Patent ID: 8601041

Claim:
A method of generating a pseudorandom sequence of terms belonging to a finite body K of cardinal q 2 intended to be used in a cryptographic procedure, the method comprising: performing, by a data processing device including a memory, an iterative calculation from an initialization n-tuple X (0) =(X (0) 1 , X (0) 2 , . . . , X (0) n ), in which n≧2, of elements of K, n-tuples X (i) =(X (i) 1 , X (i) 2 , . . . , X (i) n ), and elements of K (where i=1, 2, ...), each n-tuple X (i) being obtained on iteration number i in a predetermined manner at least from certain components Y (i) k of an m-tuple Y (i) =(Y (i) 1 , Y (i) 2 , . . . , Y (i) m ), where m≧n; performing, by the data processing device including the memory, an iterative extraction of elements of K and terms of said pseudorandom sequence in a predetermined manner from at least one of the n-tuples X and the m-tuples Y; and representing at least E(n/2) of at least one value of i, among said components Y (i) k of the m-tuple Y (i) that are used to obtain a multiplet X (i) , by a predetermined second degree polynomial function, with coefficients in K, of the components of the n-tuple X (i−1) , K being the finite body, q being a number of elements of the finite body, X being the n-tuple and Y being the m-tuple and E being an integer part for any real number.