Updating a subscriber identity module

A server comprising at least one processor configured to:

• receive, from a device over a network, an agent identifier and a subscriber identity module, SIM, identifier of a SIM on the device;
• generate a random value;
• transmit the random value and the SIM identifier of the SIM to an authentication entity;
• receive an authentication response from the authentication entity wherein the authentication response is generated using the random value;
• derive a pre-shared key using the authentication response;
• store the derived pre-shared key in association with the agent identifier in a memory;
• transmit the random value to the device over the network;
• encrypt a message using the pre-shared key;
• and
• transmit the encrypted message over the network to the device.

A method performed by a server, the method comprising:

• transmitting a random value to an authentication entity;
• receiving an authentication response from the authentication entity wherein the authentication response is generated using the random value;
• deriving a pre-shared key using the authentication response;
• transmitting the random value to a device over a network;
• encrypting a message using the pre-shared key;
• transmitting the encrypted message over the network to the device;
• receiving an update request message over the network from the device, wherein the update request message comprises an agent identifier and is encrypted prior to transmission using the pre-shared key;
• decrypting the update request message using the stored pre-shared key;
• and
• transmitting an update response message as the message over the network to the device, wherein the update response message comprises update data and is encrypted using the stored pre-shared key.