The object of the present invention is intended to solve the problem of the broadcasting of conditional access data where certain parts must be accessible either for technical reasons or for commercial reasons.This object is reached by a method for processing a conditional access digital data set by a user unit (DVR) comprising a security module (SM), this data being divided into at least two parts, a first part (FL1) including the majority of the data set and a second part (FL2) including a secondary part of the data set, characterized in that the first part (FL1) is encrypted by first control-words (CWB) and subject to first access conditions whilst the second part (FL2) is encrypted by second control-words (CWA) and subject to second access conditions, and includes the following steps: verifying if the second access conditions are fulfilled, decrypting the second part (FL2) of the data set by second control-words (CWA), immediately inserting a mark on the decrypted data, this mark being modulated according to a parameter (K2) specific to the security module (SM) and known by the managing center.