摘要 |
<p>A security apparatus including a number input device (302), an address register (312) responsive to the number input device, an encryption schema memory (316) addressable by the address register to produce an output code and a relative address code, and address incrementing logic (310) responsive the relative address code and operative to increment the address register. The apparatus also preferably includes a PIN register (304) coupled to the number input device, a public code register (306) coupled to the number input device, and merging logic (308) merging outputs of the PIN register and the public code register to be input to the address register. The apparatus also preferably includes an output shift register operative to shift out the output code of the encryption schema memory. The encryption schema memory can be read only memory, writeable memory, or both.</p> |