A balancing act

The fight against Covid-19 is a careful balance: on the one hand the spread of the virus needs to be carefully controlled, and on the other, measures which are too stringent quickly become harmful to society in other ways. Many countries have developed a tracing app as a one of many tools to address this, and the UK has duly created an app of its own. But the UK’s app was developed using technology which could never have worked, and unsurprisingly recent trials on the Isle of Wight have recently proven that failure. The idea, though, is a good one, as when someone develops symptoms, public health officials are able to contact those who have been near them. Their isolation prevents them from perpetuating the virus further.

For that reason, Apple and Google have together been working on the technology behind tracing apps. That is in itself a stunning revelation. They are fierce rivals and Apple in particular has a reputation for secrecy and insularism, even to the point of regularly canning cross-platform products after takeover. But separate to their corporate existences, both companies have large charitable arms and what seems like a genuine desire to solve big world problems through technology. Covid-19 tracing apps are something that needs the cooperation of both iPhone and Android phones, so they worked on it together.

The problem

The government therefore had the ability to use this technology, but chose instead to develop their own. This was more than a little surprising to industry specialists. One of the key problems in developing certain types of app is that both iOS and Android severely limit what an app can do when it’s not actually in use. This is for good reason, as it prevents apps from doing nefarious things in the background when the user’s not around, and also improves battery life by ensuring that only the app currently in use can consume resources. When you switch to a different app, the one you’re switching from gets a little grace period but eventually has to stop. Contact tracing apps hit this limitation full on, because Bluetooth activity in the background both consumes battery and could be exploited by malicious apps. The only people able to subvert these rules are the ones who built the platform. Hence the Google/Apple technology is the only solution.

There was industry precedent for this. Singapore developed a contact tracing app before the Google/Apple technology became available, and poor success rates initially forced the government to ask people to keep the app in the foreground “as much as possible”. Finally they dropped the app idea altogether and instead developed their own hardware.

So, entirely unsurprisingly, the Isle of Wight trial has proven that our government’s technology doesn’t work. It detected only 4% of iPhones nearby and 75% of Android phones. Not reported is the fact that those 75% of Android phones are likely older devices with less stringent versions of the Android OS – I would expect Android 10 to have a rate more in line with iPhones. By contrast, the Google/Apple model was shown to detect 99% of iPhones and Android phones nearby.

The way forward

So where do we go from here? The government – having previously eschewed the Google/Apple model – are now having to make an about-turn to embrace it. There is no release date reported for this. With such a time sensitive project, it will be interesting to see what impact it will be able have on the spread of the virus this far down the line.