Patent ID: 11882442
Assignee: TRUSTONIC LIMITED
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A terminal device comprising:
storage circuitry to store a handset identifier identifying the terminal device and a cryptographic key for proving an identity of the terminal device;
processing circuitry to generate signature information by signing a block of information including the handset identifier using the cryptographic key; and
communication circuitry to communicate on a mobile network, wherein during a network connection process for negotiating access to the mobile network with a network control device, the communication circuitry is configured to communicate the signature information to the network control device, wherein
the signature information comprises information for verifying a binding between the handset identifier and the terminal device, and
during the network connection process for negotiating access to the mobile network with the network control device, the communication circuitry is configured to receive an indication from the network control device whether the terminal device is allowed to switch from a limited communication mode, in which a limited subset of network communication functionality including emergency calls only and handshaking for the handset identifier based on retrieval of the verification information is allowed, to a full communication mode in which communication functionality other than said limited subset is allowed, in dependence on whether the binding between the handset identifier and the terminal device allows the network control device to verify the terminal device as an authorized terminal device.