arXiv subjects

Elizabeth Newton

Publications and source records attributed to Elizabeth Newton.

3 recordsLinked to original sources

arXiv2019

Quantum Secrecy in Thermal States II

In this paper we consider a scheme for cryptographic key distribution based on a variation of continuous variable quantum key distribution called central broadcast. In the continuous variable central broadcast scheme, security arises from discord present in the Hanbury Brown and Twiss effect from a thermal source. The benefit of this scheme is that it expands the range of frequencies into the microwave regime. Longer wavelengths, where the thermal photon number is higher and correlations remain robust over long distances, may even be preferable to optical wavelengths. Assming that Alice controls the source but not the distribution of the light (eg satellite broadcasts), then we demonstrate that the central broadcast scheme is robust to an entangling cloner attack. We establish the security of the protocol both experimentally and theoretically.

quant-ph↗

arXiv2018

Quantum Secrecy in Thermal States

We propose to perform quantum key distribution using quantum correlations occurring within thermal states produced by low power sources such as LED's. These correlations are exploited through the Hanbury Brown and Twiss effect. We build an optical central broadcast protocol using a superluminescent diode which allows switching between laser and thermal regimes, enabling us to provide experimental key rates in both regimes. We provide a theoretical analysis and show that quantum secrecy is possible, even in high noise situations.

quant-ph↗

arXiv2015

Novel Side Channel Attacks in Continuous Variable Quantum Key Distribution

Experimental Quantum Key Distribution (QKD) protocols have to consist of not only the unconditionally secure quantum transmission, but also a subsequent classical exchange that enables key reconciliation and error correction. There is a large body of work examining quantum attacks on the quantum channel, but here we begin to examine classical attacks to both the classical communication and the exchange as a whole. Linking together separate secure protocols can unexpectedly leak information to an eavesdropper, even if the components are unconditionally secure in isolation. Here we focus specifically on the join between quantum and classical protocols, finding that in just this crossing of the quantum-classical boundary, some security is always and unintuitively lost. This occurs with no communication between the separate parties. While this particular example applies to only Continuous Variable Quantum Key Distribution (CVQKD), it highlights the need to re-examine the way all individual protocols are actually used.

quant-ph↗