An image verification system includes an image generation apparatus and a
first verification apparatus. The image generation apparatus (a)
generates image data, (b) generates a hash value from the image data, and
(c) generates first verification data from the hash value using a common
key cryptography and not using a public key cryptography. The first
verification apparatus (a) receives the hash value and the first
verification data, (b) verifies, using the received hash value, the
received first verification data and the common key cryptography, whether
the image data is altered, and (c) generates second verification data
from the hash value using the public key cryptography, if the first
verification apparatus verifies that the image data is not altered.