Authentication in communications networks

A network entity for use in a communications network comprising:

• means for establishing an internet protocol communication with a user equipment over an interface;
• means for accessing a shared secret to be used in a key-based authentication procedure for authenticating communication with the user equipment, said shared secret having been established in a generic bootstrapping architecture (GBA);
• means for dispatching a message to a user equipment including a set of options for the key-based authentication procedure, the set of options including at least the option of using the shared secret derived from GBA in the “shared-key”-based authentication procedure;
• and means operable when the “shared-key”-based authentication procedure is selected for validating an authorisation payload received from the user equipment over the interface and computed using the shared secret.

A user equipment for using a communications network comprising:

• means for establishing a communication channel with a network entity in the communications network;
• means for receiving a message which includes a set of options for the authentication procedure, the set of options including at least the option of using the shared secret derived from GBA in the “shared-key”-based authentication procedure for authenticating communication over the channel;
• means for selecting one of the set of options;
• means operable when the “shared-key”-based authentication procedure is selected for using a security key derived from a generic bootstrapping architecture to generate the shared secret;
• means for computing an authentication payload for transmission to a network entity using the shared secret;
• and
• means for transmitting the payload in a message over the channel according to an internet protocol.