| 摘要 |
PROBLEM TO BE SOLVED: To provide the configuration method for the quantum cryptography where only two states are used, switching of a measurement system is not required, security is ensured only with bit collation and all transmission pulse streams are used. SOLUTION: A sender 1 gives an optical pulse 3 to a port A in the case of bit '0' and gives the optical pulse 3 to a port B in the case of bit '1' to send contents of a random number table 6. The optical pulse 3 is split by a beam splitter 25 whose split ratio is asymmetrical, one optical pulse 26 from the beam splitter 25 is made incident onto a beam splitter 29 through an optical fiber 16 and a delay circuit 24, and the other optical pulse 27 is is made incident onto the beam splitter 29 through a delay circuit 23, an optical fiber 17 and a π phase shifter 28, the optical pulse 3 made incident from the port A is emitted to a port A' and the optical pulse 3 made incident from the port B is emitted to a port B' and a recipient 2 reproduces the random number table 6 of the sender 1 by viewing only the port A' or B'. |
