| 摘要 |
PROBLEM TO BE SOLVED: To prevent transmitted information from being leaked to a 3rd party by storing a decoding key, decoding a message of a received ciphering text and storing it, and displaying a decoded message by a command of a possessor. SOLUTION: A CPU 2' receives a message in a ciphering text from a reception section 1 and stores it to a 1st area of a memory 3. A decoding means 22 decodes the stored ciphering message with a decoding key stored in a nonvolatile memory 6 and stores the decoded message to a 2nd area of the memory 3. When the possessor uses a key 4 to command display of the message, the content of the 2nd area of the memory 3 is displayed on a display section 5. The CPU 2' receives entry of numeral data by the key 4 or an external I/O 7 and stores the key as a ciphering key or a decoding key to the memory 6 according to the command. A ciphering means 21 ciphers the message entered by the key 4 with the ciphering key stored in the nonvolatile memory 6 and displays it on the display section 5 as the ciphering message. |
