dark_lord69 :
Ummm....
"that would take the lifetime of the universe for even the most advanced classical computers in use today."
So.. could we use all that calculation power to mine Bitcoins or Ethereum?
Not sure, but only certain types of problems get a good speedup from quantum computers. The further you get from one of those types of problems, the less you really stand to gain.
Quantum computers have the potential to accelerate cracking of crypto, due to their ability to simultaneously evaluate a large number of solutions. That said, not all types of crypto are equally susceptible to quantum attacks, and I'm not sure conventional
encryption stands
anything to gain from it.