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arXiv · 1411.7222

Hacking energy-time entanglement-based systems with classical light

Jonathan Jogenfors·Ashraf M. Elhassan·Johan Ahrens·Mohamed Bourennane·Jan-Åke Larsson
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Abstract

Photonic systems based on energy-time entanglement have been proposed to test local realism using the Bell inequality. A violation of this inequality normally also certifies security of device-independent quantum key distribution, so that an attacker cannot eavesdrop or control the system. Here, we show how this security test can be circumvented in energy-time entangled systems when using standard avalanche photodetectors, allowing an attacker to compromise the system without leaving a trace. With tailored pulses of classical light we reach Bell values up to 3.63 at 97.6% detector efficiency which is an extreme violation. This is the first demonstration of a violation-faking source that both gives tunable violation and high detector efficiency. The implications are severe: the standard Clauser-Horne-Shimony-Holt inequality cannot be used to show device-independent security for standard postselecting energy-time entanglement setups. We conclude with suggestions of improved tests and experimental setups that can re-establish device-independent security.

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Jonathan Jogenfors, Ashraf M. Elhassan, Johan Ahrens, Mohamed Bourennane, Jan-Åke Larsson. 2014-11-26. Hacking energy-time entanglement-based systems with classical light. https://doi.org/10.1126/sciadv.1500793

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