Exposure Notifications & Privacy
Exposure Notifications help protect your privacy by using random, rotating Bluetooth identifiers to determine if you may have been exposed to someone who has indicated that they have COVID-19.
With your consent, Exposure Notifications can be used by a government or public health authority app to notify you if you may have been exposed to someone who has indicated that they have COVID-19. If you choose to enable Exposure Notifications, the app will ask for your permission to collect and share random IDs. This will allow your device to use Bluetooth to broadcast a random identifier (the “Bluetooth identifiers”), a string of random numbers that changes every 10–20 minutes. They are generated cryptographically on your device from a randomly generated key (the “random device key”) that changes at least every 24 hours to further protect your privacy. The Bluetooth identifiers and the random device keys do not include information about your location or identity.
Other iOS and Android devices that have this feature enabled will be listening for these Bluetooth identifiers and broadcasting theirs as well. Your device will record and securely store the identifiers of those other devices that are in Bluetooth range for at least 5 minutes, along with the date, estimated duration of the exposure, and Bluetooth signal strength (collectively, the “Associated Metadata”). To further protect your privacy, the maximum estimated duration recorded is 30 minutes. The Bluetooth signal strength helps provide a general understanding of the proximity of the devices; generally, the closer the devices are, the higher the signal strength recorded. Other devices that receive your device’s Bluetooth identifiers will similarly record and store them, with the Associated Metadata.
The app can download a list of random device keys from individuals who have reported a positive diagnosis or present COVID-19 exposure risk as determined by the government or public health authority, and who have chosen to share their random device keys. Following download, the app can have your device check the list against the Bluetooth identifiers it has collected and stored from other devices. If there’s a match, Associated Metadata (but not the matched identifier) is made available to the app, which can notify you that there was an exposure event and provide guidance on what steps to take.
If you are notified of an exposure event, the app may generate an Exposure Risk Value, which the government or public health authority may use to tailor its guidance to you and to help it manage the COVID-19 pandemic. The Exposure Risk Value is defined and calculated based on the Associated Metadata, as well as a Transmission Risk Value (explained below) that the government or public health authority may define for the matched random device keys. Neither the Exposure Risk Value nor the Transmission Risk Value is shared with Apple.
If you are diagnosed with COVID-19 or present a potential exposure risk, your government or public health authority will provide instructions on reporting that in your app. If you choose to report, the app will ask you to share your random IDs. If you consent, the past 14 days of your random device keys will be shared with the app. The government or public health authority may also define and send a Transmission Risk Value with each random device key. The parameters that the government or public health authority uses for its Transmission Risk Value may include information you provide to them (such as symptoms you report or whether your diagnosis was confirmed by test) or other information that the government or public health authority considers might impact your transmission risk, like your occupation. Information you choose to provide to the government or public health authority is collected under the terms of the app's privacy policy and its legal obligations.
You can disable Exposure Logging by going to Settings > Privacy > Health > COVID-19 Exposure Logging or Settings > Privacy > Bluetooth > COVID-19 Exposure Logging, and tapping to turn off Exposure Logging. This will not delete the Bluetooth identifiers recorded from other devices, Associated Metadata, or your random device keys. You can delete the Bluetooth identifiers, Associated Metadata, and random device keys by going to Settings > Privacy > Health > COVID-19 Exposure Logging or Settings > Privacy > Bluetooth > COVID-19 Exposure Logging, and tapping Delete Exposure Log. Turning off Bluetooth on your device also disables the sharing and collection of random Bluetooth identifiers with other devices. This means that the app won’t be able to notify you if you’re exposed to someone with COVID-19 while Bluetooth is turned off. The remaining features of Exposure Notifications will continue to operate while you have Bluetooth turned off. Turning Bluetooth back on will re-enable the sharing and collection of random Bluetooth identifiers with other devices.
While you can have more than one app using Exposure Notifications installed on your device, only one can be active at a time. In order to select or change your active app, go to Settings > Privacy > Health > COVID-19 Exposure Logging or Settings > Privacy > Bluetooth > COVID-19 Exposure Logging and select the app you would like to be active.
Apple will disable the Exposure Notification system on a regional basis when it is no longer needed.
