Method for secure end-to-end transmission of data between a first device (500, 130, 231) and a second device (501, 101, 201) via a message broker, characterised in that the method comprises the following steps: - sharing of an entropy pool between the first device (500, 130, 231) and the second device (501, 101, 201) via the message broker, by transmitting signalling messages which comprise a message signature; and at least one signalling message of which comprises, in its payload, said entropy pool, said payload being encrypted asymmetrically, said entropy pool being a set of data able to generate a plurality of authentication keys and of symmetrical encryption keys by aggregating data stored in said entropy pool, and the authentication and encryption keys being identified by means of respective identifiers obtained by aggregating index values, each index value identifying data constituting the key, the index values making it possible to find the corresponding data in said entropy pool; and - transmission of subsequent messages between the first device (500, 130, 231) and the second device (501, 101, 201) via the message broker, each said subsequent message comprising a header and a payload (702, 802), the header comprising the identifier of an authentication key obtained from the shared entropy pool and the identifier of a symmetrical encryption key obtained from the shared entropy pool, the payload (702, 802) being encrypted symmetrically by means of the symmetrical encryption key, and the whole formed by the header and the payload (702, 802) being authenticated by means of a message authentication code obtained by means of the authentication key and inserted in the header. - sharing of an entropy pool between the first device (500, 130, 231) and the second device (501, 101, 201) via the message broker, by transmitting signalling messages which comprise a message signature; and at least one signalling message of which comprises, in its payload, said entropy pool, said payload being encrypted asymmetrically, said entropy pool being a set of data able to generate a plurality of authentication keys and of symmetrical encryption keys by aggregating data stored in said entropy pool, and the authentication and encryption keys being identified by means of respective identifiers obtained by aggregating index values, each index value identifying data constituting the key, the index values making it possible to find the corresponding data in said entropy pool; and - transmission of subsequent messages between the first device (500, 130, 231) and the second device (501, 101, 201) via the message broker, each said subsequent message comprising a header and a payload (702, 802), the header comprising the identifier of an authentication key obtained from the shared entropy pool and the identifier of a symmetrical encryption key obtained from the shared entropy pool, the payload (702, 802) being encrypted symmetrically by means of the symmetrical encryption key, and the whole formed by the header and the payload (702, 802) being authenticated by means of a message authentication code obtained by means of the authentication key and inserted in the header.