Abstract: The invention relates to a method for matching a number N of reception equipment with a number M of external security modules, each reception equipment being provided with a unique identifier, and each external security module having a unique identifier and containing information about access rights of a user to digital data distributed by an operator. The method comprises the following steps: memorizing a list of identifiers of reception equipment in each external security module, memorizing a list of identifiers of external security modules in each reception equipment, and when an external security module is connected to data reception equipment, a check plan is carried out to determine whether or not the identifier for the security module is present in the list of memorized identifiers in the connected reception equipment, and the same check plan is carried out for the identifier in the list of identifiers memorized in the security module.

Abstract: This invention relates to a method for broadcasting digital data to a targeted set of reception terminals in which said data are previously scrambled by a series of control words transmitted in a conditional access control message. This method comprises the following steps: on transmission, particularise said access control message using a reversible function F for which the inverse function F?1 is executable only in terminals in the targeted set, and on reception, redetermine the original access control message in each terminal in the targeted set using said inverse function.

Abstract: The invention relates to a method for matching a number N of reception equipment (2) with a number M of external security modules (6, 8), each reception equipment (2) being provided with a unique identifier, and each external security module (6, 8) having a unique identifier and containing information about access rights of a user to digital data distributed by an operator.

Abstract: This invention relates to a method for broadcasting digital data to a targeted set of reception terminals in which said data are previously scrambled by a series of control words transmitted in a conditional access control message. This method comprises the following steps: on transmission, particularise said access control message using a reversible function F for which the inverse function F?1 is executable only in terminals in the targeted set, and on reception, redetermine the original access control message in each terminal in the targeted set using said inverse function.

Abstract: The invention related to a method for matching reception equipment (2) with a plurality of security modules (6, 8) each having a unique identifier. The method according to the invention comprises the following steps: connecting a security module (6, 8) to the reception equipment (2), memorising the unique identifier of the connected security module (6, 8) in the reception equipment (2), on the fly.