According to an embodiment, a digital imaging apparatus includes: a camera module and a controller. The controller detects, on a basis of data of a captured image captured by the camera module, whether or not there is a distance difference between an object and a background included in the captured image. The controller adds, where it has been detected that there is the distance difference, authentication information to the data of the captured image, and stores, in a memory, the captured image to which the authentication information has been added.