The adoption of a centralized contact tracing app called "Luca" launched in Germany is increasing. Conceived to "easily and anonymously document" a user's "presence in a restaurant, a bar or at an event" or, as documented by DW, to facilitate contact tracing on school buses, Luca allegedly "enables encrypted and data protection compliant recording of contact data and fast and seamless tracking of infection chains" through a check-in system based on QR codes.
The app adds to the decentralised exposure notification app Corona-Warn, launched in June 2020.
Howver, claims about its security and data protection features were quickly contested by pundits consulted by Süddeutsche Zeitung. They argued that the app's security concept is "incomprehensible" and, more generally, that its centralised model is fundamentally at odds with that of the Corona-Warn app, thus bringing the digital contact tracing debate in the country back to where it was at the start of the pandemic.
A pre-print paper, 'Preliminary analysis of potential harms in the Luca tracing system', concluded that
"the deployment of digital presence tracing systems with centralised system architectures might dramatically increase the potential harms for individuals and communities. The centralised system design furthermore introduces new harms for venues with respect to their paper-based predecessors: venues need to be centrally registered and can be profiled in real time."