Method of registering a mobile terminal in a mobile communication network

A method of registering a mobile terminal in a mobile communication network via a base station, an access link between the base station and the core of the network being switched from a normal mode of operation to a degraded mode of operation. The method is implemented by a local mobility management entity and includes: receiving an attachment request, retransmitted by the base station and originating from the mobile terminal, the request including an identifier of the mobile terminal, dispatching, to an agent mobility management item, a request for security information specific to the mobile terminal, the request including the identifier of the mobile terminal, receiving a response to the request for security information, the response including security information specific to the mobile terminal, the security information originating from a server of subscribers of the network, and authenticating the terminal by using the security information received.