| 摘要 |
There is provided herein an apparatus and method of encryption/decryption which incorporates a microprocessor into security devices. A first such device is connected to the communication port of the accessing remote terminal, and a second such security device is connected to the communication port of the computer to which access is sought. This microprocessor is programmed to encode and decode all signals directed through the communication port of the computer terminal. The system incorporates a programmed ROM associated with the sending computer terminal containing tables of characters and a programmed ROM associated with the receiving computer terminal containing a complementary image of the tables programmed into the sending station. When data is transmitted by the sending computer terminal it is processed by the sending encryption device. The character code that is generated by the remote terminal is used as an address to access the ROM of the sending encryption device. The character in that memory location is then retrieved and transmitted in place of the original clear data. When the transmitted encrypted code is received, the microprocessor associated with the receiving device uses the received code as an address location and retrieves the character contained within that address location and thereby reclaims the clear data. |
