OUT-OF-BAND AUTHENTICATION METHOD AND SYSTEM FOR COMMUNICATION OVER A DATA NETWORK

A method and system for out-of-band authentication of messages transmitted, e.g. as packets, on a communication network, whereby a first stream of data is received by a sender control module from a sender; the first stream of data is transmitted over a first channel, e.g. a non-secure data channel, toward a receiver control module; the sender control module generates authentication data of the first stream of data; the authentication data are transmitted from the sender control module to the receiver control module on a second channel, e.g. a secure data channel, distinct from the first channel; and a stream of data received by the receiver control module is checked using the authentication data. Before sending the authentication data, the sender control module transmits a control message including synchronization data to the receiver control module over the second channel.