| 摘要 |
PURPOSE: To provide a key stream generating device which is hardly duplicated by an improper person by supplying a logic element with an enable polynomial code signal which varies with the contents of data bits shifted from a predetermined register stage. CONSTITUTION: The polynomial code signal which varies with the contents of the data bit shifted from the predetermined register stage is supplied to the logic element to vary a polynomial code. For example, an input data key 35 is buffered in an input buffer 14. A half of the bits of the input data key 35 are loaded onto a dynamic field back shift register structure 10 in parallel from the input buffer 14 and the rest of the bits of the input data key 35 is loaded on a static field back shift register structure 12 in parallel from the input buffer 14. Consequently, it is difficult for an improper person to duplicate a key stream. |
