Patent ID: 6137885
Filing Date: 2000-10-24
Classification: H04B,H04W

Abstract:
A method of enabling encrypted communication to take place directly in a single hop or merely directly between two terminals of a mobile radio network by satellite and/or of a GSM/DCS type after a call has been set up by one of them via a fixed radio station of the network, wherein during a first encryption stage, after a calling subscriber has been identified by the network from a signed response provided by an individual identity card of said subscriber via the calling terminal with which said card is associated, on receiving a random number transmitted by the station to the calling terminal, a cipher key is simultaneously generated by the card associated with the calling terminal and by the network control structure for encrypting/decrypting data transmitted by radio link between said calling terminal and the station, said cipher key then being stored in a memory of the station, and wherein said cipher key is subsequently transmitted by the station to the called terminal while setting up a radio link between said station and said called terminal for the call requested by the calling terminal, said key being for encrypting/decrypting data interchanged with said calling terminal.