Imagine a military satellite reconnecting after hours without a ground link. An update arrives bearing a valid digital signature. During the blackout, however, the credential behind that signature was revoked on Earth. The signature still checks out. Should the satellite install the update?

That is the overlooked test for the Pentagon’s postquantum transition. Stronger cryptography can establish the origin and integrity of a message. It cannot, on its own, tell a disconnected receiver whether the sender’s permission to issue that command has since been withdrawn.