摘要 |
An encryption printed circuit board (PCB) for use as an add on board to a host computer includes address registers, read/write controller, and data information transceiver adapted for connection to the host computer. The addresses registers are connected to a memory decode, auto-start PROM, I/O decoder and register select. The memory decoder is connected to the auto-start PROM and the I/O decoder is connected to the register select. A bus logic circuit is connected to the read/write controller, and outputs read/write signals to the data information transceiver and register select. The data information transceiver is connected to the auto-start PROM and to a plurality of data registers for receiving instructions from the auto-start PROM and inputting or receiving information from the data registers pursuant to instruction of the auto-start PROM program, and selection of the appropriate registers by the register select. A cipher processor, microprocessor, low address latch and memory, program, and buffer are connected to the data registers. The microprocessor is connected to a card reader through a card reader interface, and to an upper address decoder and the memory, program, buffer. Upon receipt of a load key instruction from the PC the microprocessor loads the key and a block of information from the input register into the cipher processor for either encryption or decryption and the processed block of information into the information output register for output to the PC upon receipt of a write instruction.
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