StopCovid – infection carrier contact tracker without privacy breach
Anton Kondrashov, Software Engineering bachelor’s programme graduate and System and Software Engineering master’s programme second-year student, talks about minimal privacy intrusion solution from Workin Geeks team.
Some time ago, our company got a project to track contacts between people, so that potentially infected could be tested. This app was to help the African Republic of Djibouti, which does not have many ventilators. Before we began our work, we knew of the existing apps, including Singapore’s TraceTogether by Open Trace. Stanford U students were also looking for the solutions. Open Trace promised to publish their code soon. We suggested that the client waits for that, so as not to waste resources. In two weeks, we got the source code and developed it further to suit Djibouti.
How it works
The app does not trace the geolocation, which is obvious from its access requirements. Contact is tracked through Bluetooth. This technology allows not only to exchange files but to approximate distance to other devices as well. Contact is registered only when both devices have StopCovid app turned on. This way, your data cannot be used without your consent.
The original app requests just the user’s phone number. It is used to contact the user in case of potential infection. Contact data is stored on the device and cannot be accessed by the government without the user.
When a patient is diagnosed with coronavirus, they can inform of the people they contacted (within two-meter radius) through the app. The user receives a PIN number, which allows uploading their encrypted contact data to the server. This data is now accessible to the coronavirus control centre, which can decipher contact time and person’s phone number.
Timing helps to cut off people who contacted with a still healthy person. Others can be called and offered testing at home. And so it goes, link after link. The complete virus transmission chains can be traced this way; the number of ventilators planned, more strict quarantine measures deployed for the infected.
This description is fairly accurate but simplified. If you want to understand the technology better you can read the Open Trace account (in English).
As of now, the iPhone and other Apple products do not work with the screen turned off. One has to turn the energy-saving mode on and put the iPhone in the pocket with the screen on so that it keeps tracking contacts. This creates certain difficulties. Now Apple and Google collaborate on extra abilities for developers. After the release, this drawback is likely to be removed.
Apple also bans everyone but governments to publish suchlike apps, so that collaboration with a government is necessary, though not always easy.
Around the world
Australia has already adapted TraceTogether app. According to this article, Iceland, United Kingdom, and Taiwan considering this as well.
Germany and USA await Apple and Google’s improvements. There might be other cases, but we have not heard of them.
The app that was tried in Russia was very different, tracking geolocation and other data, according to the independent researchers. We were trying to approach someone to adapt TraceTogether for Russia – unfortunately, to no avail.