Actually, reading your excellent article reminded me of the recent progress in quantum computers, and the same concerns as @edumurphy rose. for QC, decrypting crypto would be just a piece of cake. Yet, we have time , there are still problems...

Preventing the collapse of the wave functions of the QBits currently becomes exponentially difficult with the number of QBits of the processor. Research progresses, solutions are found, but we still have a few years in front of us...

The thing is that QC could have such a profound effect on our societies that nobody will care about crypto currencies anymore.... Good or bad, who knows... Think real AI, think Virtual worlds, think Matrix (?).

And the tech is so scifi. What is actually happening is that the superposition is an illusion, all states exist at once, in parallel universes. We just see a given state when we observe, because it is our universe (interpretation of Copenhagen).

So basically, we are sucking calculation power from parallel universes... Sound crazy right, well, in the current state of our knowledge, it is the best we can come up with...

Pretty cool, huh?