Koronavilkku is a contact tracing app produced by the Finnish Institute for Health and Welfare (THL) to help you find out whether you may have been exposed to coronavirus. If you have a coronavirus test and are diagnosed as infected, you can use the app to share this anonymously with those you have been in close contact with. Your privacy is strongly protected.

How does the app work?

Koronavilkku does not store your name, date of birth or contact information. It cannot identify you or the people you come into contact with. The app does not collect information about where you are.

The app transmits information that the app is working to a server. It also forwards information about whether you have been potentially exposed to infection. All communication between Koronavilkku and the server is encrypted. The information is stored anonymously on a server in Finland. The server is managed by public administration actors. The information is deleted when no longer required.

The phone receives a randomly generated code. The app assigns a random code to each phone. The code contains no information about you or your phone.

Phones swap codes with each other. When close enough to each other, the apps swap codes through a Bluetooth signal. User identity or location is not saved. The app retains the codes for 21 days before automatically deleting them.

When someone reports their infection. When a user reports their infection to the app, the app sends the codes it has collected to a server. If you have been in close contact with a code downloaded to the server, the app will send you an alert of potential exposure.

You receive an alert of potential exposure. f you receive an alert of potential exposure, the app will give you further instructions on what to do. The Koronavilkku app can also be used to make a symptom assessment through the Omaolo health check service.

If you are diagnosed with infection. If you have tested positive for coronavirus, a healthcare professional will give you a key code. When you tap this code into the Koronavilkku app, your app sends the codes it has collected to the server. Anyone you have been in close contact with will then be alerted of potential exposure. Since no personal data or information about whereabouts is sent with the codes, you cannot be linked to any potential infection.