| 摘要 |
<p>The invention relates to a method for updating a linear feedback shift register of a code generator from a known state to a new state, and to a code generator using the method. The method comprises (300) defining jumps corresponding to different powers of two for shifting from a known state to a new state. Then (302A) in each jump the feedback shift register obtained as a result of the jump in question is generated as follows: (302B) the value of one element of the obtained feedback shift register is generated from the previous state and the pre-stored mask register corresponding to said obtained element, while the mask register determines the elements of the feedback shift register of the previous state, using which elements said element value is generated, and (302C) the generation of the value of one feedback shift register element is repeated for each remaining obtained feedback shift register element by shifting the mask register to the position of said remaining element and by generating the value of said remaining element of the obtained feedback shift register from the previous state and the shifted mask register.</p> |
