| 摘要 |
PURPOSE:To disable the embezzlement of data only by recognizing an ID code and to make deciphering difficult by changing a ciphering form at every user by deciphering ciphered data by using a cipher reference table stored in an IC card. CONSTITUTION:A portable computer 2 is connected through a connection cable 3, personal computer 1 and further a public line, etc., to a host computer. Therefore, the computer 2 enables communication with the host computer. The host computer holds data to be used at the computer 2 as the data of a data base and suitably supplies the data to the computer 2 by the communication with the computer 2. In this case, an ID card 4 holds the cipher reference table and according to the ciphering form corresponding to the cipher reference table, the host computer ciphers the data and transmits them to the computer 2. |
