COVID-19 and Contact Tracing: The “Internet Of People” era

What is Digital Contact Tracing and how it works

Every day we give our data to big tech companies, why not giving it now for a good cause?

Contact tracing is a process used by health system to identify how many people have gotten in contact with an infected person in a specific period of time.

In short, when you feel sick and you go to a hospital, if doctor’s diagnosis says that you’re infected by an epidemic disease, hospital informs the government about it and the hospital asks you to fill a ‘’survey’’. This ‘’survey’’ is a list of people you have met recently. This way, the sanitary service can identify potentially infected people.

This is called Contact Tracing, i.e. tracing the ‘’path’’ of the disease.

Until nowadays, Contact Tracing is done ‘’Manually’’, an infected person lists all person that he remembers, and he can identify, but what about people that every day you meet at the market, in the train, on the street, … ? You don’t know their names, who they are, where they live… so ‘’Manually’’ Contact Tracing is not good enough. It identifies only a subset of person you get in contact with.

But why not using technology to make Contact Tracing a more effective and automatic process?

Technology helps our life everyday, it would stupid to not leverage it to trace epidemic spread.

Apple and Google, the giants of smartphones market, came up with a method to perform ‘’automatic’’ Contact Tracing using smartphones.

They started with these considerations:

• 70% of people in the world have a smartphone
• People always have their smartphone with them (inside their pocket, bags, etc.)
• 88% of smartphones are Android (Google) devices, 11,9% are iOS (Apple) and 0.1% have other operating systems.

Following these assumptions, Apple and Google have worked together to develop, in a very short time, an ‘’Internet Of People’’ (IoP) mechanism to trace the COVID-19 (aka Coronavirus) spread.

This method is based on the most used wireless technology in smartphones: the Bluetooth.

Why Bluetooth for Contact Tracing?

Smartphones are equipped with a lot of wireless communication interfaces and sensors: Bluetooth, Wi-Fi, GPS, Cellular, etc.

But why tech giants choose Bluetooth for Digital Contact Tracing?
In particular the Bluetooth Low Energy (Read my article about how Bluetooth LE technology works).

Three important reasons:

• Low power consumption technology.
  Everyone knows how it’s important to arrive at end of day with a sufficient smartphone battery charge. We do everything with our smartphones and big techs know it.
• Pervasive technology
  Almost all smartphones are equipped with Bluetooth Low Energy.
  But, not only the smartphones, also a lot of other gadgets(smartwatches, fitness tracker, etc.).
  So, we can assume that every person goes around with at least one Bluetooth antenna on.
• Last, but not least… Privacy-preserving
  In comparison to GPS (Global Positioning System) and Cellular (4G, 5G, etc.) technology, Bluetooth doesn’t track the geo-position of the user. You can’t know where exactly the user is located only using Bluetooth.
  We’ll cover this topic more in details in the next sections.

Digital Contact Tracing: How does it work?

Suppose you are on a train, traveling home and you have a long conversation with a neighbor. You don’t know each other, but you both have a smartphone in your pocket with a Digital Contact Tracing app installed on it.

During your conversation, also your smartphones are having a ‘’conversation’’ over Bluetooth channel. Both smartphones continuously say to each other: ‘’Hey! my Bluetooth identifier is …’’.

During Bluetooth “chatting”, your smartphone stores the identifier of the other smartphone in a list of Bluetooth identifiers it had a conversation with.

An identifier is an univocal code used to identify a specific smartphone in a specific period of time:

• Univocal: to recognize a specific device (who)
• Changes frequently: to recognize a specific period of time (when).
  It changes approximately every 15 mins, i.e. estimated time to get infected by a virus.

A few days after your journey on the train, you don’t feel good and you go to the hospital. The diagnosis is Coronavirus. Now; it’s time to fill the Contact Tracing list with names of people met during the last days. But who is the person you met on the train? What’s his name and Where does is he live?

Digital Contact Tracing has the answer!

Hospital operators ask you if you want to share the Bluetooth Identifiers stored in your phone with the public health system. If you consent, identifiers stored in your mobile phone are uploaded on the national health system server.

Now; Public Health System knows what “smartphones’’ (…not people!) you have met in the last days, and thanks to Digital Contact Tracing app it sends a notification to the smartphones of people who got in contact with you.
So, now, the guy you met on the train receives a notification on his mobile phone saying: “You’ve recently got in contact with someone who has been tested positive for Coronavirus, Please contact public health system for more information’’.

This is how Digital Contact Tracing works. Simple, right?

You can find further information in the Apple website section dedicated to COVID-19.

Why Digital Contact Tracing is good

• Effortless: no user-interaction required, no need to remember password or complex codes. Just put your mobile phone in your pocket.
• Free: only some Megabytes of your mobile phone memory and some “%’’ of your battery charge.

Why Digital Contact Tracing is NOT good

• Low precision: Bluetooth calculates distance by measuring the strength of the signal of another device. Bluetooth radio waves overcomes obstacles like wall, so this can generated false positives.
• Useless, if few people use it: Experts says digital contact tracing is effective only if at least 60% of people use it.

Is our privacy really at risk?

No, there is no privacy risk.

Google and Apple have developed a dedicated “framework’’ (= a set of functionalities that mobile app developers can use to build a Contact Tracing app) for COVID-19 contact tracing.

This “framework’’ allows interaction only with bluetooth antenna, no other communication interfaces are used.

Data, exchanged over Bluetooth, doesn’t contain any user sensitive data.

Then, why does Android need GPS permission?

Android system needs GPS permission to use Bluetooth Low Energy (BLE) functionalities.

So, does this mean that the Contact Tracing app tracks my geo-position? …No!

From the point of view of Android system, BLE and GPS are considered positioning system.

This, because BLE can be used to perform Indoor Positioning (IPS): A system used to locate the position of object and/or person inside a well-defined indoor area (e.g. factory, home, museum, etc.). In order to do so, indoor area has to be full of Bluetooth receivers. These Bluetooth receivers act as a “radar’’, scanning for Bluetooth emitting devices. In this way, for example, you can detect in which museum room a visitor is located.

In conclusion, Contact Tracing app, in Android system, requires the localization permission only for the use of Bluetooth Low Energy functionality.

Conclusions

In my country (Italy), one of the most affected area by COVID-19, Government has decided to create a Contact Tracing app called ‘’Immuni’’.

My suggestion is to download it on your phone if the public health system of your country has developed a similar one.

It’s free, it works by itself, it helps your country’s public health system and your fellow citizens.

Worried about privacy?

After all, every day you provide your “data’’ to big tech companies for commercial purposes.

Why, in this case, not providing your data for a good cause?