Questions tagged [quantum-key-distribution]

Quantum Key Distribution aims at establishing a secret shared by two parties, using quantum physics phenomena, in a way that ensures that an adversary can't know that shared secret.

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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. Each of these photons represent a bit of…
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Why Quantum Key Distribution (QKD) is impractical

In NSA's FAQ on Quantum Computing and Post-Quantum Cryptography, it is mentioned as Q: Should I use a QKD system to protect my NSS from a quantum computer? A: No. The technology involved is of significant scientific interest, but it only addresses…
kelalaka
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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 they talk about direct fibre optic cable and…
H M
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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?
Mohammed
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Quantum key distribution and the one-time pad

Why is QKD usually associated with OTP? QKD is about key distribution, whereas OTP is about using a key as long as the message to get perfect secrecy. Can anyone explain how they are related?
sashank
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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?
sashank
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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 schemes also. My understanding of quantum key…
Luke
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Is E91 safer than BBM92?

I would like to compare the security of these two QKD protocols which both use entangled photons that are distributed between the users Alice and Bob. In the case of E91, the photon is measured randomly in 3 different bases which allows to violate a…
Mechanix
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What are the current known weaknesses/attacks on quantum key distribution?

I am writing a paper on the implementation of QKD in the future. I want to know if there are any viable attacks on the BB84 protocol or QKD in general? I know of the Photon Number Splitting attack or spectroscopy in the case of diode manufacturing…
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What is the fundamental difference between quantum secure direct communication (QSDC) and quantum key distribution (QKD)?

I've got the following questions about the difference: Can one be considered a more powerful resource than the other? It seems to me that you could use QSDC to achieve the same thing as QKD (sharing a secret key) without the use of a…
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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 to explain how the quantum key exchange process works in detail; that is, for newbies like me. Thus I…
ecdhe
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How does quantum encryption work?

There has been a lot of buzz about quantum computing especially with D-Wave breaking the limits each month. I have basic knowledge about cryptography with an introductory course in quantum computing. So, how does quantum encryption work? and how is…
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In quantum cryptography, why can a qubit can be both 0 and 1 at the same?

The texts below are from some tutorial, and it says (in bold format below) a qubit can be both 0 and 1 at the same time. It sounds very strange to me, can you please explain why? Quantum cryptography utilises the physics of photons (light…
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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 it's still held in the case of the eavesdropper…
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Is quantum cryptography unbreakable?

People always say that "there is no such thing as unbreakable crypto!" In most cases they are right. AES, RC4, RSA, C25519, DH, .... are all cryptographic algorithms which are crackable (with extreme effort). The asymmetric stuff, you can factorize;…
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