Patent ID: 8103001

Claim:
A method of verification of rights contained in a security module associated to an apparatus processing broadcasted digital data, the rights comprising instructions and parameters authorizing a user to access to the broadcast digital data, said apparatus being connected to a management center transmitting encrypted rights messages containing the rights, comprising the steps of: receiving and reading by the security module of all or part of a rights message including at least one right and a digest obtained with a collision free unidirectional function applied on the right, wherein a set including the right and the digest of the right is encrypted with a unique key of the security module, decrypting the rights message by the security module with a global key, decrypting the set including the right and the digest of the right with the unique key, verifying the right of the decrypted set by comparing the digest of the right with a digest determined by the security module, when the digest of the right corresponds with the determined digest, updating rights stored in a rights memory, and storing all or part of said rights message in a messages memory, during a further step of the rights message re-execution, identifying at least one right present in the rights memory, searching in the messages memory a stored rights message corresponding to the at least one identified right and verifying the corresponding rights message by comparing the digest contained in the stored rights message with a digest determined by the security module when the digest contained in the stored rights message corresponds with the determined digest, comparing the right contained in the stored rights message with the corresponding right stored in the rights memory, determining a default state when a result of the comparison of the rights indicates a difference.