Method of generating the shared secret information and confidential communication system

摘要

PROBLEM TO BE SOLVED: To provide a secret communication system which allows a user's request to be reflected on security of an updated key when distributing a quantum encryption key.;SOLUTION: A transmitter 100 and a receiver 200 are connected through an optical fiber 300, and a quantum transmitter TX111 of the transmitter 100 and a quantum receiver RX211 of the receiver execute base verification and error correction on the basis of a basis of a key value transmitted by the transmitter TX111 through a quantum channel 301 and a raw key received by the receiver RX211. An amount of information having the possibility of wiretapping, which is determined in accordance with a degree of security requested by the user, is removed from key information after error correction to finally generate an encryption key by security degree control parts 120 and 220. Secret communication is performed by encryption/decryption parts 130 and 230 using the encryption key updated in this manner.;COPYRIGHT: (C)2007,JPO&INPIT