A method of checking and protecting data and identities within a communication or computing process between at least one author and at least one recipient comprises at least: a step of allocation by an anonymization authority of one and the same stamp forming a cryptonymic marking, to one or to several different authors and to their objects; a step of inserting said stamp into the communication or computing protocol associated with the data stream, by means of a stamp system, the protocol containing the identity of said author or of said object of the author or authors, and each author being able moreover to simultaneously have a plurality of different cryptonyms; a step of reading, at at least one recipient, of said protocol by means of a reading system able to detect the presence of said stamp.