Patent ID: 7747023

Claim:
A multi-user quantum cryptography system comprising: a quantum information server provided with an output; said server being so configured as to provide quantum information communication capabilities on different wavelengths via said output; and a multiplexer having an input associated with said output of said quantum information server and multiple outputs; said multiplexer being so configured as to separate the different quantum information communications by their wavelength and to supply each quantum information communication to a respective one of said multiple outputs; wherein each user is associated with a respective one of said multiple outputs to receive the quantum information communication; wherein the quantum information communication includes pairs of entangled light signals having different wavelengths, each light signal of the entangled light signal pair being sent to a particular output of the multiplexer, whereby each light signal is sent to two different users; and wherein two users connected to two different outputs of the multiplexer use information from measurements on the entangled light signals to generate a secret encryption key using a quantum cryptography protocol.