Question on "Days Since Onset of Symptoms" paragraph in CWA solution architecture document

[Ein-Tim]

Your Question

• Documentation File: https://github.com/corona-warn-app/cwa-documentation/blob/main/solution_architecture.md
• Line / Paragraph: https://github.com/corona-warn-app/cwa-documentation/blob/main/solution_architecture.md#days-since-onset-of-symptoms
• Question: CWA only considers the last ten days. If I have warned others with the information that my symptoms started more than two weeks ago, I understand https://github.com/corona-warn-app/cwa-documentation/blob/main/images/solution_architecture/dsos-date-range.png so that nobody will receive a warning. Is that correct?

@mlenkeit You seem to be the correct person to answer this question (:

[mlenkeit]

@Ein-Tim thanks for raising this! When you select "more than 2 weeks ago", the relevant Diagnosis Keys are assigned a TRL of I. They are uploaded to the cwa-server and forwarded to European Federation Gateway System (EFGS). Such keys are not distributed back to the CWA apps for matching because they are considered irrelevant for our risk calculation. Accordingly, they do no cause exposure notifications in CWA. However, they may lead to exposure notifications in apps of other participating countries, depending on the respective risk model.

[Ein-Tim]

Thanks, question answered!