When two phones have the app downloaded and are close to each other for more than a couple of minutes, they exchange completely anonymous codes.
When a person tests positive for COVID-19, they will be given what is referred to as a ‘COVID code’. The user can voluntarily enter said code into their smartphone. This will then upload the anonymous information and thus, unlock a function that shares the positive result to a database. When this is done, the app derives the COVID-19 positive patient’s random codes, which were broadcast during the time he was potentially infectious.
In this way, the database will be able to reveal users who met or spent time with the COVID-19 positive patient. The app does this by using the anonymous codes to check if any correspond to those stored in the device memory of the last two weeks.
They will be alerted and notified about what steps to take next, including either quarantine or the need to get tested.