The NHS COVID-19 app may not be perfect, but it does effectively protect your data. Are you using the app, or have you been put off?
Are you using the NHS COVID-19 app? Or have you been put off by the confused, confusing and worrying coverage about test and trace data being shared with the police?
If you’ve been put off, it’s not surprising. The twists and turns of the app are hard to keep track of.
A brief recap: the idea of an app to do contact tracing first popped up in the spring, and an immediate row blew up over how this could be done while protecting users’ privacy.
Google and Apple, whose operating systems power pretty much all smartphones, rushed out a framework that set parameters for how the app can and can’t work.
How your privacy is protected
The app we now have protects your privacy very effectively. That’s because all the data it generates is anonymised and stays on your phone unless you choose to share it.
Your phone generates a small anonymous chunk of data (‘a token’) once a day and a second one that changes every 15 minutes.
The app uses your phone’s Bluetooth low-energy chip to register when you’ve been close to someone using the app on their phone.
The phones exchange their current 15-minute tokens (they expire after two weeks) and these stay on the phones unless one of you tests positive for COVID-19 and uploads the test result to the NHS server.
At the same time as you upload the test result, all the current 15-minute tokens your phone has generated and collected from other phones will be uploaded.
The server then sends those tokens to everyone with the app and alerts those that match that they need to self-isolate.
All of the data mentioned above is anonymous: not even the police have access to it. And even if they had, they wouldn’t be able to tell who you are.
I’m impressed by the work that’s gone into making it as private as possible.
I’ve installed the app and I’d urge you to do the same: it’s not perfect, but it is built with privacy in mind.
It’s one part of a jigsaw of measures that will, I hope, help us return to something approaching normal life.
Are you using the app? Do you still have concerns?