Swiss Covid App

Swiss Covid App

The Swiss Covid App is now a reality. It is based on the Apple/Google decentralised approach that ensures privacy is protected but the App can be effective. Of course many will speculate that the App will not achieve much unless a critical mass of installations and users have it – but it is better than nothing.

It is a development by ETHZ and EPFL and is referred to on GitHub as DP-3T. Updates to get devices to work with this were delivered in iOS 13.5 and via Google Play Store (and not needing an Android version upgrade).

The App does not presently work on iOS 14 Beta 1. This is most likely due to the fact that iOS 14 has been a work in progress for some time and does not have the framework present in it right now (the API is missing in iOS 14 Beta 1 so it’s not one of the bugs reported in the press).

So is it safe to use and does it protect your privacy?

Yes is the short answer. The App relies on BlueTooth and therefore has a limited range; also the two Tech Giants have implemented BlueTooth so that it randomly changes its MAC address every 10-20 minutes. This MAC address randomisation prevents anyone finding who the phone belongs to, basically. If it was fixed, you would eventually be able to relate a phone to a person – it would not be terribly difficult to do this.

The phone is able to replay its own random MAC addresses and records the random addresses from nearby devices running the App. When someone registers themselves as COVID-positive, their addresses are uploaded into a server and each App can compare their records to those addresses.

The data locally is held for 3 weeks to cover the incubation period. It’s then all deleted. I would assume the server data is similar because if someone is positive and had an encounter with people during the infectious phase, they will likely know from the App or from symptoms that they are potentially infected.

We should all use it. It’s our social obligation to do what we can.