dorsal/arxiv
View SchemaSecurity of Quantum Key Distribution with Entangled Photons Against Individual Attacks
| Authors | Edo Waks, Assaf Zeevi, Yoshihisa Yamamoto |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0012078 |
| URL | https://arxiv.org/abs/quant-ph/0012078 |
| DOI | 10.1103/PhysRevA.65.052310 |
Abstract
Security of the Ekert protocol is proven against individual attacks where an eavesdropper is allowed to share any density matrix with the two communicating parties. The density matrix spans all of the photon number states of both receivers, as well as a probe state of arbitrary dimensionality belonging to the eavesdropper. Using this general eavesdropping strategy, we show that the Shannon information on the final key, after error correction and privacy amplification, can be made exponentially small. This is done by finding a bound on the eavesdropper's average collision probability. We find that the average collision probability for the Ekert protocol is the same as that of the BB84 protocol for single photons, indicating that there is no analog in the Ekert protocol to photon splitting attacks. We then compare the communication rate of both protocols as a function of distance, and show that the Ekert protocol has potential for much longer communication distances, up to 170km, in the presence of realistic detector dark counts and channel loss. Finally, we propose a slightly more complicated scheme based on entanglement swapping that can lead to even longer distances of communication. The limiting factor in this new scheme is the fiber loss, which imposes very slow communication rates at longer distances.
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"abstract": "Security of the Ekert protocol is proven against individual attacks where an\neavesdropper is allowed to share any density matrix with the two communicating\nparties. The density matrix spans all of the photon number states of both\nreceivers, as well as a probe state of arbitrary dimensionality belonging to\nthe eavesdropper. Using this general eavesdropping strategy, we show that the\nShannon information on the final key, after error correction and privacy\namplification, can be made exponentially small. This is done by finding a bound\non the eavesdropper\u0027s average collision probability. We find that the average\ncollision probability for the Ekert protocol is the same as that of the BB84\nprotocol for single photons, indicating that there is no analog in the Ekert\nprotocol to photon splitting attacks. We then compare the communication rate of\nboth protocols as a function of distance, and show that the Ekert protocol has\npotential for much longer communication distances, up to 170km, in the presence\nof realistic detector dark counts and channel loss. Finally, we propose a\nslightly more complicated scheme based on entanglement swapping that can lead\nto even longer distances of communication. The limiting factor in this new\nscheme is the fiber loss, which imposes very slow communication rates at longer\ndistances.",
"arxiv_id": "quant-ph/0012078",
"authors": [
"Edo Waks",
"Assaf Zeevi",
"Yoshihisa Yamamoto"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.65.052310",
"title": "Security of Quantum Key Distribution with Entangled Photons Against Individual Attacks",
"url": "https://arxiv.org/abs/quant-ph/0012078"
},
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