Abstract: This ventilation system (1), notably for a gas turbine, comprises at least one fan (2) opening into an air extraction duct (5). It comprises at least one device (6) for varying the pressure drop in the air extraction duct (5), comprising a means (8) of regulating the air flow rate in the air extraction duct (5).

Abstract: This method of establishing a cryptographic session key comprises: a subscription phase (104) during which an identifier of a local loop to the end of which a receiver must be connected is acquired, and an authentication step comprising: a) an operation (142) of automatically obtaining an identifier of the local loop to the end of which the receiver is actually connected, and b) an operation (146) of verifying that the identifier obtained during the operation a) corresponds to the identifier acquired during the subscription phase so as to authenticate the receiver.

Abstract: A method of broadcasting a scrambled multimedia program, by way of a broadcast network, in which before transmitting a license key; a network head carries out a step of authenticating a terminal, and if the terminal has successfully authenticated, the network heads sends the terminal a license transmission message containing the license key or cryptogram of the license key, by way of a point-to-point link, and if the terminal is not successfully authenticated, the network head acts (at 200) in such a way as to prevent the complete descrambling by this terminal of the scrambled multimedia program broadcast.

Abstract: This ventilation system (1), notably for a gas turbine, comprises at least one fan (2) opening into an air extraction duct (5). It comprises at least one device (6) for varying the pressure drop in the air extraction duct (5), comprising a means (8) of regulating the air flow rate in the air extraction duct (5).

Abstract: The invention concerns a method for broadcasting a plurality of multimedia programmes generated by operators of different services, whereby one or more network headends broadcast (in 102) on a reference multicast address a list associating identifiers of service operators with at least one first level service multicast address, the reference multicast address being previously known to all the terminals capable of receiving and multiplexing broadcast multiplexed contents and said reference multicast address being different from all the broadcasting multicast addresses.

Abstract: A method of broadcasting a scrambled multimedia programme, by way of a broadband network, in which before transmitting a license key: —a network head carries out a step of authenticating a terminal, and—if the terminal has been successfully authenticated, the network head sends the terminal a license transmission message containing the license key or cryptogram of the license key, by way of a point-to-point link, and—if the terminal is not successfully authenticated, the network head acts (at 200) in such a way as to prevent the complete descrambling by this terminal of the scrambled multimedia programme broadcast.

Abstract: The invention concerns a method for broadcasting a plurality of multimedia programmes generated by operators of different services, whereby one or more network headends broadcast (in 102) on a reference multicast address a list associating identifiers of service operators with at least one first level service multicast address, the reference multicast address being previously known to all the terminals capable of receiving and multiplexing broadcast multiplexed contents and said reference multicast address being different from all the broadcasting multicast addresses.

Abstract: This method of establishing a cryptographic session key comprises: a subscription phase (104) during which an identifier of a local loop to the end of which a receiver must be connected is acquired, and an authentication step comprising: a) an operation (142) of automatically obtaining an identifier of the local loop to the end of which the receiver is actually connected, and b) an operation (146) of verifying that the identifier obtained during the operation a) corresponds to the identifier acquired during the subscription phase so as to authenticate the receiver.