Device and method for managing the mutual authentication for the direct communication between mobile structures of a mobile radio communication system

A method of mutual authentication of link entities of respective mobile structures of a communication system comprising at least two mobile structures, for establishing a direct mode link between said link entities, each mobile structure comprising

• a base station adapted to establish cellular communication links with mobile communication terminals of a respective mobile structure via a determined radio interface;
• a subscriber subscription server adapted to manage security information for authentication of the mobile communication terminals of the respective mobile structure;
• a security management entity adapted to interact with the subscriber subscription server in order to obtain and store security information associated with the mobile communication terminals served by the base station;
• a link entity adapted to establish said direct mode link with another link entity of another mobile structure of the at least two mobile structures, said link entity having an identification module adapted to store a unique identifier associated with the link entity;
• an emulator of the security management entity of the respective mobile structure, accessible by the link entity and adapted to emulate the determined radio interface for accessing the subscriber subscription server of said respective mobile structure;
• and,
• a proxy module adapted to transport an authentication request from the link entity of the another mobile structure to the emulator of the security management entity of the respective mobilestructure, for the authentication of said link entity of the another mobile structure on the subscriber subscription server of the respective mobile structure, based on the unique identifier of said link entity of the another mobile structure;
• said method comprising:
• transmitting to the link entity of said each mobile structure an authentication request on the subscriber subscription server of said each mobile structure from the link entity of the another mobile structure;
• transporting, through the respective proxy modules of said each mobile structure, the authentication request received from the link entity of the another mobile structure, to the emulator of the security management entity of each another mobile structure;
• and,
• presenting, to the respective subscriber subscription servers of said each mobile structure, by the respective security management entity emulators of said each mobile structure, the authentication request from the link entity of the another mobile structure, for the authentication ofsaid link entity of the another mobile structure on the subscriber subscription server of the another structure.