Ireland has released its Covid-19 Tracking app along with related support systems and information. It looks like an excellent implementation and strong response to the pandemic while preserving privacy of Irish citizens. I wish we had this here in California.

The Irish system uses the Covid-19 contact tracing method provided by Apple and Google. This system allows your phone to keep a list of anonymized IDs of other phones that it’s been near. If you are infected, and your infection is validated by health authorities, you can then post your own phone’s IDs (they change over time, for greater privacy) as possibly infectious. In the system, each phone checks to see if there are matches to its list of recent nearby phones in that “possibly infectious” list, and notifies you if you’ve been exposed.

This app-based system is a very helpful tool in a comprehensive contact tracing and pandemic response strategy. It’s not the entire solution. As in Ireland, there must be education resources, human contact tracers that assist the process and fill in contacts who may not have had the app, a testing regimen that prioritizes people identified as exposed (right after those with clear symptoms), and a rigorous system for validating test results to allow you to send out that anonymous notification that you’ve tested positive.

Note that the decisions about sharing infected status, and on what to do if you are notified that you’ve been exposed, are left to you. This is the privacy bit. The authorities do not have a list of devices that were near each other. They don’t even know, until you decide to share, the IDs associated with you, the infected person.

This somewhat passive system is effective because of these protections. Because you can be assured of your privacy, you are more likely to download and enable the app. Because you know that infections must be validated by health authorities, you are assured that any exposure notification is real.

Exposure notification doesn’t mean that you are sick. It doesn’t even really mean that you were exposed. For the exposure tracking and notification to work, it needs to be a bit cautious, and notify people who may have been exposed so that they can get themselves tested and take other measures, such as self-isolation while they wait out the test results and any incubation period.

This exposure notification system does improve on and assist traditional exposure tracking methods because it can help health authorities get word to people who may have been exposed by people who they don’t know, such as in public setting like the grocery store.

Medical professionals are still learning about this new coronavirus, especially in the detail of how it spreads, how it attacks, and the damage it does. Unfortunately, the picture is, so far, very scary. It seems that even those who aren’t killed by the virus can have lingering health problems and damage to their organs. But I’m a tech guy, not a medical professional, so I’m not going to address all that.

But please do remember, this pandemic is made of of lots of local epidemics. Just because your community or family hasn’t yet been hit doesn’t mean you’re immune. We have bought ourselves some time by slowing the spread, and unfortunately it seems that in many places in the world that extra time has been squandered by political in-fighting and anti-science nonsense.

The Apple-Google Contact Tracing method is an excellent tool that I wish more health authorities were adopting. If you are in Ireland, or one of the other places where it’s used, please participate — for your health and the health of your community.


Apple-Google Contact Tracing Details

FAQ from Apple:

More Technical Details from Apple:

Excellent Explainer from Google:

Ireland’s Contact Tracing

Official Site:
… and especially:

The app is Open Source, and available on Github:

Download Link for iOS version:

Download Link for Android Version:

Other Interesting stories that get it right…

9to5 Mac Explains (with recent updates):

Which US States are using the Apple-Google API:

ACLU Whitepaper on Contact Tracing Privacy

California Contact Tracing