Google Covid-19 tracker explained: How it works and what it means for user privacy
As the fight against coronavirus Covid-19 continues, our phones play more than just the role of a communication tool.
Phones are now increasingly helping millions navigate their way out of the coronavirus pandemic, as countries and companies develop own apps as part of a track-and-trace system to keep infection levels low.
Google and Apple are working together on a set of underlying protocols inside Android and iOS that are able to speak to each other, even while your phone is in your pocket.
The efforts of the tech giants are live on Android phones and iPhones. This is to find these settings on your phone - and what they actually do.
What is the tracker and what does it do?
Apple and Google have worked around the clock to make sure that health apps can talk to each other across Android and iOS and get access to the features they need.
Your phone will be logging other phones it comes into contact with, using Bluetooth signals. Bluetooth is perfect for low-energy wireless transmission that can run in the background of your phone, without draining the battery excessively. This is assuming both your device and the others are running a Covid-19 tracking app that's been fully enabled.
It is worth noting that these logs don't include any identifying information about you.
The apps will be able to log the length of time you've been in contact with each person (technically speaking, each individual phone), and how far away you were, judging from the strength of Bluetooth signals. Contact that's less risky will be ignored.
How to find the settings
Open Settings and select Privacy, Health, and Covid-19 Exposure Logging. Once again, you can turn this logging on or off and read some more information about how it works. To get rid of the random IDs that are stored on your phone, tap the Delete Exposure Log option at the bottom.
For these apps to work, you'll need your phone's Bluetooth and location tracking features turned on, though your actual physical location isn't tracked—the apps won't know where in the world you are or how many times you've left the house today. They'll only know which random IDs your phone has come into contact with.
What happens when someone reports positive for Covid-19?
If a user reports themself as positive for Covid-19, the app will send that record of your rotating IDs to a server. It will then send them out to other devices using the system.
Anyone who has been nearby the person in the last two weeks will be pinged with an alert. This alert will prompt people to take action, such as getting tested and self-isolating.
There has been Google explained in a post how it the exposure notification system protects privacy
"All of the exposure notification matching happens on your device, which means that only you and your app know if you report having COVID-19 or been exposed to someone who has reported having COVID-19. Your identity is never shared with other users, Apple or Google. When you download a public health authority app, you can opt in to use exposure notifications. If you have COVID-19, you can choose to share your random IDs with the app. To help prevent tracking, your phone's random ID changes every 10–20 minutes. Your phone only stores random IDs from the last 14 days. The public health authority app is not allowed to use your phone's location or track your location in the background. Only official public health authority apps can use the system."