Exposure Notification API

Health authorities all around the world are working on social distancing apps as a way of digital contact tracing since early 2020. The aim is to provide an instrument, which allows automatic registering of encounters and following that, informs everyone that has been in contact with an infected person. Due to an incompatible BLE-Solution for both Android and iOS a mutual recognition of the particular end device was not possible. Therefor the development of a reliable instrument for relieving health offices by making the manual contact tracing digital, was distant. 

Advisory Capacity

Having the knowledge of what the exposure notification has to offer to provide a reliable solution to the occuring problem, Fraunhofer IIS was able to help both Apple and Google during their first ever cooperation and therefor took an advisory role in the development of the exposure notification API.

The new interface not only allows an exchange of randomly created codes between smartphones with differing operation systems for the first time, but also the saving of an encounter on an internal storage. The built-in function is therefor a vital part of corona warning-apps.

Operating Principle

Functionality of Contact Tracing of two smartphones with the exposure notification API.
© Fraunhofer IIS/Windisch
Contact Tracing with the Exposure Notification API.


Apples and Googles Exposure Notification API helping with international contact tracing
© Fraunhofer IIS/Windisch

Especially for borderlands, an international solution of contact tracing is vitally important. Due to the exposure notification API, it is possible to trace contacts across different country-specific social distancing apps.

The exposure notification API enables social distancing apps to provide reliable measurement results across borders, no matter the operating system used on smartphones and therefor assist health offices with contact tracing.