Quantum Computing, Game over for the world as we know it?

[stand@desk]

http://www.niagarathisweek.com/news-sto ... berthreat/

I'd posit to the board the question of whether Cyber attack via Quantum computing is a real credible threat to our way of life, or will there be quantum computing defences to save us from the Quantum outlaws? I can imaging many systems breaking down at much higher speeds than now, although one could say we already are desperately vulnerable (recent Yahoo accounts hack and many more). The experts in this article say it's not a matter of if, but when..

So what does everyone plan to:
a) do in the meantime.. ->status quo or prepare in some way (ie hoard gold in a bunker, build an earthship in Alaska, go back to some other way of life off the web..)
b) live your life.. -> status quo or really live the @#%$ out of your life and time until 2026 arrives where it could all be over anyway.
c) deem this as freaky as Y2K and laugh at 2026 when nothing out of the ordinary happens beacause everything else has rose in tandem to keep the cyber threat at bay.

Unless you are a high level techie, it would seem hard for a layperson to prepare for this upcoming wave..perhaps even they will be quite vulnerable.

[Dragline]

I would wait until anyone actually builds one of these outside of primitive prototypes before engaging in fanciful discussions about what it means.

But you can play with IBM's prototype already if you know what you are doing: https://www.wired.com/2016/05/ibm-letti ... -computer/

[daylen]

What exactly is the threat? Modern encryption techniques can be scaled far beyond the computational power of any hypothetical super computer. Sure, systems that do not prepare will be vulnerable...what's new?

[jacob]

@daylen - That a quantum computer will be able to surpass this scaling [barrier] which is what almost all modern encryption systems rely on.

https://en.wikipedia.org/wiki/Post-quantum_cryptography

[daylen]

@jacob thanks for the reference. I can't believe I haven't heard about shor's algorithm! When I learned about rsa in my abstract algebra class, the teacher made it seem like integer factorization algorithms could not be cracked!

[Campitor]

Looks like quantum computing took another small step forward via a time reversal algorithm which may help check quantum calculation accuracy.

https://www.nature.com/articles/s41598-019-40765-6

Our findings suggest several directions for investigating time reversal and the backward time flow in real quantum systems. One of the directions to pursue, is the time dependence of the reversal complexity 𝒩 of an evolving quantum state. In our work, we have shown that an isolated d-dimensional quantum particle with quadratic spectrum exhibits a polynomial complexity growth 𝒩(𝜏)=𝜏𝑑. Uncovering the 𝒩(𝜏) dependence for realistic situations, accounting for the interactions will establish a mechanism and the corresponding time-scale on which time-reversed states can spontaneously emerge. Another fundamental question is whether it is possible at all to design a quantum algorithm that would perform time-reversal more efficiently than using 𝒪(𝒩) elementary gates. So far, our time-reversal schemes were scrolling one by one through the state components but did not exploit a quantum parallelism in its full power. On a practical side the time-reversal procedure might be helpful for the quantum program testing. Having in hands a multi-qubit quantum computer it is hard to verify that it really has computed the desired result. Indeed, the full tomography of the computed state is an exponentially hard task. Alternatively, making the time-reversal of the anticipated computed state and running the same evolution drives the computer back to its initial state if and only if the computer really made a correct computation. The initial state is typically non-entangled and therefore its verification is an easy task.

[Curmudgeon]

Back to the original question (I'm just now seeing this thread), quantum technology also allows for quantum key distribution, which will allow encryption techniques to be updated to something uncrackable by a quantum (or any other) computer.

Current encryption technique involves generation of a public/private key pair. The pubic key is generally visible to anyone, and is related to the private key by some complex algorithm. Without the private key, you can't break the encryption. The 'complex algorithm' is generally reversible when some amount of compute power is applied to it, that is, you can compute the private key when the public key is known. As a result, encryption needs to be constantly upgraded as computing power rises. Unfortunately for public/private key encryption, it is believe that quantum computing will provide - if you'll excuse the pun - a quantum leap in computing power that will make discovery of the private key from the public key much easier.

With quantum key distribution (QKD), we won't need the private/public key technology. There will just be a private key, with no way to compute or crack it. If sent via QKD, we can ensure that no one has obtained the key, before sending the encrypted message. So, with no way to obtain or compute the private key, the encryption is unbreakable.

So, no, I don't think quantum computing will be 'game over'. Just another upgrade.