A method of processing a data stream comprising batches of packets each defined by a chain of communication protocols associated with at least one session, characterised in that it comprises the following steps: - receiving a plurality of batches of data packets via a communication channel and storing said batches of packets in a temporary memory; - performing, for each batch of data packets, a protocol analysis (DAPD) enabling the communication protocols in the protocol chain to be identified, and validating at least one session associated with the protocol chain when the identification of the protocol chain is complete; - Calculating at least one session digital fingerprint associated with an identified protocol chain of which the session is validated during the validation step, the calculation of the digital fingerprint is based on the extraction of metadata from each protocol identified during the analysis step, and the hashing of a dynamically defined list specific to each type of protocol, according to a so-called n-tuple type approach; and - storing said calculated digital session fingerprint(s) in at least one hash table, and saving a list of the metadata (MPID) associated with the identified protocols of the protocol chain of the validated session in a knowledge database (BDDS); - generating at least one trigger based on the protocol analysis results (DAPD), wherein activation of the trigger is indicative of a match between at least one rule for identifying target metadata and the metadata (MPID) associated with the identified protocols, the list of which is saved in the knowledge database (BDDS); - analysing the metadata (MPID) associated with the identified protocols of the data packets of the validated session, stored in the temporary memory resources, against the saved list of metadata (MPID) associated with the identified protocols in the knowledge database (BDDS), and checking whether the metadata (MPID) associated with the identified protocols comply with the trigger's rule for identifying target metadata; - if the data comply with the rule for identifying target metadata, activating the trigger and assigning a save status to at least one digital session fingerprint of the validated session; and - emptying the temporary memory of each batch of data packets, the digital session fingerprint of which does not have a save status, and saving on a storage memory for subsequent processing all the data packets for which at least one associated digital session fingerprint has a save status. - receiving a plurality of batches of data packets via a communication channel and storing said batches of packets in a temporary memory; - performing, for each batch of data packets, a protocol analysis (DAPD) enabling the communication protocols in the protocol chain to be identified, and validating at least one session associated with the protocol chain when the identification of the protocol chain is complete; - Calculating at least one session digital fingerprint associated with an identified protocol chain of which the session is validated during the validation step, the calculation of the digital fingerprint is based on the extraction of metadata from each protocol identified during the analysis step, and the hashing of a dynamically defined list specific to each type of protocol, according to a so-called n-tuple type approach; and - storing said calculated digital session fingerprint(s) in at least one hash table, and saving a list of the metadata (MPID) associated with the identified protocols of the protocol chain of the validated session in a knowledge database (BDDS); - generating at least one trigger based on the protocol analysis results (DAPD), wherein activation of the trigger is indicative of a match between at least one rule for identifying target metadata and the metadata (MPID) associated with the identified protocols, the list of which is saved in the knowledge database (BDDS); - analysing the metadata (MPID) associated with the identified protocols of the data packets of the validated session, stored in the temporary memory resources, against the saved list of metadata (MPID) associated with the identified protocols in the knowledge database (BDDS), and checking whether the metadata (MPID) associated with the identified protocols comply with the trigger's rule for identifying target metadata; - if the data comply with the rule for identifying target metadata, activating the trigger and assigning a save status to at least one digital session fingerprint of the validated session; and - emptying the temporary memory of each batch of data packets, the digital session fingerprint of which does not have a save status, and saving on a storage memory for subsequent processing all the data packets for which at least one associated digital session fingerprint has a save status.