Abstract: A mobile phone has: a close-range communication control section that performs close-range wireless communication with other mobile phones; a forwarding destination storage section that stores a forwarding destination list in which phone numbers of telephones capable of accepting forwarding are recorded; and a close-range wireless communication monitoring section that causes the close-range wireless communication section to perform close-range wireless communication and monitors establishment of close-range wireless communication with a forwarding acceptance telephone having a phone number that matches any of the phone numbers in the forwarding destination list. The mobile phone also has an incoming call forwarding destination notification section that notifies the phone number of a forwarding acceptance telephone, with which close-range wireless communication by the close-range wireless communication section has been established, to the call forwarding service center as a forwarding destination phone number.

Abstract: Specific information that can be stored in a mobile terminal device, changes over time, cannot be altered when a lock operation is requested, and can be acquired by an owner, such as a last-dialed telephone number, is managed as owner-specific authentication information, and, when an e-mail requesting a lock operation is extracted, a lock number for authentication for locking the mobile terminal device is calculated by using the owner-specific authentication information as a parameter.

Abstract: A mobile phone has: a close-range communication control section that performs close-range wireless communication with other mobile phones; a forwarding destination storage section that stores a forwarding destination list in which phone numbers of telephones capable of accepting forwarding are recorded; and a close-range wireless communication monitoring section that causes the close-range wireless communication section to perform close-range wireless communication and monitors establishment of close-range wireless communication with a forwarding acceptance telephone having a phone number that matches any of the phone numbers in the forwarding destination list. The mobile phone also has an incoming call forwarding destination notification section that notifies the phone number of a forwarding acceptance telephone, with which close-range wireless communication by the close-range wireless communication section has been established, to the call forwarding service center as a forwarding destination phone number.

Abstract: Specific information that can be stored in a mobile terminal device, changes over time, cannot be altered when a lock operation is requested, and can be acquired by an owner, such as a last-dialed telephone number, is managed as owner-specific authentication information, and, when an e-mail requesting a lock operation is extracted, a lock number for authentication for locking the mobile terminal device is calculated by using the owner-specific authentication information as a parameter.