The Empty Field That Wasn't: GPS, OTAD and Two Decades of Encrypted Broadcasts (sjmurdoch.github.io)

But if a current key leaks or is broken, all future keys are broken aren't they? Inband rekey surely carries risks?

Obviously the NSA/NIST audit over this has a position. Or, I'm wrong, or both. There must be some what-you-have adjunct which can override or second factor it.