Verschlüsselungs- und entschlüsselungs-Verfahren für Inhalt mit bedingtem Zugang.

摘要

The method involves extracting a marker (Mc) from a data packet (DP), and creating a marking block having the marker and a padding value (PAD2). The block is encrypted with an encryption key (K2). An encrypted marking value (MK2) of the encrypted block is extracted. A mixed marking block having the encrypted value and an encrypted padding element is created. The mixed block is decrypted using another encryption key (K1), to obtain a decrypted mixed block. A preset portion of the decrypted block is extracted. A new set of encrypting parameters is found if the portion matches a reference value. The new set of encrypting parameters is different from a set of encrypting parameters. Another set of encrypting parameters are substituted by the new another set of encrypting parameters.