tldr:
generates random ids (1 per 5 min i think?) that it keeps broadcasting via Bluetooth.
It saves the ids it broadcastet (sent ids) and it recieved.
If the saved ids geht too old to be relevant ist deletes them.
If you get a positive PCR you can opt-in to notify your contacts, this works by you releasing your sent ids. The released ids are regularily published by app provider.
The app checks the published ids, if it finds published keys in its list, it checks how often they are in its list (to aproximate duration) and what signal strength was (to aproximate distance).
Based in duration and distance it warns that you had a risky contact and should get tested.
Besides that it also has a few other features now
you can Scan QR-Code of vax-certificate or neg test result and then show those from App so that eventorganizers can scan them with an App that veryfies signatures
you can check in to places/events and get anon notifications if later it turns out soneone there was positive. (Think restaurants, parties, anyone can make their own event to get a QR-Code they can print out)
you can add a testprofile so that when you go get tested they scan a qr code to get the needed data, rather than having to tell them
you can write a contact diary that autodeletes after 15 days.
Dunno if anyone uses the diary.
Also, the Long delay until health-minister comissioned the check-in feature lead to a private competitor called 'Luca' that does it differently and is infamous among IT folk.
If you want to read up on Luca and speak german (or have a translate you like)
tldr: generates random ids (1 per 5 min i think?) that it keeps broadcasting via Bluetooth.
It saves the ids it broadcastet (sent ids) and it recieved.
If the saved ids geht too old to be relevant ist deletes them.
If you get a positive PCR you can opt-in to notify your contacts, this works by you releasing your sent ids. The released ids are regularily published by app provider.
The app checks the published ids, if it finds published keys in its list, it checks how often they are in its list (to aproximate duration) and what signal strength was (to aproximate distance).
Based in duration and distance it warns that you had a risky contact and should get tested.
Besides that it also has a few other features now you can Scan QR-Code of vax-certificate or neg test result and then show those from App so that eventorganizers can scan them with an App that veryfies signatures
you can check in to places/events and get anon notifications if later it turns out soneone there was positive. (Think restaurants, parties, anyone can make their own event to get a QR-Code they can print out)
you can add a testprofile so that when you go get tested they scan a qr code to get the needed data, rather than having to tell them
you can write a contact diary that autodeletes after 15 days.
Dunno if anyone uses the diary.
Also, the Long delay until health-minister comissioned the check-in feature lead to a private competitor called 'Luca' that does it differently and is infamous among IT folk. If you want to read up on Luca and speak german (or have a translate you like)
https://www.luca.fail/