Abstract: A method for secure communications in a telecommunications network is disclosed. The network comprises a group of servers Si, referred to as Authorization Servers. For a transaction between an entity A and an entity B of this method comprises: a) entity A sends to one of the Authorization Servers Si an authorization request; b) the entity A declares to the Authorization Server Si its intention to communicate with entity B and the Authorization Server Si determines an individual secret key KSiB which it shares with entity B; c) the Authorization Server Si generates a session key KN,SiAB and sends the session key KN,SiAB to entity A; d) the Authorization Server Si generates a transaction identifier IDTRN,Si; e) the authorization server Si supplies entity B the transaction identifier IDTRN,Si; f) using this transaction identifier IDTRN,Si, entity B checks the validity of the transaction, and g) entity B generates the session key KN,SiAB.

Abstract: A secure communications method is provided for use in a telecommunications network, wherein a transaction between an entity A and an entity B of the network comprises: entity A sending an authorization request to an Authorization Server S, in which request the entity A identifies itself and authenticates itself; the entity A declares to the Authorization Server its intention to communicate with a certain entity B; the Authorization Server determines a secret key that it shares with the entity B; the Authorization Server generates a session key and sends it to the entity A; the session key being a one-way function of the secret key and also being a function of an integer (transaction number) allocated to the transaction; the Authorization Server also generates a transaction identifier that is a function depending at least on the transaction number in non-invertible manner.

Abstract: The invention relates to a method for secure communications in a telecommunications network, said network comprising a group of servers Si (where i=1, 2, . . . , p, and p is a strictly positive integer), referred to as Authorization Servers.

Abstract: In a network in which to set up a call to a called endpoint a calling endpoint sends (4) the called endpoint a call set-up message including a source information element identifying the calling endpoint and a destination information element identifying the called endpoint, the call is set up on condition that the call set-up message contains a first token value (J) that corresponds to a second token value given by an equation that includes said source information element, said destination information element, and a random information element generated by the network to be associated secretly with the first token value in the network.

Abstract: A secure communications method is provided for use in a telecommunications network, wherein a transaction between an entity A and an entity B of the network comprises: entity A sending an authorization request to an Authorization Server S, in which request the entity A identifies itself and authenticates itself; the entity A declares to the Authorization Server its intention to communicate with a certain entity B; the Authorization Server determines a secret key that it shares with the entity B; the Authorization Server generates a session key and sends it to the entity A; the session key being a one-way function of the secret key and also being a function of an integer (transaction number) allocated to the transaction; the Authorization Server also generates a transaction identifier that is a function depending at least on the transaction number in non-invertible manner.

Abstract: In an audiovisual communications network, a first endpoint exchanges with a control element messages transmitting parameters registered or to be registered in the control element to enable the first endpoint to communicate with a second endpoint registered with the control element. The communications network is made secure by a method that includes an observation step for detecting whether a set of parameters among the parameters transmitted in a message is inconsistent with a current state of the addressee of said message.

Abstract: For controlling a message to be transmitted by a sender linked to a sender domain, from a terminal connected to an emitter domain to at least one recipient linked to a recipient domain, the emitter domain requests an authentication of the sender of the message by the sender domain. In response to a first request transmitted from the emitter domain, the recipient domain transmits a second request to the sender domain that transmits it to the emitter domain if data previously transmitted from the sender domain to the emitter domain are identical to data contained in the second request. The emitter domain transmits a response to the recipient domain so that the recipient domain receives the message from the emitter domain and transmits it to a recipient having accepted the message.

Abstract: In a network in which to set up a call to a called endpoint a calling endpoint sends (4) the called endpoint a call set-up message including a source information element identifying the calling endpoint and a destination information element identifying the called endpoint, the call is set up on condition that the call set-up message contains a first token value (J) that corresponds to a second token value given by an equation that includes said source information element, said destination information element, and a random information element generated by the network to be associated secretly with the first token value in the network.

Abstract: In an audiovisual communications network, a first endpoint exchanges with a control element messages transmitting parameters registered or to be registered in the control element to enable the first endpoint to communicate with a second endpoint registered with the control element. The communications network is made secure by a method that includes an observation step for detecting whether a set of parameters among the parameters transmitted in a message is inconsistent with a current state of the addressee of said message.

Abstract: The present invention concerns a method of protecting the transmission of cells in a telecommunication system, the method consisting, on the transmitter side, of simultaneously transmitting two identical flows of cells on two distinct physical links and, on the receiver side, of receiving each of the two flows of cells respectively transmitted on the said two links and selecting one of them. The method further consists, on the transmitter side, of inserting, regularly in each of the flows, cells serving as markers and thus delimiting blocks of cells or sets of blocks of cells, and, on the receiver side, of selecting, block after block or group of blocks after group of blocks, the block or group of blocks from the flow of cells which has the fewer transmission errors compared with the block or group of blocks of the same order number in the other flow.