Germany's "Corona-Warn-App" now available – alert per mobile phone

High number of app users needed to break infection chains swiftly
17 June 2020

Germany made its contact tracing app called “Corona Warn App” available for download Tuesday (June 16, 2020) from Apple's App Store and Google Play. The app should help contain the spread of Covid-19 and disrupt the chain of infections as swiftly as possible. To this end, the free and voluntary app notifies users of any contact with an infected person. The app does not gather personal user data on central servers as the files remain decentralized on the mobile phone.

App exchanges encrypted random codes

The German app does not use location detection to create movement profiles and uses bluetooth to detect other app users in the vicinity. The app stores all random codes gathered by the phone. According to the Robert Koch Institute, the research institute responsible for disease control and prevention, the incubation period is a maximum of 14 days. Thus, the data is deleted automatically after a fortnight. 

If a person reports an infection via the app, their random codes are made available to all other users. The app checks whether that code is among contacts made in the past 14 days and whether any were critical. In that case, it notifies those affected and gives clear recommendations for action. The data of the persons notified cannot be viewed at any time.

Caspar – “exemplary data protection”

Johannes Caspar, Hamburg's Commissioner for Data Protection and Freedom of Information, commented: "The app is a modern tool for detecting and preventing chains of infection. The intense discussion about the concept of the corona warning app has delayed its deployment." However, Caspar said the wait has been worthwhile: "Politicians have acknowledged the voluntary use and the technical concept has been adapted to ensure exemplary data protection. Germany’s "Corona-Warn-App" is based on open source development designed by the German software company SAP and Deutsche Telekom.