[Cryptography] cryptography Digest, Vol 13, Issue 6

[Andreas Gunnarsson]

On Wed, May 07, 2014 at 03:59:11PM -0400, Bill Cox wrote:
> Nice topic.  I'm not very knowledgable about this, but Dwave may have
> the best quantum factoring capability, with a 512 cubit machine now,
> and a machine with at least twice that in the works.

Shor's factoring algorithm is designed for the circuit model of quantum
computing. The D-Wave machines are based on quantum annealing and can
not directly implement quantum circuits. There are some papers
demonstrating that both models are in principle polynomically
translatable into each other, but as far as I know there is no practical
and efficient way of translating Shor's algorithm into something that
can run on D-Wave's hardware.

Whether or not, and to what degree, D-Wave's hardware exploits quantum
phenomena has also been questioned. Someone posted links to Scott
Aaronson's blog which contains more information.

So RSA is probably safe from quantum computers for now, and symmetric
algorithms will probably never be broken by quantum computers.

Andreas