There has been a lot of discussion about how contact tracing apps could help protect people from COVID-19 as countries try to break out of the lockout. There is a very useful article on Bloomberg News describing the problems between the different models offered, including the one developed by Apple and Google.
Apple and Google have even renamed their exposure notification framework, signaling that it doesn’t do real contact tracking, the process of tracking a virus from person to person. Instead, it lets individual smartphones know which other handsets they are close to using Bluetooth wireless signals. If a person notifies the network that they tested positive for Covid-19, everyone they might have infected will receive a warning, if they have chosen. The system performs this correspondence anonymously on each device, rather than in a central database that governments could be used to track the disease more broadly – a feature that companies say is safer and helps soothe user concerns about who sees their sensitive health data.
Check it out: COVID-19 contact tracking confidentiality link