Image processing device

An image processing method for an image processing device for encrypting image data using an encryption key, comprising the steps of:

• storing key data used presently in a first storage in which stored information is lost when the image processing device is powered off;
• storing key data to be used in the future in a second storage in which stored information is maintained when the image processing device is powered off;
• and
• transferring, in response to the image processing device being switched from a power-off state to a power-on state, the key data stored in the second storage and to be used next to the first storage to be stored in the first storage.

An encrypted communication system for communicating encrypted image data from a transmission device for encrypting image data using an encryption key to a reception device for decrypting the encrypted image data using the encryption key, the transmission device comprising:

• a first storage in which stored information is lost when the transmission device is powered off, and for storing a presently used key data;
• a second storage in which stored information is maintained when the transmission device is powered off, and for storing a key data to be used in the future;
• and
• a controller, in response to the transmission device being switched from a power-off state to a power-on state, for transferring the key data stored in the second storage and to be used next to the first storage to be stored in the first storage.