Quantum cryptography over 200 km with a simple system using polarization encoded photons
Fadri Grünenfelder, Alberto Boaron, Davide Rusca, Anthony Martin, and Hugo Zbinden.
In our last paper in Applied Physics Letters, we present a simplified BB84 protocol with only three quantum states and one decoy-state level. We implement this scheme using the polarization degree of freedom at telecom wavelength. Only one pulsed laser is used in order to reduce possible side-channel attacks. The repetition rate of 625 MHz and the achieved secret bit rate of 23 bps over 200 km of standard fiber are the actual state of the art.
Appl. Phys. Lett. 112, 051108 (2018)