Anti-coronavirus apps: the opportunities and risks of contact tracing


Author: Jan Tissler

Can technology help free us of the pandemic stringency? Automated contact tracing is at least one possible tool for this purpose. In this article we explain why the idea is so criticized and the limits characterizing this type of technology.

Smartphone apps are said to be a way out of the Covid 19 crisis. The idea is that they automatically inform you if you’ve been in contact with an infected person and therefore may be a carrier yourself. Those affected would then go into quarantine so as not to spread the disease any further and arrange to have themselves tested. This is known as contact tracing.

If this system were to work, several of the currently essential restrictions could potentially be loosened. However, this project has also been heavily criticized and experts warn of the need to proceed with caution.

1. Privacy concerns

As is well known, the EU recently developed a very strict set of rules with the General Data Protection Regulation (GDPR). Sensitive information such as health data is particularly protected. Digital contact tracing therefore needs to do a balancing act, on the one hand, to be as reliable as possible (see below) and on the other to protect the privacy of users. Of course, this type of system has vast potential for misuse, yet another topic we will discuss.

US companies Apple and Google have announced a solution that takes this into account. The way it works is easy to understand by reading this Twitter thread. What’s most important is that user names or other personally identifiable information are not processed. Instead, it works with regularly generated keys. And a central server is only used if an infection is reported. Otherwise, it runs in a decentralized manner, directly on the users' devices. In addition, no location data is collected.

Regardless, Apple and Google are only providing the technical basis here. It is then up to official institutions, such as health authorities, to develop apps that build on this. The two tech giants do not receive any of the data.

Several countries such as Germany and France had initially preferred a centralized solution. The official reason was that the information could then be used to gain further knowledge about the coronavirus and its spread. Germany at least is now leaning toward a decentralized solution, just as Switzerland and Austria had already done before.

You can find out more about data protection in this article at

2. Technical shortcomings

Technical limitations are one criticism of this form of contact tracing. The distance measurement via Bluetooth Low Energy is anything but exact, since software, hardware and usage all influence the signal strength and thus falsify the result. The “DP3T” project by ETH Zurich and EPFL Lausanne is working to mitigate this problem by taking other factors into account.

Since there is also no means of determining the exact surroundings in which the devices are located, other factors can also lead to false alarms: For example, a person who is now ill may only have been in the apartment next door.

3. Voluntariness

Apple and Google rely on voluntary use. Only then can their solution be used. At the same time, experts estimate that at least 60 percent of the population must actively participate for these apps to actually be effective. And reaching this number on a voluntary basis appears somewhat difficult. In Singapore, for example, between March 20 and April 1, this type of application only managed to reach 20 percent of the population. A similar app in Austria has so far only been used by 5 percent.

However, the concept of voluntariness is flexible and pressure could also be applied indirectly. This could mean that certain advantages, such as access to buildings, would be reserved only to users of the app.

4. Possible misuse

Privacy advocates warn that this type of contact tracing system could also be used (and misused) for other purposes in the future. No doubt the police, secret services and military would also like to know who was in contact with whom and for how long. There are always good reasons, such as the fight against crime in general or countering terrorism in particular. Once this practice has been introduced, it can also be used to monitor other groups in society, including political opponents. Edward Snowden's revelations have impressively shown how quickly a surveillance state can emerge.

Final word

As mentioned at the beginning, such “anti-pandemic apps” can only be considered as one of several measures. Virus and antibody tests must also be available at a high rate, because without tests there are no warnings. Another problem yet to be solved by science are so-called asymptomatic coronavirus infections, which show no or very few symptoms, but can still infect other people. If they are never diagnosed, they too will fall through the cracks in the app.

Other measures such as “social distancing” and mandatory masks are therefore not superfluous in combination with these apps. To the contrary: This type of warning system can only make a significant contribution if the spread of the virus is slowed. For this reason, the Swiss Federal Council, for example, remains cautious and plans to only gradually ease the current restrictions.

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