The National Health Service’s coronavirus contact tracing app will not be built on the joint Apple/Google platform, it has been confirmed.
That’s despite potentially greater privacy concerns and a limitation for iPhone users in particular that may require the app to be kept open at all times.
NHSX, the digital innovation unit of the health service, says it has its “sufficiently” overcome the those limitations to ensure the app can run in the background.
“Engineers have met several core challenges for the app to meet public health needs and support detection of contact events sufficiently well, including when the app is in the background, without excessively affecting battery life,” said a spokeswoman.
However, Apple and Google’s solution is thought to do a better job of protecting users privacy because it promises a decentralised approach, with the tracing happening on handsets themselves. The NHSX model will use a centralised model where the data will be transmitted to a server in order to process the information. However, the group believes this will make the data mode useful.
“One of the advantages is that it’s easier to audit the system and adapt it more quickly as scientific evidence accumulates,” Professor Christophe Fraser, an epidemiologist advising NHSX, told the BBC.
“The principal aim is to give notifications to people who are most at risk of having got infected, and not to people who are much lower risk. It’s probably easier to do that with a centralised system.”
The contact tracing app is designed to alert people if they’ve come into recent direct contact with a person who has tested positive for Covid-19. The app will use Bluetooth connectivity to discern which smartphone users have been in close proximity with each other.
The rest is done automatically, with recipients of the alerts advised to quarantine or get themselves tested for Covid-19. It’ll be done anonymously so those receiving the message won’t know which of their contacts have been infected. The app will rely on the public to opt-in to use the service and then register themselves as testing positive.
The NHS’s app has been built with help from the National Cyber Security Centre and the GCHQ intelligence organisation. It hasn’t been announced when the app will launch yet, but it is thought to be key to relaxing social distancing restrictions in the UK.