| 摘要 |
<p>A data protection system has an IC card. The IC card has a CPU (29) and a ROM (31). The ROM (31) stores an encryption/decryption key or an encrypting/decrypting program. According to the second embodiment, in a first data processor (1), the encryption key is read out from the ROM and transaction data is encrypted. According to the third embodiment, transaction data is encrypted in the IC card (19) in accordance with the encrypting program. The encrypted data is stored in a floppy disk (23). The IC card (19) and the floppy disk (23) are physically transported to a second aata processor (3). The second data processor (3) in the second embodiment reads out the decryption key from the IC card (19) and decrypts the encrypted data. The encrypted data in the third embodiment is decrypted in accordance with the decrypting program in the IC card (19), and the decrypted data is supplied to the second data processor (3).</p> |
