The Corona Warning App (CWA) could “help a lot” in the winter of the pandemic, but it does not work properly despite investments already worth millions. This is what the chairman of the Green parliamentary group, Katrin Göring-Eckardt, assumes. Reason enough to invite experts to a “digital exchange” about meaningful possible further developments. They were certain: The mobile prestige application is currently overwhelming the users, but also needs more functions.

First of all, the basic procedure of contact tracking is necessary Jutta Gurkmann from the Federal Association of Consumer Organizations (vzbv) emphasized that they could better explain the actual warning mechanism via Bluetooth. At present, the user comes across “a lot of lead deserts, has to click through, is referred to hotlines”. He ends up with a question-and-answer list from the federal government, but even after ten minutes of reading it still cannot really make it clear to him what different types of risk encounters actually mean. Nobody wants to work their way through there. Gurkmann therefore recommended “detox” first. The user must “find really good information with fewer clicks”.

It is also necessary to define the warnings and the resulting rights and obligations more clearly Elisa Lindinger from the Superrr Lab think tank. The app is currently raising a lot of questions and is “rather anti-nudging”. The users became dulled. Ansgar Gerhardus from the Institute for Public Health and Nursing Research at the University of Bremen put it in the same vein that a warning about a low risk in connection with two encounters is more unsettling than helping. Explanations are not understandable for laypeople. If someone goes to the family doctor with a “red app” but has no symptoms, he can at best take unpaid leave. Many employees would not even load the application. In addition, there is the “diffuse hole” that 40 percent of users do not pass on a positive result of a corona test and many warnings are omitted.

Registration using QR code The unfounded fear of negative consequences is apparently great. Linus Neumann from the Chaos Computer Club (CCC) explained his plea to enrich the CWA with an option for decentralized cluster recording. The heuristic Bluetooth method of measuring the distance to third parties via the signal strength and calculating the risk of infection has its limits and could only be expanded on the basis of the alternative interface between Apple and Google. It is therefore advisable to switch to other, epidemiologically meaningful tracing methods.

At the moment, individuals are sending codes that are stored on cell phones, Neumann explained. When clustering, for example via the CrowdNotifier, such an identifier stands for a meeting of several people and would later manually enter that they had left the location. Everyone else scanned the identifier using a QR code and stored it on their smartphone. At the same time, the organizer’s cell phone generates a second code to alert everyone involved if necessary. This procedure can be transferred to check-ins for restaurants and is “more privacy-friendly and faster than a contact diary”.

“Infections take place in places where there are many people,” reported Hajo Zeeb from the Leibniz Institute for Prevention Research and Epidemiology in Bremen. A cluster recognition is therefore important, organizers have to provide QR codes for logging in and out. Unlike in South Korea, for example, the aspect of voluntariness must be preserved. The federal government has concerns here that it does not want to allow the CWA as a check-in tool for restaurants, for example. The consumer advocate Gurkmann could imagine such an approach if it adheres to the “strict earmarking”. Contact data would have to be given anyway. Test laboratories should also be able to feed their reports 100 percent digitally into the app, emphasized Zeeb.

Dependence on Google and Apple The health authorities also complained that they had practically no gain in knowledge from the CWA users. At the moment it cannot even be clarified whether the goal of shortening the time between risk exposure and a test will be achieved. Patrick Hennig from the startup Nexenio explained that the company wanted to create an open standard for a secure, data-saving exchange with the health authorities as part of the Luca app and thus simplify contact tracking. There is no central evaluation unit. Rather, the system relies on decentralized keys that can be applied to different devices, which, in addition to the citizen or an organizer, the health department could also use within a certain period of time. If the user sees that this has decrypted data at around 9: 30, this is an indication of having been part of a chain of infection. In addition, there is the option of voluntarily sharing his contact diary from the check-ins with the authorities.

As an alternative to the smartphone, Stefan Köpsell brought Head of the data protection and security working group at the Barkhausen Institute of TU Dresden, the corona warning buzzer developed there. This has the advantage of not being dependent on Google and Apple. Here, too, no more information would be collected than necessary. However, the professor raised the question of how strongly the acceptance of relevant applications is linked to data protection: “We also don’t see hundreds of thousands of people on the street because the encryption is to be weakened.”

New functions of the CWA Even with a high level of data protection, the CWA could be expanded, for example “into a real corona information channel”, underlined Göring-Eckardt. For the Greens, cluster detection is also “the alpha and omega”. The federal government announced three more “updates” for the CWA after the online meeting of the heads of government of the federal states with Chancellor Angela Merkel (CDU). This would, for example, implement automatic reminders after a positive test of a warning that has not yet taken place for one’s own contact persons, integrate a mini-dashboard with current information on the course of the infection and improve the measurement accuracy by migrating to the new Apple and Google interface. In addition, the intervals for notification of a warning should be significantly reduced. Other extensions such as a contact diary are currently being checked and – if possible – “promptly implemented in 2021”.

(emw)