Germany on Sunday announced that it would back the approach supported by Apple and Google for tracing coronavirus infections, abandoning a home-grown alternative it supported previously.

Chancellery Minister Helge Braun and Health Minister Jens Spahn told the Welt am Sonntag newspaper that Berlin would adopt a ‘decentralized’ approach to digital contact tracing.

Until last Friday, Germany backed an initiative called Pan-European Privacy-Preserving Proximity Tracing (PEPP-PT), whose centralized approach was criticized by as opening the way to state surveillance.

“We will back a decentralized architecture that will only store contacts on devices. That is good for trust,” Braun told ARD public television in an interview.

Decentralized Privacy-Preserving Proximity Tracing (DP-3T) is an open source protocol developed in response to the 2019–20 coronavirus pandemic to facilitate digital contact tracing of infected participants. The protocol, like competing protocol Pan-European Privacy-Preserving Proximity Tracing (PEPP-PT), uses Bluetooth Low Energy to track and log encounters with other users.The protocols differ in their reporting mechanism, with PEPP-PT requiring clients to upload contact logs to a central reporting server and whereas with DP-3T, the central reporting server never has access to contact logs nor is it responsible for processing and informing clients of contact. Because contact logs are never transmitted to third parties, it has major privacy benefits over the PEPP-PT approach.

Apple and Alphabet’s Google said earlier this month they would develop new tools to support decentralized contact tracing. The Google / Apple contact tracing project is "heavily inspired" by the DP-3T protocol, according to Google.

On the 21 April 2020, the Swiss Federal Office of Public Health announced that the Swiss national coronavirus contact tracing app will be based on DP-3T. On the 22 April 2020, the Austrian Red Cross, leading on the national digital contact tracing app, announced its migration to the approach of DP-3T.Estonia also confirmed that their app would be based on DP-3T.

Nations are developing apps to assess at scale the risk of catching COVID-19, where the chain of infection is proving hard to break.

Using Bluetooth means the location of an infection event cannot be known to the authorities. However, users who will choose to opt in will share epidemiologically useful data under a decentralized approach.