| 摘要 |
PURPOSE:To prevent secret data from being leaked from a communication line, by providing a communication terminal with a unidirectional function device, a common encoding device, etc. CONSTITUTION:At first, a beginner inputs messaged data in addition to a pass word YA and an opening key XA in a console 1 and stores a terminater opening key XB in an ROM 2. The pass word YA and opening key XB are converted into K2identical(XB)YA modn value by the unidirectional function device 3 and set up as a key of the common encoding device 4. The input data are encoded (E is an encoding function) as E{K2, XB}, E{K2 data} by the device 4 and sent to a file 5 on the host side together with the opening key XA of the originater. When the terminater takes up the encoded message file of the originater which is stored in the file 5, the terminater inputs his pass word YB and opening key XB to a console 6. |
