Four months after an earlier UK contact-tracing app was scrapped, the UK government has given the green light to a new and improved version, with trials that started Thursday.
The trial pool has been widened this time to include residents on the Isle of Wight alongside residents in the London borough of Newham and selected NHS volunteers.
The new contact-tracing app – a critical element in the fight to stamp out the COVID-19 pandemic – differs from its predecessor in several ways. In particular, the UK government this time decided to adopt Google and Apple’s decentralised model.
This approach should help mitigate some of the security and privacy concerns that dogged the earlier version and ensure a larger number of contacts is properly detected. (Because Apple restricts how Bluetooth is used by third-party apps, the technology used in the UK government’s previous attempt only detected 4% of iPhones.)
“From a privacy perspective [the decentralised model] is, in principle, a huge relief,” said Ben Rapp, founder and principal at Securys Limited. “It significantly reduces the risk of the app being used for other kinds of surveillance and of the data being repurposed by other arms of government in the future.”
Rapp also praised the redrafted privacy notice from NHSX, saying it was clearly taking privacy concerns more seriously this time. “Both the main privacy notice and the detailed supplementary version are clear and well-drafted and reflect appropriate decisions about the lawful basis for processing and the safeguards for storage and retention of data,” Rapp said.
He also noted that by publishing the DPIA and source code, NHSX had demonstrated an “admirable exercise in transparency.”
What’s new in V2.0?
The new app also has additional features that reflect the changing nature of the UK’s current lockdown restrictions, namely a QR barcode scanning facility, so users can check in when they visit a venue and be told if others there later test positive for the coronavirus.
Other features include an alert system that informs users of the coronavirus risk level close to their home; a symptom-checking tool, which allows users to book a free test and get the results via the app; and a countdown function that begins if they are told to self-isolate, so users can track how long to stay at home. The app is also available in five languages, with plans to add more at a later date.
While changing the app’s model should improve its success rate – one report in the The Guardian claims it can correctly identify seven out of 10 qualifying matches – the latest version isn’t without issues. Some handsets are still incorrectly recording that they within two meters of another phone running the app for 15 minutes or more when they were further apart, causing false positives.
Part of the problem stems from Apple's and Google’s refusal to share raw Bluetooth signal data; both companies have said they will soon release a new version of their tool to help counteract the issue.
Dido Harding, executive chair for NHS Test and Trace, acknowledged, “there is no silver bullet when it comes to tackling coronavirus.” But Harding said the app “is a great step forward and will complement all of the work we are doing with local areas across the country.
“By launching an app that supports our integrated, localised approach to NHS Test and Trace, anyone with a smartphone will be able to find out if they are at risk of having caught the virus, quickly and easily order a test, and access the right guidance and advice,” Harding said.
Simon Thompson, managing director of the NHS test and trace app, is also confident the new app will help the UK better manage the spread of coronavirus.
“[The UK government has] worked with some of the most innovative organisations in the World, such as Apple, Google, scientists from the Alan Turing Institute and Oxford University and governments across the world to come up with a state-of-the-art product which works to protect people every day,” he said. “It’s like NHS Test and Trace in your pocket.”