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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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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 ...
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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 ...
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Does the bit generated password using QKD protocols need to be converted to another base?

I am currently implementing some QKD protocols using Qiskit and I came up with the following question: After the protocol is finished, a true random password is generated using 0s and 1s, however, and ...
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Density operator

How I calculate density operator for pure quantum state for bb84 in 2D? BB84 protocol, proposed in 1984 by Bennett and Brassard – that's where the name comes from. The idea is to encode every bit of ...
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Quantum key distribution using BB84 protocol

Quantum key distribution using BB84 protocol. The Secure key rate $R$, is given by $$ \quad R=1 - 2h(e_b) \tag{1}\label{q1}$$ where $e_b$ is the quantum bit error rate (QBER), $h(x)$ is the Shannon ...
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Which QKD schemes don’t utilize an authenticated classical channel?

This Wikipedia article discusses one drawback of quantum key-distribution: The main drawback of Quantum Key Distribution is that it usually relies on having an authenticated classical channel of ...
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Has anyone implemented the BB84 protocol?

Has anyone implemented the BB84 protocol and put it in production? The BB84 is a quantum key distribution scheme developed by Charles Bennett and Gilles Brassard in 1984. It is the first quantum ...
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Determination of the key rate of BBM92 Quantum Key Distribution (numerically)

I'm currently working on a Python Program which aim to return the secret key rate of a specific Quantum Key Distribution protocol (Brassard, Benett and Mermin 1992 i.e. BBM92). A colleague will ...
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How is QKD (Quantum Key Distribution) advantageous over McEliece/AES?

I don't understand the popularity of the idea of QKD (often coupled with OTP). From what I can tell, a quantum-safe key exchange algorithm like McEliece has just as much security while operating over ...
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Would Zero-Knowledge Proof (ZKP) Remove the Need for Quantum Key Distribution? (QKD)?

Would zero-knowledge proof (ZKP) remove the need for quantum key distribution (QKD) since we no longer need keys to be passed around?
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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 ...
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challenges in quantum key distribution

Quantum key distribution (QKD) promises unconditional security in data communication and is currently being deployed in commercial applications. Nonetheless, before QKD can be widely adopted, it faces ...
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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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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 ...
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Differences between Single photon QKD system (BB84) and EPR photon-pair QKD system (BBM92) for quantum public key distribution?

What are some differences between a Single photon QKD system (BB84) and an EPR photon-pair QKD system (BBM92) for quantum public key distribution?
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How do quantum key distribution systems tolerate noise?

It seems to me that any noise in the signal would result in Alice and Bob generating different keys, without a simple way to tell the difference. How do quantum key distribution systems tolerate ...
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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 is the motivation behind quantum key distribution with Continuous variable?

Quantum Key Distribution protocol is a technique that allow two parties to share common secret key for cryptographic purpose and defined as being secure, by definition. But I am still wondering what ...
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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 ...
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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. ...
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QKD - Does BB84 Protocol rely on a prearranged code?

First of all, sorry if the title is not that clear, I'll provide an in-depth explanation behind my question. So, basically, I was reading about quantum cryptography and came across BB84. The protocol ...
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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 ...
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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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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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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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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?
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Do Quantum Key Distribution and Physical Unclonable Functions combine, and how?

I see there's a project to combine Quantum Key Distribution, Physical Unclonable Functions, and classical crypto, in order to secure a high speed (100Gb/s) optical link. While there does not seem to ...
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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 ...