Quantum cryptography communication method, quantum cryptography communication apparatus, and quantum cryptography communication system

摘要

In quantum cryptography communication, a sequence of signals in the form of quantum states randomly selected from a plurality of quantum states each having a different phase modulation angle is transmitted from a data transmitting apparatus. In a data receiving apparatus, if the sequence of samples is received, a plurality of bases corresponding to a plurality of different phase modulation angles are randomly selected, and a homodyne detection process is performed using the selected bases. Information indicating the bases used in the homodyne detection process is sent to the transmitting apparatus. In the data transmitting apparatus, depending on the bases used in the receiving apparatus, bit values are assigned to the plurality of different quantum states selected by the transmitting apparatus, and information indicating the assigned bit values is sent to the data receiving apparatus.