Efficient Quantum Key Distribution Scheme and a Proof of Its Unconditional Security

By Hoi-Kwong Lo, Hoi Fung Chau, M. Ardehali. Journal of Cryptology, 2000

513 citations recorded by the source corpus.

AbstractWe devise a simple modification that essentially doubles the efficiency of the BB84 quantum key distribution scheme proposed by Bennett and Brassard.We also prove the security of our modified scheme against the most general eavesdropping attack that is allowed by the laws of physics. The first major ingredient of our scheme is the assignment of significantly different probabilities to the different polarization bases during both transmission and reception, thus reducing the fraction of discarded data. A second major ingredient of our scheme is a refined analysis of accepted data: We divide the accepted data into various subsets according to the basis employed and estimate an error rate for each subset separately. We then show that such a refined data analysis guarantees the security of our scheme against the most general eavesdropping strategy, thus generalizing Shor and Preskill’s proof of security of BB84 to our new scheme. Until now, most proposed proofs of security of single-particle type quantum key distribution schemes have relied heavily upon the fact that the bases are chosen uniformly, randomly, and independently. Our proof removes this symmetry requirement.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/acce4a92c051332ce122f194bbd65da5b0dc544b

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Citations in the corpus

Tight finite-key analysis for quantum cryptography (2011, background): “The protocol is asymmetric, so that the number of bits measured in the two bases (n bits in the X basis and k bits in the Z basis) are not necessarily equal [41].”
Quantum Cryptography (2006, unknown): “For instance, it does also apply to the scheme by Lo, Chau and Ardehali [43], which works similar to standard BB84 except that Alice and Bob choose their bases (computational or Hadamard) with some bias, but we do not know yet if this approach can be used to prove the six-state scheme [19] secure.”
Twin-field quantum key distribution over 830-km fibre (2019, methodology): “The efficient QKD scheme [39] can be directly applied in the above protocol, where we let pZ ≈ 1 in the asymptotic limit.”
Advances in quantum cryptography (2019, unknown): “where R(·) is the secret key rate of an efficient BB84 protocol [196] with tagging argument [197], and μ, L are the intensity and the distance respectively.”
Quantum key distribution with entangled photon sources (2007, background): “where q is the basis reconciliation factor (1/2 for the BB84 protocol due to the fact that half of the time Alice and Bob disagree with the bases, and if one uses the efficient BB84 protocol [50], q ≈ 1), the subscript λ denotes for one half of the expected photon number μ, Qλ is the overall gain, δ”
Practical decoy state for quantum key distribution (15 pages) (2005, methodology): “time Alice and Bob disagree with the bases, and if one uses the efficient BB84 protocol [ 10 ],q ≈ 1),”