| 摘要 |
The aim of the present invention is to propose a method for preventing th e abusive use of conditional access data, in particular by means of clones o f security modules whose security has been compromised. This aim is achieved by a method of revocation of security modules that are intended to receive security messages broadcast to a plurality of security modules, the said sec urity modules comprising at least one personal key, this method comprising t he steps, prior to revocation: dividing the set of security modules into at least two groups, determining, for each group, an asymmetric key comprising a public key and a plurality of private keys, loading a private key per secu rity module, transmitting a security message per group, the said message bei ng encrypted by the public key of the said group; revocation consisting in t he following steps: dispatching to each member of the same group as the secu rity module to be revoked, with the exception of the security module or modu les to be revoked, a new private key corresponding to the public key of anot her group, each private key being encrypted by the personal key of the said security module.
|
