| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a private key distribution method and device for realizing long distance communication without suffering reduction of the number of private keys due to relay, being advantageous for accelerating a communication speed without wasting any bit, and for enhancing safety by incorporating any efficient mechanism to generate high quality random numbers. <P>SOLUTION: One of a pair of photons connected through entanglement is distributed to a transmission station, relay station and reception station. After the photon reaches a safe region such as the relay station, a base for measuring the photon is determined between the adjacent stations, and the photon is observed in each station so that a private key to be used for safe information transmission between the relay stations can be acquired by the base matching each time. Also, high quality random numbers to serve as a private key are physically and automatically generated each time by observation in such a state of superposition as entanglement, and a procedure equivalent to the transmission of the private key itself is carried out by one type of quantum cipher. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
