ELECTRONIC MAIL CIPHER COMMUNICATION SYSTEM AND ELECTRONIC MAIL RELAY DEVICE USED FOR THE SAME, AND ELECTRONIC MAIL CIPHER COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To easily cipher and decipher electronic mail on a network level. SOLUTION: A transmission-side terminal 1 inserts a specific pattern into the body of electronic mail and sends the electronic mail. A transmission-side relay device 2 connected to the transmission-side terminal 1 detects the specific pattern in the electronic mail body by a pattern detection part 22, ciphers body information following the specific pattern by a ciphering processing part 23, and sends the mail to the Internet 3. A reception-side relay device 4 connected to a reception-side terminal 5 detects the specific pattern in the electronic mail body by a pattern detection part, deciphers the body ciphered information following the specific pattern, and sends the mail to the reception-side terminal 5.