A transmitter cell phone 10 is provided with a controller 11 for fulfilling functions of a data encryptor, a first key encryptor, and an encryption file generator. The data encryptor encrypts data, using a first encryption key. The first key encryptor encrypts the first encryption key, using a second encryption key. The encryption file generator generates an encryption file of the data from the data encrypted by the data encryptor, the first encryption key encrypted by the first key encryptor, and user-specific information permitting identification of a user of the mobile communication terminal.