Method for the allocation and management of subscriptions for the reception of broadcast products

A method for the managing group messages for at least one receiver comprising a security module, the security module comprising an identification address, this method being carried out by a management center and comprising the steps of:

• a. defining a maximum length for a group message;
• b. defining a group command for a plurality of security modules;
• c. forming a group message comprising at least the group command;
• d. filling the group message with a starting address and a range;
• e. determining a remaining length in the group message following the steps c and d;
• f. defining a bitmap of variable length;
• g. starting at identification address equal to the starting address and initializing an index value and the bitmap length of the bitmap;
• h. updating the bit of the bitmap for the security module pertaining to the identification address to activate/deactivate the command for said security module;
• i. compressing the bitmap;
• j. determining that a length of the compressed bitmap is smaller than the remaining size in the group message, and updating the index value, the length of the bitmap and the identification address and re-executing the steps h to j;
• k. updating the range in the group message with the index value and filling the group message with the bitmap.