Secret communication method and secret communication device thereof
It is possible to provide a secret communication method and its communication device for performing secret communication by using a small amount of communication paths as a whole while evading an overlapped public communication. The secret communication method includes: a step for estimating an error ratio of the initial random numbers X, Y
a step for estimating the upper limit of a wiretap information amount
a step for deciding an encryption function decided from an error correction code based on the error probability estimation value, an error correction decoding function g, and an encryption/decryption auxiliary variable
a step for uniquely deciding a confidentiality increase matrix C according to the encoding ratio of the estimation value of the upper limit value of the wiretap information amount and the encoding ratio of error correction code
a step for uniquely generating an encrypted document Z from information M to be sent to a receiver by using an encryption function, an initial random number X, and a confidentiality increase matrix C
a step for sending the encrypted text Z
and a step for decrypting the encrypted text Z into a transmitted document MB by using an initial random number Y, the confidentiality increase matrix C, the encryption/decryption auxiliary variable, and the error correction decoding function g.