  The aim of this paper is to evaluate the security of a block-based image
encryption for the vision transformer against jigsaw puzzle solver attacks. The
vision transformer, a model for image classification based on the transformer
architecture, is carried out by dividing an image into a grid of square
patches. Some encryption schemes for the vision transformer have been proposed
by applying block-based image encryption such as block scrambling and rotating
to patches of the image. On the other hand, the security of encryption scheme
for the vision transformer has never evaluated. In this paper, jigsaw puzzle
solver attacks are utilized to evaluate the security of encrypted images by
regarding the divided patches as pieces of a jigsaw puzzle. In experiments, an
image is resized and divided into patches to apply block scrambling-based image
encryption, and then the security of encrypted images for the vision
transformer against jigsaw puzzle solver attacks is evaluated.
