How does Bluetooth location tracking work?

How does Bluetooth location tracking work?

One of the greatest frustrations surrounding the UK’s seemingly endless lockdown has been the slow pace of progress towards a resolution.

It’s clearly unsustainable to permanently maintain a two-metre gap from everyone else. Our pavements are too narrow, our public transport is too sporadic, and our schools are too small.

For months, the UK Government has been championing an app which will use Bluetooth location tracking to identify anyone who’s been in close proximity to infected individuals.

And despite the obvious security concerns – which we’ll come back to – this app could slash infection rates by enabling people exposed to Covid-19 to self-isolate.

But how does the technology behind Bluetooth location tracking actually work? And will this app erode personal privacy?

A rapidly changing picture

Firstly, it’s important to note that this technology is still in development, and the current situation may change rapidly.

At the time of writing, the NHS track and trace app has been in testing on the Isle of Wight for over six weeks, on both Android and iOS devices.

It was supposed to have been rolled out nationally by mid-May.

Although officials haven’t explained this delay, rumours suggest there are problems with the Bluetooth technology underpinning the app.

When it’s turned on, Bluetooth constantly searches for compatible devices to connect to.

Two Bluetooth-enabled devices with the app installed will swap low-energy signals when they come into proximity, supplying each other with an anonymous ID key.

Each Bluetooth ‘handshake’ will be stored for 28 days. If the owner of one handset tests positive for Covid-19, they are required to log this in their app.

Phones ‘shaken’ within the last 14 days may receive a message advising recipients to self-isolate, or request a test if they’re eligible for one.

This should happen within four hours of a positive test result being logged.

People won’t know which device belonged to someone who subsequently tested positive, since this data will be anonymous.

The app could replace a national lockdown with a far more localised one, only requiring people to quarantine if they pose a significant risk of infecting others.

Automated messaging is also far faster than the manual test and trace system currently being used across the UK, requiring much less administration.

Personal privacy or public protection?

The prospect of the Government storing so much personally identifiable information for 28 days hasn’t been well-received by privacy campaigners.

Even if 60 per cent of the population install and use the app (the minimum required to stop a pandemic spreading), it’s unclear whether today’s technology is accurate enough.

Bluetooth transmissions can travel considerable distances, and some experts believe phones may ‘shake hands’ with devices too far away to pose any risk of infection.

Of course, the NHS’s Covid-19 app isn’t unique.

Bluetooth location tracking is underpinning new/prototype test, track and trace apps around the world.

Yet this mass surveillance offers little transparency around data collection, storage, management or deletion.

The NHS app requires the first half of each user’s postcode – ostensibly for outbreak mapping, but representing another invasion of privacy.

The Government has also promised to delete data after the pandemic has ended, once the app isn’t needed. But what if that never happens?

After all, Covid-19 is only one of several human coronaviruses in circulation.

The common cold is another, and no vaccine or cure has ever been invented.

Covid – and the apps used to track it – may become permanent fixtures in our lives.

Back To Top