TY - JOUR
T1 - Secret-key distillation across a quantum wiretap channel under restricted eavesdropping
AU - Pan, Ziwen
AU - Seshadreesan, Kaushik P.
AU - Clark, William
AU - Adcock, Mark R.
AU - Djordjevic, Ivan B.
AU - Shapiro, Jeffrey H.
AU - Guha, Saikat
N1 - Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/8
Y1 - 2020/8
N2 - The theory of quantum cryptography aims to guarantee unconditional information-theoretic security against an omnipotent eavesdropper. In many practical scenarios, however, the assumption of an all-powerful adversary is excessive and can be relaxed considerably. In this paper we study secret-key distillation across a lossy and noisy quantum wiretap channel between Alice and Bob, with a separately parameterized realistically lossy quantum channel to the eavesdropper Eve. We show that under such restricted eavesdropping, the key rates achievable can exceed the secret-key-distillation capacity against an unrestricted eavesdropper in the quantum wiretap channel. Furthermore, we show upper bounds on the key rates based on the relative entropy of entanglement. This simple restricted eavesdropping model is widely applicable, for example, to free-space quantum optical communication, where realistic collection of light by Eve is limited by the finite size of her optical aperture. Future work will include calculating bounds on the amount of light Eve can collect under various realistic scenarios.
AB - The theory of quantum cryptography aims to guarantee unconditional information-theoretic security against an omnipotent eavesdropper. In many practical scenarios, however, the assumption of an all-powerful adversary is excessive and can be relaxed considerably. In this paper we study secret-key distillation across a lossy and noisy quantum wiretap channel between Alice and Bob, with a separately parameterized realistically lossy quantum channel to the eavesdropper Eve. We show that under such restricted eavesdropping, the key rates achievable can exceed the secret-key-distillation capacity against an unrestricted eavesdropper in the quantum wiretap channel. Furthermore, we show upper bounds on the key rates based on the relative entropy of entanglement. This simple restricted eavesdropping model is widely applicable, for example, to free-space quantum optical communication, where realistic collection of light by Eve is limited by the finite size of her optical aperture. Future work will include calculating bounds on the amount of light Eve can collect under various realistic scenarios.
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U2 - 10.1103/PhysRevApplied.14.024044
DO - 10.1103/PhysRevApplied.14.024044
M3 - Article
AN - SCOPUS:85090973728
SN - 2331-7019
VL - 14
JO - Physical Review Applied
JF - Physical Review Applied
IS - 2
M1 - 024044
ER -