Abstract: The invention relates to a method for securely transmitting data by hiding in point-to-point and point-to-multi-point digital transmission systems. The data stream (DS) on the transmitter side is supplied to a modulation unit (MOD). The modulation and coding parameters (MP) of the modulation process (MV) and of said modulation unit (MOD) can be changed in time. The modulation parameters (MP) are transmitted to a demodulator (DEM) by means of a secure channel (SK). The electric transmission signal (ES) is situated at the output of the modulation unit (MOD). Said signal is transmitted by means of a channel (K). The demodulator (DEM) that knows the hiding sequence regenerates the original signal and supplies the receiving data stream (DE) at the output.