A encrypted quantum key has been transmitted over a distance of 184.6 km, which is 50% further than the previous record of 122 km. The work was done by researchers in the US, based at the Los Alamos National Laboratory (LANL) in New Mexico and the National Institute of Standards and Technology (NIST) in Boulder, Colorado (New Journal of Physics 8 193). The previous record of 122 km was set by researchers at Toshiba
This information is sent in the form of photons and an eavesdropper