The document identification method includes: a step of generating an image, a step of marking a plurality of documents to form the image on each document with unique variations on each document, the majority of the images formed on the documents presenting a physical anti-copy characteristic satisfying a predefined criterion such that the characteristic of the majority of the copies that can be produced based on these images do not satisfy the pre-defined criterion, a step of characterizing the variations to form a unique imprint of the mark formed, for each document and a step of memorizing the unique imprint.