A method and a system for protecting a static digital datum contained in a first element of an electronic circuit, intended to be exploited by a second element of this circuit, in which: on the side of the first element, the static datum is converted into a dynamic data flow by at least one first linear shift feedback register representing a different polynomial according to the value of the static datum; the dynamic flow is transmitted to the second element; and on the side of the second element, the received dynamic flow is decoded by at least one second shift register representing at least one of the polynomials that has been used by the first element.