CIPHER TEXT TRANSFERRING METHOD AND DEVICE

摘要

PROBLEM TO BE SOLVED: To transmit and receive a cipher text without using the cryptographic key and decoding key of a communication opposite party by providing a cipher text transferring device with a function of converting a cipher text into another cipher text that can be decoded by a receiver side or with a function for distributing a program to decode the cipher text. SOLUTION: A transfer control section 12 in the cipher text transferring device 1 stores the cipher text sent from a sender side in a cipher text storage section 14. The transfer control section 12 extracts decoding key data for decoding the cipher text from a decoding key storage section 15 to supply the data to a decoding section 16. The decoding section 16 decodes the stored cipher text into a plain text. The transfer control section 12 extracts the cryptographic key data for enciphering the plain text to be decodable by a receiver side from a decoding key storage section 17 to supply the data to an encryption 18. Then the encryption section 18 enciphers the plain text and transfers the cipher text to the receiver side via a cipher text transmission section 19.