Page 159 - ISCI’2017
P. 159

Analyzing in (19)  1,0  , 3 , 2 ,   , f m ( ) 1−x   symbols appearance probability we will get the same assed

            values as in (16) and (17).

               It is also should be pointed out that in (16) V  symbols appearance unequiprobability is no more

            than 1 in number of appearance of symbols  1 , 0  , 3 , 2 ,    V , ,  and  also as an assessed value of probability
                                    1
            for each symbol  ∆p  =      .
                                  p n  − 1
               Thus theorem 1 for three modulo transformation is proved. Also it should be mentioned that above-

            described theorem 1 proving can be applied to k-modulo transformation, of course under condition

                                                                                        X
                                                             X
            when couples of polynomials  ( ) ( )( f  X  f ,  1  X ,  1 ( ) ( )),,  f 2  X  , ( f k 2 ( ) fX ,  k 1 −  ( ))  are coprime and
                                                       ) ( f
                                                                             −
                      X ,
                   f
            tuple  ( ) m is undefined, module m value is meant.
                   m
               On the whole the procedure  of PRS generation  based on  multimodulo transformation can  be
            brought to the following.
               1. To set or generate system options  –  general  options tuples ( f s ( ) pX ,  s  n ,  s ) according  to the

            requirement of statement 1.

                                                           k
               2. To set or install secret key of generator k , = 1÷ p n  − 1.

               3. Determine initial value of generator  a 0  using the rule:


                                                                    n ,
                                                  a = θ k (mod (f  ( ) )),
                                                                  x
                                                   0
                   (
            where  ( ) ) nxf  ,   – basic transformation module.
               4. Determine element  a  of generator using the rule:
                                      i
                                                           x
                                         a =  a i 1 −  ( θ mod (f  ( ) )) Rn ,  =  ( f  ( ) ) (a θ i ),
                                           i
                                                                            0
                                                                      x
                                                                        n , 1
            where  ≥i  1 – number of PRS generating element, a  – ( 1−i  ) element of an array over a  field of
                                                                1 − i
                        n
            extension  p .
               5. Determine element b  of PRSG using the rule:
                                      i
                               b =  a (mod ( f 1 ( ) )), n 1  =  R ( f 1 ( ) ) ( ) =  R ( f 1 ( ) ) ( fnx , 1  (R  ( ) ) nx ,  (a θ i )),
                                              x
                                                               a
                                                                i
                                                                                     0
                                     i
                                i
                                                           x
                                                            n , 1
                                        n ,
            where 1<  ( f 1 ( ) ) (fnx ,  1  <  ( ) ).
                                     x
               6. Determine element c  of PRSG using the rule:
                                      i

                             c =  R ( f n ( ) mx ,  n ) (R ( f n−1 ( ) mx ,  n−1 )  ( (   R ( f 2  ( ) mx , 2 ) (R ( f 1  ( ) mx , 1 ) (a θ i ))) )) 0 ,  ≤ i ϕ≤  ( ) p ,
                                                                               
                              i
                                                                          0
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