How does phone data work

Contact tracking via cell phone data : This is how the Corona app works

An initiative of 130 scientists and technology experts from various institutions and companies from eight European countries today presented a technology with the help of which it should be possible Track contacts of people infected with Covid-19 using your mobile phone. The Robert Koch Institute (RKI), which works on behalf of the German Ministry of Health, is involved.

The federal government has high hopes for the app for tracking corona infection chains, which is currently being tested in Berlin. The deputy government spokeswoman Ulrike Demmer said on Wednesday in Berlin that they are looking for a solution “with high pressure” together with the Robert Koch Institute (RKI). She emphasized that this app could work across borders in Europe.

A spokesman for the Ministry of Health said that the tracking of contact persons of corona infected people is "digitally easier than when someone in the health department starts calling".

Based on the technology, an app is to be developed over the next few weeks that as many people as possible should download. Exact schedules will be presented shortly. It's clear: The app only makes sense if as many people as possible download it.The participation of the population in the project should be voluntary.

The Tagesspiegel spoke to the initiators of the project.

How can technology help contain the spread of the coronavirus?
Salathé: Technology can be used to reproduce situations in which two or more people were together with short-range telephones for a long period of time. With Covid-19, we have the problem that the disease can be contagious for a few days before a person develops symptoms and can be tested. That is what makes this traceability so important.

Does that mean we could all get out with an app?
Salathé: With as many cases as we would have had with a further exponential distribution, an app would be of little use. The only thing that helps is lockdown. But when there are fewer, we can use technology to try to trace every small outbreak and contain a new bushfire in time. The coronavirus won't go away anytime soon, not until the vaccine is there. But you can't keep a society or economy behind closed doors for that long. Our Asian colleagues have shown us that it is possible to resume public life with the virus - also with the help of technology.

The surveillance technology of the Asian countries is seen as a deterrent example to many Europeans.
Boos: Our goal is to fight Covid-19 without spying on people. Our privacy is a fundamental right. The intention of the solution we have developed is to respect that. It should be safe, anonymous and voluntary. Thank you for bringing the best of both worlds together.

How exactly does it work?
Wiegand: Our solution is based on Bluetooth technology. This makes it possible to measure the distances between two smartphones. The aim is to determine whether someone has been less than two meters from someone else for a longer period of time. And especially in closed rooms. If you use an app with our technology, your mobile phone automatically identifies itself to the smartphones of other app users in your area. Every encounter within a critical distance that lasted longer than a few minutes is stored encrypted on the phone for 21 days. It is completely irrelevant who owns the other phone or where the encounter took place. We do not create any movement profiles and we do not track cellular data. We only measure distances.

How do you ensure that the saved encounters cannot be traced back to real people?
Wiegand: Communication is encrypted. The cell phones send each other codes that change constantly. These codes are stored, decentralized, directly on the device. Your cell phone number will not be sent, your whereabouts, not even your Mac address. You yourself are not identifiable, neither for the other users nor for the operator of the app.

[Follow the current developments on the coronavirus in Berlin and the coronavirus worldwide in our live blogs.]

How do I find out if I have had contact with an infected person?
Wiegand: A person who tests positive for the coronavirus receives a code from the health department. You can enter it in your app. You do this voluntarily. If you choose to do so, your distance history for the last 21 days will be uploaded to a secure server. All app users who have been at a critical distance from your phone in the past few days will then receive a warning.

There are epidemiologists who do not consider a technical solution to be sensible. One point of criticism is that the distance alone does not say anything about whether an infection could have taken place.
Salathé: We don't yet know everything about the coronavirus and its routes of infection, but we do know: Infection via droplets is possible. And larger drops come two meters away. That is why the RKI recommends keeping a suitable distance, which is why the health authorities also ask for this feature for tracing. Our technology does the same thing, only automatically.

What if I don't have my mobile phone with me or it gets stuck in my jacket on the cloakroom?
Wiegand: We not only have epidemiologists, engineers and programmers on our team, we also have behavioral researchers on board. They think that believing in the usefulness of such an app could induce people to adapt their behavior, for example to carry their phone with them.

If app users will receive constant warnings on their mobile phones in the future, couldn't that also spread panic? And if suddenly everyone wants to be tested, are the test capacities sufficient?
Wiegand: Most panic arises when people don't know who is infected and who is not. But of course, technology cannot win the fight against the coronavirus on its own. The test capacities must be expanded in parallel. And we will all have to learn to change our habits: to keep our distance and avoid large crowds. If everyone joins in, the warnings will be limited.

Background information on the coronavirus:

Keyword participate: How many people have to download the Corona app for it to work? Not everyone has a smartphone, especially among older people.
Salathé: A realistic goal is 60 percent of the people involved in an encounter. Studies from Oxford have shown that this is enough to achieve a noticeable effect. You would achieve an effect at 30 or 40 percent, just less strongly. Above all, it is important that we reach those who travel a lot and meet others. When travel activity increases again, it is also essential that the various apps are compatible with one another across borders.

How are you going to achieve that?
Boos: Every country that wants to participate can develop an app based on our technology or integrate the technology into an existing app. We developed this solution together with 130 colleagues from 8 European countries. Leading minds from science and business worked together for many nights, without an order, of their own accord, because we are convinced: We want to use the potential of technology to fight the coronavirus and to be able to lift the restrictions on our freedom again. We do not want to introduce any new restrictions or touch our core values. Our solution is a thoroughly European one, based on common ideas, common work and our common values.

Thomas Wiegand heads the Fraunhofer Heinrich Hertz Institute HHI and is head of the focus group “AI for Health” at the ITU / WHO. Marcel Salathé is Professor of Digital Epidemiology at the EPFL in Lausanne. Hans-Christian Boos is the founder of the AI ​​company Arago and a member of the digital council of the federal government.

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