Method of Mutual Authentication Based on Visual Cryptography and Control Method of Device for Performing Mutual Authentication

In the method of mutual authentication based on visual cryptography, a first image is shared and pre-stored between a device and a server that performs the mutual authentication. When the server receives a mutual authentication request from the device, a first authentication code is generated. A second image, where the first authentication code is identifiable upon overlapping with the first image, is generated and transmitted to the device. The device overlaps the first image with the second im