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Canada’s COVID Alert app

I installed and setup Health Canada’s COVID Alert app this morning.

It’s really simple to do that. You don’t enter any personal information. You just select which province you’re in, agree to let it use your Bluetooth, and give it permission to share the random codes that you collect with its servers (more on this below). The app is then active and working. But to be clear, it doesn’t collect your location (it doesn’t use GPS or location services). It doesn’t collect the places or times that you are next to someone who also has the COVID Alert app. And it doesn’t know if you’re with someone who was previously diagnosed with COVID-19.

Built on top of the private exposure framework that was collectively developed by Apple and Google, the app works by using Bluetooth to exchange “random codes” between nearby phones that have the app. These are anonymous and random codes that are used to track which phones have been next to which phones for any meaningful period of time. The app also uses Bluetooth signal strength to estimate proximity. So it knows how long your phone has been proximate to someone else’s (with the app) and how close they got to each other.

That’s pretty much all that happens with the app unless you test positive for COVID-19. At that point, you will be given a one-time key along with your diagnosis. The onus is then on you to anonymously self-report on the app. Once you do that, anyone who was exposed — i.e. next to your phone in the last 14 days — will receive an alert on their phone via the app. And since the app doesn’t know any names or who anybody is, it’s of course all completely anonymous.

It’s great to see all of this coming together. The private sector worked to build the underlying framework and now you have government building on top of it to deliver public health tools. I know that some or many of you will be concerned about privacy, but that appears to have been very well thought out. If you haven’t already downloaded the app, I would encourage you to check it out. It’s available for iOS and Android and can be downloaded over here.


  1. Deanna Rowe

    The problem with this app doesn’t support older versions of iOS, limiting who can use it and decreasing it’s effectiveness.


  2. Pingback: How many people are actually using a COVID Alert app? |

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