1. An image encoding device comprising: an image division section for dividing one frame of image into a plurality of image fragments, grouping the plurality of image fragments into N sets (N: an integer of 2 or more), and outputting the N sets of image fragments as N partial images; an image swapping section for swapping at least one image fragment with another between the N partial images to output N partial images each having shuffled image fragments; and an encoding section for encoding the N partial images output from the image swapping section.