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arXiv · 1912.00768

Measurement-Protected Quantum Key Distribution

Spiros Kechrimparis·Heasin Ko·Young-Ho Ko·Kap-Joong Kim·Byung-Seok Choi·Chahan M. Kropf·Chun Ju Youn·Joonwoo Bae
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Abstract

In the distribution of quantum states over a long distance, not only are quantum states corrupted by interactions with an environment but also a measurement setting should be re-aligned such that detection events can be ensured for the resulting states. In this work, we present measurement-protected quantum key distribution where a measurement is protected against the interactions quantum states experience during the transmission, without the verification of a channel. As a result, a receiver does not have to revise the measurement that has been prepared in a noiseless scenario since it would remain ever optimal. The measurement protection is achieved by applications of local unitary transformations before and after the transmission, that leads to a supermap transforming an arbitrary channel to a depolarization one. An experimental demonstration is presented with the polarization encoding on photonic qubits. It is shown that the security bounds for prepare-and-measure protocols can be improved, for instance, errors up to 20.7% can be tolerated in the Bennett-Brassard 1984 protocol.

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Spiros Kechrimparis, Heasin Ko, Young-Ho Ko, Kap-Joong Kim, Byung-Seok Choi, Chahan M. Kropf, Chun Ju Youn, Joonwoo Bae. 2019-12-02. Measurement-Protected Quantum Key Distribution. https://doi.org/10.1109/jsac.2025.3568037

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