Patent ID: 7400724

Claim:
A quantum cryptography system for a secure key generation comprising: one or more transmitters with an electronic transmitter circuit and a transmitter optic; one or more receivers with an electronic receiver circuit and a receiver optic; a quantum channel, which connects the transmitter(s) with the receiver(s) and serves for the transmission of light signals; at least 2 signal sources in the transmitter optic, which emit light signals in distinguishable, also non-orthogonal, quantum mechanical states; an electronic transmitter circuit, which allows only one of the signal sources to emit at one instant in time; and at least 2 analysis channels in the receiver optic, which can analyze distinguishable quantum mechanical conditions and forward distinguishable signals which identify the conditions to the electronic receiver circuit; where the signal sources are spatially arranged in such a manner that the wave fronts of the light signals emitted by them superimpose each other at least partially at the input of the quantum channel; and/or the analysis channels are spatially arranged in such a manner that the wave fronts of the light signals coming from the quantum channel are spatially split up and the quantum mechanical state of at least two of the parts can be analyzed.