[Cryptography] NSA looking for quantum-computing resistant encryption. How will encryption be affected by quantum computing

[Henry Baker]

At 07:41 AM 8/31/2015, Erik Granger wrote:
>www.engadget.com/2015/08/30/nsa-quantum-resistant-encryption/
>
>I read this article and as a non-expert in quantum computing, I'm wondering what sort of impact quantum computing will have on our encryption.
>
>Will it just make brute forcing easier, thus requiring certificates to have a shorter shelf life?
>
>Or is it something more worrying?
>
>Less worrying?

Perhaps the NSA is more worried about people who *might* run a quantum computation?

http://arxiv.org/abs/quant-ph/9907007

Counterfactual Computation

Suppose that we are given a quantum computer programmed ready to perform a computation if it is switched on.  Counterfactual computation is a process by which the result of the computation may be learnt *without actually running the computer*.  [Something D-Wave seems to have become quite good at...]

http://arxiv.org/pdf/quant-ph/9907007v2