SIGN AT cannot request signatures from a certified trust service provider (TSP), receipts will be signed using a substitue signature. The receipts will contain a hint
Sicherheitseinrichtung ausgefallen (German from "SCU unavailable"). These receipts are valid and will be contained in the DEP7 export. When the TSP is reachable again,
SIGN AT automatically creates a zero-valued receipt marking the end of the outage.