Patent ID: 8032752

Claim:
A data transmission apparatus that moves move-target data to a data reception apparatus, said data transmission apparatus comprising: an encrypting unit operable to encrypt the move-target data stored in said data transmission apparatus so as to generate encrypted data; a communication control unit operable to transmit the generated encrypted data to the data reception apparatus; an authentication and key exchange unit operable to perform authentication between said data transmission apparatus and the data reception apparatus, and to transmit an encrypted encryption key to the data reception apparatus, only when the authentication is successful; a synchronous control unit operable to control an operation of transmitting and receiving synchronization data, the synchronization data synchronizing a timing of deleting or invalidating the move-target data stored in said data transmission apparatus and a timing of decrypting the encrypted encryption key transmitted to and stored in the data reception apparatus; and a data managing unit operable to delete or invalidate the move-target data stored in said data transmission apparatus, based on the operation controlled by said synchronous control unit and the synchronization data, wherein, after the transmission of the encrypted data to the data reception apparatus, said synchronous control unit transmits, to the data reception apparatus, the synchronization data and a decryption key for decrypting the encrypted encryption key, such that the synchronization data synchronizes the timing of deleting or invalidating the move-target data stored in said data transmission apparatus and the timing of decrypting the encrypted encryption key using the decryption key.