An image verification system has an image generation device and a first image verification device. The image generation device includes (a) an image data generation unit that generates image data, and (b) a first verification data generation unit that generates first verification data from the image data using a common key in common key cryptography. The first image verification device includes (a) a first verification unit that verifies, using the image data, the first verification data and the common key, whether the image data is altered, and (b) a second verification data generation unit that generates second verification data from the image data using a private key in public key cryptography without editing the image data, if the first verification unit verifies that the image data is not altered.