Apple and Google’s coronavirus contact-tracing framework fails to accurately log exposures on a commuter bus, Dublin academic study finds
Researchers in Ireland have found flaws in the way coronavirus contact-tracing technology developed by Apple and Google detects distances between handsets.
The technology, termed Exposure Notifications by the companies, is intended to form the basis for contact-tracing apps developed in different areas around the world.
It provides a framework for allowing the apps to detect whether the user has been in close enough contact with another individual to have been exposed to the virus.
When an individual tests positive for Covid-19, such apps can alert those they have come into contact with to have themselves tested or to self-isolate.
The UK last week it had also found inaccuracies in the Apple and Google distance calculations.
Government officials said the tech was unable to to distinguish a phone in someone’s hand three metres away from a device in someone’s pocket one metre away.
“Measuring distance is clearly mission critical to any contact-tracing app,” UK health secretary Hancock said during a briefing on Friday.
Apple responded that it was unaware of the distance-logging issue and that the government hadn’t communicated its concerns.
Tests by Trinity College, Dublin carried out on a bus raised similar concerns.
The team of academics behind the study found that the “metal-rich environment” of the bus caused distance calculations to become less effective.
The study found that under such conditions “there is only a weak dependence of detection rate on distance”.
The tests collected data from 60 pairs of handsets placed on a Dublin commuter bus.
Using settings employed for a Swiss app based on the technology the researchers found that no exposure notifications were triggered, in spite of the fact that all the handset pairs were within 2 metres of one another for at least 15 minutes.
The detection rate went up to 8 percent when the exposure duration threshhold was reduced to 10 minutes, a setting that would be likely to trigger false positives under other conditions.
Ireland’s Health Service Executive has indicated it plans to press ahead with its app’s launch, which is based on the Apple and Google tech, in the next few days.
The agency told the BBC it plans to submit a memo to the government this week and would launch the Covid Tracker app shortly afterward, “subject to approval”.
The app has been trialled by the An Garda Siochana police force with the results deemed sufficient to press ahead with the launch.
The app supports UK mobile numbers, meaning those travelling into the country from Northern Ireland or Great Britain can make use of it.
Countries including Germany and Italy have already launched contact-tracing apps based on Apple and Google’s technology.
One of the developers of Germany’s Corona-Warn app indicated the tech was 80 percent accurate in logging contacts across a variety of scenarios.
The Robert Koch Institute, which published the app last week, said on Friday it had been downloaded 9.6 million times.
The UK government, after cancelling development of a first version of its app last week, has indicated it plans to launch some sort of app by the autumn, but even then it may not include contact-tracing features.