Abstract: A method of communication between two communicating entities, a first communicating entity generating a data message including useful data and an authentication header, the method including: generating a message identifier from a given parameter and a date and inserting the identifier into an authentication header; inserting a plurality of authentication data including at least one user identifier and one equipment identifier into the authentication header; determining and inserting a security profile into the authentication header defining the conditions: of encryption of the useful data of at least the transmission of the message by the first communicating entity; of generation of a data signature of the message and of the format of the generated signature, and inserting the useful data into the message to be transmitted.

Abstract: A method of communication between two communicating entities, a first communicating entity generating a data message including useful data and an authentication header, the method including: generating a message identifier from a given parameter and a date and inserting the identifier into an authentication header; inserting a plurality of authentication data including at least one user identifier and one equipment identifier into the authentication header; determining and inserting a security profile into the authentication header defining the conditions: of encryption of the useful data of at least the transmission of the message by the first communicating entity; of generation of a data signature of the message and of the format of the generated signature, and inserting the useful data into the message to be transmitted.

Abstract: A sealing device (1) for a watch crown that includes a cover (2) possessing an annular part (3) that fits and rests on the periphery of a cabochon (4) of a watch crown (5) against a seal (6). Said cover (2), which is articulated on one of the shoulders (7) protecting the crown (5) of a watchcase (8) has, at its end, a closure lug (9). The latter is designed to receive a buckle (10) integral with a fastening arm (12). This fastening arm (12) makes it possible for the cover (2) to exert sufficient pressure on said seal (6) by means of a simple lever effect when the end of the fastening arm (12) is inserted into a receptacle (15).