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Questions tagged [bb84]

For questions related to quantum cryptography protocol BB84.

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Probability of error in BB84 if Eve is using Breidbart's basis

I'm taking a course on quantum cryptography and I have a homework to calculate probability of error in BB84. The task says to assume that Eve uses the Breidbart basis with eigenvectors $$|φ_0⟩ = \cos(...
demonsrun's user avatar
4 votes
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Is there a BB84 "man"-in-the-middle attack forcing the same keys on Alice and Bob known to Eve

Consider the following scenario: Alice and Bob run BB84 to each other. Eavesdropper Eve is present in the middle. Here we assume that she has access to all channels: the quantum channel, in the ...
Bruno Rijsman's user avatar
3 votes
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Mutual information between Alice and Eve in a BB84 intercept resend attack

I'm new to information theory and i need to calculate $I(A,E)$. To calculate it I need conditional entropy $H(A|E)$. I assume the BB84 protocol standard states $\{ |0\rangle,|1\rangle \},\{|+\rangle,|-...
forgetfuled's user avatar
3 votes
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Entangling attack on BB84 protocol

I am trying to solve the exercise 5.3 from the book "A Gentle Introduction to Quantum Computing". The exercise reads as follows: Suppose Eve attacks the BB84 quantum key distribution of ...
Jorge Vázquez Pérez's user avatar
1 vote
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Doubt in Shor-Preskill's proof of security proof of BB84

I was going through the proof of security of the modified Lo-Chau protocol, which eventually leads to the proof of security of BB84. In the error correction step, Nielson-Chuang mention that any ...
Schroedinger'sStupid's user avatar
1 vote
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Can quantum teleportation be used to break BB84?

BB84 is a key quantum distribution scheme, which is supposed to be "provably secure" and resistant to an individual eavesdropper. However, from what I can tell, is seems as if one could ...
bddicken's user avatar
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What do we mean by family of CSS codes?

In proving the security of BB84 in Nielsen and Chuang (10th anniversary edition - Section 12.6.5), they argue that a codeword in $\text{CSS}(C_1, C_2)$ is represented by $$\frac{1}{\sqrt{|C_2|}} \sum\...
Josh's user avatar
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Why Alice and Bob don't get the same result when they measure in the same basis?

I'm simulating the BB84 protocol using simulaqron. My problem is that when Alice and Bob measure in the same basis, they don't get the same result. How can I fix this error? . BB84.py ...
yassine tech's user avatar