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Questions tagged [quantum-cryptography]

Quantum cryptography describes the use of quantum mechanical effects to perform cryptographic tasks. This is not to be confused with quantum computing or cryptanalysis techniques such as Shor's algorithm.

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What makes Quantum Cryptography secure?

This is my current understanding of how Quantum Cryptography works: (The first bit is Quantum Key Distribution) Alice sends a beam of photons to Bob through a quantum channel such as an optical fiber....
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What does a “real” quantum computer need for cryptanalysis and/or cryptographic attack purposes?

The cryptographic world has been buzzing the word "quantum" for a while now (even the NSA is currently preparing itself for a post-quantum crypto world) and quantum-related hardware engineering is ...
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Are hash functions strong against quantum cryptography and/or independent enough of mathematics?

I work on ethereum and other blockchain technologies. And seeing that quantum pc's are someday going to see the light I have some questions / doubts. I was wondering if hash functions are strong ...
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Is quantum key distribution safe against MITM attacks too?

i read this recently: http://www.newscientist.com/article/dn12786-quantum-cryptography-to-protect-swiss-election.html and some parts of this: http://en.wikipedia.org/wiki/Quantum_key_distribution ...
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In layman's terms, how does Shor's algorithm work?

I've just been reading up on Shor's algorithm, and I find it both fascinating and baffling. I don't really understand much about it, other than that it can factor semiprimes in polynomial time. Could ...
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What is post Quantum Cryptography?

Post-quantum cryptography is cryptography under the assumption that the attacker has a large quantum computer; post-quantum cryptosystems strive to remain secure even in this scenario. Post-quantum ...
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New quantum attack on lattices (or Shor strikes again)?

Lior Eldar and Peter W. Shor published a paper on arXiv.org in which they present a new quantum algorithm against a variant of BDD. They claim that their new algorithm can efficiently solve the ...
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Are there any applications of Quantum Computation to Cryptography? (besides Cryptanalysis)

I know that people may be yelling "of course!" at the title of the question, but my concern is not about how to construct quantum-resistant primitives, but rather how to use the power of quantum ...
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Cryptocurrency for quantum computers that is physically impossible to double-spend?

Could a cryptocurrency running (at least partially) on a quantum computer (and/or on a quantum network) be developed in which it is physically impossible to double-spend? In other words, a coin in ...
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Is full Homomorphic encryption quantum resistant?

Since most of our asymmetric encryption algorithms are going to be out-of-date in a couple of year due to Shor's algorithm, I was wondering about the future of FHE schemes. I have found this paper, ...
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Could quantum computers “break” symmetric crypto-systems (e.g. AES)?

These days I'm reading about quantum computing and quantum cryptography which I've found extremely interesting. Well, I also read some blog posts of Bruce Schneier talking about how quantum computers ...
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Quantum key distribution simulation

I'm looking for a simulation of the Quantum Key Distribution protocol. Does anyone here have one that they could recommend?
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Quantum key exchange skepticism/confusion

I was hoping somebody could explain some issues I have with quantum key exchange that I don't quite understand. I've read bits and pieces about BB84 but I'm sure my questions probably apply to other ...
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What authentication techniques can be used by QKD Systems?

As it is well known that QKD systems are prone to simple MITM attacks… what authentication techniques are being used in QKD to prevent those attacks in practice?
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Is quantum randomness different to conventional randomness?

I've been reading a question regarding the uses of quantum computing. There is a broad theme throughout the answers that seems to suggest that randomness generated via quantum means is somehow better ...
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Can quantum computers break quantum cryptography?

I happened to learn that encryption by quantum cryptography would be impossible to break as it's state changes the instant of an eavesdropping event(by non-quantum systems) occurs. But I'm not sure if ...
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What exactly is a quantum key distribution network for?

There are many diagrams out there explaining how quantum key distribution works on a physics /optics and mathematics level. I understand these explanations fairly well so I'm not asking about the ...
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Understanding Quantum Key Distribution

I have watched dozens of videos on YouTube talking about Quantum Cryptography and how the BB84 algorithm works. However none of them bothered himself to explain how quantum key exchange process works ...
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Small Quantum Signatures - Reality check needed

I've been thinking a bit lately about how to get quantum resistant signatures fast and (relatively) small. One idea I've been keen on exploring is finding a crypto PRNG that allows fast-forwarding, e....
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How can Shor's Algorithm be applied to ECC?

I have not found a specific answer to this question on here. Shor's algorithm can be used to factorize a large (semi)prime $N$ by reducing the task to period-finding of a function $f(x)=x^a$ mod $N$. ...
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How exactly works the quantum communication done by China?

This video and this article announced that spacial quantum communication were finally done using satellites. As a recap, when two particles are entangled, if a measurement is done to one of them, ...
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How could consumer level OTP + QKD over the internet ever be practical?

Please note, I am in no way questioning the future usefulness of quantum key distribution (QKD) in certain applications. I have no doubt it will prove useful for large banks, and in certain military ...