[lostcolony]

Of course they do. They want a mathematically perfect, impossible to crack system, that also happens to have a common key that works for everything, that they alone own. And by 'they', I mean their government. Not enemy governments.

What happens when (not if) that common key leaks or is abused is not their concern. Until, of course, it invariably happens, and they find their citizens having their bank accounts siphoned, their agents being discovered and blackmailed for their basic 'civilian' internet use, etc.

[kwhat4]

There is no common key in the MITM scenario. It's still securely encrypted using over the counter algorithms, but instead of the end users exchanging keys, you exchange with the MITM and different key sets are used by both parties.

[lostcolony]

Fair enough; logic still applies. A criminal element just needs to comprise the MITM to compromise all communication flowing through it.