, even if that implies that the athlete cannot share the entire activity. The shape and size of the zones can also be varied.

Dhondt also has tips for users. “As a user, you can also better protect your privacy on sports apps. Setting a privacy zone is still a good idea, but make the zone around places that you want to keep hidden large enough. Often the minimum is 200 meters, but you can increase the zone to more than a kilometer. The bigger the better,” he emphasizes.