A method for generating a pseudorandom sequence characterized in that it comprises the following steps: a) providing a differential equation of initial value x' = f ( x,t), b) providing an initial value for the differential equation x o = x ( t 0). c) providing an integration step δ t for the differential equation for time discretization t k = t 0 + k · δ t,k = 1,2,3..., d) carrying out the numerical integration of the differential equation from the initial value and with the step δ t for obtaining the approximation to solution x k = x ( t k), e) generating a first sequence of values by sampling the values x k numerically representable in floating point in the form of 0.d 0 d 1 d 2 d 3 d 4...d r...d w · 10 e, e being the exponent, w the length of the mantissa, d 0 the most representative digit of the mantissa and d r a digit such that it and all the digits to its left of the approximation to solution x k coincide with the exact value of the solution of the differential equation, f) generating the pseudorandom sequence with digits d i...d r from a selection of the sequence of values x k wherein i is a predetermined integer value verifying 0 < i ≤ r, g) the pseudorandom sequence is expanded into a sequence with a greater number of elements according to the following steps: - pre-establishing a positive integer value DIM, - constructing two vectors V 1 and V 2 of dimension DIM of integers from the pseudorandom sequence, - constructing an expansion matrix M e of dimension DIM×DIM from the product V 1· V 2 T wherein V 2 T is the transposed vector of V 2, - generating the expanded sequence by means of concatenating the rows of the matrix M e. a) providing a differential equation of initial value x' = f ( x,t), b) providing an initial value for the differential equation x o = x ( t 0). c) providing an integration step δ t for the differential equation for time discretization t k = t 0 + k · δ t,k = 1,2,3..., d) carrying out the numerical integration of the differential equation from the initial value and with the step δ t for obtaining the approximation to solution x k = x ( t k), e) generating a first sequence of values by sampling the values x k numerically representable in floating point in the form of 0.d 0 d 1 d 2 d 3 d 4...d r...d w · 10 e, e being the exponent, w the length of the mantissa, d 0 the most representative digit of the mantissa and d r a digit such that it and all the digits to its left of the approximation to solution x k coincide with the exact value of the solution of the differential equation, f) generating the pseudorandom sequence with digits d i...d r from a selection of the sequence of values x k wherein i is a predetermined integer value verifying 0 < i ≤ r, g) the pseudorandom sequence is expanded into a sequence with a greater number of elements according to the following steps: - pre-establishing a positive integer value DIM, - constructing two vectors V 1 and V 2 of dimension DIM of integers from the pseudorandom sequence, - constructing an expansion matrix M e of dimension DIM×DIM from the product V 1· V 2 T wherein V 2 T is the transposed vector of V 2, - generating the expanded sequence by means of concatenating the rows of the matrix M e. - pre-establishing a positive integer value DIM, - constructing two vectors V 1 and V 2 of dimension DIM of integers from the pseudorandom sequence, - constructing an expansion matrix M e of dimension DIM×DIM from the product V 1· V 2 T wherein V 2 T is the transposed vector of V 2, - generating the expanded sequence by means of concatenating the rows of the matrix M e.