CONSTITUTION METHOD FOR QUANTUM PASSWORD

摘要

PROBLEM TO BE SOLVED: To provide the constitution method of a quantum password, which does not require a highly precise synchronous clock, by using a remote quantum correlation without using polarization and executing simultaneous measurement only on a receiver-side. SOLUTION: A transmitter 1 generates photons 26 and 27 from a pump photon 25 by using an optical parametric amplifier 24. The photon 26 is transmitted to an optical fiber 28 after it passes through a delay 29 and the photon 27 is transmitted to an optical fiber 32. On a reception-side, the photon 26 is counted in a light receiver 31 and the photon 27 is counted in a light receiver 34 or 35 after it passes through a delay 33. The signals are simultaneously counted in the light receiver 31 and the light receiver 34 or 35. Whether a phase difference which the delay 29 gives and that which the delay 33 gives are a specified combination or not is recognized by a classic channel. Only when it is the specified combination, the signal of one bit is registered.