Patent ID: 7461323

Claim:
A method of distributing a quantum key from a transmitting device to a receiving device by adopting, as the quantum key, a result of estimating transmission data by correcting an error in reception data with probability information obtained by measuring photons on a quantum communication path, the method comprising: first generating including the transmitting device and the receiving device generating a first parity-check matrix separately; first notifying including the transmitting device notifying the receiving device of first error-correction information generated based on the first parity-check matrix and transmission data, through a public communication path; first correcting including the receiving device correcting an error in reception data based on the first error-correction information; second generating including the transmitting device and the receiving device generating, when the error in the reception data is not successfully corrected, second parity-check matrix separately so that a second error-correction information generated based on the second parity-check matrix and the transmission data includes the first error-correction information; second notifying including the transmitting device notifying the receiving device of the second error-correction information through the public communication path; second correcting including the receiving device correcting an error in the reception data based on the first error-correction information and the second error-correction information; and disposing including the transmitting device and the receiving device disposing, when the error in the reception data is successfully corrected, a part of the transmission data and a part of the reception data with the error corrected, respectively, according to an amount of the first error-correction information or the second error-correction information.