This invention relates to a transmission method for conditional access content, in which said content is broadcast in the form of data packets (DP). These data packets contain at least one marker having a known value and a useful part (PL). This method includes the following steps: extraction of said marker (Mc) from the data packet (DP) and replacement of this marker with an encryption key identification information (PAR); encryption of said useful part (PL) by an encryption key (K1) that can be identified by said encryption key identification information (PAR); formation of an encrypted data packet containing at least said encryption key identification information (PAR) and the encrypted useful part (PLK1); transmission of said encrypted data packet to at least one receiver.