The invention relates to a method for carrying out a sensitive operation in the course of a communication between a processing unit and a first service server, said first server being accessible via a first domain name and/or first electronic address. The method comprises the step of using at least one second domain name different from the first and/or a second electronic address different from the first to carry out all or part of the sensitive operation. The invention also relates to a system corresponding to the method and comprising the server and/or the processing unit.