To make it difficult to steal a key for decoding a password sentence by converting a plain sentence into the password sentence through the use of a first random number string generated from measuring data on a substance A, and transmitting it to a transmission destination in a transmission source and converting the password sentence into the plain sentence through the use of a second random number string generated from measuring data on a substance B in a transmission destination.
In a password communication method, a substance A is arranged in a transmission source, and a substance B obtaining measuring data having correlation with measuring data on the substance A is arranged in a transmission destination. Data on the substance A are measured, a first random number string is generated from measuring data, a plain sentence is converted into the password sentence by using the first random number string and the password sentence is transmitted to the transmission destination in a transmission source. In the transmission destination, data of the subsistence B are measured, a second random number string is generated from measuring data and the password sentence sent from the transmission source is converted into the plain sentence by using the second random number string. The substance A and the substance B are in the relation of a twin and it is desirable that a substance obtaining measuring data having correlation does not exist except the substance A and the substance B.
NOMURA AKIMASA
KUSUYAMA YUKIHIRO
