Quantifying backflash radiation to prevent zero-error attacks in quantum key distribution

摘要

Single-photon avalanche diodes (SPADs) are the most widespread commercial solution for single-photon counting in quantumudkey distribution applications. However, the secondary photon emission that arises from the avalanche of charge carriers thatudoccurs during the detection of a photon may be exploited by an eavesdropper to gain information without inducing errors in theudtransmission key. In this paper, we characterize such backflash light in gated InGaAs/InP SPADs and discuss its spectral andudtemporal characterization for different detector models and different operating parameters. We qualitatively bound the maximumudinformation leakage due to backflash light and propose solutions for preventing such leakage.