In practical quantum key distribution systems, imperfect physical devices open security loopholes that challenge the core promise of this technology. Apart from various side channels, a vulnerability of single-photon detectors to blinding attacks has been one of the biggest concerns, and has been addressed both by technical means as well as advanced protocols. In this work, we present a countermeasure against such attacks based on self-testing of detectors to confirm their intended operation without relying on specific aspects of their inner working, and to reveal any manipulation attempts. We experimentally demonstrate this countermeasure with a typical InGaAs avalanche photodetector, but the scheme can be easily implemented with any single photon detector.
@article{arxiv.2204.06155,
title = {Countering detector manipulation attacks in quantum communication through detector self-testing},
author = {Lijiong Shen and Christian Kurtsiefer},
journal= {arXiv preprint arXiv:2204.06155},
year = {2025}
}