A group of European experts said on Wednesday they would soon launch technology for smartphones to help trace people who had come into contact with those infected with coronavirus, helping the health authorities act swiftly to halt its spread.

The initiative proposes keeping a record of when a smartphone comes in close range with another, so that should an individual test positive for the virus, others at risk of infection can be quickly identified.

The ability to track down those at risk of infection more accurately could make it possible to ease country-wide lockdowns that have brought economic activity in many countries to a near halt

The European initiative, called Pan-European Privacy Preserving Proximity Tracing, follows the successful use of smartphones in some Asian countries to track the spread of the virus and enforce quarantine orders, although their methods would violate strict European data protection rules.

PEPP-PT, which brings together 130 researchers from eight countries, aims to launch its platform by April 7, said Hans-Christian Boos, founder of German tech startup Arago and a member of Chancellor Angela Merkel’s digital advisory council.

Merkel, in isolation after being treated by a doctor who tested positive for COVID-19, said she would recommend such an app as long as it was effective and voluntary.

“I would of course also be prepared to use it myself to help other people,” the conservative leader told reporters.

Epidemiologists say contact tracing will become a vital weapon in containing future flare-ups in COVID-19, the flu-like disease caused by coronavirus, once national lockdowns succeed in slowing the rapid spread of the virus.

“We all know that, as a society and an economy, we cannot go on like this for an extended period of time,” Marcel Salathe, professor of digital epidemiology at the Swiss Federal Institute of Technology in Lausanne, told a news briefing.

“There is a more efficient way to break this exponential trend of growth.”

The illness can be passed on by people showing no symptoms, putting a premium on warning those at risk of infection swiftly after an individual tests positive.

Logging Connections

The new platform would make anonymous use of low-energy Bluetooth technology in a way that respects the European Union’s General Data Protection Regulation (GDPR), and would not require the intrusive tracking of location data.

It would log connections made between smartphones on a device, rather than a central server, for two weeks, using strong encryption. Only local health authorities, deemed ‘trusted’ persons, could download data so they can notify people at risk of infection and tell them to go into isolation.

A study by researchers at Oxford University’s Big Data Institute said 60% of a country’s population would need to be involved for the approach to be effective. Those without smartphones could wear Bluetooth-enabled armbands.

German research body Fraunhofer Heinrich Hertz Institute (HHI) has worked on the technology platform with Vodafone and others. It has recruited volunteers from the German army to measure how different smartphone brands communicate with each other.

The PEPP-PT project is similar to Singapore’s TraceTogether app but differs in some respects: By using country codes it can work across borders, said Fraunhofer HHI head Thomas Wiegand.

Separately, a group of Berlin startups, led by data management company via, fintech group finleap and insurance tech firm Wefox Group, said that it planned to launch its own contact tracing app called Healthy Together next week.

Sascha Gartenbach, founder and chief executive of via, said the Healthy Together group was in touch with PEPP-PT on collaborating. “Our approaches are complementary,” he told Reuters. (Additional reporting by Andreas Rinke, Holger Hansen and Michelle Martin; Editing by Keith Weir and Edmund Blair)