Monitoring virtually impossible: This is how the Corona warning app works

It is nearly time. The Corona warning app is in the starting blocks. Its main purpose is to inform people whether they have been around infected people. But who can use the app at all and how does it work?

Many people are also hoping for the Corona warning app, which has been announced for months, to help them get out of the corona crisis into normality. It is intended to help identify and break through the infection chains at an early stage. What can the app do? The app can help people to be informed when they have been near infected people. You do not find out who these people were – and also not whether you are currently next to infected people.

How does this work?

With the app, a smartphone is transformed into a small "Bluetooth lighthouse" that constantly transmits an identification number to the surrounding area. At the same time, the phone listens to whether it can receive Bluetooth signals from others. If users who both have the app running next to each other for a certain time, the smartphones exchange their IDs. Does the app endanger user privacy? When programming the app and the associated services, a multi-level concept was implemented to ensure the highest possible level of data protection. It is not the users' identities that are exchanged, but anonymized IDs that change several times an hour. The IDs of the contact persons are not stored centrally, but decentrally on the respective smartphones. Only the list of anonymized IDs of the infected is kept on a central server.

How does the Corona Warning app differ from other Corona programs?

According to the guidelines of Google and Apple, there can only be one official tracing app per country that tracks possible infectious contacts. This is the Corona Warning App of the Robert Koch Institute (RKI), which is developed by SAP and Telekom. At the same time, there are other applications with different goals: The RKI data donation app, for example, collects information from fitness trackers to see whether there are any abnormalities in the regions. Other apps monitor how many people are in a certain area, such as on a stretch of beach on the Baltic Sea.

How does the German app differ from applications in other countries?

Apps in Asian countries such as China, Singapore, South Korea or India do not meet German data protection requirements because, for example, they can expose users or create a motion profile by analyzing the GPS signals. The app in France is similar to the approach in Germany, but insists on the central storage of the contact details. Other countries such as Switzerland or Austria, like Germany, follow the data protection guidelines of Apple and Google and can therefore also use the technical interfaces (APIs) of the tech companies.

Which smartphones can the app be installed on?

The current iOS 13.5 is a minimum requirement for the iPhone. This is available for devices from the iPhone 6s or iPhone SE. An old iPhone 5, 5S or 6 is not enough. With Android phones, the situation is somewhat more confusing. On the one hand, Bluetooth LE must be supported. This is the case from Android 6. On the other hand, the Google Play Services also have to run because the company does not provide the interfaces itself via Android, but via these Google services. Android phones without Google Play Services, like the latest Huawei models, are left out.

Is the warning app automatically activated by the operating systems from Google and Apple?

No, the exchange of anonymized contact IDs via Bluetooth only takes place if you voluntarily install the Corona warning app and actively agree to the data exchange.

Is there a risk that the Corona Warning app will not be used secretly to monitor the population?

No, that is almost impossible. The source code of the app can be viewed transparently on the GitHub platform. No back doors or other anomalies were found in several code analyzes.

Is there a separate legal basis for the warning app?

No, the Federal Government believes that the existing data protection laws are sufficient and is supported in the Bundestag by the FDP. The Greens and the Left, on the other hand, demand that the use of the app be regulated by law. So not only the installation of the app has to be voluntary. There should also be no obligation to carry a smartphone with the app running and show it when visiting restaurants, shopping or events. The AfD also demands that there should be no discrimination against non-users.

How many people have to use the app to get the desired effect?

A study from Oxford says that the full effect can only be achieved if 60 percent of the population or more participate. But that will probably not be possible. Even a popular app like WhatsApp took years to achieve such a high installation rate. But experts also point out that every installation counts and effects can be achieved at a significantly lower rate.

Federal Minister of Health Jens Spahn said that the app must still be able to run while listening to music on a cell phone – what's the technical problem?

"Listening to music on the cell phone" stands for applications that run parallel to the warning app. That could also be Google Maps or another app. With the iPhone in particular, the challenge was that Apple has so far not allowed a program to continuously send and receive Bluetooth signals in the background. With the API for the Corona warning app, Apple is now making a targeted exception. And the parallel operation of the apps is now also optimized at Google. The app developers now had to ensure that these interfaces were used optimally.

*Privacy

How can the app be prevented from discharging the battery too quickly?

In principle, this has already been solved by agreeing on the use of Bluetooth LE. LE stands for Low Energy (low power consumption). The developers of the app promise that the application will not use as much power as streaming music to a Bluetooth speaker. Practice will show whether the promise can be kept.

How safe can the warning app be against false alarms?

Since the Bluetooth technology was not developed for measuring distances, there will certainly also be false alarms. It may also be that infected people were behind a glass wall and triggered an alarm, although there was no risk of infection due to the "contact". Therefore, even the developers point out that the app can only make a limited contribution to normalization. It is not a silver bullet. If you want to protect yourself and others from infection, you should also keep your distance with the app and wear a mask.

. (tagsToTranslate) Technology (t) Corona Viruses (t) Apps (t) Health Policy (t) Jens Spahn (t) Corona Crisis (t) Pandemics (t) Sars-Cov-2 (t) Covid-19