The invention relates to a data modulation method applicable to make data streams tend to have desired properties, useful for clock recovery, making signals more distinguishable, or enforcing run-length conditions. A stream of input data and a corresponding stream of output data are grouped into elements of a finite field. Input elements of said input data are modified by a transform generating output elements of the output data, such that a current output element is a linear combination of a current input element and at least one previous output element. A multiplier applied to at least one previous output element is a non-zero and non-unity element of the finite field. A set of initial conditions inherent to the transform, is selected such that the output elements resulting from the transform tend to have the desired property.