Method and device for securing documents against forgery

摘要

The invention relates to a method for securing a document, comprising: a first step of forming a first marking (205, 210) on a first surface of said document using a first marking means; a second step of forming a second marking (215) on another surface of said document or in the body of said document using a second marking means; the two markings being stacked when the document is backlit and a least one (215) of said markings being a marking which, when copied using identical marking means to those used to form said markings, produces an error rate that is higher than a predetermined value when measured point-by-point.