Authentication of a mobile device by a network and key generation

An apparatus for implementing a cryptographic system, wherein:

• the apparatus initiates communication with a visited network, the visited network including a verification entity, and the visited network able to communicate with a home network of the apparatus;
• the apparatus receives from the visited network an ephemeral public key of the home network;
• the cryptographic system of the apparatus uses the ephemeral public key of the home network and a static private key of the apparatus to participate in at least a portion of an asymmetric key agreement protocol with the home network to compute a secret value, wherein an ephemeral private key of the apparatus is not used in the asymmetric key agreement protocol and the asymmetric key agreement protocol is a Menezes-Qu-Vanstone (MQV) key agreement protocol;
• the cryptographic system obtains a response value derived from the secret value;
• and
• the apparatus sends the response value to the verification entity of the visited network for use in authenticating the apparatus.

A non-transitory processor readable medium having stored thereon processor readable instructions that, when executed, cause a mobile device to:

• initiate communication with a visited network, the visited network including a verification entity, and the visited network able to communicate with a home network of the mobile device;
• receive from the visited network an ephemeral public key of the home network;
• use the ephemeral public key of the home network and a static private key of the mobile device to participate in at least a portion of an asymmetric key agreement protocol with the home network to compute a secret value, wherein an ephemeral private key of the mobile device is not used in the asymmetric key agreement protocol and the asymmetric key agreement protocol is a Menezes-Qu-Vanstone (MQV) key agreement protocol;
• obtain a response value derived from the secret value;
• and
• send the response value to the verification entity of the visited network for use in authenticating the mobile device.