Abstract: The present invention proposes a solution to prevent a program flow in a processing unit from being modified with respect to an intended program flow, thereby ensuring that important steps such as verifying or authenticating are not bypassed. The invention is particularly aimed at security modules within receiver/decoders in a pay-TV system and involves performing a set of predetermined operations during the processing of entitlement management messages and/or entitlement control messages, said operations being redundant with respect to the normal processing of said messages while leading to the calculation of keys which can then be used to verify that the intended program flow has been respected.

Abstract: A method of verification of rights is disclosed, contained in a security module associated to an apparatus processing broadcasted digital data. The apparatus is connected to a management center transmitting encrypted rights messages for accessing the digital data. The method includes reception and reading by the security module of all or part of a rights message including at least one right and means for verifying the right, decryption and verification of the rights message and updating of a rights memory, and storage of all or part of the rights message in a messages memory. During a further verification step, the method includes identification of at least one right present in the rights memory, search of the corresponding stored rights message and verification of the rights message, comparison of the right contained in the rights message with the corresponding right stored in the rights memory, and determination of a default state when the result of the comparison indicates a difference.

Abstract: The present invention proposes a solution to prevent a program flow in a processing unit from being modified with respect to an intended program flow, thereby ensuring that important steps such as verifying or authenticating are not bypassed. The invention is particularly aimed at security modules within receiver/decoders in a pay-TV system and involves performing a set of predetermined operations during the processing of entitlement management messages and/or entitlement control messages, said operations being redundant with respect to the normal processing of said messages while leading to the calculation of keys which can then be used to verify that the intended program flow has been respected.

Abstract: A method for securing a portable security module for use with a decoding element, the portable security module and the decoding element allowing to descramble scrambled audiovisual information. The method comprises analyzing at the portable security module a sequence of command messages, the command messages of the sequence being received at the portable security module at distinct times.

Abstract: A method of verification of rights is disclosed, contained in a security module associated to an apparatus processing broadcasted digital data. The apparatus is connected to a management center transmitting encrypted rights messages for accessing the digital data. The method includes reception and reading by the security module of all or part of a rights message including at least one right and means for verifying the right, decryption and verification of the rights message and updating of a rights memory, and storage of all or part of the rights message in a messages memory. During a further verification step, the method includes identification of at least one right present in the rights memory, search of the corresponding stored rights message and verification of the rights message, comparison of the right contained in the rights message with the corresponding right stored in the rights memory, and determination of a default state when the result of the comparison indicates a difference.