| 摘要 |
The present invention prevents code breaking of an important text or data even if a plain text and a cipher text are wire-tapped. An identifier judgment circuit judges whether data (a plain message) created by a user contains an identifier such as ">". If such an identifier is detected, the text or data specified by that identifier is supplied to a first encryption circuit, and the rest of the text or data is supplied to a second encryption circuit. The first encryption circuit enciphers the text or data using a first algorithm and supplies the enciphered data to a transmission circuit. The second encryption circuit enciphers the text or data using a second algorithm and supplies the enciphered data to the transmission circuit. The transmission circuit transmits the enciphered data through the Internet to another server. |
