When and where can my data as a guest be viewed?

The guest’s data is encrypted in the QR code that he creates for himself. When visiting a restaurant, for example, the QR code is scanned by the host. Now both the guest’s and the host’s encrypted data are encrypted again together and stored in trust for the first time. Only in the case of infection, only the institution responsible for this uses this data. After four weeks, they are irretrievably deleted.