Questions tagged [key-distribution]
For questions about quantum key distribution (QKD). It is a secure communication method which implements a cryptographic protocol involving components of quantum mechanics. (Wikipedia) In case it's also a question about quantum-cryptography, use the [cryptography] tag along with this.
25
questions
2
votes
1answer
65 views
In the E91 protocol, how can Alice and Bob detect Eve if she waits to measure until A&B publish their bases?
I'm studying the E91 protocol. Suppose Eve has a qubit entangled with Alice's and Bob's qubits.
I understand how Alice and Bob can detect Eve if Eve measures before A&B by testing Bell's ...
0
votes
1answer
49 views
BB84 Protocol doubt
I was studying BB84 protocol from lecture notes by John Watrous. I had some doubts which i thought of asking. Here is the protocol.
Alice prepares strings $x=(01110100)$ and $y=(11010001)$. based on ...
2
votes
1answer
30 views
Why is Measurement Device Independent (MDI) Quantum Key Distribution (QKD) truly MDI?
This is a repost from a question I posted in the physics stack exchange
I am having a hard time understanding why MDI-QKD is truly measurement device independent. My current vision is that Charlie (...
3
votes
1answer
56 views
Doubt in CSS error correction step
At the end of page 3 in Simple proof of security of the BB84 QKD, the following equation (equation 4) is given :
$$
\begin{array}{r}
\frac{1}{2^{n}\left|C_{2}\right|} \sum_{z}\left[\sum_{w_{1}, w_{2} ...
3
votes
1answer
62 views
Doubt in Simple proof of Security of the BB84 QKD
I am not able to understand an argument from Simple proof of Security of the BB84 QKD; I need your help. In page 2 it is mentioned that "Alice can measure her half of the encoded EPR pairs before ...
2
votes
1answer
122 views
Major Security proofs available for Device-Independent QKD
I've lately started working on a DI-QKD project. I've started looking into Vazirani and Vidick's PRL paper on Device-Independent QKD security proof. It's proving to be quite time-consuming for me to ...
1
vote
1answer
84 views
Can we do error correction for entangled particles?
There are several quantum error correction techniques, such as 3-qubit bit-flip code, and Shor’s 9-qubit code. 3-qubit bit-flip code is a straightforward technique for correcting a single error (...
2
votes
1answer
87 views
Understanding the (2,3) threshold quantum secret sharing scheme in Cleve et al. 1999
In the paper "How to share quantum secret" by R.Cleve et al (arxiv).
There is an example of secret sharing using qutrit in a (2,3) threshold scheme.
$$\alpha\vert0\rangle+\beta\vert1\rangle+\...
4
votes
0answers
79 views
Average secret key rate calculation
I am working on a problem related to average secret key rate calculation in satellite quantum key distribution (QKD). The problem is similar to a paper on arXiv:1712.09722 (P. No. 21).
In a single ...
2
votes
1answer
174 views
Quantum bit error rate
I am trying to understand the quantum key distribution and Quantum Bit Error Rate (QBER). I have question: Why is the QBER given by the average of the diagonals of the crosstalk matrix? Why the need ...
2
votes
1answer
98 views
What is meant with "reconciliation" in CV QKD?
I am working on a paper about Continuous Variable QKD. (https://arxiv.org/abs/1711.08500v2)
I read about direct and reverse reconciliation in this paper. I don't understand what exactly Reconciliation ...
2
votes
1answer
80 views
The Methodology of Quantum Key Distributions Systems
While reading an answer in Cryptography.SE I saw this
As for security, that's one possible way to perform Quantum Key Distribution, another real thing. However, most current QKD systems sold today do ...
3
votes
1answer
58 views
How are Franson Interferometers used to prove security in Photonic QKD Experiments?
I am currently reading this paper about Quantum Key Distribution Protocols which use Franson Interferometers to secure against eavesdroppers. I am having trouble understanding how the interferometers ...
2
votes
1answer
73 views
What is the intuition behind the following entanglement distillation protocol for continuous variable systems?
The protocol is:
We start with a supply
of identically prepared bipartite non-Gaussian states. The overall protocol then amounts to an iteration of the following
basic steps.
The states will be mixed ...
1
vote
0answers
47 views
In the BICONF information reconciliation protocol for QKD: should I also run BINARY on the complementary bits subset?
The descriptions of the BICONF information reconciliation protocol in the literature appear to be inconsistent.
All descriptions agree that in each iteration Alice and Bob should select a random ...
1
vote
1answer
85 views
BB84 and B92 protocols: what is maximum and minimum bits that Alice and Bob might agree on?
Say Alice wants to transmit a 10-bit key.
For the BB84 protocol, if we assume that Alice and Bob use the same basis to encode and decode 6 qubits (and different ones for the other 4), then what ...
7
votes
0answers
165 views
What authentication protocol to use for BB84 and other QKD protocols?
Just like other classical and quantum key distribution protocols, BB84 is vulnerable to "man"-in-the-middle attacks, where Eve pretends to be Bob to Alice, and Eve pretends to be Alice to ...
5
votes
3answers
187 views
In what ways can qubits be used for applications that do not require entanglement?
Many good questions on this site have explored how entanglement lies at the boundary between the quantum world and the classical. For example in computational speedups, or teleportation or superdense ...
3
votes
1answer
80 views
Counting channel uses of the lossy bosonic channel or definition of channel uses
The PLOB-bound ("Fundamental Limits of Repeaterless Quantum Communications") gives an asymptotic upper bound on the secret-key rate per used lossy bosonic channel.
However, I'm not sure how to count ...
7
votes
1answer
226 views
What role do Hecke operators and ideal classes perform in “Quantum Money from Modular Forms?”
Cross-posted on MO
The original ideas from the 70's/80's - that begat the [BB84] quantum key distribution - concerned quantum money that is unforgeable by virtue of the no-cloning theorem. A ...
2
votes
1answer
299 views
What is the difference between quantum key distribution and quantum key exchange?
Both the words 'Quantum Key Distribution' and 'Quantum Key Exchange' are used in quantum cryptography in the problem of a secure key distribution for encryption/decryption between parties. There are ...
1
vote
1answer
106 views
Implementing BB84 protocol with easily-obtained consumer hardware
Following on from my question on educational quantum computing toys, I was wondering whether it is possible to implement the BB84 key distribution protocol with easily-obtained consumer hardware - ...
6
votes
1answer
108 views
Lattice based cryptography vs BB84
Am I correct in thinking that post-quantum cryptography such as lattice-based solutions run on classical computers are resistant to quantum attacks (as opposed to RMS), whereas quantum key ...
12
votes
2answers
588 views
Why is the efficiency of Ekert 91 Protocol 25%?
In Cabello's paper Quantum key distribution without alternative measurements, the author said "the number of useful random bits shared by Alice and Bob by transmitted qubit, before checking for ...
18
votes
2answers
1k views
Advantage of quantum key distribution over post-quantum cryptography
Post-quantum cryptography like lattice-based cryptography is designed to be secure even if quantum computers are available. It resembles currently employed encryptions, but is based on problems which ...
