| 摘要 |
PROBLEM TO BE SOLVED: To increase the safety of quantum key delivery and increase a key delivery rate while avoiding a remarkable drop of the safety even when a plurality of photons are mixed into a unit time slot. SOLUTION: The common private encryption key delivery system between signal reception and transmission sides includes a generation means for generating a photon pair ab formed from two photons a, b prepared in such an initial state F as to have a maximum quantum mechanics correlation with respect to an internal or external freedom, a holding means for holding the output photon a for a timeΔT, an encoding means for converting the state of the photon pair ab to a state m1 or m2 different in the weakened degree of the quantum correlation according to 1 or 0 of an encode target key information bit by operating the state of the accepted photon b and then returning the photon b to the reception side, and a decoding means for determining the state m1 or m2 of the photon pair ab by causing two-photon interference between the photon a and the returned photon b. The reception side has the photon pair generating means, the holding means and the decoding means. The reception side does not emit the photon a to the outside. COPYRIGHT: (C)2010,JPO&INPIT |
