Among other things, at a cloud-based service, digital image files are received from which digital images can be displayed on devices. For each of the digital image files, data is embedded in the digital image file on behalf of a party who has rights in the digital image file. The existence of the embedded data is not perceptible in any digital image that is displayed using the digital image file. The embedded data includes information from which the digital image file can be authenticated. At the cloud-based service, a digital image file is received that is to be authenticated. The digital image file is authenticated based on the embedded data.