Abstract: Scan matching can be used for art authentication. A digital scan of at least a portion of the authentic painting (or other type of artwork) is created. If a scan exists that is trusted to be a digital image identifying the authentic artwork, a subsequent scan can be created of the work a buyer intends to purchase. If the subsequently created scan matches the trusted scan of the artwork, the buyer can conclude that the artwork to be purchased is the authentic one. The trusted scan passes to the buyer as a blockchain transaction.