Does anyone own or use some device related to quantum cryptography?

>>59123482
I imagine the answers to most of your questions is because it's all still in the research phase. China, according to ACM, is going fucking hard with quantum technologies and supercomputers in general. It seems like it would be a very exciting time to be a scientist/engineer there.
That's about all I can contribute to the conversation, OP, sorry.

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>>59123482

OP, you seem to be misinformed on the current potential of quantum computation. Firstly, quantum computers are immensely difficult to engineer, and there is much debate on whether current quantum computers actually harness the power if information superposition. For these reasons, quantum computation theory is mostly an academic endeavor, although this may change, as China, the US, and Russia are trying to 'beat' each other to quantum computing.

Although, it was recently leaked (within a few years ago) that the NSA had allocated nearly $80B in R&D money for quantum cryptography. Enter: Peter Shor. Shor's algorithm proved that very large biprimes could be factored in a reasonable amount of time using quantum computation, thus rendering modern cryptography ineffective against such a computer. However, the idea of quantum computing really started materializing in the 80's, and Shor proved his algorithm sometime in the 90's, IIRC, so we are still in a technological standstill. Not much has changed since then, and developments are very slow.

>>59123482
You're talking about completely different things.

QKD is still an academic thing because it's only a set of measures to detect taps on physical (fibre) links - however though it's "theoretically" able to detect a splice, in practice actually none of the techniques do. They've all been broken one way or another. I'd say it was destined to remain academic but China are testing it in the field, because why not? You can always use it on top of something else, and it's fine when composed correctly.

Quantum computers are currently able to factor 6. They think maybe in a few years they might be able to factor 15. Wow. Throwing money at it isn't necessarily going to fix the fundamental entanglement problems. We're not talking 5 years here. Maybe another 20? The point is we want our cryptosystems to last past that, so we need to be looking at resistant alternatives now.

We have a fair bit of so-called "post-quantum" cryptography that doesn't rely on the difficulty of factoring or discrete logarithms - SIDH, lattice-based systems like NTRU, ring-LWE systems like NewHope and so on. Research is still very actively ongoing. Nearly all symmetric crypto will be fine (with a few things that might fall in theory to QPF), but we might need to make sure people are using 256-bit keys (technically hashes can be cube-rooted, but that needs so many resources that a time/memory tradeoff on a classical computer beats it).