On the Effectiveness of Time Travel to Inject COVID-19 Alerts.

Digital contact tracing apps allow to alert people who have been in contact with people who may be contagious. The Google/Apple Exposure Notification (GAEN) system is based on Bluetooth proximity estimation. It has been adopted by many countries around the world. However, many possible attacks are known. The goal of some of them is to inject a false alert on someone else’s phone. This way, an adversary can eliminate a competitor in a sport event or a business in general. Political parties can also prevent people from voting.