A secret key transmission method capable of suppressing the damage scale when the secret key is decrypted

摘要

The transmission apparatus 100 includes a secret key storage unit 103 for storing three secret keys K1 to K3, and a secret key storage unit 103 for storing therein secret keys A secret key selection unit 104 for selecting and reading the secret key Ks of the secret key K, a message generation unit 106 for generating a message M as a carrier for transmitting the secret key, A cipher 105 for encrypting the message M using the secret key Ks to generate a cipher text Ca and a cipher 105 for generating a cipher text Cm by encrypting the message M itself as an encryption key 107 and transmitters 111 and 112 for transmitting the ciphertexts Ca and Cm to the receiving apparatus 200 as the transmission of the secret key Ks and the receiving apparatus 200 comprises A decoder 221 for decrypting the cipher text Ca using a single secret key Ki and generating a decrypted text Mi, And a decoder 222 for decoding the decrypted text Mi with a decryption key to generate a decrypted text Mii. At this time, when the decrypted statements Mi and Mii coincide with each other, the secret key Ki is recognized as the secret key transmitted from the transmitting apparatus.