Avoiding Vadim Makarov attack on the Single-Photon Detector

Qin Liu, Antía Lamas-Linares, Christian Kurtsiefer +3 more

The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.

João Batista Rosa Silva, Rubens Viana Ramos, Elvio César Giraudo

Yan Liang, Heping Zeng

Mikhail S. Elezov, Roman V. Ozhegov, Yury Kurochkin +2 more

Nowadays, the superconducting single-photon detectors (SSPDs) are used in Quantum Key Distribution (QKD) instead of single-photon avalanche photodiodes. Recently bright-light control of the SSPD has been demonstrated. This attack employed a “backdoor” in the detector biasing technique. We developed the autoreset system which returns the SSPD to superconducting state when it is latched. We investigate latched state of the SSPD and define limit conditions for effective blinding attack. Peculiarity of the blinding attack is a long nonsingle photon response of the SSPD. It is much longer than usual single photon response. Besides, we need follow up response duration of the SSPD. These countermeasures allow us to prevent blind attack on SSPDs for Quantum Key Distribution.

Gaëtan Gras, Davide Rusca, Hugo Zbinden +1 more

Detector blinding attacks have been proposed in the last few years, and they could potentially threaten the security of quantum key distribution systems. Even though such attacks are technically challenging to implement, it is important to consider countermeasures to avoid information leakage. In this paper, we present a countermeasure against these kinds of attacks based on the use of multipixel detectors. We show that with this method, we are able to estimate an upper bound on the information an eavesdropper could have on the key exchanged. Finally, we test a multipixel detector based on superconducting nanowire single-photon detectors to show it can fulfill all the requirements for our countermeasure to be effective.

Oliver Graydon