[Cryptography] The race to Quantum machines.

[Ron Garret]

On May 28, 2019, at 1:53 PM, Phillip Hallam-Baker <phill at hallambaker.com> wrote:

> The other point to bear in mind is that we won't know whether there is a limit to quantum entanglement until we encounter it.

That’s true, but...

> There is no law of physics that states we must be able to form arbitrarily complex superpositions of quantum states. That is an assumption in our current models of physics.

That’s not quite true.  (Or perhaps it’s more correct to say that it’s true, but misleading.)  It’s true in the same sense that the speed of light being a constant is the same in all reference frames is an “assumption.”  The evidence that this is correct is overwhelming, and the evidence that quantum mechanics applies to arbitrarily large systems of entangled states is likewise overwhelming.  All attempts to find an experimental regime where quantum mechanics fails have failed.  If you seek solace against the possibility of cryptographic keys falling to quantum computers you are better off looking for it in engineering constraints than in the prospect of discovering new physics.

rg