Israeli opt-in "The Shield" app uses GPS and SSIDs for contact tracing


The Israeli Ministry of Health's mobile app, "The Shield", is intended to alert users if they have been at a location in Israel at the same time as a known COVID-19 patient.

The app, which is available for both Android and iOS, works by collecting the GPS and WiFi network (SSID) information of a user's mobile device throughout the day. This data is saved only on the mobile device and is not transmitted to the Ministry of Health, other government agencies, or any organisation. The locations newly-diagnosed patients disclose when asked will be added to JSON file that is updated in the app every hour and is compared to each users' locations as stored in their phones. Users will be prompted to report matches to the Ministry of Health. The app has limitations: there may be false positives because data is being collected from patients, and asymptomatic carriers will not be included. The app has been reviewed by the Israeli cybersecurity firm Profero for security vulnerabilities. At a later date, to improve accuracy, the app may ask users to voluntarily upload their GPS data if they are known to have been exposed or are infected.


Writer: Lawrence Abrams
Publication: Bleeping Computer