How effective will the UK Covid-19 contact tracing app be and will it protect your privacy?

Trials of the government's contract tracing app - which alerts mobile phone users if they have come into contact with someone with Covid-19 symptoms - began this week on the Isle of Wight.

Ministers see it as a key element in their test, track and trace strategy to stop the spread of the disease and enable the easing of the lockdown restrictions.

NHSX, the digital department of the NHS and the app's developers, say it will play a vital role in reducing the transmission of the virus by alerting people who may have ben exposed without knowing it and take the precautionary measures to protect themselves and others.

Questions have been raised whether the app will drain its user's phone's battery.

But questions remain over the viability of the coronavirus contact tracing app as it is incompatible with the contact-tracing API currently being developed by Google and Apple, meaning the two cannot interact.

Civil rights' campaigners and ministers have also raised concerns regarding privacy around a state-controlled system which potentially involves tracking the movements of millions of people.

  • ITV News Correspondent Dan Rivers is on the Isle of Wight where the app is being trialled

  • Would Google and Apple's apps be more effective?

Among other things, the operating system (OS) on your phone controls how apps can use Bluetooth.

Both iOs and Android operating systems prohibit constant Bluetooth signal broadcasts in order to preserve battery life and protect privacy.

iPhone and Android apps using the latest version of the OS can only send Bluetooth signals when the app is running in the foreground.

There may be no Bluetooth signal if your phone is locked or you are not looking at the app.

The NHSX app's effectiveness is likely to be hindered by these restrictions as they mean the app will be blocked from communicating with app users nearby.

Put simply, two people might spend several minutes in proximity to each other, but unless they open the app, their encounter may not register on the system.

Apps and APIs developed by Google and Apple can override these restrictions as these companies control the operating system making them more effective and reliable.

The app is seen as a key part of the government's test, track and trace scheme. Credit: PA
  • Will my privacy be compromised?

NHSX insists the app "strongly protects your privacy and security" and has "been designed with privacy in mind".

It added: "The app does not collect personally identifiable data from users.

"Users will always remain anonymous.

"The anonymous data collected by the NHS COVID-19 App will only ever be used for NHS care, management, evaluation and research," the department said in a statement.

But anonymising the data does not eliminate the risk of a privacy breach, according to some experts.

A study by UCLouvain in Belgium and Imperial research in 2019 found anonymising data still leaves individuals vulnerable to being identified.

The research showed that once bought, data can often be reverse engineered to re-identify individuals, despite the anonymisation techniques.

This week, ministers called on the government to put effective safeguards in place to protect an individual's privacy before rolling out the app.

The Joint Human Rights Committee said it was essential legislation was enacted to ensure the mass surveillance of personal data did not result in the unjustifiable "violation of fundamental rights".

In its report, the committee warned that assurances by ministers about intended privacy protections would not carry any weight unless they were enshrined in law.

"State-controlled apps that enable the mass surveillance of personal data, and that could then enable the (proportionate or otherwise) violation of fundamental rights are novel," the committee said.

It called for the creation of an independent body, with powers similar to the Information Commissioner, to oversee the use of the app and its privacy protections.

Matt Hancock announced that the trial was being launched on the Isle of Wight. Credit: PA
  • Can I use the app abroad?

The app is unlikely to work outside of the UK's borders.

Dominic Raab defended the app's inability to operate abroad saying the UK had “very high standards” which were not necessarily shared by other countries.

The Foreign Secretary said: “The reality is we want the app to be focused on the UK and we want the technology to be tailored to make sure we can deal with the specific challenges that we have got in this country.”