If SIGN AT
cannot request signatures from a certified trust service provider (TSP), receipts will be signed using a substitute signature. The receipts will include the note 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.