contact tracing

Coronavirus tracking apps: how do they work?

For some time now, the world has entered a critical phase, full of instability and responsible for a health and economic crisis. Coronavirus has perhaps forever changed many of the balances that govern our societies.

To combat contagion, many countries have resorted to specific displacement tracking apps, specifically designed to know the origin of an infection and contain the damage as much as possible.

Work is also underway in Italy to implement a tracking app, but with very different characteristics from those that have been used in the East.

Immune and how it works

The app that will soon be made available in Italy is called Immuni and partly follows the European model outlined by the PEPP-PT (Pan-European Privacy-Preserving Proximity Tracing) Consortium. In fact, Immuni’s is a hybrid model that exploits in part centralization of data on a server and decentralization on the device. Now it is turning towards a more decentralized model (according to the DP-3T model and married by Google-Apple), which will be the one used when the app is actually available, in late May.

The app stores locally, on the device, all the bluetooth codes of the other devices, equipped with the same app (whether these are smartphones, smart watches or stand alone devices such as bracelets). Encryption and pseudo-anonymization systems prevent associating the code with the identity of the owner of that device (in the pure centralized model of Pepp-PT, however, these codes are on the server).

Functions are triggered when a citizen is tested positive after a coronavirus test. Before making the analog questionnaire, the health worker asks him if he installed the Immuni app.
If the answer is yes, the operator generates, with a different app, a code with which the citizen can upload the data collected by his app to a server.

Here is the list of anonymised bluetooth codes with which he came into contact.
For each of these codes, the server calculates the risk that there has been a and therefore makes sure that a notification arrives to the devices of people potentially at risk, always via. The notification has a message decided by the health authorities and asks to follow a protocol.

And in the East?

The fundamental difference in the Italian app is that it makes the data it collects totally anonymous, in addition to the fact that it will not be mandatory for citizenship, but optional.
First of all, in the Eastern countries, coercive and restrictive measures through apps and information systems had the geolocation of citizens as their main purposes, to prevent the violation of the rules, to track the positives automatically.

This is the type of implementation that has been used in countries like China, Singapore and South Korea.
Of course, this type of application uses particularly invasive methods if compared to the Italian Immuni app, this is to be read in correlation also to the highly democratic model typical of our country.
For example, China is using the most invasive tool from the point of view of privacy.

It’s called Health Code, it is integrated with Alipay (Alibaba’s payment system) and WeChat (the “Chinese Whatsapp”) applications.
Being aware of the movements of individual users, the time spent in the places of the epidemic, exposure to potential carriers of the virus and access to many other databases (video surveillance, cameras, purchases made digitally) automatically assigns people an assimilable QR code to one of the three codes (green, yellow, red). In this way, citizens are given a specific permit to go to public places or be forced into forced quarantine.