A method for generating a random number sequence whose randomness properties are determined a priori, includes defining a parametric map, calculating, in function of parameters of the map, the entropy and the Lyapunov exponent of random number sequences obtainable using the parametric map, and identifying at least a set of values of parameters for which the entropy and the Lyapunov exponent are positive numbers the map has no attracting point. The method further includes assigning a pre-established value as a first feedback value and cyclically carrying out the following steps for generating a random number sequence: determining the parameters inside the set as the numerical values of respective physical quantities, outputting a random number, according to the map with the parameters and the assigned feedback value, and assigning as new feedback value the output random number.