Patent ID: 6941128

Claim:
A mobile communication terminal comprising: a storage for storing control data used to control an operation of the mobile communication terminal; first means, operating in response to input a security code created by a predetermined algorithm, for setting an operation mode of the mobile communication terminal to a registration preparing state where a lock code, which is used to protect a part of the control data, can be registered; second means, operating in response to input the lock code with the registration preparing state being set, for registering the lock code in the storage and setting the operation mode to a protective state where the part of the control data cannot be changed; third means, operating in response to input a lock release code corresponding to the lock code with the protective state being set, for releasing the protective state temporarily, thereby enabling the part of the control data to be changed; and fourth means for deleting the registered lock code after the change of the part of the control data and restoring the registration preparing state.