it is actually an NSA key. If the NSA is going to use Microsoft products for classified traffic, they're going to install their own cryptography. They're not going to want to show it to anyone, not even Microsoft. They are going to want to sign their own modules. So the backup key could also be an NSA internal key, so that they could install strong cryptography on Microsoft products for their own internal use.
Though given alternative methods of bypassing any Microsoft security, not really necessary.
Hell of a name, you've got to admit.
Bruce Schneier's discussion at the time:
http://web.archive.org/web/20011005071623/http://www.counter...
One of his speculations:
it is actually an NSA key. If the NSA is going to use Microsoft products for classified traffic, they're going to install their own cryptography. They're not going to want to show it to anyone, not even Microsoft. They are going to want to sign their own modules. So the backup key could also be an NSA internal key, so that they could install strong cryptography on Microsoft products for their own internal use.
Though given alternative methods of bypassing any Microsoft security, not really necessary.