[Cryptography] Quantum computers will never overcome noise issues?

[Viktor Dukhovni]

> On Feb 15, 2018, at 8:52 PM, jamesd at echeque.com wrote:
> 
> Any technology useful for processing information in the extreme quantum domain is also useful for doing classical extremely fast at extremely low energies, operating in the near quantum domain.
> [...]
> Any technology useful for implementing quantum computers, would also be useful for implementing classical computers at enormously greater speeds and lower energies than today's classical computers.

You keep saying that, but without any plausible justification.  Scalable universal quantum computers (if they can be made!) would provide *asymptotic* algorithmic speedups.  Merely "faster by some constant" classical computers do no such thing, and for the problems of interest it is the asymptotic speedups that matter, no realistically attainable constant speedup is large enough.

-- 
	Viktor.