How Does COVID Tracing work?

A couple of weeks ago Canada released the COVID Alert app to the general public. The app is intended to help tracing efforts in the province to curb the spread of COVID-19. Understandably, there are some questions regarding its privacy and security implications. Although I focus here on the Canadian version of the app, the underlying architecture is used by a lot of other public health authorities all over the world. You can find the full list of countries here.

The first important thing about COVID Alert is that although the app itself is being branded and released by Health Canada (and other public health authorities) much of the core technology is provided by Apple and Google for iOS and Android respectively.

Earlier this year, Apple and Google, in a joint effort, released a framework called the Exposure Notification System (ENS) designed specifically for building COVID tracing apps. The framework provides a set of tools for developers on both platforms and is intended to be used by public health authorities all over the world. It has been created with the explicit goal of preserving user privacy by design in an effort to encourage broader adoption. More on that here.

As of now, the system is 100% opt-in. You don’t have to download the apps if you don’t feel comfortable. Nor would you be forced to opt-in at a later stage. However, the…