Non-techie guide to contact tracing apps using Apple and Google APIs

Manual contact tracing is a time-intensive, error-prone process that relies on people accurately recounting where they went and who they saw over a two-week period. Contact tracing apps can augment and speed up that process while also identifying encounters people may not remember or even be aware of.

Unfortunately, trying to understand how the tracing apps work and whether they use your personal information remains a significant challenge.

That’s why we put together this Non-Techie Guide to Contact Tracing Apps (from the folks who help build them).

Without getting into the technical jargon or specific timing, format and function of the, frankly, quite sophisticated tech used in these apps, we explain the basics of how the apps work and how they help control the spread of Covid-19.

Refer to or share the full graphic on this page or keep reading for a simplified, non-techie summary of how contact tracing apps work.

Download the app:

Sarah does her part by installing the approved government or state app which uses the Apple and Google technology on her phone. She is not required to enter any personally identifiable information as she sets up the app.

How it works:

As Sarah goes about her day, the app sends out a Bluetooth code called a Key. Other phones running the app record these random Keys. Each phone’s Keys are anonymous and change frequently to ensure security.

How it tracks:

As Sarah encounters other app users throughout the day, their phones log these Keys as contacts. Sarah never knows which phones are logged or who they belong to. The information is stored only on individual phones and is not shared with any organisation, including Apple, Google or the government.

How it updates:

A few days later, Sarah develops symptoms of coronavirus. She tests positive for COVID-19 at a test centre. From her phone, Sarah can now authorise the app to share her Keys from the last 14 days as a confirmed positive case.

How it traces:

All phones running the app periodically check their logged Keys against those associated with confirmed positive cases like Sarah. If an encounter meets the health authority criteria of a ‘close contact event’, a notification is triggered.

How it notifies:

Users then receive an exposure notification alerting them that they have been in close contact with someone who has tested positive for COVID-19. The app gives guidance and information from the government or health authority about what to do next.

How it helps:

Sarah recovers at home. She never knows who the app has notified but knows that she has helped slow the spread of COVID-19 by helping others act fast. People who received exposure notifications can take all recommended precautions to avoid exposing others to the coronavirus.