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

Claim 6:
7. A method for a terminal device seeking access to a mobile network, the method comprising:
retrieving a handset identifier identifying the terminal device and a cryptographic key for proving an identity of the terminal device from storage circuitry of the terminal device;
generating signature information by signing a block of information including the handset identifier using the cryptographic key; and
during a network connection process for negotiating access to the mobile network with a network control device, communicating 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, an indication from the network control device is received 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.