  Quantum Key Distribution (QKD) allows the distribution of cryptographic keys
between multiple users in an information-theoretic secure way, exploiting
quantum physics. While current QKD systems are mainly based on attenuated laser
pulses, deterministic single-photon sources could give concrete advantages in
terms of secret key rate (SKR) and security owing to the negligible probability
of multi-photon events. Here, we introduce and demonstrate a proof-of-concept
QKD system exploiting a molecule-based single-photon source operating at room
temperature and emitting at 785nm. With an estimated SKR of 0.5 Mbps, our
solution paves the way for room-temperature single-photon sources for quantum
communication protocols.
