If we do not trust the NSA to be a registrar of Clipper Chip key halves,
I would not trust Mitre either.  Mitre does lots of work for NSA, at least
in the Trusted Product Evaluation Program (evaluation of commercial off the
shelf software for its efficacy in safeguarding classified information), and
I assume in other, less open, programs.

There are at least two other FFRDCs (Federally Funded Research and Development
Corporations) that work for NSA: Aerospace Corporation and the Institute for
Defense Analysis.  Now, if NSA were to be untrustworthy (a position that I
am neutral about, for purposes of this posting), it would be in a position to
exert economic pressure upon Mitre to release key halves on demand.  It could
just say, "If you don't cooperate with us, we'll place all our evaluation
contracts with Aerospace and IDA."

I am not saying that people at NSA, Mitre, Aerospace, or IDA are dishonest
folk.  But since they are people, and people occasionally go bad, the
system works better if organizations that you are depending upon to be
independent really are.

And, of course, I speak for myself, not my employer.