A method for protecting digital media from illegal
copying by placing in predetermined locations of the digital media a set of Logical Digital Signatures (LDS), each of which causes retrieval of a different Sense Code (SC) and comprise a different signature, and utilizing an
authentication module, which contains, or has access, to the signatures, for detecting the presence of the logical errors. The method comprises activating the
authentication module whenever the content of the storage media is accessed, performing read operation of the locations wherein the LDSs are located, storing the Sense Code (SC) obtained from each read operation in a memory, and allowing access to the content of said storage media if information was retrieved following the LDS read operation and it matches the information that was originally stored, as accessible by the
authentication module, and if different SCs were obtained from the reading operation of the different LDSs, otherwise preventing the access to the content of the storage media.