Due to the COVID-19 pandemic, many of our habits have changed drastically. Social distancing is now the norm because of the sheer amount of asymptomatic people carrying the virus. Knowing who has tested positive and who came into contact with those persons is essential to containing the spread of the virus, and that's why Google and Apple teamed up to create a COVID-19 contact tracing API called Exposure Notification. This API is meant for use in contact tracing applications from public health agencies, and it supports both iOS and Android. Today, Google and Apple announced a few improvements to the API.

One of the improvements gives public health agencies more flexibility in determining the level of risk associated with an exposure event. Another improvement is support for interoperability between countries for the app to work on a more global scale. With better Bluetooth calibration on hundreds of devices (the Exposure Notification API uses Bluetooth LE in order to ping nearby devices), contact tracing will be less prone to false positives.

Google and Apple are also addressing privacy concerns that have been raised by users and developers. You can now easily turn off the notifications with a toggle and, if the feature is turned on, you will also get a periodic reminder that it's on. On Android 11, users will no longer have to enable Location Services in order for the Exposure Notification API to work. The reason the API requires location access to be enabled is that Bluetooth scanning can be used to infer a device's location. Google tied Bluetooth (and WiFi) scanning to location services to warn users of this fact, but this has scared some users into thinking that all contact tracing apps are actively tracking their location.

Here's a summary of Google and Apple's improvements to the Exposure Notification API, per Google's blog post on the matter:

Improvements to the Exposure Notification API

  • When an exposure is detected, public health authorities now have more flexibility in determining the level of risk associated with that exposure based on technical information from the API.
  • Bluetooth calibration values for hundreds of devices have been updated to improve the detection of nearby devices.
  • The API now supports interoperability between countries, following feedback from governments that have launched Exposure Notification apps.
  • To help public health authorities build apps more efficiently, we’ve added reliability improvements for apps and developer debug tools.
  • We’ve improved clarity, transparency and control for users. For example, the Exposure Notifications settings on Android now include a simple on/off toggle at the top of the page. In addition, users will also see a periodic reminder if ENS is turned on.

Public health authorities have used this API, jointly developed by Google and Apple, in 16 countries, including those in North and South America, Africa, Asia, and Europe. More areas are planning apps using the API, with 20 U.S. states and territories (accounting for over 45% of the U.S. population) exploring its usage. We are tracking the apps that use the Exposure Notification API in a separate article, in case you're interested. Using contact tracing to contain the spread of COVID-19 is essential in establishing a return to normalcy, but we're still a long way off from that goal.