Covid-19: S'pore invents world's first nationwide contact tracing app

Good for those who can't remember what they ate for lunch yesterday.

Zhangxin Zheng | March 20, 2020, 06:59 PM

Follow us on Telegram for the latest updates on Covid-19:

The Government Technology Agency (GovTech) has collaborated with the Ministry of Health (MOH) to develop a mobile app that supports contact tracing efforts during the Covid-19 period.

This is likely the world's first nationwide contact tracing effort via Bluetooth, even though other countries might have their own model.

TraceTogether app

Called TraceTogether, the mobile app enables community-driven contact tracing through short-distance Bluetooth signals between mobile phones that have the app installed.

The app estimates the distance between users, as well as the duration of their encounters to identify those who were in close contact with a confirmed Covid-19 case.

The records of these encounters are encrypted and stored locally on each user's phone for 21 days, which covers the incubation period of the coronavirus.

Why do we need this app?

Prior to this, contact tracing has been done via interviews, which is dependent on an interviewee to recall their movements and the people they have come into contact with, as well as to provide access to these contacts.

Some patients might also be too ill to take part in the contact tracing.

This app can fill the gap and ensure more, if not all suspected cases are notified earlier — an effective preventive measure against the spread of the virus.

This is especially useful in cases where the infected persons do not know everyone whom they have been in close proximity with for an extended duration.

The app thus potentially reduces the occurrence of unlinked cases.

How to use the app

TraceTogether can be downloaded from Google Play store and Apple App store.

Turn on the Bluetooth for the app to work. The app does not need Wi-Fi or mobile data to function after it has been installed.

It can be used by anyone with a Singapore mobile number.

Here's what you will see when you first open the app:

For those who are concerned about whether the app will drain your phone's battery, there are some ways to save battery while having the app run in the background.

The power saver mode will be triggered when users having their devices facing down, or when users put their phones or devices upside down in their pockets.

This allows TraceTogether to scan your surroundings and keep track of who you were in contact with, while reducing the drain on your phone's battery.

What data does the app collect? Is it safe?

The only data that TraceTogether collects is the user's mobile number, so that MOH can contact you more quickly if you have been in close proximity with a Covid-19 case.

With the user's consent, TraceTogether exchanges Bluetooth proximity data with nearby phones running the same app. However, this data is anonymised and encrypted, and does not reveal user's identity or the other person's identity.

This data is stored only on the user’s phone. Should MOH need the data for contact tracing, they will seek your consent to share it with them.

Geolocation data is also not collected, which means that means the app cannot identify where users have been to.

The data collected is stored locally in the user’s phone in an encrypted form. The data will never be accessed, unless the user has been in close contact with a Covid-19 case and is contacted by the contact tracing team.

Mobile numbers are not revealed to other TraceTogether users. They are substituted by a random permanent ID.

The mobile number and its corresponding permanent ID are stored in a secure server.

As an added layer of protection, TraceTogether creates temporary IDs that change regularly.

Only these temporary IDs are exchanged between phones.

Therefore, your mobile number remains secret and is not exchanged with other mobile phones.

These measures protect users from malicious actors who may seek to eavesdrop and track interactions over time.

Only functions during virus outbreak

TraceTogether will cease and users will be prompted to disable the app once Covid-19 outbreak is over.

Users can also choose to stop TraceTogether's function anytime by turning off Bluetooth permission or deleting the app.

If contact tracing is required for a future outbreak, you will be prompted to re-enable permissions, or you can reinstall the app.

Find out more here:


Top photo taken by Syahindah Ishak and all screenshots by Zheng Zhangxin