Dear Editor,

please find enclosed a manuscript on "Countering detector manipulation attacks in quantum communication through detector self-testing".

This work addresses one of the key vulnerabilities of quantum key distribution systems that are based on typical single photon detectors - namely optical manipulation attacks through blinding and "fake states" and the like, that allow to perform a man-in-the-middle attack on a quantum key distribution system that is not detected by the standard protocols. The countermeasure we propose and demonstrate experimentally does not rely on specific assumptions on the detection or manipulation mechanism, but carries out a self-testing that would be able to reveal every manipulation mechanism caused by anything but single photon-level signals, thus restoring the strength of the quantum key distribution concepts on its reliance on a measurement process.

We believe the work will have significant impact on the community, and would allow to protect against detector manipulation attacks in a simple way, as it neither requires the technological much more complex protocol of a measurement-device independent implementation, nor does it present a targeted countermeasure against a specific implementation of a detector manipulation attack. As such, we feel that this concept is of interest to a wide spectrum of researchers involved in quantum technologies. The key idea is fundamentally rooted in physics yet far-reaching, so we like to ask you to consider this work for publication in Physical Review X.

Possible referees for this work could be Antonio Acin (ICFO, Spain), Norbert Lutkenhaus (IQC, Waterloo, Canada), Hugo Zbinden (U Geneva), Christoph Marquardt (MPL, Erlangen), Masahide Sasaki (NICT, Japan).

We would strongly prefer that this manuscript is not reviewed by Hoi-Kwong Lo (U Toronto) or Xiongfeng Ma (Tsinghua).

We look forward for your reply.


With Best Regards,

Christian Kurtsiefer