Hacking the Bell test using classical light in energy-time entanglement–based quantum key distribution
2015 (English)In: Science Advances, ISSN 2375-2548, Vol. 1, no 11, 1500793Article in journal (Refereed) Published
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 (QKD) so that an attacker cannot eavesdrop or control the system. 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. We reach Bell values up to 3.63 at 97.6% faked detector efficiency using tailored pulses of classical light, which exceeds even the quantum prediction. This is the first demonstration of a violation-faking source that gives both tunable violation and high faked detector efficiency. The implications are severe: the standard Clauser-Horne-Shimony-Holt inequality cannot be used to show device-independent security for energy-time entanglement setups based on Franson’s configuration. However, device-independent security can be reestablished, and we conclude by listing a number of improved tests and experimental setups that would protect against all current and future attacks of this type.
Place, publisher, year, edition, pages
2015. Vol. 1, no 11, 1500793
Bell’s Theorem; Energy-Time Entanglement; Quantum Hacking; Quantum Key Distribution
Accelerator Physics and Instrumentation
IdentifiersURN: urn:nbn:se:liu:diva-127721DOI: 10.1126/sciadv.1500793PubMedID: 26824059OAI: oai:DiVA.org:liu-127721DiVA: diva2:927171