The invention solves the problem of systematic image marking of portable communicating objects, such as smart cards or mobile terminals, involved in a campaign in a database connected to a downloading server, thereby releasing the server. Access to a communicating object targeted by the campaign is authorized for a single-unit operation while the server manages the preprocessing of data for the communicating object during the campaign. Access is inhibited for a single-unit operation concerning an object targeted by the campaign when access is requested while the server manages transmission of a data message to the communicating object during the campaign. Access is also prohibited while the server manages an acknowledgement transmitted by the communicating object and the post-processing of data concerning the communicating object.