As if they could.
Serious crypto needs will be met with one-time pads that are unbreakable by anyone.
One-time pad is extremely simple and also provable to be mathematically secure against any brute force attack.
A universe full of quantum computers is no match for one-time-pad.
It does however re-introduce the key-exchange problem.
And the key is also at least as long as the message itself...
It requires a true random number source.... but this is easy using something like diode noise.
The old German Enigma was actually a type of one-time-pad ... but it had a horribly flawed mechanical random number generator. (and some doofus thought it a great idea to make it so no letter could ever be encrypted as itself i.e. A = A ... lol)