A method and system for determining the authenticity of an item such as an original work of art, an art print, valuable jewelry or other valuable items utilizes images of one or more unique patterns of features, preferably at a microscopic level, as one or more "signatures" of the item. The image of this unique signature is recorded and stored electronically as data representing the unique pattern. The data are registered with identifying text and stored in a secure storage location, to prevent unauthorized duplication or use of the stored data. Following this registration and storage, an item presented as authentic can be examined microscopically at prescribed sites on the item where the original images were taken. Comparison is made at one or more of the sites, and a decision is made as to whether the item exhibits substantially identical features to those originally registered, so as to be the same authentic item. Comparison can be made electronically or visually/microscopically. The storage location can be a central location-remote from local verification stations, with data transferred to and from local stations by telephone lines or other communication links.