| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that device overhead occurs by generating a loss of a quantum cryptographic optical key when distributing a quantum cryptographic key by means of a single photon optical signal between transmitting and receiving nodes including a mobile of which the attitude is changed.SOLUTION: The quantum cryptographic key distribution system comprises: transmission means for transmitting a quantum cryptographic optical signal formed from a periodical optical pulse stream of single photons linearly polarized to four types belonging to two kinds of different basis and a first reference optical signal formed from a periodical optical pulse stream of linearly polarized single photons; and reception means including Belle measurement means which defines single photons constituting the first reference optical signal as a second reference optical signal converted into two kinds of linearly polarized light and synchronously performs Belle measurement on the quantum cryptographic optical signal and the second reference optical signal. The reception means generates a quantum cryptographic key by using a result where a polarizing direction of the single photons belonging to the two kinds of basis is also matched with the two kinds of basis or a result where the polarizing direction is not matched with both the two kinds of basis, in a Belle measurement result of the Belle measurement means. |
