A method of protection against the copying of digital data stored on an information carrier envisages, on the basis of a first identification of an encryption of the digital data and of a second identification of a watermarking of digital data, the determination of a first mark if it has been possible to identify the encryption and the watermarking. A third identification of a type of the information carrier is followed by the determination of a second mark if it has been possible to determine the first mark and if it has been possible to identify a determined type of information carrier. A fourth identification of cryptographic signature data accompanying the digital data is followed by the determination of a third mark if it has been possible to determine the second mark and if it has been possible to identify a cryptographic signature datum. A permission for digital copying of the digital data is delivered if it has been possible to determine the third mark.