| 摘要 |
PROBLEM TO BE SOLVED: To protect data without loading any burden on an operator and lowering the convenience, by making easily encipher/decipher data on a portable terminal. SOLUTION: A portable terminal 10-1a has a memory for non-enciphered data storage and a memory for enciphered data storage. When moving from an office 10 to a mobile environment 12, according to a cryptographic key designated by the operator, non-enciphered data in the memory for non- enciphered data storage are enciphered and an encipher mode is set while defining the memory for enciphered data storage as the access object of data. When returning from the mobile environment 12 to the office 10, on the other hand, according to a decipher key designated by the operator, the enciphered data in the memory for enciphered data storage are deciphered. These deciphered data, namely, non-enciphered data are written in the memory for non-enciphered data storage and the encipher mode is set while defining the memory for non- enciphered data storage as the access object of data. |
