Security mechanism for mobile users

An apparatus configured for use within a core network of a cellular communication network, the apparatus comprising:

• a transfer entity configured to exchange user data packets with user terminals over a signaling connection within a Non Access Stratum, via a radio link;
• and
• a data transmission verification entity configured to selectively send verifiable acknowledgements, in respect of user data packets received from user terminals, to those user terminals across said signaling connection, the data transmission verification entity being configured to send a verifiable acknowledgement to a user terminal in response to receipt from that user terminal of a user data packet containing a request for the verifiable acknowledgement;
• wherein the verifiable acknowledgement allows the user terminal to verify that the verifiable acknowledgement has actually been sent by the apparatus within the core network.

A method of sending data from a wireless communication device to a core network node within a cellular network, the method comprising:

• exchanging user data packets between the wireless communication device and the core network node over a signaling connection within a Non Access Stratum, via a radio link;
• including, within a user data packet sent to said core network node across the signaling connection, a request to return to the wireless communication device a verifiable acknowledgement for the sent user data packet;
• and
• at said wireless communication device, using the verifiable acknowledgement, received from said core network node over said signaling connection, to confirm delivery of the user data packet sent to the core network node over said signaling connection;
• wherein the verifiable acknowledgement allows said wireless communication device to verify that the verifiable acknowledgement has actually been sent by the core network node with which the wireless communication device intends to communicate.

An apparatus configured for use within a core network of a cellular communication network, the apparatus comprising:

• a transfer entity configured to exchange user data packets with user terminals over a signaling connection within a Non Access Stratum, via a radio link;
• and
• a data transmission verification entity configured to selectively send verifiable acknowledgements, in respect of user data packets received from user terminals, to those user terminals across said signaling connection, the data transmission verification entity being configured to send a verifiable acknowledgement to a user terminal in response to an internally or core generated trigger indicating a mobility event for that user terminal;
• wherein the verifiable acknowledgement allows the user terminal to verify that the verifiable acknowledgement has actually been sent by the apparatus within the core network with which the user terminal intends to communicate.